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Dkk-3 expression in the tumor endothelium: A novel prognostic marker of pancreatic adenocarcinomas
Cancer Science
Abstract
Dkk-3 is proposed to be a new specific marker for tumor endothelial cells. Here we analyzed the clinical relevance of Dkk-3 expression in pancreas adenocarcinomas and determined its role on endothelial cell growth in vitro. Microvessel density in tumor samples was immunohistochemically determined using Dkk-3 and CD31 as endothelial cell markers, respectively. Based on the median microvessel density as a cut-off point, patients were categorized into high and low microvessel density groups and a correlation with survival and clinical parameters was assessed. Moreover, the role of Dkk-3 expression on chemosensitivity of endothelial cells was analyzed. In contrast to CD31 staining, Dkk-3-positive vessels were found only in tumor tissue and Dkk-3 microvessel density significantly correlated negative with tumor grading. In survival analysis the median survival time was 7 months for patients with Dkk-3 low, and 15 months for Dkk-3 high microvessel density (P = 0.0013). Subset analysis of patients receiving gemcitabine therapy showed that overall survival was significantly decreased in Dkk-3 low tumors than in high tumors (P = 0.009). In Cox regression Dkk-3 emerged as a significant independent parameter (P = 0.024). Dkk-3 overexpression in endothelial cells resulted in significantly enhanced growth inhibition after 5-fluorouracil or gemcitabine treatment compared to control endothelial cells and cancer cell lines. Dkk-3 low microvessel density was associated with tumor progression and worse clinical outcome. Overexpression of Dkk-3 enhanced endothelial cell growth inhibition to chemotherapeutic drugs. Therefore, we suggest that Dkk-3 high microvessel density may help to select patients who may benefit from chemotherapy.
... Dickkopf-3 (DKK3) is considered a tumor suppressor as it is often deleted in cancers [4,5] and is frequently downregulated owing to epigenetic inactivation in cervical, lung, prostate, bladder, gallbladder, and breast cancers [6][7][8][9][10][11][12][13]. In addition, a significant relationship between aberrantly reduced DKK3 expression and poor prognosis was reported in uterine, cervical, colorectal, and pancreatic cancers [10,[14][15][16][17]. Previous in vitro studies have shown that the tumor suppressor potential of DKK3 is mediated via angiogenesis in ovarian cancer cell lines and via mitochondrial and Fas death receptor pathways in mucinous ovarian cancer cells [18,19]. ...
... Taken together with the results of a previous report showing the absence of DKK3 in 63% cases of 56 ovarian carcinoma tissue samples [20], we concluded that >50% invasive epithelial ovarian cancers lose DKK3 during carcinogenesis. DKK3 is frequently downregulated in various cancers [6,10,14,[16][17][18][34][35][36], and therefore, this study supports the hypothesis that downregulation of DKK3 occurs commonly during carcinogenesis. ...
Simple Summary
Dickkopf-3 (DKK3) is considered a tumor suppressor as it possesses anti-tumoral properties and is frequently downregulated in various cancers. However, the role of DKK3 in ovarian cancer is not known. In this study, we showed that DKK3 loss occurred in 56.1% of patients with ovarian cancer and that it was significantly associated with poor survival and chemoresistance. Secreted DKK3 possessed anti-tumoral properties and enhanced paclitaxel susceptibility by inhibiting the β-catenin-P-glycoprotein signaling pathway in ovarian cancer. This study revealed promising therapeutic effects of secreted DKK3, which targets paclitaxel-resistant ovarian cancer.
Abstract
Dickkopf-3 (DKK3), a tumor suppressor, is frequently downregulated in various cancers. However, the role of DKK3 in ovarian cancer has not been evaluated. This study aimed to assess aberrant DKK3 expression and its role in epithelial ovarian carcinoma. DKK3 expression was assessed using immunohistochemistry with tissue blocks from 82 patients with invasive carcinoma, and 15 normal, 19 benign, and 10 borderline tumors as controls. Survival data were analyzed using Kaplan–Meier and Cox regression analysis. Paclitaxel-resistant cells were established using TOV-21G and OV-90 cell lines. Protein expression was assessed using Western blotting and immunofluorescence analysis. Cell viability was assessed using the MT assay and 3D-spheroid assay. Cell migration was determined using a migration assay. DKK3 was significantly downregulated in invasive carcinoma compared to that in normal, benign, and borderline tumors. DKK3 loss occurred in 56.1% invasive carcinomas and was significantly associated with disease-free survival and chemoresistance in serous adenocarcinoma. DKK3 was lost in paclitaxel-resistant cells, while β-catenin and P-glycoprotein were upregulated. Exogenous secreted DKK3, incorporated by cells, enhanced anti-tumoral effect and paclitaxel susceptibility in paclitaxel-resistant cells, and reduced the levels of active β-catenin and its downstream P-glycoprotein, suggesting that DKK3 can be used as a therapeutic for targeting paclitaxel-resistant cancer.
... DKK3 positivity in tumour ECs is significantly associated with higher mean microvessel count and worse disease-free survival in colorectal cancer than in DKK3-negative tumours (31). In contrast, in gastric and pancreatic cancers, patients with strong DKK3 expression in the tumour endothelium or with high intratumour microvessel density had significantly better survival (45,46). ...
... Because of the differences between the tumour-associated endothelium in abnormal microvessels and the normal endothelium, it is possible to target only the tumour associated endothelium. Unlike in normal blood vessels, DKK3 was positive in tumour vessels of colorectal cancer, glioma, high-grade non-Hodgkin's lymphomas, melanoma, gastric cancer, prostatic cancer, pancreatic cancer, and oesophageal adenocarcinoma (5,12,27,32,45,46). DKK3 overexpression has no effect on the proliferation and migration of ECs; however, it enhanced tube formation capacity in Matrigel assays in vitro and microvessel density in vivo. ...
Dickkopf-3 (DKK3), also known as REIC, is a secreted glycoprotein. DKK3 is aberrantly expressed in various types of human malignant tumours. Promoter methylation status, intracellular protein expression, and protein expression in tumour vessels are significantly correlated with clinical prognostic factors, including survival. In malignant cells, DKK3 is involved in the induction of apoptosis, inhibition of invasion, and remodelling of tumour vasculature. These activities are carried out via the regulation of the beta-catenin signalling and c-Jun N-terminal kinase-dependent cellular pathway, both of which are critical for carcinogenesis. This review explores the potential value of DKK3 as a clinical biomarker and a therapeutic candidate in human malignancies.
... Dkk-3 has been demonstrated to be closely involved in the development and progression of cardiovascular disease [8,9]. Several studies showed that Dkk-3 overexpression could suppress endothelial cell growth and angiogenesis [19,20]. High expression of Dkk-3 in human coronary artery plaques could accelerate the atherosclerotic process and promoted plaque accumulation, while reduction of Dkk-3 attenuated the atherosclerotic lesion burden through decreasing the size of atherosclerotic lesions and increasing the stability of plaques [8]. ...
... As an antagonist of Wnt/β-catenin pathway [6,7,27], the overexpression of Dkk-3 could accelerate the atherosclerotic process and resulted in detrimental outcomes of atherosclerosis through inhibiting this pathway [8]. The high expression of Dkk-3 also appears to downregulate the level of vascular endothelial growth factor [7,20] and then suppresses endothelial cell growth and angiogenesis [19,20]. On the other hand, besides the adverse effects of Dkk-3 overexpression, it is necessary to maintain a certain level of Dkk-3 in tissues or blood in normal physiological process [10]. ...
Background:
Dickkopf-3 (Dkk-3) is implicated in the progression of atherosclerosis. This study aimed to investigate the association between serum Dkk-3 and the prognosis of ischemic stroke.
Methods:
We measured serum Dkk-3 levels in 3344 ischemic stroke patients from CATIS (China Antihypertensive Trial in Acute Ischemic Stroke). The primary outcome was a combination of death and vascular events within 3 months after ischemic stroke.
Results:
During 3 months of follow-up, the cumulative incidence rates of primary outcome among ischemic stroke patients in five quintiles of serum Dkk-3 (from low to high) were 4.49%, 3.74%, 2.54%, 5.23%, and 6.73%, respectively (log-rank p = 0.004). Multivariable Cox proportional hazards regression analyses showed that compared with the third quintile of serum Dkk-3, the adjusted hazard ratios (95% confidence intervals) associated with the first and fifth quintile were 3.49 (1.46-8.34) and 4.23 (1.86-9.64) for primary outcome, 3.47 (1.06-11.36) and 5.30 (1.81-15.51) for death, and 2.66 (1.01-7.01) and 3.35 (1.33-8.40) for vascular events, respectively. Multivariable-adjusted Cox proportional hazards regression model with restricted cubic splines showed a U-shaped association between serum Dkk-3 and the risk of primary outcome (p for nonlinearity = 0.030). Moreover, adding serum Dkk-3 to conventional risk factors could improve the predictive power for primary outcome (net reclassification improvement 28.44%, p < 0.001; integrated discrimination improvement 0.48%, p = 0.001).
Conclusions:
Both low and high serum Dkk-3 levels are associated with increased risks of death and vascular events within 3 months after ischemic stroke, indicating that serum Dkk-3 may have a special effect on the prognosis of ischemic stroke. We also found that serum Dkk-3 might be a prognostic biomarker for ischemic stroke. Further studies are needed to replicate our findings and to determine the optimal levels of serum Dkk-3.
... DKK-3 is also expressed in various adult tissues and acts as a tumor suppressor of different malignancies (Veeck and Dahl, 2012). Expression of DKK-3 in tumor tissues is mostly located in microvascular ECs (Untergasser et al., 2008;Fong et al., 2009). DKK-3 is expressed in the adult heart (Krupnik et al., 1999), more specifically in microvascular ECs (Fong et al., 2009;Tunica et al., 2009;Zhang et al., 2014). ...
... Expression of DKK-3 in tumor tissues is mostly located in microvascular ECs (Untergasser et al., 2008;Fong et al., 2009). DKK-3 is expressed in the adult heart (Krupnik et al., 1999), more specifically in microvascular ECs (Fong et al., 2009;Tunica et al., 2009;Zhang et al., 2014). ...
The heart is a highly structured organ consisting of different cell types, including myocytes, endothelial cells, fibroblasts, stem cells, and inflammatory cells. This pluricellularity provides the opportunity of intercellular communication within the organ, with subsequent optimization of its function. Intercellular cross-talk is indispensable during cardiac development, but also plays a substantial modulatory role in the normal and failing heart of adults. More specifically, factors secreted by cardiac microvascular endothelial cells modulate cardiac performance and either positively or negatively affect cardiac remodeling. The role of endothelium-derived small molecules and peptides—for instance NO or endothelin-1—has been extensively studied and is relatively well defined. However, endothelial cells also secrete numerous larger proteins. Information on the role of these proteins in the heart is scattered throughout the literature. In this review, we will link specific proteins that modulate cardiac contractility or cardiac remodeling to their expression by cardiac microvascular endothelial cells. The following proteins will be discussed: IL-6, periostin, tenascin-C, thrombospondin, follistatin-like 1, frizzled-related protein 3, IGF-1, CTGF, dickkopf-3, BMP-2 and−4, apelin, IL-1β, placental growth factor, LIF, WISP-1, midkine, and adrenomedullin. In the future, it is likely that some of these proteins can serve as markers of cardiac remodeling and that the concept of endothelial function and dysfunction might have to be redefined as we learn more about other factors secreted by ECs besides NO.
... While early reports have shown that 10-45% of all ECs carry β-catenin mutations, with a slightly higher propensity in endometrioid ECs, no functional relationship or associated prognostic values have been assigned [16][17][18][19][20][21][22][23][24][25][26]. Recently, more emphasis has been placed on secreted Wnt antagonists, including members of the Dickkopf family [27][28][29][30][31][32][33][34][35]. The Dickkopf proteins are secreted Wnt inhibitors which induce removal of the Wnt co-receptor low-density lipoprotein receptor-related protein (LRP), and thus prevent Wnt signaling. ...
... Despite these findings, an evaluation of Dkk3 expression linked to survival and recurrence in a higher-powered study would be of considerable value in this setting. Nonetheless, the role of Dkk3 as a potential prognostic marker is supported by prior reports in pancreatic cancer [33], where low Dkk3 expression in tumor endothelium is associated with a shorter survival, compared to patients with high Dkk3 expression (15 months vs. 7 months). ...
Emerging evidence implicates the Wnt antagonist Dickkopf-3 (Dkk3) as a tumor suppressor and potential biomarker in solid tumors. We investigated whether Dkk3 plays an important role in the carcinogenesis of endometrial cancer (EC).
We analyzed Dkk3 mRNA expression via real-time RT-PCR in twenty-seven human primary EC tissues, and six matched normal endometrial controls. Dkk3 levels were correlated with various clinicopathologic characteristics. Additionally, enforced Dkk3 expression was examined in proliferation and tumorigenesis in vitro and in vivo, using MTT, soft agar assay, invasion assay, a xenograft mouse model, and a β-catenin-responsive SuperTopFlash luciferase assay.
Compared with matched normal endometrial cases, Dkk3 was down-regulated in EC (p<0.0001). Among cancer cases, Dkk3 expression was significantly reduced in patients with higher stage (p=0.002), positive pelvic lymph nodes (p=0.0004), non-endometrioid histology (p=0.02), and cytology-positive ECs (p=0.02). Enforced expression of Dkk3 in EC cell lines showed reduced proliferation (p<0.0001), anchorage-independent growth (p=0.005), invasion (p=0.02), and reduced TCF activity (p=0.04), confirming Dkk3 as a negative regulator of the β-catenin/Wnt signaling pathway. Tumor growth in Dkk3-injected mice was not statistically different, though did plateau towards the end, and was associated with increased lymphoid infiltration and tumor necrosis.
Dkk3 gene expression is frequently downregulated in endometrial cancer, and is associated with poor prognostic clinicopathologic markers. The results also identify a role for Dkk3 as a tumor suppressor in EC, affecting both proliferation and invasiveness. These findings may prove to be important in the design of novel biomarkers and treatment modalities for advanced EC.
... In addition, gene expression pattern in TECs is different from that in NECs. Our recent microarray analysis showed that several genes in TECs, such as VEGFR-2 and reported TEC markers, including TEM-8 (St Croix et al, 2000), CD13 (Pasqualini et al, 2000), and Dkk-3 (Untergasser et al, 2008; Fong et al, 2009), were expressed excessively. Of these, we have chosen VEGF-A and COX-2 mRNAs to examine their expression in TECs. ...
... We have previously reported abnormalities of TECs (Hida et al, 2004; Hida and Klagsbrun, 2005; Ohga et al, 2009); they grow faster and migrate better than NECs (Matsuda et al, 2010). In our isolated mouse TECs, several genes, such as VEGFR-2, CD13 (Pasqualini et al, 2000), and Dkk-3 (Untergasser et al, 2008; Fong et al, 2009), which are reported to be the upregulated genes in TECs, were indeed upregulated. Furthermore, TECs are cytogenetically abnormal (Hida et al, 2004; Akino et al, 2009). ...
Tumour stromal cells differ from its normal counterpart. We have shown that tumour endothelial cells (TECs) isolated from tumour tissues are also abnormal. Furthermore, we found that mRNAs of vascular endothelial growth factor-A (VEGF-A) and cyclooxygenase-2 (COX-2) were upregulated in TECs. Vascular endothelial growth factor-A and COX-2 are angiogenic factors and their mRNAs contain an AU-rich element (ARE). AU-rich element-containing mRNAs are reportedly stabilised by Hu antigen R (HuR), which is exported to the cytoplasm.
Normal endothelial cell (NEC) and two types of TECs were isolated. We evaluated the correlation of HuR and accumulation of VEGF-A and COX-2 mRNAs in TECs and effects of HuR on biological phenotypes of TECs.
The HuR protein was accumulated in the cytoplasm of TECs, but not in NECs. Vascular endothelial growth factor-A and COX-2 mRNA levels decreased due to HuR knockdown and it was shown that these ARE-mRNA were bound to HuR in TECs. Furthermore, HuR knockdown inhibited cell survival, random motility, tube formation, and Akt phosphorylation in TECs.
Hu antigen R is associated with the upregulation of VEGF-A and COX-2 mRNA in TECs, and has an important role in keeping an angiogenic switch on, through activating angiogenic phenotype in tumour endothelium.
... However, it is not known if stromal Dkk-3 plays a protective or tumorpromoting role in prostate disease. In addition, Dkk-3 is upregulated in the tumor endothelium, suggesting it plays a role in angiogenesis [11][12][13]. ...
Aberrant transforming growth factor–β (TGF-β) signaling is a hallmark of the stromal microenvironment in cancer. Dickkopf-3 (Dkk-3), shown to inhibit TGF-β signaling, is downregulated in prostate cancer and upregulated in the stroma in benign prostatic hyperplasia, but the function of stromal Dkk-3 is unclear. Here we show that DKK3 silencing in WPMY-1 prostate stromal cells increases TGF-β signaling activity and that stromal cell-conditioned media inhibit prostate cancer cell invasion in a Dkk-3-dependent manner. DKK3 silencing increased the level of the cell-adhesion regulator TGF-β–induced protein (TGFBI) in stromal and epithelial cell-conditioned media, and recombinant TGFBI increased prostate cancer cell invasion. Reduced expression of Dkk-3 in patient tumors was associated with increased expression of TGFBI. DKK3 silencing reduced the level of extracellular matrix protein-1 (ECM-1) in prostate stromal cell-conditioned media but increased it in epithelial cell-conditioned media, and recombinant ECM-1 inhibited TGFBI-induced prostate cancer cell invasion. Increased ECM1 and DKK3 mRNA expression in prostate tumors was associated with increased relapse-free survival. These observations are consistent with a model in which the loss of Dkk-3 in prostate cancer leads to increased secretion of TGFBI and ECM-1, which have tumor-promoting and tumor-protective roles, respectively. Determining how the balance between the opposing roles of extracellular factors influences prostate carcinogenesis will be key to developing therapies that target the tumor microenvironment.
... Discrepancies in methodology that are, possibly, responsible for the diversity in clinical outcomes include the choice of endothelial marker (i.e., pan-endothelial cell markers such as CD31, CD34, vWF, or factors selective for the activated/proliferating endothelium, such as CD105), the type of the fixative used, the method of MVD assessment (i.e., Weidner's hot-spot method [11], lumen method [59,60], Chalkley's method [61], and computerized image analysis system [62]), form of vessel quantification (highest-MVD, average MVD, and microvascular volume), the designation cut-off value for increased vascularity, the magnification size (i.e., 200x, 400x), and the field size (ranging from 0.12 mm 2 to 1.00 mm 2 ) [58,[63][64][65]. More specifically, in melanoma, a further mechanism, by which discrepancies between MVD assessment and survival may occur, is vasculogenic mimicry [58,66,67]. ...
Background
We conducted a meta-analysis, in order to appraise the effect of microvessel density (MVD) on the survival of patients with cutaneous melanoma.
Methods
This study was conducted according to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. A systematic literature search in electronic databases (MEDLINE, Web of Science, and Cochrane Central Register of Controlled Clinical Trials) was performed. Fixed Effects or Random Effects model was used, based on the Cochran Q test.
Results
In total 9 studies (903 patients) were included. Pooled HR for overall survival (OS) and disease-free survival (DFS) were 2.62 (95% CI: 0.71–9.60, p = 0.15) and 2.64 (95% CI: 0.82–8.47, p = 0.10), respectively. Odds ratios of overall survival between high and low MVD groups, at 12 (1.45, 95% CI: 0.16–13.24), 36 (2.93, 95% CI: 0.63–13.59), and 60 (4.09, 95% CI: 0.85–19.77) months did not reach statistical significance. Significant superiority of low MVD group, in terms of DFS, at all time intervals (OR: 4.69, p < 0.0001; OR: 2.18, p = 0.004; OR: 7.46, p = 0.01, resp.) was documented.
Discussion
MVD does not affect the HR of OS and DFS. A strong correlation with DFS rates at 12, 36, and 60 months was recorded.
... However, another report indicates that DKK3 expression is overexpressed in PANC-1 cell line (derived from human pancreatic ductal carcinoma), and that its down-regulation results in reduction in cellular proliferation (Zenzmaier et al., 2012). DKK3 protein expression in tissue samples revealed that DKK3 protein expression is observed both in cancer cells and tumor endothelium (Fong et al., 2009). Prognosis DKK3 expressing endothelium is sensitive to anticancer drug. ...
... In malignant cells, DKK3 can function as either a tumorsuppressor gene or oncogenic factor depending on cell type and context (Zenzmaier et al. 2013). Moreover, several reports have described increased DKK3 expression in tumor-associated cells, such as stromal and endothelial cells, where it appears to support differentiation and tissue remodeling and is associated with a favorable prognosis (St Croix et al. 2000;Untergasser et al. 2008;Fong et al. 2009;Muhlmann et al. 2010;Zenzmaier et al. 2013). These data suggest that DKK3 plays a distinct and complex role in cancer cell survival, differentiation and apoptosis. ...
Dickkopf (DKK) 3 is a DKK glycoprotein family member that controls cell fate during embryogenesis and exerts opposing effects on survival in a cell type-dependent manner; however, the mechanisms governing its pro-apoptosis versus pro-survival functions remain unclear. Here, we investigated DKK3 function in Li21 hepatoma cells and tPH5CH immortalized hepatocytes. DKK3 knockdown by siRNA resulted in reactive oxygen species accumulation and subsequent apoptosis, which were abrogated by administration of the antioxidant N-acetyl-cysteine. Moreover, forced DKK3 over-expression induced resistance to hydrogen peroxide (H2O2)-induced apoptosis. Expression analysis by cDNA microarray showed that xanthine dehydrogenase (XDH) expression was significantly lower in Li21 and tPH5CHDKK3-over-expressing cells in response to H2O2 treatment when compared to that in their respective mock-transfected controls, whereas a marked increase was observed in H2O2-treated DKK3 knockdown cells. Thus, these data suggest that DKK3 promotes cell survival during oxidative stress by suppressing the expression of the superoxide-producing enzyme XDH.
... The EpCAM(+) cells will most probably presented as immature cells, the mir-92b is a inhibitor of cell differentiation, so it is reasonable that the expression level of mir-92b is higher in EpCAM(+) LCSCs. Buechner J. et al revealed that mir-92b expression was downregulated in MYCN ((v-myc myelocytomatosis viral related oncogene, neuroblastoma derived (avian)) repressed SK-N-BE cells [47], In addition, MYCN-regulated mir-92b that could target the 3 , UTR sequence of DKK3 (Dickkopf-3), which functions as a tumor suppressor in a range of tumors484950. However, further studies involving analysis of mechanism of miR-92b upregulation in liver cancer stem cells are required. ...
microRNAs (miRNAs) are short noncoding RNAs that negatively regulate gene expression. Although recent evidences have been indicated that their aberrant expression may play an important role in cancer stem cells, the mechanism of their deregulation in neoplastic transformation of liver cancer stem cells (LCSCs) has not been explored. In our study, the HCC model was established in F344 rats by DEN induction. The EpCAM(+) cells were sorted out from unfractionated fetal liver cells and liver cancer cells using the FACS analysis and miRNA expression profiles of two groups were screened through microarray platform. Gain-of-function studies were performed in vitro and in vivo to determine the role of miR-92b on proliferation and differentiation of the hepatic progenitors. In addition, luciferase reporter system and gene function analysis were used to predict miR-92b target. we found that miR-92b was highly downregulated in EpCAM(+) fetal liver cells in expression profiling studies. RT-PCR analysis demonstrated reverse correlation between miR-92b expression and differentiation degree in human HCC samples. Overexpression of miR-92b in EpCAM(+) fetal liver cells significantly increased proliferation and inhibited differentiation as well as in vitro and in vivo studies. Moreover, we verified that C/EBPß is a direct target of miR-92b and contributes to its effects on proliferation and differentiation. We conclude that aberrant expression of miR-92b can result in proliferation increase and differentiation arrest of hepatic progenitors by targeting C/EBPß.
... Consequently, the angiogenic switch renders the tumor vasculature amenable to vessel sprouting [32]. Besides the prostate elevated Dkk-3 expression has also been shown in vessels from other tumors for example in colorectal cancer, glioma, non-Hodgkin lymphoma, melanoma, and pancreatic adenocarcinoma whereas vessels from normal tissue express low/not detectable Dkk-3 levels [33][34][35]. Dkk-3 has been shown to support tube formation in primary endothelial colonyforming cells and DKK3 overexpression reduced ANGPT1 expression in a murine B16F10 melanoma model [34]. Moreover, Dkk-3 and ANGPT2 were inversely regulated in human umbilical vein endothelial cells after knockdown of Axl [36], suggesting a role of Dkk-3 in tumor angiogenesis. ...
BACKGROUND Compartment-specific epithelial and stromal expression of the secreted glycoprotein Dickkopf-related protein (Dkk)-3 is altered in age-related proliferative disorders of the human prostate. This study aimed to determine the effect of Dkk-3 on prostate stromal remodeling that is stromal proliferation, fibroblast-to-myofibroblast differentiation and expression of angiogenic factors in vitro.
METHODS Lentiviral-delivered overexpression and shRNA-mediated knockdown of DKK3 were applied to primary human prostatic stromal cells (PrSCs). Cellular proliferation was analyzed by BrdU incorporation ELISA. Expression of Dkk-3, apoptosis-related genes, cyclin-dependent kinase inhibitors and angiogenic factors were analyzed by qPCR, Western blot analysis or ELISA. Fibroblast-to-myofibroblast differentiation was monitored by smooth muscle cell actin and insulin-like growth factor binding protein 3 mRNA and protein levels. The relevance of Wnt/β-catenin and PI3K/AKT signaling pathways was assessed by cytoplasmic/nuclear β-catenin levels and phosphorylation of AKT.
RESULTS Knockdown of DKK3 significantly attenuated PrSC proliferation as well as fibroblast-to-myofibroblast differentiation and increased the expression of the vessel stabilizing factor angiopoietin-1. DKK3 knockdown did not affect subcellular localization or levels of β-catenin but attenuated AKT phosphorylation in PrSCs. Consistently the PI3K/AKT inhibitor LY294002 mimicked the effects of DKK3 knockdown.
CONCLUSIONS Dkk-3 promotes fibroblast proliferation and myofibroblast differentiation and regulates expression of angiopoietin-1 in prostatic stroma potentially via enhancing PI3K/AKT signaling. Thus, elevated Dkk-3 in the stroma of the diseased prostate presumably regulates stromal remodeling by enhancing proliferation and differentiation of stromal cells and contributing to the angiogenic switch observed in BPH and PCa. Therefore, Dkk-3 represents a potential therapeutic target for stromal remodeling in BPH and PCa. Prostate 73: 1441–1452, 2013. © 2013 The Authors. Prostate published by Willey-Blackwell. This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
... The Dickkopf (DKK) family consists of four members that share two conserved cysteine-rich domains (Fong et al. 2009). It has been demonstrated that DKKs, including DKK3, display regionalized expression and control cell fate during development in vertebrates (Monaghan et al. 1999, Suwa et al. 2003, Ang et al. 2004, Diep et al. 2004, Fjeld et al. 2005, Nie 2005). ...
The expression of dickkopf homolog 3 gene (Dkk3) is down-regulated in some human cancers, suggesting a possible tumor suppressor role of this gene. The role and regulation of Dkk3 in thyroid cancer have not been defined. In this study we explored the relationship of the promoter methylation with inactivation of Dkk3 and tumor behaviors in papillary thyroid carcinoma (PTC). We used methylation-specific PCR and RT-PCR to examine the promoter methylation and expression of Dkk3 and tumor characteristics. We found mRNA expression of Dkk3 in 44.9% of PTC tumors versus 100% of matched normal thyroid tissues (P < 0.01). In contrast, an opposite distribution pattern of Dkk3 gene methylation was found; specifically, 38.8% of PTC tumors versus 0% of matched normal thyroid tissues harbored Dkk3 methylation. An inverse correlation between promoter methylation and mRNA expression of Dkk3 in PTC tumors was also found. Moreover, we also found an inverse correlation between Dkk3 expression and some aggressive pathologic characteristics of PTC, including high TNM stages and lymph node metastasis, but a positive correlation between Dkk3 promoter hypermethylation and pathologic aggressiveness of the tumor. Treatment of PTC cell line TPC-1 with the demethylating agent 5-azaC reduced Dkk3 promoter methylation and enhanced its expression, establishing functionally the impact of Dkk3 methylation on its expression. Our data thus for the first time demonstrate that Dkk3 gene is a potential tumor suppressor gene in thyroid cancer and aberrant promoter methylation is an important mechanism for its down-regulation, which may play a role in the tumorigenesis and aggressiveness of PTC.
... [34][35][36] Recently, DKK3 was associated with tumor angiogenesis and was considered a putative proangiogenic factor and marker for neo angiogenesis, 37 as well as a differentiation factor involved in remodeling of the tumor vasculature. 38 In the present study, it is shown that DKK3 can regulate the transcriptional patterns of SM22 via promoter activation. It is also demonstrated that DKK3 can act as a cytokine and that it can positively modulate the canonical Wnt signaling and induce β-catenin translocation and ultimately induction of Wnt target genes. ...
Rationale:
Smooth muscle cells (SMCs) are a key component of tissue-engineered vessels. However, the sources by which they can be isolated are limited.
Objective:
We hypothesized that a large number of SMCs could be obtained by direct reprogramming of fibroblasts, that is, direct differentiation of specific cell lineages before the cells reaching the pluripotent state.
Methods and results:
We designed a combined protocol of reprogramming and differentiation of human neonatal lung fibroblasts. Four reprogramming factors (OCT4, SOX2, KLF4, and cMYC) were overexpressed in fibroblasts under reprogramming conditions for 4 days with cells defined as partially-induced pluripotent stem (PiPS) cells. PiPS cells did not form tumors in vivo after subcutaneous transplantation in severe combined immunodeficiency mice and differentiated into SMCs when seeded on collagen IV and maintained in differentiation media. PiPS-SMCs expressed a panel of SMC markers at mRNA and protein levels. Furthermore, the gene dickkopf 3 was found to be involved in the mechanism of PiPS-SMC differentiation. It was revealed that dickkopf 3 transcriptionally regulated SM22 by potentiation of Wnt signaling and interaction with Kremen1. Finally, PiPS-SMCs repopulated decellularized vessel grafts and ultimately gave rise to functional tissue-engineered vessels when combined with previously established PiPS-endothelial cells, leading to increased survival of severe combined immunodeficiency mice after transplantation of the vessel as a vascular graft.
Conclusions:
We developed a protocol to generate SMCs from PiPS cells through a dickkopf 3 signaling pathway, useful for generating tissue-engineered vessels. These findings provide a new insight into the mechanisms of SMC differentiation with vast therapeutic potential.
... We have shown that TECs have an altered phenotype and they express specific markers such as tumor endothelial markers, 13 epithelial growth factor (EGF) receptor, 14 CD13 15 and Dkk-3. 16,17 TECs also show different biological activities from NECs, for example, they grow and migrate faster than NECs. 18 We have reported that TECs are more sensitive to certain drugs, such as EGFR inhibitors 14 and the green tea polyphenol epigallocatechin-3 gallate (EGCG). ...
Tumor angiogenesis is necessary for solid tumor progression and metastasis. Cyclooxygenase (COX)-2 is known to play an important role in cancer growth and invasion, and it activates the signaling pathways controlling cell proliferation, migration, apoptosis, and angiogenesis. COX-2 is reported to be expressed in many cancer cells. Several studies have reported successful treatment of cancer cells with COX-2 inhibitors (COX-2is). However, the effect of COX-2 inhibition on the tumor endothelium remains to be elucidated. Our study shows that COX-2 is expressed in the vasculature of surgically resected human tumors. To investigate the effects of COX-2 inhibition on the tumor endothelium in vitro, we isolated tumor endothelial cells (TECs) from human melanoma and oral carcinoma xenografts in mice, in which we confirmed that tumor growth was suppressed by inhibiting angiogenesis with the COX-2is NS398. COX-2 mRNA was upregulated in TECs compared to normal endothelial cells (NECs). Cell migration and proliferation were suppressed by NS398 in TECs but not in NECs. The effects of NS398 in vivo were consistent with the in vitro results. The number of CD133+/vascular endothelial growth factor receptor-2+ cells in circulation was significantly suppressed by COX-2 inhibition. In addition, the number of progenitor marker-positive cells decreased in the tumor blood vessels after COX-2i treatment, which suggests that the homing of progenitor cells into the tumor was also blocked. We conclude that NS398 specifically targets both TECs and vascular progenitor cells without affecting NECs.
... In contrast, some investigators reported that REIC expression in the tumor endothelium was an independent favorable marker for the patients with pancreatic or gastric carcinoma. 22,23 We introduced REIC-expressing plasmid into AGS cells, and found that forced REIC expression could reduce cellular proliferation, heteroploid cells, migration, invasion and lamellipodia formation with cellular G 1 arrest and apoptosis induced. However, it was the converse for GES-1 treated with REIC siRNA. ...
REIC is downregulated in immortalized cell lines compared with the parental normal counterparts. It may inhibit colony formation, tumor growth and induce apoptosis. Here, gastric carcinoma or epithelial cells transfected with REIC-expressing plasmid, its siRNA or treated with recombinant REIC were subjected to the phenotypes' measurement or related molecules' detection. REIC expression was examined in gastric carcinomas by RT-PCR, western blot and immunohistochemistry. REIC overexpression or treatment resulted in a low karyoplasmic ratio and proliferation, G₁ arrest, high apoptosis, low migration, invasion or lamellipodia formation in AGS cells. REIC knockdown caused the opposite in GES-1 cells. Anti-REIC antibody blocked the effects of REIC overexpression on proliferation, G₁/S progression and apoptosis. Ectopic REIC expression downregulated the expression of β-catenin, phosphorylated S6K (Thr389), phosphorylated Akt1/2/3 (Ser473), cyclin D2 and E, WAVE2 and upregulated phosphorylated mTOR (Ser2448) expression and the mRNA level of Akt1, Akt2, mTOR, Raptor and Rictor in AGS cells. REIC expression was negatively associated with tumor size, lymph node metastasis, dedifferentiation or poor prognosis of carcinoma. The serum REIC level was significantly higher in healthy individuals than the carcinoma patients and inversely linked to tumor size by ELISA. The possible mechanisms underlying the forced REIC overexpression or recombinant REIC mediated the reversal of the aggressive phenotypes of gastric carcinoma cells are to downregulate β-catenin and WAVE2 expression and to alter other related target proteins. Downregulated REIC expression was closely linked to aggressive behaviors and poor prognosis of gastric carcinoma.
... Tissue microarrays have been shown to have potential utility to identify possible patterns associated with pancreas cancer, possibly leading to the discovery of a gene or protein that might be a predictive or prognostic tool54555657. Other possible markers in early development include the following: in vitro, activated leukocyte cell adhesion molecule (ALCAM, CD166) as a marker of cell adhesion and chemoresistance [58]; pancreatic stellate cells (PSCs), isolated according to CD10 surface expression, are associated with lymph node status, increased invasiveness, and decreased survival [59]; lack of or weak nuclear staining of the basic helix-loop-helix domain containing class-B2 transcriptional factor BHLHB2 which is induced by hypoxia, a common finding in pancreas cancer, confers a median survival of 13 months compared to 27 months with strong staining (p = 0.03) and is touted as an independent prognostic factor for survival [60]; and finally, Dkk-3 (a member of the Wnt signaling cascade and a possible tumor suppressor) overexpression correlates with tumor growth inhibition after gemcitabine or 5FU exposure and as such may be a predictor of chemotherapy efficacy [61]. The targeting of angiogenesis has not been a successful endeavor for the treatment of pancreas cancer. ...
The incidence and mortality of pancreas cancer converge. There has been little advancement in the treatment of pancreas cancer since the acceptance of gemcitabine as the standard therapy. Unfortunately, the efficacy of gemcitabine is dismal. While there is much discussion for the development of biomarkers to help direct therapy in this area, there is little action to move them into clinical practice. Herein, we review potential pancreatic cancer biomarkers and discuss the limitations in their implementation.
... Dickkopf (Dkk) family proteins, including Dkk1/2/3/4, are secreted modulators of the canonical Wnt signaling pathway [3] . Dkk1, Dkk2 and Dkk4, antagonists of Wnt signaling [4,5] , interact with Wnt coreceptors, low-density lipoprotein receptor-related protein 5/6 (LRP5/6) and Kremen [6,7] . ...
To elucidate the role of dickkopf3 (Dkk3) in human pancreatic cancer cell growth.
Dkk3 mRNA and protein expression in human pancreatic cancer cell lines were detected by real-time reverse transcription polymerase chain reaction (real-time RT-PCR), Western blotting and immunofluorescence. Methylation of the Dkk3 promoter sequence was examined by methylation-specific polymerase chain reaction (MSP) and Dkk3 mRNA expression was determined by real-time RT-PCR after 5-aza-2'-deoxycytidine (5-aza-dC) treatment. The effects of Dkk3 on cancer cell proliferation and in vitro sensitivity to gemcitabine were investigated by CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS) after transfecting the Dkk3 expression plasmid into human pancreatic cancer cells. The expression of β-catenin, phosphorylated extracellular signal-regulated protein kinases (pERK) and extracellular signal-regulated protein kinases (ERK) was also examined by real-time RT-PCR and Western blotting after upregulating Dkk3 expression in human pancreatic cancer cells.
The results show that the expression levels of both Dkk3 mRNA and protein were low in all pancreatic cancer cell lines tested. The Dkk3 promoter sequence was methylated in the MIA PaCa-2 and AsPC-1 cell lines, which showed reduced Dkk3 expression. These two cell lines, which initially had a methylated Dkk3 promoter, showed increased Dkk3 mRNA expression that was dependent upon the dosage and timing of the DNA demethylating agent, 5-aza-dC, treatment (P < 0.05 or P < 0.01). When Dkk3 expression was upregulated following the transfection of a Dkk3 expression plasmid into MIA PaCa-2 cells, the ability of cells to proliferate decreased (P < 0.01), and the expression of β-catenin and pERK was downregulated (P < 0.01). Sensitivity to gemcitabine was enhanced in Dkk3 expression plasmid-transfected cells.
Our findings, for the first time, implicate Dkk3 as a tumor suppressor in human pancreatic cancer, through the downregulation of β-catenin expression via the ERK-mediated pathway.
... In a cancer-profiling array, Dkk-3 was downregulated in 5 of 7 PaCa samples, but was upregulated in the remaining two (8). Additionally, Dkk-3 expression in tumor epithelial cells was demonstrated in ~17% of pancreatic ductal adenocarcinomas (PDACs) by immunohistochemistry (16), while exocrine or ductal cells of normal adult pancreatic tissue were negative (17), indicating a role for Dkk-3 in a subset of PDACs. Malignant neoplasms arise mainly from exocrine regions of the gland with PDACs accounting for >90% of PaCa cases. ...
Pancreatic cancer (PaCa) is the fourth leading cause of cancer deaths in Western societies, with pancreatic ductal adenocarcinomas (PDACs) accounting for >90% of such cases. PDAC is a heterogeneous disease that includes a subset showing overexpression of the secreted glycoprotein Dickkopf-related protein 3 (Dkk-3), a protein shown to be downregulated in various cancers of different tissues. The biological function of Dkk-3 in this subset was studied using the Dkk-3 expressing PANC-1 cell line as a model for PDACs. The influence of Dkk-3 overexpression and knockdown on cellular differentiation and proliferation of PANC-1 was investigated. Confocal microscopy showed that Dkk-3 was expressed in a fraction of PANC-1 cells. While lentiviral-mediated overexpression of DKK3 did not alter cellular proliferation, knockdown of DKK3 resulted in significant reduction of cellular proliferation and concomitant induction of cell cycle inhibitors CDKN2B (p15INK4b), CDKN1A (p21CIP1) and CDKN1B (p27KIP1). In parallel, pancreatic epithelial cell differentiation markers AMY2A, CELA1, CTRB1, GCG, GLB1 and INS were significantly upregulated. PANC-1 cells differentiated using exendin-4 showed analogous induction of cell cycle inhibitors and differentiation markers. Thus, we conclude that Dkk-3 is required to maintain a highly dedifferentiated and consequently proliferative state in PANC-1, indicating a similar function in the Dkk-3 overexpressing subset of PDACs. Therefore, Dkk-3 represents a potential target for the treatment of Dkk-3-positive subtypes of PaCa to drive cells into cell cycle arrest and differentiation.
... The functions of other members of this family have been well elucidated, although the role of DKK3 still remains unclear (10,11). DKK3 functions as a tumor suppressor in a range of tumors (12)(13)(14)(15)(16)(17)(18). DKK3 has also been shown to function as a tumor suppressor with prognostic significance in human neuroblastoma (19). ...
The MYCN oncogene is frequently amplified in neuroblastoma. It is one of the most consistent markers of bad prognosis for this disease. Dickkopf-3 (DKK3) is a secreted protein of the DKK family of Wnt regulators. It functions as a tumor suppressor in a range of cancers, including neuroblastoma. MYCN was recently found to downregulate DKK3 mRNA. In this study, we show that MYCN knockdown in MYCN-amplified (MNA) neuroblastoma cell lines increases secretion of endogenous DKK3 to the culture media. MicroRNAs (miRNAs) are ∼20 nt long single-stranded RNA molecules that downregulate messenger RNAs by targeting the 3' untranslated region (3'UTR). Many miRNAs regulate genes involved in the pathogenesis of cancer and are extensively deregulated in different tumors. Using miRNA target prediction software, we found several MYCN-regulated miRNAs that could target the 3'UTR sequence of DKK3, including mir-92a, mir-92b and let-7e. Luciferase expression from a reporter vector containing the DKK3-3'UTR was decreased when this construct was cotransfected with mir-92a, mir-92b or let-7e in HEK293 cells. Mutation of the mir-92 seed sequence in the 3'UTR completely rescued the observed decrease in reporter expression when cotransfected with mir-92a and mir-92b. Antagomir and miRNA-mimic transfections in neuroblastoma cell lines confirmed that DKK3 secretion to the culture media is regulated by mir-92. Consistent with reports from other cancers, we found DKK3 to be expressed in the endothelium of primary neuroblastoma samples and to be absent in tumors with MYCN amplification. Our data demonstrate that MYCN-regulated miRNAs are able to modulate the expression of the tumor suppressor DKK3 in neuroblastoma.
Simple Summary
Wnt has diverse regulatory roles at multiple cellular levels and numerous targeting points, and aberrant Wnt signaling has crucial roles in carcinogenesis, metastasis, cancer recurrence, and chemotherapy resistance; based on these facts, Wnt represents an appealing therapeutic target for cancer treatment. Although preclinical data supports a role for the Wnt signaling pathway in uterine carcinogenesis, this area remains understudied. In this review, we identify the functions of several oncogenes of the Wnt/β-catenin signaling pathway in tumorigenesis and address the translation approach with potent Wnt inhibitors that have already been established or are being investigated to target key components of the pathway. Further research is likely to expand the potential for both biomarker and cancer drug development. There is a scarcity of treatment choices for advanced and recurrent endometrial cancer; investigating the sophisticated connections of Wnt signaling networks in endometrial cancer could address the unmet need for new therapeutic targets.
Abstract
This review presents new findings on Wnt signaling in endometrial carcinoma and implications for possible future treatments. The Wnt proteins are essential mediators in cell signaling during vertebrate embryo development. Recent biochemical and genetic studies have provided significant insight into Wnt signaling, in particular in cell cycle regulation, inflammation, and cancer. The role of Wnt signaling is well established in gastrointestinal and breast cancers, but its function in gynecologic cancers, especially in endometrial cancers, has not been well elucidated. Development of a subset of endometrial carcinomas has been attributed to activation of the APC/β-catenin signaling pathway (due to β-catenin mutations) and downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway also appears to be linked to estrogen and progesterone, and new findings implicate it in mTOR and Hedgehog signaling. Therapeutic interference of Wnt signaling remains a significant challenge. Herein, we discuss the Wnt-activating mechanisms in endometrial cancer and review the current advances and challenges in drug discovery.
Background:
Dkk3 protein attenuates the expression of Wnt3a, Wnt5a and LRP6, and their interaction, and interacts with βTrCP to suppress wnt/β-catenin pathway.
Methods:
We performed a bioinformatics analysis of Dkk3 mRNA expression through Oncomine, TCGA and Kaplan-Meier databases up to July 10, 2017.
Results:
Up-regulated Dkk3 expression was higher in gastric, breast, and ovarian cancers than normal tissues (p< 0.05). Bitter's database showed a higher Dkk3 expression in ovarian cytoadenocarcinoma than clear cell adenocarcinoma (p< 0.05). Dkk3 was more expressed in ductal breast cancer in situ than invasive ductal breast cancer (p< 0.05), in mixed lobular and ductal cancer, and lobular cancer than ductal breast cancer (p< 0.05). In TCGA data, Dkk3 expression was lower in gastric cancers with than without Barret's esophagus (p< 0.05), and in the cancers of elder than younger patients (p< 0.05). Dkk3 expression was higher in squamous cell carcinoma than adenocarcinoma (p< 0.05). Dkk3 expression was higher in ductal than lobular breast cancer, or in younger than elder patients with breast cancer (p< 0.05). According to Kaplan-Meier plotter, Dkk3 expression was negatively correlated with overall, progression-free, relapse-free or distant-metastasis-free survival rate of gastric, breast or ovarian cancer patients, but versa for lung cancer patients (p< 0.05).
Conclusion:
Dkk3 expression might be employed as a potential marker to indicate carcinogenesis and histogenesis, even prognosis.
Background
Dickkopf-related protein 3 (DKK3) is a secreted protein that is involved in the regulation of cardiac remodeling and vascular smooth muscle cell differentiation, but little is known about its role in atherosclerosis.
Methods
We tested the hypothesis that DKK3 is atheroprotective using both epidemiological and experimental approaches. Blood DKK3 levels were measured in the Bruneck Study in 2000 (n=684) and then in 2005 (n=574). DKK3-deficient mice were crossed with apolipoprotein E-/- mice to evaluate atherosclerosis development and vessel injury-induced neointimal formation. Endothelial cell migration and the underlying mechanisms were studied using in vitro cell culture models.
Results
In the prospective population-based Bruneck Study, the level of plasma DKK3 was inversely related to carotid artery intima-media thickness and 5-year progression of carotid atherosclerosis independently from standard risk factors for atherosclerosis. Experimentally, we analyzed the area of atherosclerotic lesions, femoral artery injury-induced reendothelialization, and neointima formation in both DKK3-/-/apolipoprotein E-/- and DKK3+/+/apolipoprotein E-/- mice. It was demonstrated that DKK3 deficiency accelerated atherosclerosis and delayed reendothelialization with consequently exacerbated neointima formation. To explore the underlying mechanisms, we performed transwell and scratch migration assays using cultured human endothelial cells, which exhibited a significant induction in cell migration in response to DKK3 stimulation. This DKK3-induced migration activated ROR2 and DVL1, activated Rac1 GTPases, and upregulated JNK and c-jun phosphorylation in endothelial cells. Knockdown of the ROR2 receptor using specific siRNA or transfection of a dominant-negative form of Rac1 in endothelial cells markedly inhibited cell migration and downstream JNK and c-jun phosphorylation.
Conclusions
This study provides the evidence for a role of DKK3 in the protection against atherosclerosis involving endothelial migration and repair, with great therapeutic potential implications against atherosclerosis.
Highly effective delivery of therapeutic agents into target cells using nanocarriers and subsequently rapid intracellular release are of great importance in cancer treatment. Here, we developed an enzyme and redox dual-responsive polymeric micelle with active targeting abilities to achieve rapid intracellular drug release. To overcome both its poor solubility in water and instability in the blood circulation, camptothecin (CPT) was chemically conjugated to monomethyl poly(ethylene glycol) (mPEG) via a redox-responsive linker to form polymeric prodrugs. The enzyme-responsive function is achieved by connecting hydrophobic polycaprolactone segments and hydrophilic PEG segments with azo bonds. Additionally, the end of the PEG segment was decorated with phenylboronic acid (PBA), endowing the nanocarriers with active targeting abilities. The dual-responsive targeting polymeric micelles can be generated by self-assembly of a mixture of the polymeric prodrug and enzyme-responsive copolymer. The in vitro drug release profile revealed that CPT was rapidly released from the micelles under a simulated condition similar to the tumor cell microenvironment. In vivo and ex vivo fluorescence imaging indicated that these micelles possess excellent specificity to target hepatoma carcinoma cells. The antitumor effect in mice liver cancer cells (H22) tumor-bearing Kunming (KM) mice demonstrated that this nanocarrier exhibits high therapeutic efficiency in artificial solid tumors and low toxicity to normal tissues, with a survival rate of approximately 100% after 160 days of treatment.
Background:
Pancreatic ductal adenocarcinoma (PDAC) continues to be associated with a poor prognosis. This systematic review aimed to summarize the literature regarding potential prognostic biomarkers to facilitate validation studies and clinical application.
Methods:
A systematic review was performed (2004-2014) according to PRISMA guidelines. Studies were ranked using REMARK criteria and the following outcomes were examined: overall/disease free survival, nodal involvement, tumour characteristics, metastasis, recurrence and resectability.
Results:
256 biomarkers were identified in 158 studies. 171 biomarkers were assessed with respect to overall survival: urokinase-type plasminogen activator receptor, atypical protein kinase C and HSP27 ranked the highest. 33 biomarkers were assessed for disease free survival: CD24 and S100A4 were the highest ranking. 17 biomarkers were identified for lymph node involvement: Smad4/Dpc4 and FOXC1 ranked highest. 13 biomarkers were examined for tumour grade: mesothelin and EGFR were the highest ranking biomarkers. 10 biomarkers were identified for metastasis: p16 and sCD40L were the highest ranking. 4 biomarkers were assessed resectability: sCD40L, s100a2, Ca 19-9, CEA.
Conclusion:
This review has identified and ranked specific biomarkers that should be a primary focus of ongoing validation and clinical translational work in PDAC.
To explore how uterine innervations affect expression of Dickkopf-3 (DKK-3) during peri-implantation, we first examined the consequence of uterine neurectomy on embryo implantation events. We observed that amputation of autonomic nerves innervating the uterus led to the failure of on-time implantation in rats. We then analyzed the effect of neurectomy on expression of DKK-3 further using immunohistochemistry and quantitative real-time reverse transcription polymerase chain reaction. We observed that disconnection of autonomic nerve innervation significantly increased DKK-3 expression in the endometrium before and during invasion of the blastocyst. We also observed high levels of DKK-3 immunoreactivity in the vasculature of the uterus during peri-implantation. Thus, we speculate that DKK-3 may relate to implantation. Besides, our findings provide a new line of evidence that DKK-3 may be regulated by the autonomic nervous system.
Dickkopf-3 (DKK3) may act as a tumor suppressor as it is down-regulated in various types of cancer. This study assessed the DKK3 protein expression in gastric cancer and its potential value as a prognostic marker.
DKK3 expression was evaluated by immunohistochemistry in 158 gastric cancer samples from patients who underwent gastrectomy from 2002 to 2008. Clinicopathological parameters and survival data were analyzed.
Loss of DKK3 expression was found in 64 of 158 (40.5 %) samples, and it was associated with advanced T stage (p < 0.001), lymph node metastasis (p < 0.001), UICC TNM stage (p < 0.001), tumor location (p = 0.029), lymphovascular invasion (p = 0.035), and perineural invasion (p = 0.032). Patients without DKK3 expression in tumor cells had a significantly worse disease-free and overall survival than those with DKK3 expression (p < 0.001, and p = 0.001, respectively). TNM stage (p = 0.028 and p < 0.001, respectively) and residual tumor (p < 0.001 and p = 0.003, respectively) were independent predictors of disease-free and overall survival. Based on the preoperative clinical stage assessed by computed tomography (CT), loss of DKK3 expression was predominantly associated with worse prognosis in patients with clinically node-negative advanced gastric cancer (AGC). The combination of DKK3 expression status and CT increased the accuracy of CT staging for predicting lymph node involvement from 71.5 to 80.0 % in AGC patients.
Loss of DKK3 protein expression was significantly associated with poor survival in patients with gastric cancer and was strongly correlated with the TNM stage. DKK3 might be a potential biomarker of lymph node involvement that can improve the predictive power of CT.
The prognosis for hepatocellular carcinoma (HCC) remains dismal due to the lack of diagnostic markers for early detection. This review will discuss the clinical potential of the dickkopf (DKK) family members as diagnostic and/or prognostic markers for HCC. In comparison to serum α-fetoprotein (AFP) level, which remains the gold standard for HCC diagnosis, high serum DKK1 levels have higher diagnostic value for HCC, especially for AFP-negative HCC, and can distinguish HCC from non-malignant chronic liver diseases. Additionally, the combination of serum DKK1 and AFP levels enhances diagnostic accuracy for HCC compared to serum DKK1 or AFP levels alone. Although DKK1 offers potential for its use in HCC diagnosis this review will discuss the challenges facing DKK1 and also shed some light on recent developments on the remaining DKK family members: DKK2, DKK3 and DKK4.
Dickkopf (DKK) proteins interact with low-density lipoprotein receptor-related protein 5/6 (LRP5/6) to modulate WNT signaling. The interaction is mediated by a cysteine-rich domain (C2) in the DKK protein and beta-propeller domains (PD) of LRP5/6. However, the third member of the DKK family (DKK3) does not bind to LRP5/6. To determine why DKK3 does not bind to the receptor domains, we performed a molecular modeling simulation study including homology modeling, protein-protein docking and molecular dynamics (MD). The computed affinities (ΔGbinding) between the C2 and PD models were consistent with the previously reported experimental results. The C2 model of DKK3 showed the lowest affinity for PD models. Multiple sequence alignment of C2 domains revealed that the DKK3 genes have a unique 7-amino-acid insertion (L249-E255 in human DKK3) and P258 in a finger loop 1 (FL1). Interestingly, the insertion sequence is evolutionally conserved. MD simulations of high-affinity complex models of C2 and PD showed that FL1 directly interacts with the PD models and stabilizes the complex models. We also built a 7-amino-acid-deletion/P258G mutant model of DKK3C2 and estimated its affinities for the PD models. The affinity for human LRP5PD2 was increased by the substitution (ΔGbinding＝－48.9kcal/mol) and the affinity was compatible with that of high-affinity ligands. The results suggested that the lack of affinity between human DKK3 and human LRP5/6 results from: i) insertion of the 7 amino acids, and ii) P258 in human DKK3. The sequence differences thus suggest an explanation for this unique property of DKK3.
The reduced expression in immortalized cells REIC/Dkk-3 gene, tumor suppressor gene, is downregulated in various malignant tumors. In a prostate cancer study, an adenovirus vector carrying the REIC/Dkk-3 gene (Ad-REIC) induces apoptosis. In the current study, we examined the effects of REIC/Dkk-3 gene therapy in pancreatic cancer.
REIC/Dkk-3 expression was assessed by immunoblotting and immunohistochemistry in the pancreatic cancer cell lines (ASPC1, MIAPaCa2, Panc1, BxPC3, SUIT-2, KLM1 and T3M4) and pancreatic cancer tissues. The Ad-REIC agent was used to investigate the apoptotic effect in vitro and anti-tumor effects in vivo. We also assessed the therapeutic effects of Ad-REIC therapy with gemcitabine.
The REIC/Dkk-3 expression was lost in the pancreatic cancer cell lines, and decreased in pancreatic cancer tissues. Ad-REIC induced apoptosis and inhibited cell growth in the ASPC1 and MIAPaCa2 lines in vitro, and Ad-REIC inhibited tumor growth in the mouse xenograft model using ASPC1 cells. The anti-tumor effect was further enhanced in combination with gemcitabine. This synergistic effect may be caused by the suppression of autophagy via the enhancement of mTOR signaling.
Ad-REIC induces apoptosis and inhibits tumor growth in pancreatic cancer cell lines. REIC/Dkk-3 gene therapy is an attractive therapeutic tool for pancreatic cancer.
Dickkopf-3 (Dkk3) has been proposed as tumor suppressor gene and a marker for tumor blood vessels and has pro-angiogenic properties. Dkk3 is expressed in platelets and megakaryocytes from healthy controls and patients with BCR-ABL1-negative myeloproliferative neoplasms (MPN). The aim of this study is, to find out whether patients with MPN have higher Dkk3 serum levels than normal controls.
We analyzed Dkk3 serum levels with ELISA in patients with newly diagnosed and untreated MPN, including 10 essential thrombocythemia (ET), 10 polycythemia vera (PV), 10 primary meylofibrosis (PMF) and 10 healthy blood donors and correlated these findings with biological and clinical key data and the JAK2-V617F status. Dkk3 levels were corrected to platelet count, Dkk3c, as patients with MPN have higher platelet counts than controls.
As expected, patients with MPN have higher platelet counts than normal controls. Dkk3 serum levels of patients with MPN (5.4±6.1ng/ml) showed no significant difference compared to normal controls (4.4±3.8ng/ml). Regarding Dkk3c, a significant difference to controls was found in PV (8.5±8.7ng/ml; p=0.04), but not in ET and PMF (5.7±3.8ng/ml; p=0.07 and 2.7±3.6ng/ml; p=0.9; respectively. Dkk3c correlated with the JAK2-V617F mutational burden (p=0.014, Rho=0.445).
Dkk3 levels corrected to platelet count showed higher levels in PV than normal controls. Elevated Dkk3c level could possibly correlate to platelet activation in PV patients and increased Dkk3 release. Whether this remains a surrogate marker of platelet release or it contributes to the thrombophilic state through its pro-angiogenic properties remains to be shown.
Im Rahmen von Oncotyrol, dem Exzellenzzentrum für personalisierte Krebsmedizin in Tirol, wird unter anderem daran geforscht, prädiktive Biomarker zu finden und neue Medikamente und Therapieansätze zu entwickeln. Unsere Arbeitsgruppe beschäftigt sich mit der Tumorangiogenese, also mit der Blutgefäßversorgung von malignen Tumoren. Nachfolgend geben wir einen kurzen Überblick über die Grundlagen und unsere Forschungen zur Tumorangiogenese.
Objective:
The aim of this study was to assess the expression of DKK3 protein and its target, beta-catenin, in uterine cervical squamous cell carcinoma and to determine potential clinical correlations.
Materials and methods:
Six carcinoma in-situ (CIS) tissues and 88 invasive cervical cancer tissues were included in the study. Twenty-two normal cervical tissues and one gastric cancer tissue were used as controls. The expression of DKK3 and beta-catenin proteins was evaluated by immunohistochemical analysis. Clinical and pathological parameters were obtained from medical records. Survival data were estimated using Kaplan-Meier estimates and compared with a log-rank test. Multivariate analysis was performed using the Cox regression method.
Results:
DKK3 was predominantly present in the cytoplasm. Beta-catenin was observed only on the cellular membrane of both normal and cancer cells in contrast to earlier reports, in which beta-catenin was localized to the cytoplasm and nucleus of cancer cells. The expressions of beta-catenin and DKK3 were not correlated. Three of 6 CIS (50%) and 57 of 88 invasive cancer specimens (64.8%) had lower DKK3 expression than normal controls. DKK3 expression was decreased in a stage-dependent manner (P = 0.021). The patients with low expression of DKK3 were older than those with high expression of DKK3 (P < 0.01). Moreover, the patients with low DKK3 expression had a significantly lower 5-year disease-free survival rate than those with high DKK3 expression (P = 0.026). A multivariate analysis showed that International Federation of Gynecology and Obstetrics clinical stage and parametrial involvement were independent prognostic factors.
Conclusion:
Decreased DKK3 expression was associated with advanced International Federation of Gynecology and Obstetrics clinical stages and was predictive of lower disease-free survival in patients with cervical squamous cell carcinoma. DKK3 may be implicated in cervical carcinogenesis through a beta-catenin-independent mechanism.
This chapter provides a practical overview of frequently used markers in the diagnosis and differential diagnosis of both
common and rare pancreatic and ampullary neoplasms, with a specific focus on pancreatic ductal adenocarcinoma and its mimickers.
The chapter contains 40 questions; each question is addressed with a table, concise note and representative pictures if applicable.
In addition to the literature review, the authors have included their own experience and tested numerous antibodies reported
in the literature. The most effective diagnostic panels of antibodies have been recommended for many entities, such as pVHL,
maspin, S100P and IMP-3 being suggested as the best diagnostic panel for identifying pancreatic ductal adenocarcinoma. Furthermore,
immunophenotypes of normal pancreatic and ampullary tissues have been described, which tends to be neglected in the literature.
Prognostic markers for pancreatic ductal adenocarcinoma and pancreatic endocrine neoplasm have been briefly mentioned.
KeywordsDuctal adenocarcinoma-Pancreatic endocrine neoplasm-Acinar cell carcinoma-Solid-pseudopapillary neoplasm-Pancreatic endocrine neoplasm-pVHL-Maspin-S100P-IMP-3-Beta-catenin-MUC1-MUC2-MUC5AC-CK17
REIC is down-regulated in immortalized cell lines compared with the parental normal counterparts, and could inhibit colony formation, tumor growth and induce apoptosis. Here, its expression was examined by immunohistochemistry on tissue microarray containing colorectal non-neoplastic mucosa (NNM), adenoma and adenocarcinoma. Colorectal carcinoma tissue and cell lines were studied for REIC expression or its secretory level by Western blot, RT-PCR or enzyme-linked immunosorbent assay (ELISA). The results demonstrated that REIC was differentially expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620, and WiDr with its secretion concentration less than 300 pg/mL. Carcinomas showed statistically lower REIC expression than matched NNM with no difference for protein content. Immunohistochemically, REIC expression was significantly decreased from NNM, adenoma to adenocarcinoma (p<0.05). REIC expression was negatively correlated with depth of invasion, TNM staging, dedifferentiation, Capase-3 and nuclear inhibitor of growth 5 (ING5) expression (p<0.05), while not with age, sex, tumor size, lymphatic or venous invasion, or lymph node metastasis (p>0.05). Kaplan-Meier analysis indicated that REIC expression was not associated with the prognosis of colorectal carcinomas (p>0.05). Cox's analysis demonstrated that lymphatic and venous invasion, lymph node metastasis, and UICC staging were independent prognostic factors for carcinoma (p<0.05). Our study indicated that down-regulated REIC expression might play an important role in colorectal adenoma-adenocarcinoma sequence and subsequent progression. Aberrant REIC expression might be employed as a good marker of pathogenesis and development of colorectal carcinomas.
The proteins secreted by various cells (the secretomes) are a potential rich source of biomarkers as they reflect various states of the cells at real time and at given conditions. To have accessible, sufficient and reliable protein markers is desirable as they mark various stages of disease development and their presence/absence can be used for diagnosis, prognosis, risk stratification and therapeutic monitoring. As direct analysis of blood/plasma, a common and noninvasive patient screening method, can be difficult for candidate protein biomarker identification, the alternative/complementary approaches are required, one of them is the analysis of secretomes in cell conditioned media in vitro. As the proteins secreted by cells as a response to various stimuli are most likely secreted into blood/plasma, the identification and pre-selection of candidate protein biomarkers from cell secretomes with subsequent validation of their presence at higher levels in serum/plasma is a promising approach. In this review, we discuss the proteins secreted by three progenitor cell types (smooth muscle, endothelial and cardiac progenitor cells) and two adult cell types (neonatal rat ventrical myocytes and smooth muscle cells) which can be relevant to cardiovascular research and which have been recently published in the literature. We found, at least for secretome studies included in this review, that secretomes of progenitor and adult cells overlap by 48% but the secretomes are very distinct among progenitor cell themselves as well as between adult cells. In addition, we compared secreted proteins to protein identifications listed in the Human Plasma PeptideAtlas and in two reports with cardiovascular-related proteins and we performed the extensive literature search to find if any of these secreted proteins were identified in a biomarker study. As expected, many proteins have been identified as biomarkers in cancer but 18 proteins (out of 62) have been tested as biomarkers in cardiovascular diseases as well.
While the role of Wnt signaling is well established in colorectal carcinogenesis, its function in gynecologic cancers has not been elucidated. Here, we describe the current state of knowledge of canonical Wnt signaling in endometrial cancer (EC), and its implications for future therapeutic targets. Deregulation of the Wnt/β-catenin signaling pathway in EC occurs by inactivating β-catenin mutations in approximately 10-45% of ECs, and via downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway is intimately involved with estrogen and progesterone, and emerging data implicate it in other important signaling pathways, such as mTOR and Hedgehog. While no therapeutic agents targeting the Wnt signaling pathway are currently in clinical trials, the preclinical data presented suggest a role for Wnt signaling in uterine carcinogenesis, with further research warranted to elucidate the mechanism of action and to proceed towards targeted cancer drug development.
Aberrant activation of the Wnt signaling pathway is a major trait of many human cancers. Due to its vast implications in tumorigenesis and progression, the Wnt pathway has attracted considerable attention at several molecular levels, also with respect to developing novel cancer therapeutics. Indeed, research in Wnt biology has recently provided numerous clues, and evidence is accumulating that the secreted Wnt antagonist Dickkopf-related protein 3 (Dkk-3) and its regulators may constitute interesting therapeutic targets in the most important human cancers. Based on the currently available literature, we here review the knowledge on the biological role of Dkk-3 as an antagonist of the Wnt signaling pathway, the involvement of Dkk-3 in several stages of tumor development, the genetic and epigenetic mechanisms disrupting DKK3 gene function in cancerous cells, and the potential clinical value of Dkk-3 expression/DKK3 promoter methylation as a biomarker and molecular target in cancer diseases. In conclusion, Dkk-3 rapidly emerges as a key player in human cancer with auspicious tumor suppressive capacities, most of all affecting apoptosis and proliferation. Its gene expression is frequently downregulated by promoter methylation in almost any solid and hematological tumor entity. Clinically, evidence is accumulating of Dkk-3 being both a potential tumor biomarker and effective anti-cancer agent. Although further research is needed, re-establishing Dkk-3 expression in cancer cells holds promise as novel targeted molecular tumor therapy.
Pancreatic ductal adenocarcinoma (PDAC) carries a dismal prognosis. There is a need to identify prognostic subtypes of PDAC to predict clinical and therapeutic outcomes accurately, and define novel therapeutic targets. The purpose of this review was to provide a systematic summary and review of available data on immunohistochemical (IHC) prognostic and predictive markers in patients with PDAC.
Relevant articles in English published between January 1990 and June 2010 were obtained from PubMed searches. Other articles identified from cross-checking references and additional sources were reviewed. The inclusion was limited to studies evaluating IHC markers in a multivariable setting.
Database searches identified 76 independent prognostic and predictive molecular markers implicated in pancreatic tumour growth, apoptosis, angiogenesis, invasion and resistance to chemotherapy. Of these, 11 markers (Ki-67, p27, p53, transforming growth factor β1, Bcl-2, survivin, vascular endothelial growth factor, cyclo-oxygenase 2, CD34, S100A4 and human equilibrative nucleoside transporter 1) provided independent prognostic or predictive information in two or more separate studies.
None of the molecular markers described can be recommended for routine clinical use as they were identified in small cohorts and there were inconsistencies between studies. Their prognostic and predictive values need to be validated further in prospective multicentre studies in larger patient populations. A panel of molecular markers may become useful in predicting individual patient outcome and directing novel types of intervention.
The management of pancreatic ductal adenocarcinoma (PDAC) continues to present a great challenge particularly with regard to prediction of outcome following pancreaticoduodenectomy. Molecular markers have been extensively investigated by numerous groups with the aim of enhancing prognostication; however, despite hundreds of studies that have sought to assess the potential prognostic value of molecular markers in predicting the clinical course following resection of PDAC, at this time, no molecular marker assay forms part of recommended clinical practice.
We conducted a systematic review and meta-analysis of the published literature for immunohistochemistry-based biomarkers of PDAC outcome. A dual search strategy was applied to the PubMed database on January 6, 2010, to identify cohort studies that reported associations between immunohistochemical biomarker expression and survival outcomes in PDAC, and conformed to the REMARK (REporting recommendations for tumor MARKer prognostic studies) criteria.
A total of 103 distinct proteins met all inclusion criteria. Promising markers that emerged for the prediction of overall survival included BAX (HR = 0.31, 95% CI: 0.71-0.56), Bcl-2 (HR = 0.41, 95% CI: 0.27-0.63), survivin (HR = 0.46, 95% CI: 0.29-0.73), Ki-67: (HR = 2.42, 95% CI: 1.87-3.14), COX-2 (HR = 1.39, 95% CI: 1.13-1.71), E-cadherin (HR = 1.80, 95% CI: 1.33-2.42), and S100 calcium-binding proteins, in particular S100A2 (HR = 3.23, 95% CI: 1.58-6.62).
We noted that that there was incomplete adherence to the REMARK guidelines with inadequate methodology reporting as well as failure to perform multivariate analysis. Addressing the persistent incomplete adoption of these criteria may eventually result in the incorporation of molecular marker assessment within PDAC management algorithms.
Dickkopf-3 (Dkk3) has been proposed as tumour suppressor gene and a marker for tumour blood vessels. We analysed the expression and function of Dkk3 in platelets and megakaryocytes from healthy controls and patients with BCR-ABL1-negative myeloproliferative neoplasms (MPN). Dkk3 protein and gene expression in platelets was compared with endothelial and other blood cell populations by ELISA, real-time PCR, and immunofluorescence. Moreover, megakaryocytes were isolated from bone marrow aspirates by CD61 microbeads. Immunohistochemical studies of Dkk3 expression were performed in essential thrombocythemia (ET), polycythemia vera (PV), primary myelofibrosis (PMF) and control reactive bone marrow cases (each n=10). Compared to all other blood cell populations platelets showed the highest concentration of Dkk3 protein (150 ± 19 ng/mg total protein). A strong DKK3 gene and protein expression was also observed in isolated megakaryocytes. Dkk3 co-localised with VEGF in α-granules of platelets and was released similar to VEGF upon stimulation. Addition of recombinant Dkk3 had no influence on blood coagulation (aPTT, INR) and platelet aggregation. Significantly more Dkk3+ megakaryocytes/mm2 could be found in bone marrow biopsies from patients with MPN (ET 40 ± 10, PV 31 ± 4, PMF 22 ± 3) than in controls (15 ± 3). The mean proportion of Dkk3+ megakaryocytes was increased in MPN as well (ET 83% ± 15%; PV 84% ± 12%; PMF 77% ± 8%) compared to controls (53% ± 11%). Dkk3+ megakaryocytes correlated with microvessel density in PV and PMF. We conclude that Dkk3 might be involved in the pathogenesis of MPN.
To determine the role of Wnt antagonist Dickkopf (DKK) 1 in human endothelial colony-forming cells (ECFCs) in view of the emerging importance of Wnt pathways in vascular biology.
Endothelial progenitor cells have been proposed to be crucial in tumor neovascularization. Recombinant DKK1 has been tested in ECFC angiogenic properties in vitro. DKK1 enhanced ECFC proliferation and the capacity of ECFCs to form pseudotubes in Matrigel. These effects have been attributed to enhancement of vascular endothelial growth factor receptor 2, SDF-1, and CXCR4. DKK1 gene silencing has been realized on ECFCs and mesenchymal stem cells, and we found that DKK1 silencing in the 2 cell types decreased their angiogenic potential. We then examined the possible role of DKK1 in tumor neovasculogenesis and found that blood vessels of breast cancer tissues expressed DKK1 far more strongly in human breast tumors than in normal breast tissues. By studying 62 human breast tumors, we found a significant positive correlation between DKK1 expression and von Willebrand factor. In vivo, DKK1 strongly enhanced the vascularization of Matrigel plugs and increased tumor size in a xenograft model of human breast carcinoma in nude mice.
DKK1 enhances angiogenic properties of ECFCs in vitro and is required for ECFC and mesenchymal stem cell angiogenic phenotypes in vivo. DKK1 also increases tumoral angiogenesis. Thus, we demonstrated a major role of DKK1 in angiogenic processes.
Hepatocellular carcinoma (HCC) is the second most common malignancy in Asia, with a 5-year survival rate of less than 5% due to high recurrence after surgery and resistance to chemotherapy. A variety of therapeutic interventions to treat HCC, particularly gene therapy, have recently been investigated in tumor model systems to provide a more complete understanding of hepatocarcinogenesis and effectively design therapeutic strategies to treat this disease. In our study, we constructed an adenoviral vector expressing small interfering RNA (siRNA) targeting a newly discovered gene named upregulated gene 11 (URG11). We introduced this vector into HCC cells to investigate the role of URG11 in HCC carcinogenesis. We observed that upon URG11 knockdown, HCC cell proliferation was inhibited through downregulation of several G1-S phase related molecules including cyclin D1 and apoptosis was induced as a result of Bcl-2 downregulation. Besides decreased expression of cyclin D1, CDK4, pRb and Bcl-2, URG11 also suppressed several other proteins including CAPN9, which was identified by cDNA microarray and 2D gel electrophoresis. Moreover, Ad-URG11-siRNA significantly suppressed HCC tumor growth in nude mice. In conclusion, Ad-URG11-siRNA can significantly suppress HCC tumor growth in vitro and in vivo by silencing the URG11 gene, and the use of this vector for gene therapy may represent a novel strategy to treat human HCC.
The Wnt pathway plays an important role in embryonic development, and defects in this pathway have been implicated in the tumorigenesis. The Dickkopf 3 (DKK3) is a putative Wnt signaling inhibitor that is frequently inactivated in human cancers. However, the expression of DKK3 in ovarian cancer remains unknown.
We investigated the expression of DKK3 in silico using the Digital Differential Display. DKK3 mRNA expression was also analyzed by real-time RT-PCR in ovarian carcinomas and normal ovarian tissues. DKK3 protein expression was determined by immunohistochemistry in the same ovarian carcinomas and normal ovarian tissues.
A significantly reduced expression of DKK3 (P < 0.05) was found after comparison of normal ovary- and tumor-derived libraries in the Cancer Genome Anatomy Project (CGAP). DKK3 mRNA expression was reduced in 63% (35 of 56) of tumors compared with normal ovarian samples (P < 0.02). Analysis of 13 matched pairs of ovarian carcinomas and adjacent normal tissues showed significant transcriptional downregulation of DKK3 (>twofold) in 9 paired carcinomas (69%). Loss or weak membranous expression of DKK3 protein was observed in 66% of ovarian cancers (37 of 56) including all tumors with low transcriptional level of DKK3 gene analyzed by real-time PCR.
To our best knowledge, this is the first time to demonstrate altered expression of DKK3 in ovarian cancer. The latter could be a relevant mechanism for the activation of the Wnt pathway in the carcinogenesis of ovarian cancer but additional studies are required to elucidate the function of DKK3 silencing in ovarian carcinogenesis.
Dickkopf-3 (Dkk-3) may act as a tumor suppressor as it is downregulated in various types of cancer. Moreover, a putative role in tumor neovascularization is discussed. Here, we investigated the expression of Dkk-3 protein in gastric cancer and its potential value as a prognostic marker. Dkk-3 expression was analyzed by immunohistochemistry in 136 tumor samples and was correlated with microvessel density (MVD), tumor stage, and grading as well as the clinical outcome of the patients. Dkk-3 expression was detected in endothelial cells of the tumor vessels in 129/136 (94.9%) and in tumor cells in 85/136 (62.5%) samples. MVD was high and low in 57 (42.9%) and 76 (57.1%) specimens respectively. In tumor cells, overexpression of Dkk-3 was found in 41 (30.1%) of all cases and was correlated significantly to pT-stage (p < 0.05) and UICC stage (p < 0.05). Survival analysis regarding Dkk-3 expression in tumor endothelial cells showed that Dkk-3 is an independent predictor of disease-free survival (p < 0.05). Dkk-3 expression in tumor vessels of patients with gastric cancer identifies a population of patients with relatively favorable prognosis.
Background:
Pancreatic cancer represents the fourth-leading cause of cancer death in the United States, with a dismal 5-year survival rate of less than 5%. Despite advancements in screening and early detection of other cancers such as breast and colon cancer, no reliable screening test exists for pancreatic cancer. Subsequently, the majority of patients present with advanced-stage disease leading to a poor prognosis. Because of the relatively low incidence, current efforts are focused on early detection and screening only in patients at high risk for the development of the disease.
Methods:
We discuss the practical considerations encountered when determining if an individual should be screened for pancreatic cancer. The current literature was reviewed regarding risk factors, genetic syndromes, screening modalities, and screening studies of pancreatic cancer. The current high-risk pancreatic screening program at our institute is also summarized.
Results:
Current efforts to detect pancreatic cancer at a curative phase are focused on screening individuals at high risk for the development of this disease. They include kindreds with two or more first-degree relatives affected with this disease and those with known hereditary pancreatic cancer syndromes. Hereditary pancreatic cancer syndromes include Peutz-Jeghers syndrome, familial breast cancer syndrome, and familial atypical multiple mole melanoma syndrome. Of all the screening modalities available, endoscopic ultrasound is the most sensitive and specific screening tool to evaluate the pancreas and has been proven to detect early precancerous and cancerous changes in clinical studies.
Conclusions:
Early detection and screening for pancreatic cancer in the current state should be limited to high-risk patients, although hereditary/familial factors account for only 10% of patients with pancreatic cancer. Continued efforts are needed to discover effective test to identify patients with nonhereditary risk factors who will benefit from screening and also to develop less invasive and more cost-effective screening modalities aimed at controlling pancreatic cancer.
BACKGROUND
Recently, the usefulness of intratumoral microvessel density (IMD) and expression of several angiogenic factors as prognostic indicators have been demonstrated in several human solid tumors.METHODS
One hundred four patients with pancreatic ductal adenocarcinoma were examined retrospectively. The investigated clinicopathologic and immunohistologic data included staining for vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), basic fibroblast growth factor (bFGF), CD34 (for calculating IMD), p53, and Ki-67.RESULTSMultivariate analysis for both overall and relapse-free survival revealed two independent variables, IMD and TP staining in stromal cells (TPs, P < 0.02). Whereas the frequency of hepatic metastasis was correlated significantly with cytoplasmic expression of TP or bFGF in tumor cells (TPc, bFGFc), IMD, and p53 status, local recurrence was significantly more common in patients with positive staining for TPs, bFGF in stromal cells (bFGFs), and for the pM category (P < 0.05). TPc, bFGFc, VEGF, and p53 expression correlated with IMD (P < 0.01), although TPs and bFGFs expression did not. VEGF and IMD status correlated with p53 expression (P < 0.001), although TP, bFGF, and Ki-67 status did not.CONCLUSIONSTPs expression and IMD were revealed to be valuable tools for predicting overall and relapse-free survival in patients with pancreatic adenocarcinoma. Whereas TPc and bFGFc are likely to participate in hepatic metastasis by means of their angiogenic properties, TPs and bFGFs may be related to local tumor progression. Angiogenesis in human pancreatic carcinoma may be dependent on VEGF, TP, and bFGF. p53 abnormality is likely to take part in VEGF-related angiogenesis. Cancer 2001;92:1788–97. © 2001 American Cancer Society.
The purpose of this study was to evaluate the role of angiogenesis, proliferative activity (assessed by Ki-67 expression),
p53 and ras-oncogene (H-ras) expression, and conventional clinicopathologic factors in predicting overall survival rates in patients with pancreatic
ductal adenocarcinoma. We followed-up 22 patients with ductal adenocarcinoma of the pancreas for a median of 19 months (range,
2 to 44 months). Angiogenesis was quantitated as vascular surface density (VSD) and the number of vessels per mm2 stroma (NVES) after microvessels were immunostained, using factor VIII-related antigen. p53, H-ras, and Ki-67 proteins were
also determined immunohistochemically. VSD and NVES showed significant correlations with increased proliferative activity,
poor tumor differentiation, and tumor size of 3 cm or more (P = 0.001, P = 0.013, and P = 0.047, respectively). The overall 2-year survival rate of 33.3% in patients with high VSD and NVES values was significantly
worse than that of 66.6% estimated in patients with low microvessel count (log rank, 3.97; P = 0.046). In multivariate analysis using the Cox model, VSD was found to be an independent prognostic factor of survival
(P = 0.039). H-ras and p53 expressions were not correlated with angiogenesis parameters. We conclude that, in pancreatic ductal adenocarcinoma, angiogenesis
is closely related to tumor growth and patient survival.
To evaluate whether angiogenic factors are of clinical relevance to actual human pancreatic cancers, we studied the intratumoral microvessel density (IMD), and PD-ECGF, VEGF protein expression in 40 pancreatic cancers using immunohistochemistry. We also investigated PD-ECGF and VEGF gene expression using reverse transcriptase-PCR (RT-PCR). Of the 40 pancreatic cancers studied, 30 carcinomas (75.0%) were evaluated to be PD-ECGF-positive and 10 carcinomas (25.0%) were determined to be PD-ECGF-negative. In contrast, 27 carcinomas (67.5%) were evaluated to be VEGF-positive, whereas 13 carcinomas (32.5%) were VEGF-negative. VEGF gene expression was moderately associated with an increase in the IMD (r2 = 0.181, P = 0.006), but no significant relationship was found between PD-ECGF gene expression and the IMD (r2 = 0.093, P = 0.059). However, tumours with positive expression for both PD-ECGF and VEGF had a higher IMD (P = 0.027). The results of the immunohistochemistry agreed well with the results of the quantitative RT-PCR. The median survival time of the hypervascular group was significantly shorter than that of the hypovascular group (P < 0.0001). In comparing the survival according to PD-ECGF and VEGF gene expression, the median survival time of the patients with positive PD-ECGF expression was significantly shorter than those with negative PD-ECGF expression (P = 0.040). Furthermore, the median survival time of the patients with positive VEGF expression was significantly shorter than those with negative VEGF expression (P = 0.048). However, the Cox multivariate analysis indicated that the IMD and VEGF expression were independent prognostic factors of the various clinicopathologic variables in pancreatic cancer patients (P = 0.0021 and P = 0.0443, respectively).
Despite major advances in the field of tumor angiogenesis, relatively little attention has been paid to the permeability of blood vessels in tumors. The leakiness of tumor vessels is well documented in experimental tumor models and in human cancer, but the mechanism is poorly understood, as are the implications to the rate of cancer growth, predisposition to metastasis, and delivery of macromolecular therapeutics to tumor cells. Sixteen experts in the fields of cancer biology and vascular biology gathered at the William Guy Forbeck "Focus on the Future" Conference to discuss this topic. The meeting was the first of its kind focused on the significance of blood vessel leakiness in tumors. The participants discussed the cellular basis of tumor vessel leakiness, endothelial barrier function of blood vessels, monitoring tumor vessel leakiness, mediators of endothelial leakiness, consequences of tumor vessel leakiness, genomic analysis of vascular targets, targeting drugs to tumor vessels, and therapeutic manipulation of tumor vessels. The group concluded that a more complete understanding of the basic biology of tumor vessels will be necessary to fully appreciate the consequences of vessel leakiness in cancer. New research tools such as intravital measurements of tumor blood flow and vessel leakiness, in vivo phage display, magnetic resonance imaging, and use of selective angiogenesis inhibitors will contribute to this understanding.
In many cases, silencing of gene expression by CpG methylation is causally involved in carcinogenesis. Furthermore, cancer-specific CpG methylation may serve as a tumor marker. In order to identify candidate genes for inactivation by CpG methylation in prostate cancer, the prostate cancer cell lines LNCaP, PC3, and Du-145 were treated with 5-aza-2' deoxycytidine and trichostatin A, which leads to reversion of epigenetic silencing. By microarray analysis of 18,400 individual transcripts, several hundred genes were found to be induced when compared with cells treated with trichostatin A. Fifty re-expressed genes were selected for further analysis based on their known function, which implied a possible involvement in tumor suppression. Twelve of these genes showed a significant degree of CpG methylation in their promoters. Six genes were silenced by CpG methylation in the majority of five analyzed prostate cancer cell lines, although they displayed robust mRNA expression in normal prostate epithelial cells obtained from four different donors. In primary prostate cancer samples derived from 41 patients, the frequencies of CpG methylation detected in the promoter regions of these genes were: GPX3, 93%; SFRP1, 83%; COX2, 78%; DKK3, 68%; GSTM1, 58%; and KIP2/p57, 56%. Ectopic expression of SFRP1 or DKK3 resulted in decreased proliferation. The expression of DKK3 was accompanied by attenuation of the mitogen-activated protein kinase pathway. The high frequency of CpG methylation detected in the promoters of the identified genes suggests a potential causal involvement in prostate cancer and may prove useful for diagnostic purposes.
dickkopf (dkk) genes encode a small family of secreted Wnt antagonists, except for dkk3, which is divergent and whose function is poorly understood. Here, we describe the generation and characterization of dkk3 mutant mice. dkk3-deficient mice are viable and fertile. Phenotypic analysis shows no major alterations in organ morphology, physiology, and
most clinical chemistry parameters. Since Dkk3 was proposed to function as thyroid hormone binding protein, we have analyzed
deiodinase activities, as well as thyroid hormone levels. Mutant mice are euthyroid, and the data do not support a relationship
of dkk3 with thyroid hormone metabolism. Altered phenotypes in dkk3 mutant mice were observed in the frequency of NK cells, immunoglobulin M, hemoglobin, and hematocrit levels, as well as lung
ventilation. Furthermore, dkk3-deficient mice display hyperactivity.
Wnt signalling plays a critical role in the development of cancer. Recent studies indicate that Wnt signalling is negatively regulated by secreted Wnt antagonists such as secreted frizzled related proteins (sFRPs) and Dickkopfs (Dkks). We compared Dkk family expression levels in normal prostate and prostate cancer cells and found a reduction in Dkk-3 expression in cancer cells. Ectopic expression of Dkk-3 inhibited colony formation in LNCaP and PC3 prostate cancer cell lines and inducible expression of Dkk-3 reduced LNCaP cell proliferation. Moreover, small interfering RNA-mediated downregulation of Dkk-3 enhanced cell cycle progression in untransformed RWPE-1 prostate epithelial cells. Immunohistochemical analysis revealed that Dkk-3 is expressed in a subset of normal prostate gland acini and that Dkk-3 expression is reduced in prostate tumours, particularly those with a high Gleason grade, suggesting a role for Dkk-3 in postmitotic differentiation. Consistent with this, depletion of Dkk-3 disrupted acinar morphogenesis of RWPE-1 cells in a three-dimensional cell culture model. Our results are consistent with the loss of Dkk-3 expression resulting in impairment of glandular structure and uncontrolled prostate epithelial cell (PrEC) proliferation, both of which are crucial for prostate cancer progression.
Epidemiologic studies have provided strong evidence linking chronic pancreatitis with pancreatic carcinoma. For patients with alcoholic and idiopathic chronic pancreatitis, the standardized incidence rate was 16.5; for those with tropical pancreatitis it was 100. The molecular events leading to the development of this cancer continue to be the subject of intense research, with mutations of the K-ras oncogene playing a major role. Although early diagnosis of pancreatic cancer continues to be elusive, better tools for the differential diagnosis of pancreatic and biliary strictures are becoming available. Surgery continues to offer the only possibility of cure; however, most patients still have local recurrence after resection. More aggressive treatment protocols combining preoperative chemoradiation and intraoperative radiation with surgery are being used.
The suggested link between angiogenesis in breast cancer and metastasis remains unsubstantiated. We tested this relationship in primary breast carcinomas from 37 patients with a median follow-up 9.5 years (Cohort 1) and 50 patients with a median follow-up of 1.5 years (Cohort 2). Angiogenesis was assessed by counting vessel density after immunohistochemical staining of vascular endothelium for factor VIII. Patients were grouped according to whether metastasis (defined as spread to axillary lymph nodes, distant sites or both) had occurred. The mean +/- SD scores in Cohort 1 when metastasis was absent and present, respectively, were 15.6 +/- 4.9 (n = 21) and 14.1 +/- 3.7 (n = 16). In Cohort 2 the scores were 15.4 +/- 5.8 (n = 26) and 14.5 +/- 4.9 (n = 24). There was no significant difference between these scores in either cohort. Multivariate analysis demonstrated lymph node involvement (P < 0.001) and tumour size (P < 0.001) but not angiogenesis score (P > 0.05) to predict distant metastasis. This evidence argues against any prognostic significance of angiogenesis in breast carcinoma.
Angiogenesis is required for invasive tumor growth and metastasis and constitutes an important point in the control of cancer progression. Its inhibition may be a valuable new approach to cancer therapy. Avascular tumors are severely restricted in their growth potential because of the lack of a blood supply. For tumors to develop in size and metastatic potential they must make an “angiogenic switch” through perturbing the local balance of proangiogenic and antiangiogenic factors. Frequently, tumors overexpress proangiogenic factors, such as vascular endothelial growth factor, allowing them to make this angiogenic switch. Two strategies used in the development of antiangiogenic agents involve the inhibition of proangiogenic factors (eg, anti-vascular endothelial growth factor monoclonal antibodies) as well as therapy with endogenous inhibitors of angiogenesis, such as endostatin and angiostatin. Therapy with endogenous angiogenic inhibitors such as endostatin and angiostatin may reverse the angiogenic switch preventing growth of tumor vasculature. Preclinical studies have shown that endostatin effectively inhibits tumor growth and shrinks existing tumor blood vessels. Phase 1 clinical trials of endostatin and angiostatin are ongoing, and preliminary results show minimal toxicities. Semin Oncol 29 (suppl 16):15-18. Copyright 2002, Elsevier Science (USA). All rights reserved.
Epidemiologic studies have provided strong evidence linking chronic pancreatitis with pancreatic carcinoma. For patients with alcoholic and idiopathic chronic pancreatitis, the standardized incidence rate was 16.5; for those with tropical pancreatitis it was 100. The molecular events leading to the development of this cancer continue to be the subject of intense research, with mutations of the K-ras oncogene playing a major role. Although early diagnosis of pancreatic cancer continues to be elusive, better tools for the differential diagnosis of pancreatic and biliary strictures are becoming available. Surgery continues to offer the only possibility of cure; however, most patients still have local recurrence after resection. More aggressive treatment protocols combining preoperative chemoradiation and intraoperative radiation with surgery are being used.
To gain a molecular understanding of tumor angiogenesis, we compared gene expression patterns of endothelial cells derived
from blood vessels of normal and malignant colorectal tissues. Of over 170 transcripts predominantly expressed in the endothelium,
79 were differentially expressed, including 46 that were specifically elevated in tumor-associated endothelium. Several of
these genes encode extracellular matrix proteins, but most are of unknown function. Most of these tumor endothelial markers
were expressed in a wide range of tumor types, as well as in normal vessels associated with wound healing and corpus luteum
formation. These studies demonstrate that tumor and normal endothelium are distinct at the molecular level, a finding that
may have significant implications for the development of anti-angiogenic therapies.
Following phase II clinical observations that patients with pancreas cancer experienced improvement in disease-related symptoms with GEM, a quantitative definition of clinical benefit (CB) was developed as a primary efficacy measure (Andersen, 1994, Proc ASCO 13:461). CB has 3 components: pain (based on analgesic consumption and pain intensity), Karnofsky performance status, and lean body mass increase. Each parameter was measured at baseline and regularly during study. Clinical benefit was define as a sustained improvement (≥4 weeks) in at least one parameter without a worsening in any other. Following a lead-in period to characterize and stabilize pain, 126 chemonaive patients with confirmed advanced or metastatic adenocarcinoma of the pancreas (measurableor evaluable) were randomized to GEM 1000 mg/m² over 30 min wkly × 7 followed by 1 wk of rest, and then wkly × 3 every 4 wks thereafter, or to 5FU 600 mg/m² over 30 mins once wkly. Patients on both treatment arms were balanced in terms of gender, age and disease stage. CB response was the primary endpoint: 23.8% of the GEM pts were CB responders versus 4.8% of 5FU pts (P = 0.0022). The median survival (months) was 5.65 for GEM versus 4.41 for 5FU (P = 0.0025), with 24% of GEM pts and 6% of 5FU pts alive at 9 months. WHO ≥grade 3 neutropenia was seen in 23% of GEM pts and 5% of 5FU pts, and ≥ grade 3 non-hematological toxicity (N&V, diarrhea) was seen in 15% of GEM pts and 10% of 5FU pts. This randomized study confirms the previously reported positive effect of gemcitabine on clinical benefit, and shows a survival benefit for GEM as initial treatment of patients with pancreatic cancer.
Pancreatic cancer represents the fourth-leading cause of cancer death in the United States, with a dismal 5-year survival rate of less than 5%. Despite advancements in screening and early detection of other cancers such as breast and colon cancer, no reliable screening test exists for pancreatic cancer. Subsequently, the majority of patients present with advanced-stage disease leading to a poor prognosis. Because of the relatively low incidence, current efforts are focused on early detection and screening only in patients at high risk for the development of the disease.
We discuss the practical considerations encountered when determining if an individual should be screened for pancreatic cancer. The current literature was reviewed regarding risk factors, genetic syndromes, screening modalities, and screening studies of pancreatic cancer. The current high-risk pancreatic screening program at our institute is also summarized.
Current efforts to detect pancreatic cancer at a curative phase are focused on screening individuals at high risk for the development of this disease. They include kindreds with two or more first-degree relatives affected with this disease and those with known hereditary pancreatic cancer syndromes. Hereditary pancreatic cancer syndromes include Peutz-Jeghers syndrome, familial breast cancer syndrome, and familial atypical multiple mole melanoma syndrome. Of all the screening modalities available, endoscopic ultrasound is the most sensitive and specific screening tool to evaluate the pancreas and has been proven to detect early precancerous and cancerous changes in clinical studies.
Early detection and screening for pancreatic cancer in the current state should be limited to high-risk patients, although hereditary/familial factors account for only 10% of patients with pancreatic cancer. Continued efforts are needed to discover effective test to identify patients with nonhereditary risk factors who will benefit from screening and also to develop less invasive and more cost-effective screening modalities aimed at controlling pancreatic cancer.
The suggested link between angiogenesis in breast cancer and metastasis remains unsubstantiated. We tested this relationship in primary breast carcinomas from 37 patients with a median follow-up 9.5 years (Cohort 1) and 50 patients with a median follow-up of 1.5 years (Cohort 2). Angiogenesis was assessed by counting vessel density after immunohistochemical staining of vascular endothelium for factor VIII. Patients were grouped according to whether metastasis (defined as spread to axillary lymph nodes, distant sites or both) had occurred. The mean +/- SD scores in Cohort 1 when metastasis was absent and present, respectively, were 15.6 +/- 4.9 (n = 21) and 14.1 +/- 3.7 (n = 16). In Cohort 2 the scores were 15.4 +/- 5.8 (n = 26) and 14.5 +/- 4.9 (n = 24). There was no significant difference between these scores in either cohort. Multivariate analysis demonstrated lymph node involvement (P < 0.001) and tumour size (P < 0.001) but not angiogenesis score (P > 0.05) to predict distant metastasis. This evidence argues against any prognostic significance of angiogenesis in breast carcinoma.
The growth of a tumour beyond a certain size requires angiogenesis. We assessed whether intensity of angiogenesis correlates with metastasis of non-small-cell lung cancer by counting microvessels and grading their density within the initial carcinomas in 87 T1N0M0 patients. After radical surgery, metastases developed in 22. Both microvessel count and density grades correlated significantly with metastatic disease as well as tumour size and proliferative activity. The likelihood of metastasis increased as the vessel count increased. On multivariate analysis, the microvessel density count was the only independent predictor of metastasis.
Experimental evidence suggests that the growth of a tumor beyond a certain size requires angiogenesis, which may also permit metastasis. To investigate how tumor angiogenesis correlates with metastases in breast carcinoma, we counted microvessels (capillaries and venules) and graded the density of microvessels within the initial invasive carcinomas of 49 patients (30 with metastases and 19 without).
Using light microscopy, we highlighted the vessels by staining their endothelial cells immunocytochemically for factor VIII. The microvessels were carefully counted (per 200x field), and their density was graded (1 to 4+), in the most active areas of neovascularization, without knowledge of the outcome in the patient, the presence or absence of metastases, or any other pertinent variable.
Both microvessel counts and density grades correlated with metastatic disease. The mean (+/- SD) count and grade in the patients with metastases were 101 +/- 49.3 and 2.95 +/- 1.00 vessels, respectively. The corresponding values in the patients without metastases were significantly lower--45 +/- 21.1 and 1.38 +/- 0.82 (P = 0.003 and P less than or equal to 0.001, respectively). For each 10-microvessel increase in the count per 200x field, there was a 1.59-fold increase in the risk of metastasis (95 percent confidence interval, 1.19 to 2.12; P = 0.003). The microvessel count and density grade also correlated with distant metastases. For each 10-microvessel increase in the vessel count per 200x field, there was a 1.17-fold increase in the risk of distant metastasis (95 percent confidence interval, 1.02 to 1.34; P = 0.029).
The number of microvessels per 200x field in the areas of most intensive neovascularization in an invasive breast carcinoma may be an independent predictor of metastatic disease either in axillary lymph nodes or at distant sites (or both). Assessment of tumor angiogenesis may therefore prove valuable in selecting patients with early breast carcinoma for aggressive therapy.
Epidemiologic studies have provided strong evidence linking chronic pancreatitis with pancreatic carcinoma. For patients with alcoholic and idiopathic chronic pancreatitis, the standardized incidence rate was 16.5; for those with tropical pancreatitis it was 100. The molecular events leading to the development of this cancer continue to be the subject of intense research, with mutations of the K-ras oncogene playing a major role. Although early diagnosis of pancreatic cancer continues to be elusive, better tools for the differential diagnosis of pancreatic and biliary strictures are becoming available. Surgery continues to offer the only possibility of cure; however, most patients still have local recurrence after resection. More aggressive treatment protocols combining preoperative chemoradiation and intraoperative radiation with surgery are being used.
A study of tumour blood flow in 36 patients with 38 malignant melanomas using Doppler Ultrasound flowmetry has shown that tumour blood flow can be detected in most melanomas more than 0.9 mm thick, and is absent in most melanomas less than this thickness. Histological quantitation of blood vessels using lectin staining to delineate vascular endothelium and automated image analysis has shown a high degree of correlation between vascularity at the tumour base and tumour thickness. Since it is likely that the development of a vascular plexus at the tumour base is a prerequisite for dissemination, the development of these blood vessels may prove to be an independent prognostic factor for thin melanomas. This work also provides a new model for dynamic, in vivo investigation of the vascularity of human tumours.
To determine the absolute and relative value of microvessel density (MVD), p53 and c-erbB-2 protein expression, peritumoral lymphatic vessel invasion (PLVI), and conventional prognosticators in predicting relapse-free (RFS) and overall survival (OS) rates in patients with node-negative breast carcinoma (NNBC).
We monitored 254 consecutive patients with NNBC for a median of 62 months. Intratumoral MVD was measured after microvessels were immunostained using anti-CD31 antibody. p53 and c-erbB-2 protein and hormone receptors were also determined immunocytochemically. Results were analyzed by both univariate and multivariate statistical analysis.
Univariate analysis showed that MVD was significantly predictive of both RFS (odds ratio [OR], 8.30; P = .0001) and OS (OR, 4.50; P = .012) when tested as a continuous or dichotomous variable. Likewise, tumor size (OR, 3.16; P = .0012), PLVI (OR, 4.36; P = .0009), estrogen receptor (ER) status (OR, 2.35; P = .016), progesterone receptor (PR) status (OR, 2.00; P = .017), and expression of p53 protein (OR, 2.82; P = .004) were significantly associated with RFS. Tumor size (OR, 3.80; P = .0038) and expression of p53 protein (OR, 2.58; P = .024) were significantly associated with OS by univariate analysis. Multivariate analysis showed that MVD (P = .0004), p53 protein expression (P = .0063), tumor size (P = .0144), and PLVI (P = .0033) were all significant and independent prognostic factors for RFS. However, only tumor size (P = .004) and MVD (P = .047) were independent predictors for OS. c-erbB2 expression was not associated with outcome by either univariate or multivariate analysis.
MVD, p53 expression, PLVI, and tumor size are independent prognostic indicators of recurrence, which are useful in selection of high-risk NNBC patients who may be eligible to receive adjuvant therapies.
Tumor growth and metastasis require angiogenesis; and microvessel density, a measure of tumor angiogenesis, correlates with metastasis in breast and lung carcinoma. To determine how microvessel density correlated with metastasis in prostate carcinoma, we counted microvessels within the initial invasive carcinomas of 74 patients (29 with metastasis, 45 without). Microvessels were highlighted by immunostaining endothelial cells for factor VIII-related antigen. Without knowledge of the patient's cancer stage, microvessels were counted in a 200 field (0.739 mm2) in the most active areas of neovascularization. The mean microvessel count in tumors from patients with metastases was 76.8 microvessels per 200 field (median, 66; standard deviation, 44.6). The counts within carcinomas from patients without metastasis were significantly lower, 39.2 (median, 36; standard deviation, 18.6) (P < 0.0001). Microvessel counts increased with increasing Gleason's score (P < 0.0001), but this increase was present predominantly in the poorly differentiated tumors. Although Gleason's score also correlated with metastasis (P = 0.01), multivariate analysis showed that Gleason's score added no additional information to that provided by microvessel count alone. Assay of microvessel density within invasive tumors may prove valuable in selecting patients for aggressive adjuvant therapies in early prostate carcinoma.
To investigate the potential correlations between a high microvascular count and the survival rate in colorectal cancer.
Three markers for endothelial cells--Ulex Europaeus Lectin (UEA), a polyclonal anti-von Willebrand factor (vWF) antibody, and a monoclonal anti-CD31 antibody (all from Dakopatts, Glostrup, Denmark)--were used for immunohistochemical detection of microvessels in whole-mount sections from 15 colorectal cancers. Areas with higher microvascular density were homogeneously distributed in the sections, regardless of the marker used. The anti-vWF antibody was subsequently used for quantification of microvessels in full-cross tumor biopsies collected from 212 consecutive surgical specimens. The correlations between the mean number of microvessels in areas with the highest microvascular density and tumor differentiation, tumor stage according to Dukes', and survival time were investigated.
A significantly longer survival time was shown for patients who had tumors with a mean of more than 10 anti-vWF-positive microvessels, as compared with those who had < or = five. Tumors with a microvascular count between six and 10 microvessels behaved in-between. There was no correlation between the number of microvessels and tumor differentiation or Dukes' stage.
The number of microvessels measurable in tumor biopsies seems to be a prognostic predictor independent of Dukes' stage in colorectal cancer. However, our results are opposite to the findings in other tumor types investigated so far; we found that a high microvascular count predicted a longer survival time, rather than a shorter one. Determination of the microvascular count can be of importance in therapy selection even before, or immediately after, surgery, ie, before Dukes' stage is known.
We wish to thank Jeff Arbeit, Karen Smith-McCune, Noel Weidner, Ella Bossy-Wetzel, and Christine Jolicoeur for providing the tissue sections used to prepare Figure 3Figure 3; Noel Bouck, Karen Smith-McCune, David Olson, Dowdy Jackson, and Jeff Arbeit for comments on the manuscript; and Wendy Gee and Terry Schoop of BioMed Arts (San Francisco) for artwork. The work from the authors' laboratories reviewed herein was supported by grants from the National Cancer Institute.
Mesothelial cells are actively involved in inflammatory processes by expressing a set of cell adhesion molecules (CAMs). Transmigration of leukocytes into inflamed tissues requires a chemotactic stimulus and engagement of platelet-endothelial cell adhesion molecule-1 (PECAM-1). To investigate the kinetics involved in peritonitis, pure cultures of mesothelial cells are necessary. In previous studies, we have found that human mesothelial cells (HOMES) show a weak constitutive expression of PECAM-1, which cannot be further stimulated by cytokines. It is known that all serous cavities and body fluids contain numerous macrophages which strongly express this adhesion molecule. To identify the cells responsible for the expression of PECAM-1, mesothelial cells freshly obtained from omental tissue were isolated using PECAM-1-conjugated magnetic beads by cell sorting. For these studies, the negative as well as the positive fraction of isolated cells were used. As a control, freshly isolated monocytes were studied. Cell cultures were characterized by light and electron microscopy, as well as immunocytochemistry. The negative cell fraction was cultivated and stimulated for different times with tumor necrosis factor-alpha (30 and 300 U/ml), interleukin-1 beta (10 and 100 U/ml) and interferon-gamma (500 U/ml) and PECAM-1 expression was analyzed by a comparative quantitative cell enzyme immunoassay (EIA). The positive cell fraction was treated in the same manner. Both fractions of isolated cells showed strong positivity for cytokeratins 8, 18, 7 and 19, as well as vimentin. CD68, a monocyte marker, was not detected on mesothelial cells. In addition, EIA analysis confirmed the constitutive expression of PECAM-1 obtained from previous studies. This expression on HOMES was not inducible, irrespective of the type and concentration of cytokine studied. These data confirm PECAM-1 expression on mesothelial cells obtained from human omental tissue and suggest a critical role in transmigration of leukocytes during peritoneal inflammation.
Most patients with advanced pancreas cancer experience pain and must limit their daily activities because of tumor-related symptoms. To date, no treatment has had a significant impact on the disease. In early studies with gemcitabine, patients with pancreas cancer experienced an improvement in disease-related symptoms. Based on those findings, a definitive trial was performed to assess the effectiveness of gemcitabine in patients with newly diagnosed advanced pancreas cancer.
One hundred twenty-six patients with advanced symptomatic pancreas cancer completed a lead-in period to characterize and stabilize pain and were randomized to receive either gemcitabine 1,000 mg/m2 weekly x 7 followed by 1 week of rest, then weekly x 3 every 4 weeks thereafter (63 patients), or to fluorouracil (5-FU) 600 mg/m2 once weekly (63 patients). The primary efficacy measure was clinical benefit response, which was a composite of measurements of pain (analgesic consumption and pain intensity), Karnofsky performance status, and weight. Clinical benefit required a sustained (> or = 4 weeks) improvement in at least one parameter without worsening in any others. Other measures of efficacy included response rate, time to progressive disease, and survival.
Clinical benefit response was experienced by 23.8% of gemcitabine-treated patients compared with 4.8% of 5-FU-treated patients (P = .0022). The median survival durations were 5.65 and 4.41 months for gemcitabine-treated and 5-FU-treated patients, respectively (P = .0025). The survival rate at 12 months was 18% for gemcitabine patients and 2% for 5-FU patients. Treatment was well tolerated.
This study demonstrates that gemcitabine is more effective than 5-FU in alleviation of some disease-related symptoms in patients with advanced, symptomatic pancreas cancer. Gemcitabine also confers a modest survival advantage over treatment with 5-FU.
Angiogenesis is essential for growth and metastasis of solid malignancies. In several tumours, tumour vessel count and expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, have been associated with prognosis. To determine if vessel count and VEGF expression are prognostic factors in pancreatic cancer, we examined these parameters in resected tumour specimens from 22 patients who did not receive pre-operative therapy. Paraffin-embedded tumour specimens were immunohistochemically stained for factor VIII (surrogate for vessels) and VEGF. Vessel counts and VEGF expression were evaluated without knowledge of patient outcome. The median follow-up for the entire group had not been reached as of 23.1 months (range 10-69 months). The mean vessel count and VEGF expression were no different between those patients who had recurrences and those who did not. By linear regression analysis, the correlation of VEGF expression with vessel count did not reach statistical significance (P = 0.0685). Survival and time to recurrence were similar in patients with high and low vessel counts and VEGF expression of 1, 2 or 3. Tumour differentiation or lymph node positivity had no effect on either VEGF expression or vessel count. Our data suggest that, in contrast to findings in other solid malignancies, vessel count and VEGF expression are not predictors of survival or recurrence in patients with resectable adenocarcinoma of the pancreas.
Tumor angiogenesis has proved to be a useful prognostic determinant for patients with various solid tumors. In this study, we investigated the quantitative expression of angiogenesis in colorectal carcinoma to determine how angiogenesis correlates with clinicopathologic factors and prognosis. One hundred twenty-seven specimens resected from patients with primary colorectal carcinoma were investigated immunohistochemically using a polyclonal antibody against factor-VIII-related antigen, and areas with the highest vascular density at the invasive tumor margin were counted at 200 times magnification. The microvessel count, defined as angiogenesis density (AD), became significantly higher with increase in histologic grade (p = 0.02) and Dukes stage (p = 0.001). AD was also significantly higher in patients with lymph node metastasis (p = 0. 005), lymphatic invasion (p = 0.042), vascular invasion (p < 0.001), and liver metastasis (p = 0.0004) than in those without. In addition, patients with synchronous distant hematogenous metastasis in stage D disease showed significantly higher AD than patients with nonhematogenous metastasis (p = 0.006). When 27 cases of disease recurrence after surgical resection with curative intent were stratified according to mode of spread, AD in cases with a hematogenous pattern of relapse proved to be significantly higher than in cases with nonhematogenous spread (p < 0.001). No significant differences were, however, found in AD when they were subdivided as to operative nodal status (p = 0.39 and 0.08 in the node-negative and the node-positive group, respectively). Multivariate analysis indicated that AD was an independent prognostic factor (p = 0.0004) in colorectal carcinoma. Quantitative evaluation of tumor angiogenesis at the invasive tumor margin is suggested to be a good prognostic indicator and a useful predictor for hematogenous spread and recurrence in patients with colorectal carcinoma.
We wish to thank Terry Schoop of Biomed Arts Associates, San Francisco, for preparation of the figures, Cori Bargmann and Zena Werb for insightful comments on the manuscript, and Normita Santore for editorial assistance. In addition, we are indebted to Joe Harford and Richard Klausner, who allowed us to adapt and expand their depiction of the cell signaling network, and we appreciate suggestions on signaling pathways from Randy Watnick, Brian Elenbas, Bill Lundberg, Dave Morgan, and Henry Bourne. R. A. W. is a Ludwig Foundation and American Cancer Society Professor of Biology. His work has been supported by the Department of the Army and the National Institutes of Health. D. H. acknowledges the support and encouragement of the National Cancer Institute. Editorial policy has rendered the citations illustrative but not comprehensive.
Normal human cells stop proliferation after a certain number of cell divisions. This phenomenon is called cellular aging. The fact that the senescence phenotype is dominant and the immortal one is recessive indicates that immortalization of human cells may be caused by loss of functions of certain genes in normal cells. Based on this evidence, several cDNA clones whose expression was down-regulated during the immortalization process of human cells were isolated by the representative difference analysis (RDA) system in our laboratory. One of them, which was named REIC, was expressed to a lower degree in three human immortalized cell lines as compared with their parental normal counterparts. In addition, the expression of REIC was markedly lower in eight human tumor-derived cell lines (Hep3B and HuH-7 hepatocellular carcinomas, HuH-6 Clone 5 hepatoblastoma, HuCCT-1 cholangiocarcinoma, A549 lung cancer, HaCaT immortalized keratinocyte, HeLa cervical carcinoma, and Saos-2 osteosarcoma). In contrast, among the human tissues examined, the heart and brain, which contain a large number of post-mitotic cells, showed the highest expression of REIC. The full-length REIC cDNA revealed that the predicted protein is 350 amino acids in length and possesses coiled-coil tertiary structures in each of the amino- and carboxyl-termini. Furthermore, a search of the protein database revealed a match of this gene product with Dkk-3, which is a novel inhibitor of Wnt oncogene. These results indicate that the REIC cloned by us may function as a tumor suppressor.
Treatment options for pancreatic cancer remain limited due to the large proportion of patients presenting with advanced disease at the time of diagnosis. Surgery offers the best chance for cure. Localized chemoradiation modestly improves median survival in both localized and locally advanced disease. Interstitial brachytherapy and intraoperative radiotherapy improve local control without providing significant impact on overall survival. Technological advances now allow us to deliver three dimensional conformal external beam irradiation with improved efficacy and decreased morbidity. Novel treatment approaches, such as intraoperative photoelectron radiation (Photon Radiosurgery System; PeC Photoelectron Corporation) and the development of more effective radiosensitizers, are presently under investigation.
To gain a molecular understanding of tumor angiogenesis, we compared gene expression patterns of endothelial cells derived from blood vessels of normal and malignant colorectal tissues. Of over 170 transcripts predominantly expressed in the endothelium, 79 were differentially expressed, including 46 that were specifically elevated in tumor-associated endothelium. Several of these genes encode extracellular matrix proteins, but most are of unknown function. Most of these tumor endothelial markers were expressed in a wide range of tumor types, as well as in normal vessels associated with wound healing and corpus luteum formation. These studies demonstrate that tumor and normal endothelium are distinct at the molecular level, a finding that may have significant implications for the development of anti-angiogenic therapies.
Unresectable pancreatic cancer has a dismal prognosis with a median survival of 3-5 months in untreated disease. Since the introduction of gemcitabine, pancreatic cancer may no longer be regarded a chemotherapy-resistant tumor. Treatment with single-agent gemcitabine achieved clinical benefit and symptoms improvement in 20-30% of patients. While 1-year survival was observed in 2% of 5-fluorouracil (5-FU)-treated patients, it was raised to 18% by single-agent gemcitabine. Good treatment tolerability and low incidence of side effects are clear advantages of single-agent gemcitabine. Improvement of efficacy is, however, expected from combination treatment. Gemcitabine and cisplatin given as first-line treatment in three studies achieved a median survival of 7.4-8.3 months. One-year survival was raised to 28% as reported in one study. Comparable activity was obtained by a combination of gemcitabine with 5-FU. Nine studies using gemcitabine in combination with standard-dose or high-dose 5-FU reported a median survival ranging from 5.5 to 13 months. Notwithstanding these promising results, recommendations regarding palliative chemotherapy of pancreatic cancer remain tentative and still need confirmation by presently ongoing phase III trials. Inclusion of pancreatic cancer patients into clinical trials should be a major goal. Outside clinical trials, patients should present with an adequate PS (Karnofsky-performance index greater than or = 70) to qualify for chemotherapy.
The purpose of this study was to evaluate the role of angiogenesis, proliferative activity (assessed by Ki-67 expression), p53 and ras-oncogene (H-ras) expression, and conventional clinicopathologic factors in predicting overall survival rates in patients with pancreatic ductal adenocarcinoma. We followed-up 22 patients with ductal adenocarcinoma of the pancreas for a median of 19 months (range, 2 to 44 months). Angiogenesis was quantitated as vascular surface density (VSD) and the number of vessels per mm2 stroma (NVES) after microvessels were immunostained, using factor VIII-related antigen. p53, H-ras, and Ki-67 proteins were also determined immunohistochemically. VSD and NVES showed significant correlations with increased proliferative activity, poor tumor differentiation, and tumor size of 3 cm or more (P = 0.001, P = 0.013, and P = 0.047, respectively). The overall 2-year survival rate of 33.3% in patients with high VSD and NVES values was significantly worse than that of 66.6% estimated in patients with low microvessel count (log rank, 3.97; P = 0.046). In multivariate analysis using the Cox model, VSD was found to be an independent prognostic factor of survival (P = 0.039). H-ras and p53 expressions were not correlated with angiogenesis parameters. We conclude that, in pancreatic ductal adenocarcinoma, angiogenesis is closely related to tumor growth and patient survival.
The 5-year survival for pancreatic cancer is usually less than 5%, and no treatment has demonstrated consistent effect on patient survival and disease-related symptoms. Early studies with gemcitabine suggested a modest antitumor activity with significant improvement in disease-related symptoms. This phase II study reports the activity of gemcitabine on 33 consecutive patients with unresectable pancreatic carcinoma. Twenty-three patients had metastatic and 10 locally advanced unresectable disease. Twenty-six patients had not received any previous treatment and seven had received first-line chemotherapy with 5-fluorouracil. Gemcitabine 1,000 mg/m2 was administered intravenously in 30 minutes in the first cycle once weekly for up to 7 weeks followed by 1 week rest; then in subsequent cycles, once weekly for 3 of every 4-week cycle. Four patients obtained partial response (12%). Fifteen patients (45%) had stable disease with a median duration of 32 weeks (range: 16-75 weeks), and 14 patients experienced progressive disease. Median duration of response was 34.5 weeks (range: 19-50 weeks). Median survival was 33 weeks (range: 2-91 weeks). All 4 responding patients and 14 of 15 (93%) patients with stable disease had improvement in performance status and decrease in daily analgesic requirement. Toxicity was mild and mainly consisted of moderate and rapidly reversible myelosuppression. We conclude that gemcitabine chemotherapy was very well tolerated and determined a significant clinical improvement with modest antitumoral activity in patients with advanced pancreatic cancer.
Recently, the usefulness of intratumoral microvessel density (IMD) and expression of several angiogenic factors as prognostic indicators have been demonstrated in several human solid tumors.
One hundred four patients with pancreatic ductal adenocarcinoma were examined retrospectively. The investigated clinicopathologic and immunohistologic data included staining for vascular endothelial growth factor (VEGF), thymidine phosphorylase (TP), basic fibroblast growth factor (bFGF), CD34 (for calculating IMD), p53, and Ki-67.
Multivariate analysis for both overall and relapse-free survival revealed two independent variables, IMD and TP staining in stromal cells (TPs, P < 0.02). Whereas the frequency of hepatic metastasis was correlated significantly with cytoplasmic expression of TP or bFGF in tumor cells (TPc, bFGFc), IMD, and p53 status, local recurrence was significantly more common in patients with positive staining for TPs, bFGF in stromal cells (bFGFs), and for the pM category (P < 0.05). TPc, bFGFc, VEGF, and p53 expression correlated with IMD (P < 0.01), although TPs and bFGFs expression did not. VEGF and IMD status correlated with p53 expression (P < 0.001), although TP, bFGF, and Ki-67 status did not.
TPs expression and IMD were revealed to be valuable tools for predicting overall and relapse-free survival in patients with pancreatic adenocarcinoma. Whereas TPc and bFGFc are likely to participate in hepatic metastasis by means of their angiogenic properties, TPs and bFGFs may be related to local tumor progression. Angiogenesis in human pancreatic carcinoma may be dependent on VEGF, TP, and bFGF. p53 abnormality is likely to take part in VEGF-related angiogenesis.
The human REIC gene is a recently found mortalization-related gene and a candidate tumor suppressor gene expression of which is largely attenuated in many immortalized and tumor-derived cell lines (Biochem. Biophys. Res. Commun. 268 (2000) 20-24). To gain insight into the mechanisms of the down-regulation, we investigated the genomic structure and promoter activity of the human REIC gene. The gene, identical with the DKK-3 gene, resides on chromosome 11p15.1, consists of nine exons, and has two promoters. Methylation in the main promoter region was detected in 11 out of 21 cell lines tested (52%) derived from a variety of human tumors, in which the expression of the REIC gene was decreased. In ten of these 11 cell lines the minor promoter was also methylated. Similarly, the REIC gene expression was decreased in 14 of 24 fresh non-small cell lung cancer specimens (58%) compared to that in corresponding non-cancerous tissue, though allelic loss and tumor-specific mutation were rare. Of these 14 tumors, at least five tumors exhibited heavy methylation of the REIC promoter region. These results indicate that the down-regulation of the REIC gene expression is ascribed to the aberrant promoter hyper-methylation at least in a subset of human tumors. The expression was restored upon treatment of SQ5 cells with 5-aza-deoxycytidine, confirming DNA methylation as the mode of downregulation. A notable single nucleotide polymorphism in the coding region (cSNP) with an amino acid substitution of glycine (GGG) to arginine (AGG) was found at codon 335 of the REIC gene. However, the distribution of the cSNP showed no significant difference between lung cancer patients and healthy population.
Angiogenesis is required for tumour growth. Its evaluation, by intratumoural microvessel density (IMD), has prognostic significance in many solid tumours. There is controversy regarding its use in pancreatic cancer and little is known about its role in ampullary tumours. The aim is to study IMD as a prognostic marker in resected ductal adenocarcinomas of head of pancreas and cancers of the ampullary region.
Forty-seven patients (23 pancreatic and 24 ampullary, mean age 62.0 years) surviving a potentially curative (R0/R1) resection were analysed. Paraffin-embedded sections of these tumours were immunohistochemically stained for CD-34 and IMD was determined (magnification x200). This was correlated with histopathological data and survival using Cox's multivariate analysis.
Mean survival for the pancreatic cancer group was 18.4 months (SE=2.7) and 81.2 months (SE=9.9) for the ampullary cancer group. In the pancreatic cancer group, IMD was found to have independent prognostic significance to survival on multivariate analysis (P=0.002, Hazard Ratio (HR) 13.60) along with microscopic resection margin involvement (P=0.003, HR 15.18). For ampullary cancers, IMD was higher in those with lymph node metastasis (P=0.02, Mann-Whitney U -test).
IMD in resected pancreatic cancers correlates with survival.
Angiogenesis is required for invasive tumor growth and metastasis and constitutes an important point in the control of cancer progression. Its inhibition may be a valuable new approach to cancer therapy. Avascular tumors are severely restricted in their growth potential because of the lack of a blood supply. For tumors to develop in size and metastatic potential they must make an "angiogenic switch" through perturbing the local balance of proangiogenic and antiangiogenic factors. Frequently, tumors overexpress proangiogenic factors, such as vascular endothelial growth factor, allowing them to make this angiogenic switch. Two strategies used in the development of antiangiogenic agents involve the inhibition of proangiogenic factors (eg, anti-vascular endothelial growth factor monoclonal antibodies) as well as therapy with endogenous inhibitors of angiogenesis, such as endostatin and angiostatin. Therapy with endogenous angiogenic inhibitors such as endostatin and angiostatin may reverse the angiogenic switch preventing growth of tumor vasculature. Preclinical studies have shown that endostatin effectively inhibits tumor growth and shrinks existing tumor blood vessels. Phase 1 clinical trials of endostatin and angiostatin are ongoing, and preliminary results show minimal toxicities.
Advances in chemotherapy for pancreatic cancer have been limited. In the past decade, the standard therapy for metastatic disease has switched from 5-fluorouracil (5-FU) to gemcitabine. However, several other cytotoxic agents have shown limited but promising efficacy in pancreatic cancer, and many of these appear to be well suited for combination chemotherapy. Although 5-FU and cisplatin have not demonstrated substantial survival benefits when combined with gemcitabine, results of several phase III trials with other agents are still pending. For locally advanced disease, most recent studies have incorporated gemcitabine into combined-modality therapy. Similarly, in surgically resectable disease, current trials are incorporating gemcitabine into adjuvant therapy. Other trials are using neoadjuvant therapy as a possible means to improve upon current surgical results. However, much hope comes from the development of newer "targeted" therapies for this disease. Although matrix metalloproteinase inhibitors and farnesyl transferase inhibitors did not appear to be effective in initial studies, other targeted therapies are beginning to enter clinical trials.
Cyclo-oxygenase-2 expression has been reported to play an important role in the metaplasia-dysplasia-carcinoma sequence in Barrett's oesophagus. However, the existence of cyclo-oxygenase-2 expressing cells in Barrett's epithelium is still uncertain.
To identify the cells that express cyclo-oxygenase-2 protein and to investigate the relationship between cyclo-oxygenase-2 expression and mucin-phenotype of Barrett's epithelium.
Sections from 466 biopsy samples of Barrett's epithelium from 358 non-medicated patients were immunohistochemically examined for the cyclo-oxygenase-2 expression, mucin-phenotype, cell proliferation and apoptosis.
Cyclo-oxygenase-2 expression was detected in 71.0% of Barrett's epithelium biopsy samples. In Barrett's epithelium with the gastric predominant mucin-phenotype, cyclo-oxygenase-2 expression was mainly found in stromal and deep epithelial cells, whereas in intestinal predominant mucin-phenotype, it was mostly in superficial epithelial cell. A significant elevation of proliferating cell nuclear antigen index and suppression of apoptotic index was observed in Barrett's epithelium with superficial epithelial cyclo-oxygenase-2 expression. Neither such elevation of proliferating cell nuclear antigen index nor the suppression of apoptotic index could be found in chronic non-steroidal anti-inflammatory drugs users.
Barrett's epithelium with intestinal mucin and superficial epithelial cyclo-oxygenase-2 expression possess a higher proliferation potential, but this risk may be thwarted by non-steroidal anti-inflammatory drugs administration.
Microvessel density (MVD) has been shown to be associated with a poor prognosis in gastric, colorectal, breast, and lung cancers. However, there are few positive results in pancreatic cancer. We hypothesized that high counts of MVD, determined by the lumen method as compared with the hot-spot method, would show a significant correlation with a poor prognosis in pancreatic cancer.
Thin slices from the center and periphery of 41 resected pancreatic tumors were immunostained with factor VIII monoclonal antibody. MVD was determined under high magnification by the lumen method, which counts only those structures showing vessel formation positive for factor VIII. The relationship between MVD and clinical and histological variables and the development of liver metastases and survival was assessed with logistic and Cox regression analyses, respectively.
Liver metastasis developed in 22 patients (54%) after surgery. Peripheral MVD, as measured by the lumen method, and N-category (TNM classification) were both significantly associated with liver metastasis. Survival rates were 50%, 15%, and 10% for 1, 3, and 5 years, respectively. Poor survival was significantly associated with male sex; high peripheral MVD, as measured by the lumen method; arterial invasion; and T-category ranking (TNM classification).
High peripheral MVD, as assessed by the lumen method, is associated with the occurrence of liver metastasis and with a poorer prognosis in pancreatic cancer.
Alteration in genes which takes place during malignant conversion and progression could be potential targets for gene therapy. We previously identified REIC/Dkk-3 as a gene whose expression is reduced in many human cancers. Here, we showed that expression of REIC/Dkk-3 was consistently reduced in human prostate cancer tissues in a stage-dependent manner. Forced expression of REIC/Dkk-3 induced apoptosis in human prostate cancer cell lines lacking endogenous REIC/Dkk-3 expression but not in REIC/Dkk-3-proficient normal prostate epithelial and stromal cells. The apoptosis involved c-Jun-NH2-kinase activation, mitochondrial translocation of Bax, and reduction of Bcl-2. A single injection of an adenovirus vector carrying REIC/Dkk-3 showed a dramatic antitumor effect on a xenotransplanted human prostate cancer. Thus, REIC/Dkk-3 could be a novel target for gene-based therapy of prostate cancer.