Cancer Science

Published by Wiley Open Access
Online ISSN: 1349-7006
Publications
Article
Transforming growth factor (TGF)-beta signaling facilitates tumor growth and metastasis in advanced cancer. Use of inhibitors of TGF-beta signaling may thus be a novel strategy for the treatment of patients with such cancer. In this study, we synthesized and characterized a small molecule inhibitor, A-83-01, which is structurally similar to previously reported ALK-5 inhibitors developed by Sawyer et al. (2003) and blocks signaling of type I serine/threonine kinase receptors for cytokines of the TGF-beta superfamily (known as activin receptor-like kinases; ALKs). Using a TGF-beta-responsive reporter construct in mammalian cells, we found that A-83-01 inhibited the transcriptional activity induced by TGF-beta type I receptor ALK-5 and that by activin type IB receptor ALK-4 and nodal type I receptor ALK-7, the kinase domains of which are structurally highly related to those of ALK-5. A-83-01 was found to be more potent in the inhibition of ALK5 than a previously described ALK-5 inhibitor, SB-431542, and also to prevent phosphorylation of Smad2/3 and the growth inhibition induced by TGF-beta. In contrast, A-83-01 had little or no effect on bone morphogenetic protein type I receptors, p38 mitogen-activated protein kinase, or extracellular regulated kinase. Consistent with these findings, A-83-01 inhibited the epithelial-to-mesenchymal transition induced by TGF-beta, suggesting that A-83-01 and related molecules may be useful for preventing the progression of advanced cancers.
 
Article
Vasohibin-1 is a recently identified negative feedback inhibitor or suppressor of angiogenesis induced by vascular endothelial growth factor (VEGF)-A. The status of vasohibin-1 in human breast carcinoma has not been examined. We examined 151 breast specimens including 98 cases of invasive ductal carcinoma (IDC), 12 of ductal carcinoma in situ (DCIS), 16 of fibroadenoma (FA), six of inflammatory lesion, nine of fibrocystic change and seven of non-pathological breast tissue. We immunolocalized vasohibin-1 and compared its immunoreactivity to that of VEGF-A, basic fibroblastic growth factor (bFGF), VEGF receptor 2 (Flk-1), CD31, CD34 and Ki-67/MIB-1. The correlation of vasohibin-1 immunoreactivity with overall survival (OS), and disease-free survival (DFS) of the patients with breast carcinoma was also evaluated. In addition, we evaluated Ki-67 and CD31, and Ki-67 and vasohibin-1 double-immunostaining for further characterization of neovascularization. Vasohibin-1 was detected in endothelial cells of human breast and its immunodensity was significantly higher in IDC and inflammatory lesions than the other types (P<0.001). In addition, a significant positive correlation was detected between vasohibin-1 and VEGF-A, bFGF or Flk-1 (P<0.001). There was also positive associations between vasohibin-1 and OS (P=0.004) and between vasohibin-1 and DFS (P<or=0.001) in carcinoma cases. Results of double-immunostaining demonstrated the ratio of Ki-67-positive cells among vasohibin-1-positive endothelial cells (46.5%) was significantly higher than those among CD31-positive cells (23.5%). This is the first study demonstrating the status of vasohibin-1 in human breast lesions, which indicates that vasohibin-1 is associated with neovascularization and may especially play important roles in the regulation of intratumoral angiogenesis in human breast cancer.
 
Article
The standardized assessment of Ki67 labeling index (LI) is of clinical importance to identify the patients with primary breast cancer who could benefit from chemotherapy. In this study, we evaluated the inter-observer concordance of Ki67 LI assessment. Six surgical pathologists participated and all the slides were prepared from archival breast cancer tissues fixed in 10% buffered formalin for 24 hours and stained with MIB-1. Three independent studies were conducted. 1) Thirty stained slides were assessed using two different methods: the scoring system, the positive rate scored from 1 (0-9%) to 10 (90-100%) by visual estimate; the counting method, approximately 1000 cells counted in hot spots. 2) Twenty tumors with Ki67 LI 5 to 25% were assessed. 3) Fifteen printed photographs of stained slides were assessed to avoid variations by selecting different fields. In study 1, the counting system {the intraclass correlation coefficient (ICC), 0.66 (95% confidence interval 0.52-0.78)} demonstrated a better correlation than the scoring system {ICC, 0.57 (0.42-0.72)}. In study 2, the assessment for Ki67 LI of 5 to 25% demonstrated a correlation {ICC, 0.68 (0.50-0.81)} similar to that of study 1 (unrestricted range of Ki67 LI). In study 3, the assessment of Ki67 LI by counting yielded a good concordance {ICC, 0.94 (0.88-0.97)}. In conclusion, the counting system yielded a better concordance and the concordance was high when the assessed field was pre-determined, indicating that the selection of the evaluation area is critical for obtaining reproducible Ki67 LI in breast cancer. This article is protected by copyright. All rights reserved.
 
Article
Axitinib is an oral, potent, and selective inhibitor of vascular endothelial growth factor receptor (VEGFR) 1, 2, and 3. This phase I study evaluated the safety, pharmacokinetics, pharmacodynamics, antitumor activity, and recommended starting dose of axitinib in patients with advanced solid tumors. Twelve patients received single-dose axitinib 5 mg and were monitored for > or =48 h. Continuous 5 mg twice-daily dosing was then initiated. One patient had dose-limiting toxicity (grade 3 proteinuria and fatigue). Common treatment-related adverse events were anorexia, fatigue, and diarrhea. Grade 3 treatment-related adverse events were fatigue and hypertension. Maximum axitinib plasma concentration occurred 1-4 h after steady-state dosing. Eleven patients experienced thyroid-stimulating hormone elevation; time-course change and fatigue onset appeared to be related in some patients. Significant correlation was observed between thyroid-stimulating hormone change and area under the plasma concentration-time curve (AUC; r = 0.80, P = 0.005). Axitinib decreased plasma soluble vascular endothelial growth factor receptor 2 (s-VEGFR2), with significant correlation between change in s-VEGFR2 and AUC (r = -0.92, P < 0.0001). Fluorodeoxyglucose positron emission tomography revealed a substantial decrease in tumor metabolic activity associated with axitinib. Tumor size decreased in nine patients. The time-course of thyroid-stimulating hormone change appeared correlated with fatigue. There were significant correlations between thyroid-stimulating hormone or s-VEGFR2 and axitinib exposure. Axitinib 5 mg twice-daily is the recommended starting dose for Japanese patients. This trial is registered with ClinicalTrials.gov, identifier NCT00447005.
 
Article
Adult T-cell leukemia (ATL) is a fatal T-cell malignancy associated with human T-cell leukemia virus type I infection. The aberrant expression of nuclear factor-κB (NF-κB) is considered to contribute to the malignant phenotype and chemo-resistance of ATL cells. Because of the poor prognosis of ATL, the development of new therapeutic strategies is direly needed. In the present study, we show that an IκB kinase 2 (IKK2) inhibitor, IMD-0354, efficiently inhibits the survival of CD4(+) CD25(+) primary ATL cells and prevents the growth of or induces apoptosis of patient-derived ATL cell lines. Assays of transcription with integrated forms of reporter genes revealed that IMD-0354 suppresses NF-κB-dependent transcriptional activity. Moreover, the daily administration of IMD-0354 prevents the growth of tumors in mice inoculated with ATL cells. Our results suggest that targeting IKK2 with a small molecule inhibitor, such as IMD-0354, is an attractive strategy for the treatment of ATL.
 
Article
Transfection of the mouse Fut1 and Fut2, and human FUT1 genes into human ovarian carcinoma-derived RMG-1 cells resulted in 20-30-fold increases in cellular alpha1,2-fucosyltransferase activity, and in alteration of the glycolipid composition, including not only fucosylated products, but also precursor glycolipids. Although globo-series glycolipids were not significantly affected by the transfection, the major glycolipids belonging to the lacto-series type 1 chain family in RMG-1 cells and the transfectants were the Lc4Cer, Lewis a (Le)a and Leb, and H-1 glycolipids, respectively, suggesting that fucosylation of Lc4Cer to the H-1 glycolipid prevents the further modification of Lc4Cer to Lea and Leb in the transfectants. Also, the lacto-series type 2 chains in RMG-1 cells were LeX, NeuAc-nLc4Cer and NeuAc-LeX, and those in the transfectants were LeX and LeY, indicating that the sialylation of nLc4Cer and LeX is restricted by increased fucosylation of LeX. As a result, the amount of sialic acid released by sialidase from the transfectants decreased to 70% of that from RMG-1 cells, and several membrane-mediated phenomena, such as the cell-to-cell interaction between cancer cells and mesothelial cells, and the cell viability in the presence of an anticancer drug, 5-fluorouracil, for the transfectants was found to be increased in comparison to that for RMG-1 cells. These findings indicate that cell surface carbohydrates are involved in the biological properties, including cell-to-cell adhesion and drug resistance, of cancer cells.
 
Article
Sphingolipids display a wide spectrum of biological activities, including cell growth, differentiation and apoptosis. However, precise mechanisms by which these compounds exert anticancer or cancer-preventive effects are not known. In the present study, we evaluated the preventive efficacy of enriched dietary monoglucosylceramide 1-O-beta-glucosyl-N-2'-hydroxyarachidoyl-4,8-sphingadienine (G(1)CM) on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) and beta-catenin-accumulated crypt (BCAC) formation in F344 rats during initiation stage. We also examined whether G(1)CM affects cell proliferation and apoptosis in these lesions. Pure G(1)CM was isolated from rice bran. Forty-two rats were divided randomly into five experimental groups. Rats in groups 1-3 were given subcutaneous injections of DMH (40 mg/kg body weight) once a week for 2 weeks. One week before the first injection of DMH, rats in groups 2 and 3 were fed a diet containing 200 and 1,000 p.p.m. G(1)CM, respectively, for 5 weeks. Rats in group 4 were fed a diet containing 1,000 p.p.m. G(1)CM. Rats in group 5 were given the basal diet alone and served as untreated controls. The experiment was terminated 5 weeks after the start. Dietary G(1)CM at both doses (groups 2 and 3) significantly inhibited the induction of ACF and BCAC (P<0.001) when compared to group 1 treated with DMH alone. In groups 2 and 3, the proliferating cell nuclear antigen labeling indices of epithelial cells in ACF and BCAC were also lower than in group 1 (P<0.0001 for ACF, P<0.05 for BCAC). These results, that dietary G(1)CM has possible chemopreventive effects in the present short-term colon carcinogenesis bioassays, suggest that longer exposure may cause suppression of tumor development.
 
Article
In our study we found that pyrrolo[1,2-b][1,2,5]benzothiadiazepines (PBTDs) mediated apoptosis in primary leukemia cells from 27 chronic myelogenous leukemia (CML) patients at onset through the activation of the caspase-9 and -3, and cleavage of poly (ADP-ribose) polymerase (PARP). The bax:bcl-2 ratio was increased as a consequence of down-regulation of bcl-2 and up-regulation of bax proteins in response to treatment with PBTDs. In addition, PBTDs were able to induce cell death in primary leukemia cells derived from 23 CML-chemoresistant patients. Furthermore, the effects of PBTDs on the Akt-mTOR (mammalian target of rapamycin) pathway were determined by Western blot. PBTDs possessed inhibitory activity against mTOR and also impeded hyper-phosphorylation of Akt as a feedback of inhibition of mTOR by rapamycin. The results presented in this study demonstrate that we have identified the PBTDs as restoring the apoptotic pathways both in primary leukemia cells derived from CML patients at onset and in primary leukemia cells derived from CML-chemoresistant patients, thus showing their ability to undergo apoptosis. These compounds constitute a promising therapeutic approach for patients with leukemia. They provide the basis for new strategies for an additional anticancer drug in leukemia therapies, especially when conventional ones fail.
 
Article
In a previous study, we developed a novel mouse model for colitis-related carcinogenesis, utilizing a single dose of azoxymethane (AOM) followed by dextran sodium sulfate (DSS) in drinking water. In the present study, we investigated whether colonic neoplasms can be developed in mice initiated with a single injection of another genotoxic colonic carcinogen 1,2-dimethylhydrazine (DMH), instead of AOM and followed by exposure of DSS in drinking water. Male crj: CD-1 (ICR) mice were given a single intraperitoneal administration (10, 20 or 40 mg/kg body weight) of DMH and 1-week oral exposure (2% in drinking water) of a non-genotoxic carcinogen, DSS. All animals were killed at week 20, histological alterations and immunohistochemical expression of beta-catenin, cyclooxygenase (COX-2) and inducible nitric oxide synthase (iNOS) were examined in induced colonic epithelial lesions (colonic dysplasias and neoplasms). Also, the beta-catenin gene mutations in paraffin-embedded colonic adenocarcinomas were analyzed by the single strand conformation polymorphism method, restriction enzyme fragment length polymorphism and direct sequencing. The incidences of colonic neoplasms with dysplastic lesions developed were 100% with 2.29+/-0.95 multiplicity, and 100% with 10.38+/-4.00 multiplicity in mice given DMH at doses of 10 mg/kg or 20 mg/kg and 2%DSS, respectively. Although approximately half of the mice given DMH at a dose of 40 mg/kg bodyweight were dead after 2-3 days after the injection, mice who received DMH 40 mg/kg and 2%DSS had 100% incidence of colonic neoplasms with 9.75+/-6.29 multiplicity. Immunohistochemical investigation revealed that adnocarcinomas, induced by DMH at all doses and 2%DSS, showed positive reactivities against beta-catenin, COX-2 and iNOS. In DMH/DSS-induced adenocarcinomas, 10 of 11 (90.9%) adenocacrcinomas had beta-catenin gene mutations. Half of the mutations were detected at codon 37 or 41, encoding serine and threonine that are direct targets for phosphorylation by glycogen synthase kinase-3beta. The present results suggests that, as in the previously reported model (AOM/DSS) our experimental protocol, DMH initiation followed by DSS, may provide a novel and useful mouse model for investigating inflammation-related colon carcinogenesis and for identifying xenobiotics with modifying effects.
 
Article
The usefulness of mucin-depleted foci (MDF), which have recently been proposed as a new preneoplastic biomarker in rat colon carcinogenesis, was histologically investigated in rat colonic tissues treated with 1,2-dimethylhydrazine dihydrochloride (DMH). The relationship among aberrant crypt foci (ACF), MDF and beta-catenin accumulated crypts (BCAC) was examined by comparing the corresponding computer-captured images. Twelve male F344 rats were given DMH s.c. at a dose of 40 mg/kg body weight, once a week for 2 weeks, and randomly divided into two groups. Rats in group 1 were given normal drinking water, while those in group 2 were given drinking water containing indomethacin (IND) at 16 ppm for 6 weeks. All animals were sacrificed 8 weeks after the first DMH treatment. The resected colons were fixed in 10% formalin, and stained with Alcian blue for observation of ACF and MDF. Histological and immunohistochemical analysis revealed that the numbers of ACF, MDF and overlapping lesions in group 2 (treated with IND) were significantly decreased, compared with those in group 1. The number of BCAC in group 2 was also significantly lower than that in group 1. The reduction (61.5%) of MDF by IND was much greater than that (29.3%) of ACF. Analyses of the computer-captured images indicated that MDF had more frequent dysplastic changes and overexpression of beta-catenin than did ACF. MDF having over 4 crypts or MDF with the appearance of ACF corresponded well to BCAC. These results suggest that MDF may be useful as an early biomarker in colon carcinogenesis.
 
Article
Polyethylene glycol (PEG) has been reported to inhibit the development of colonic lesions in carcinogen-treated rats when administered orally. However, the precise mechanism for the chemopreventive activity of PEG remains largely elusive. Based on a characteristic feature of PEG as a 'fusogen', we investigated its potential as a chemotherapeutic agent through the induction of multinucleated cell formation and apoptosis induction in PC-3 prostate cancer cells. When PC-3 cells were treated with 0.5 and 1.0% PEG 1000, multinucleated cells were induced at a frequency of 8.4 and 13%, respectively, 36 h after PEG treatment under high cell density (1 x 10(6) cells in 100 microL PEG solution) in vitro. Although abnormality of cell cycle progression was not evident in PEG-treated PC-3 cells, multinucleated cells substantially disappeared at around 38 h due to apoptosis. In contrast, no apparent growth suppression was observed when PC-3 cells were exposed to up to 1.0% PEG at a much lower cell density, namely under ordinary culture conditions. Furthermore, injection of 0.5% PEG solution in vivo into PC-3 xenografts implanted in BALB/c-nu/nu male mice significantly suppressed tumor growth compared to phosphate-buffered saline injection. Multinucleated TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive cells were observed inside the PEG-injected tumors. PEG was here demonstrated to have anticell proliferation and antitumor effects via induction of apoptosis, possibly by cell fusion. PEG injection therapy could therefore be adopted as an alternative chemotherapeutic strategy for localized prostate cancers, including those that become refractory to androgen-deprivation therapy.
 
Article
We investigated intratumoral tumor-infiltrating lymphocytes (TILs), including CD4(+) and CD8(+) T cells, in non-small cell lung cancers (NSCLCs) and their relationships with clinicopathological variables and post-operative survival. Tumor specimens from 178 NSCLCs were consecutively obtained by surgery at the Hokkaido University Medical Hospital between 1976 and 1994. CD8(+) T cells, CD4(+) T cells and Ki-67/CD8(+) T cells were visualized immunohistochemically, and counted within cancer cell nests and in cancer stroma. CD8(+) T cells and CD4(+) T cells were observed at higher frequencies within cancer cell nests in moderately and poorly differentiated tumors compared with well differentiated tumors (P < 0.01), and in tumors with high Ki-67 expression compared with low Ki-67 expression (P < 0.01), that showed severe cellular atypia and a higher growth rate. Patients with higher numbers of CD8(+) T cells within cancer cell nests showed significantly shorter survival times compared to those with lower numbers of CD8(+) T cells within cancer cell nests (5-year survival rates, 47% and 60%, respectively; P = 0.03). Moreover, patients with higher labeling index of Ki-67/CD8(+) T cells showed significantly shorter survival than those with lower labeling index of Ki-67/CD8(+) T cells within cancer cell nests (5-year survival rates, 41% and 69%, respectively; P = 0.02), and the labeling index of Ki-67/CD8(+) T cells within cancer cell nests was found to be a significant and independent unfavorable prognostic factor by multivariate analysis (P = 0.01). On the other hand, higher numbers of CD4(+) T cells in cancer stroma, but not within cancer cell nests, were correlated with longer survival times in patients with NSCLC (5-year survival rates, 64% and 43%, respectively; P = 0.04). CD4(+) T cells in cancer stroma might reflect immune responses against cancer cells, while CD8(+) T cells do not appear to work as effectors in tumor tissues of NSCLC. Moreover, the higher labeling index of Ki-67/CD8(+) T cells within cancer cell nests is a strong indicator of unfavorable clinical outcome.
 
Article
c-Met is often overexpressed in non-small cell lung cancer, but it remains unsolved whether its overexpression leads to its activation. We used an antibody specific to phospho-c-Met (Tyr1235) to investigate c-Met activation immunohistochemically in 130 surgically resected lung adenocarcinomas. The expression of c-Met and hepatocyte growth factor (HGF) was also investigated. Phospho-c-Met was positive in 21.5% (28/130) of cases. c-Met was positive in 74.6% of cases (97/130) and was expressed at high levels in 36.1% of cases (47/130). HGF was expressed at high levels in 31.5% of cases (41/130). Phospho-c-Met was correlated with high levels of HGF (P =0.0010) and high levels c-Met expression (P = 0.0303), but it was also found to be positive in 12 cases with little to no HGF expression. Phospho-c-Met expression was significantly associated with tumor differentiation (P = 0.0023) and papillary histology (P = 0.0011), but not with pathological stage, lymph node metastasis or survival. High levels of c-Met and HGF were also associated with papillary histology (P = 0.0056 and P = 0.0396, respectively), but not with tumor differentiation. Phospho-c-Met was correlated with phospho-Akt (P = 0.0381), but not with phospho-Erk or phospho-Stat3. Phospho-Akt expression was marginally correlated with the expression of phospho-epidermal growth factor receptor (EGFR) (P = 0.0533) and, importantly, it was strongly correlated with the expression of either phospho-c-Met or phospho-EGFR (P = 0.0013). The data suggest that in lung adenocarcinoma tissue, c-Met activation may take place either ligand-dependently or ligand-independently via c-Met overexpression. c-Met activation may play special roles in the papillary subtype and in well differentiated lung adenocarcinomas.
 
Article
Osteopontin (OPN) plays an important role in the development, invasion, and metastasis of malignancies. Recently, several studies have reported that OPN enhances chemoresistance in small-cell lung cancer and breast cancer by blocking caspase-9 and caspase-3-dependent cell apoptosis. The aim of this study was to assess the value of OPN and caspase-3 for predicting tumor recurrence after curative resection in hepatocellular carcinoma (HCC) patients. We found that OPN expression increased concordantly with increasing metastatic potential in human HCC cell lines, whereas caspase-3 expression declined. In a tumor tissue microarray immunohistochemical analysis, we found that patients with higher levels of OPN and lower levels of caspase-3 had a significantly poorer prognosis than patients with lower OPN and higher caspase-3 levels. The combination of OPN and caspase-3 expression thus served as an effective prognosticator. These findings suggest that OPN alone or in combination with caspase-3 may act as an independent indicator for HCC patients after curative resection.
 
Article
This study aimed to determine the expression profiles of microRNAs (miRNAs) in endometrial serous adenocarcinoma and to examine the association between miRNA expression and clinical outcomes. Twenty-one patients diagnosed with endometrial serous adenocarcinoma between January 2001 and December 2006 were enrolled. miRNA expression profiles were examined using miRNA microarray and qRT-PCR. miRNA expression levels were correlated with clinicopathological variables and survival rates. A total of 120 miRNAs were differentially expressed in endometrial serous adenocarcinoma compared to normal endometria. Of these, 54 miRNAs were down-regulated (>2-fold), including miR-101, miR-10b*, miR-152, and miR-29b, and the remainder were up-regulated (>2-fold), including miR-200a, miR-200b, and miR-205. Decreased expression of miR-10b*, miR-29b, and miR-455-5p was correlated with vascular invasion (P = 0.048, P = 0.013, and P = 0.032, respectively). Univariate analysis revealed that lower expression of miR-101, miR-10b*, miR-139-5p, miR-152, miR-29b, and miR-455-5p was significantly correlated with poor overall survival (P < 0.05), and reduced expression of miR-152, miR-29b, and miR-455-5p was significantly correlated with poor disease-free survival (P < 0.05). Multivariate analysis demonstrated that decreased expression of miR-152 (P = 0.021) was a statistically independent risk factor for overall survival, and decreased expression levels of miR-101 (P = 0.016) and miR-152 (P = 0.010) were statistically independent risk factors for disease-free survival. In addition, transfection of miR-101 or miR-152 precursors into an endometrial serous carcinoma cell line inhibited cell growth (P < 0.0001 and P = 0.01, respectively). Moreover, strong positive immunoreactivity of cyclooxygenase-2 (COX-2) was significantly correlated with down-regulation of miR-101 (P = 0.035). These findings suggest that the dysregulation of miRNAs is associated with the poor prognosis in endometrial serous adenocarcinoma patients.
 
Article
The present study aimed to assess the impact of smoking and sex for the risk of non-small-cell lung cancer (NSCLC) with or without epidermal growth factor receptor (EGFR) mutation. We conducted a case-control study using 152 patients with EGFR-mutated (EGFRmut) NSCLC, 283 with EGFR-wild-type (EGFRwt) NSCLC and 2175 age- and sex-frequency-matched controls. Smoking was a significant risk factor for EGFRwt NSCLC (odds ratio [OR] for ever-smokers, 4.05; 95% confidence interval [CI], 2.79-5.88) but not for EGFRmut NSCLC (OR, 0.73; CI, 0.46-1.14). Sex did not affect this association. The association was observed consistently with other smoking-related parameters including pack-years. Sex was the sole risk factor for EGFRmut NSCLC (OR for women relative to men, 2.19; CI, 1.41-3.39) and there was no significant interaction between women and smoking. In contrast, sex, smoking and their interaction were significant in EGFRwt NSCLC. The impact of sex on EGFR mutation status was assessed by several indicators of reproductive history among women. Total fertile years showed a significant positive association with EGFRmut NSCLC but not with EGFRwt NSCLC. Other indicators showed similar trends and this result may partly explain the sexual difference in the acquisition of EGFR mutation. In conclusion, our case-control study clearly demonstrated that the impacts of smoking and sex on the risk of EGFRmut NSCLC are different from those for EGFRwt NSCLC. Further epidemiological evaluation is warranted.
 
Article
To search for potential protein markers of colorectal cancer (CRC), the changes in protein expression levels between microdissected tumor cells and normal mucosa epithelia were analyzed by an acetylation stable isotopic labeling method coupled with linear quadrupole ion trap fourier transform mass spectrometry (LTQ-FTMS). In total, 137 proteins were up-regulated or down-regulated significantly in cancer by at least two-fold. Based on gene ontology analysis, the largest part of differential proteins were unknown for both subcellular localization and biological process. In particular, the significant up-regulation of transgelin-2 (TAGLN2) in CRC was validated by Western blot analysis and further evaluated by immunohistochemistry in paired tumor and normal mucosa samples from 120 consecutive CRC patients, 20 adenomas, and eight synchronous hepatic metastases of CRC. TAGLN2 expression was frequently observed in cancer cells, precancerous lesions, and hepatic metastases, whereas in normal epithelia expression was rarely observed. The overexpression of TAGLN2 was associated with lymph node and distant metastasis, advanced clinical stage (P < 0.001), and shorter overall survival in CRCs. Cox regression analysis indicated that high tumor-TAGLN2 expression represents an independent prognostic factor. Consequently, over-expression of TAGLN2 may serve as a new biomarker for predicting progression and prognosis of CRC.
 
Article
Margin status, a major prognostic parameter in oral cancer, was analyzed vis-à-vis the histopathologic parameters of risk scores and stromal myofibroblasts. Specimens of tongue carcinoma (n = 50) were submitted to a risk score assignment consisting of the worst pattern of invasion, lymphocytic infiltration, and perineural invasion. Frequency of stromal myofibroblasts (alpha-smooth muscle actin stain) was assessed. A triple immunostaining assay with E-cadherin, Ki-67 and alpha-smooth muscle actin was used to identify carcinoma cells undergoing epithelial-mesenchymal transition. Margins were considered 'clean' if the tumor was >or=5 mm away from them. Patients <or=60 years were considered as 'young'. Kaplan-Meier survival analysis with univariate and Cox multivariate regression model with stepwise forward selection, and Fisher's exact tests were used. Abundant myofibroblasts were found in 27 (54%) cases. Carcinoma cells devoid of E-cadherin but amalgamated with the stromal myofibroblasts were identified in 18 (36%) cases. Local recurrence and overall survival were negatively influenced by abundance of stromal myofibroblasts (P = 0.004 and P = 0.008, respectively). High-risk scores (P = 0.011), positive margins, and 'young' age (P = 0.027, each) had an unfavorable impact on recurrence. Multivariate analysis revealed that only abundance of stromal myofibroblasts had an independent adverse effect on local recurrence (hazard ratio [HR] 4.369; P = 0.014; 95% confidence interval [CI], 1.356-14.074). It seems that abundant stromal myofibroblasts (camouflaging some malignant cells) and high-risk scores have an unfavorable impact on the risk of recurrence in particular in 'young' patients. Therefore, the treatment concept should be adjusted accordingly and target concomitantly the epithelial malignancy and its allied stroma.
 
Article
Maspin, a 42 kDa protein produced in normal breast cells, has been shown to inhibit the invasion and metastasis of breast cancer in an animal model. Ingestion of acetylsalicylic acid (aspirin) by breast cancer patients has been reported to restore the systemic synthesis of maspin through the stimulation of systemic nitric oxide production. Studies were carried out to determine the effect of aspirin on the incidence of breast cancer metastasis, which is reported to occur in 50% of patients who have previously received chemotherapy, radiation, and/or surgery. Thirty-five female patients (aged 41-65 years) with breast cancer who had previously received these therapies took one 75 mg/70 kg body weight enteric-coated aspirin tablet every 24 h, after an adequate meal, for 3 years. Their plasma nitric oxide and maspin levels were measured. The occurrence of metastasis was ascertained monthly by a qualified oncologist, and confirmed, if necessary, by biopsy. Daily ingestion of aspirin by participants resulted in an increase in maspin levels from 0.95 ± 0.04 to 4.63 ± 0.05 nM after 24 h. These levels were maintained for 3 years. These studies suggest that daily ingestion of aspirin might significantly reduce the incidence of breast cancer metastasis in patients who have previously received anticancer therapies.
 
Article
Preclinical models have shown that TAC-101 (4-[3,5-bis(trimethylsilyl) benzamide] benzoic acid), an oral synthetic retinoid, has antitumor activity in hepatocellular carcinoma (HCC). We conducted a phase I study in Japanese patients with advanced HCC to examine the pharmacokinetics, recommended dose, safety, and efficacy of TAC-101. The administered dose of TAC-101 was 10 mg/day in four patients (level 1), 20 mg/day in six (level 2), and 30 mg/day in three (level 3). There was no dose-limiting toxicity at level 1. Only one patient each had dose-limiting toxicity at level 2 (grade 2 fatigue, recovery requiring eight or more consecutive days of rest) and at level 3 (grade 3 splenic vein thrombosis). Level 3 (30 mg/day) was considered the maximum tolerated dose and 20 mg/day the recommended dose by a panel of medical experts, placing maximum emphasis on safety. The most frequent adverse events were fatigue, headache, and dermal symptoms such as rash. Pharmacokinetic parameters in Japanese patients with HCC were similar to those in patients in the United States, most of whom were Caucasian. Although no patient had a complete or partial response, the disease control rate was 38.5%. In conclusion, the recommended dose of TAC-101 for patients with HCC is 20 mg/day. TAC-101 had an acceptable toxicity profile, warranting further evaluation in clinical trials.
 
Article
The objective of the current study was to investigate the expression pattern and clinicopathological significance of SCC-S2 in patients with non-small-cell lung cancer (NSCLC). The expression profile of SCC-S2 in NSCLC tissues and adjacent noncancerous lung tissues was detected by real-time RT-PCR, western blot analysis, and immunohistochemistry. In 25 lung cancer tissues examined, 18 (72%) of them exhibited stronger levels of SCC-S2 mRNA compared with their corresponding normal tissues. SCC-S2 protein level was up-regulated in cancerous lung tissues compared to adjacent normal tissue. Moreover, the expression level of SCC-S2 in 93 archived NSCLC tissues was measured by immunohistochemical staining. SCC-S2 was found to be overexpressed in 71 of 93 (76.3%) human lung cancer samples and correlated with lymph node metastasis (P = 0.0181), p-TNM stage (P = 0.0042), Ki-67 expression (P = 0.0028), and poor survival (P = 0.012). In addition, depleting SCC-S2 expression by small-interfering RNA inhibited growth and invasion in lung cell lines. These results indicate that SCC-S2 plays an important role in NSCLC and might be a useful therapeutic target of NSCLC.
 
Article
Murine studies have shown that immunological targeting of fibroblast activation protein (FAP) can elicit protective immunity in the absence of significant pathology. Fibroblast activation protein is a product overexpressed by tumor-associated fibroblasts (TAF) and is the predominant component of the stoma in most types of cancer. Tumor-associated fibroblasts differ from normal adult tissue fibroblasts, and instead resemble transient fetal and wound healing-associated fibroblasts. Tumor-associated fibroblasts are critical regulators of tumorigenesis, but differ from tumor cells by being more genetically stable. Therefore, in comparison to tumor cells, TAF may represent more viable therapeutic targets for cancer immunotherapy. To specifically target TAF, we constructed a DNA vaccine directed against FAP. This vaccine significantly suppressed primary tumor and pulmonary metastases primarily through CD8(+) T-cell-mediated killing in tumor-bearing mice. Most importantly, tumor-bearing mice vaccinated against FAP exhibited a 1.5-fold increase in lifespan and no significant pathology. These results suggest that FAP, a product preferentially expressed by TAF, could function as an effective tumor rejection antigen.
 
Article
The purpose of this study was to investigate the potential of circulating tumor cells (CTC) as a surrogate marker of the clinical outcome in metastatic colorectal cancer (mCRC) patients in order to identify Japanese patients responsive to oxaliplatin-based chemotherapy. Between January 2007 and April 2008, 64 patients with mCRC were enrolled in this prospective study. The treatment regimen was oxaliplatin-based chemotherapy. Collection of CTC from whole blood was performed at baseline and at 2 and 8-12 weeks after initiation of chemotherapy. Isolation and enumeration of CTC was performed using immunomagnetics. Patients with ≥3 CTC at baseline and at 2 and 8-12 weeks had a shorter median progression-free survival (8.5, 7.3 and 1.9 months, respectively) than those with <3 CTC (9.7, 10.4 and 9.1 months, respectively) (log-rank test: P = 0.047, P < 0.001 and P < 0.001, respectively). Patients with ≥3 CTC at 2 and 8-12 weeks had a shorter median overall survival (10.2 and 4.1 months, respectively) than those with <3 CTC (29.1 and 29.1 months, respectively) (P < 0.001 and P = 0.001, respectively). A spurious early rise in carcinoembryonic antigen level was observed in 11 patients showing a partial response. In contrast, no rise in early CTC level was observed among responders. Our data support the clinical utility of CTC enumeration in improving our ability to accurately assess treatment benefit and in expediting the identification of effective treatment regimens for individual Japanese patients.
 
Article
Colorectal cancer is a leading cause of cancer-related deaths world-wide. Despite the development of new anticancer agents, there will be an estimated 150,000 new cases and 50,000 deaths associated with this disease during the next year.((1)) This is due, in part, to the limitations of chemotherapy, resulting from drug resistance and organ system toxicities. To overcome the inherent limitations associated with standard chemotherapy techniques, the development of novel drug targets is of utmost importance in combating this disease. There is accumulating evidence that a small fraction of cancer cells, referred to as cancer stem cells, may play a critical role in the pathogenesis of this disease. In fact, the identification of cancer stem cells can be accomplished based on the expression of surface markers associated with a cancer stem-like phenotype. This stem-like phenotype includes indefinite self-replication, pluripotency, and most importantly, resistance to chemotherapeutics. Therefore, understanding the properties of cancer stem cells may ultimately lead to new therapeutic approaches. Recently, several studies have shown that Notch signaling is critical in maintaining cancer stem cell properties. This review provides a summary of colonic crypt organization and colon carcinogenesis with a focus on stem cells. Moreover, we discuss novel therapeutic strategies that are under development for targeting Notch signaling in cancer stem cells.
 
Article
The epithelial-mesenchymal transition (EMT) is a process in which polarized epithelial cells are converted into motile mesenchymal cells. During cancer development, EMT is conducive to tumor dissemination and metastatic spread. While overexpression of metadherin (MTDH) in breast cancer cell lines and tissues has been found to be associated with aggressive tumor behavior, its precise role in invasion and metastasis is largely unknown. Here we report that MTDH overexpression could significantly enhance the invasion and migration of breast cancer cells by inducing EMT. Metadherin overexpression led to upregulation of mesenchymal marker fibronectin, downregulation of epithelial marker E-cadherin, and the nuclear accumulation of beta-catenin. Also, transcription factors Snail and Slug were upregulated in breast cancer cells overexpressing MTDH. Overexpression of MTDH enhanced the invasiveness and migration ability of breast cancer cells in vitro. In addition, overexpression of MTDH led to increased acquisition of CD44(+) /CD24(-/low) markers that are characteristic of breast cancer stem cells. We also showed that NF-kappa was involved in the expression of EMT-related markers. Taken together, our results suggest that MTDH could promote EMT in breast cancer cells in driving the progression of their aggressive behavior.
 
Article
FBXW7 is a cell cycle regulatory gene that ubiquitinates positive cell cycle regulators such as c-Myc and cyclin E, allowing for cell cycle exit. Defects in the FBXW7 gene that lead to cell cycle re-entry and expedite the G1-S transition is thought to be one of the causes of cancer development. However, its clinical importance for breast cancer patients remains undetermined. This prompted us to investigate its expression level in breast cancer patients to establish its clinical significance. The expression level of FBXW7 mRNA was assessed in 186 cases of primary invasive breast cancer. Correlations between FBXW7 mRNA expression and clinicopathological factors, prognoses and immunohistochemical expression levels of Ki-67, FBXW7, c-Myc and cyclin E were analyzed. In vitro investigation of FBXW7 gene silencing in a breast cancer cell line was conducted. FBXW7 mRNA was expressed at significantly lower levels in patients with high histological grade and hormone receptor-negative tumors. Patients with lower FBXW7 mRNA expression had a poorer prognosis for breast cancer-specific survival than those with higher expression. A high Ki-67 labeling index and positive cyclin E protein expression were significantly correlated with lower FBXW7 mRNA expression. In vitro, silencing FBXW7 enhanced expression of c-Myc and cyclin E proteins and upregulated both cell proliferation and G1-S transition. In breast cancer, reduced FBXW7 mRNA expression may have independent prognostic potential through the enhanced function of cell cycle regulatory proteins.
 
Article
Current treatment modalities for cancer combine cytotoxic drugs against DNA and novel targeted drugs affecting signal transduction pathways, which are required for growth progression and metastasizing tumors. Classical chemotherapeutic regimens for gastro-intestinal tumors include antimetabolites based on 5-fluorouracil (5FU), the platinum analog oxaliplatin and the topoisomerase inhibitor irinotecan. The thymidine analog trifluorothymidine (TFT) has been shown to bypass resistance pathways for 5FU derivatives (S-1, UFT, Xeloda) in model systems, while concurrent application with a thymidine phosphorylase inhibitor (TPI) increases the bioavailability of TFT, thereby potentiating the in vivo efficacy of TFT. The formulation TAS-102 is given orally in a 1.0:0.5 molar ratio (TFT:TPI). The formulation is dual-targeted due to the cytotoxic effect of TFT, which is enhanced by TPI, while TPI also exerts antiangiogenic effects by inhibiting thymidine phosphorylase (TP), also known as platelet-derived endothelial cell growth factor. Evidence is accumulating from in vitro and in vivo preclinical studies that these properties favor further combinations with other cytotoxic agents currently being used in the treatment of gastro-intestinal tumors. Also treatment with targeted agents will synergistically down-regulate signal transduction pathways responsible for growth and progression of tumors. In this review, we summarize the available information on (clinical) pharmacology, mechanisms of action, pharmacodynamic and pharmacokinetic properties, early clinical trials and future directions of the new potent combination drug TAS-102.
 
Article
We investigated the ability of TZT-1027 (Soblidotin), a novel antimicrotubule agent, to induce antivascular effects, because most vascular targeting agents that selectively disrupt tumor vasculature also inhibit tubulin polymerization. Treatment with 10(-7) g/mL TZT-1027 rapidly disrupted the microtubule cytoskeleton in human umbilical vascular endothelial cells (HUVEC), and significantly enhanced vascular permeability in HUVEC monolayers. In addition, single intravenous administration of 2 mg/kg TZT-1027 to mice bearing Colon26 tumors significantly reduced tumor perfusion and caused extravascular leakage of erythrocytes 1 h after administration. Subsequently, thrombus formation with deposition of fibrin and tumor necrosis was observed 3 and 24 h after administration, respectively. These results strongly suggest that TZT-1027 possesses antivascular effects. TZT-1027 induced apoptosis not only in HUVEC but also in C26 cancer cells (cell line of Colon26 solid tumor) in vitro, suggesting it exerts direct cytotoxicity against tumor cells in addition to its antivascular effects. A single intravenous administration of 1, 2 and 4 mg/kg TZT-1027 significantly prolonged the survival of mice with advanced-stage Colon26 tumors in a dose-dependent manner. Furthermore, TZT-1027 itself less markedly enhanced the permeability of normal vessels, but was additive with vascular endothelial growth factor, indicating the possibility that TZT-1027 selectively exerts its activity on tumor vessels. In summary, these results suggest that TZT-1027 exerts both an indirect antivascular effect and a direct cytotoxic effect, resulting in strong antitumor activity against advanced-stage tumors, and that TZT-1027 may be useful clinically for treating solid tumors.
 
Article
TZT-1027 is a novel synthetic dolastatin 10 derivative that inhibits tubulin polymerization. A phase I study was conducted to determine the maximum tolerated dose (MTD) of TZT-1027, and to assess its pharmacokinetic profile in Japanese patients with advanced solid tumors following administration of the drug weekly for 3 weeks. Eligible patients had advanced solid tumors that failed to respond to standard therapy or for which no standard therapy was available, and met the following criteria: performance status ≤2 and acceptable organ function. The MTD was defined as the highest dose at which more than two-thirds of the patients experienced grade 4 hematological toxicity or grade 3/4 non-hematological toxicity during weekly TZT-1027 administration for 3 weeks. Forty patients were enrolled in the present study. Twelve doses between 0.3 and 2.1 mg/m2 were evaluated. Grade 4 neutropenia was the principal dose-limiting toxicity (DLT). At a dose of 2.1 mg/m2, two patients developed DLT: one patient developed grade 4 neutropenia, grade 3 myalgia, and grade 4 constipation, and the other one developed grade 4 neutropenia and grade 3 constipation. At a dose level of 1.8 mg/m2, toxicity was acceptable and no DLT was observed. The area under the curve and maximum concentration of TZT-1027 tended to increase linearly with the dose. The DLT observed were neutropenia, myalgia, and constipation, and the MTD was 2.1 mg/m2. The recommended dose for a phase II study was determined to be 1.8 mg/m2 for the drug administered weekly for 3 weeks.
 
Article
TZT-1027 (Soblidotin), an antimicrotubule agent, has been demonstrated to show potent antitumor effects, though the relationships among antitumor effect, cytotoxicity and anti-vascular effect of TZT-1027 have not been studied. We established in vivo human lung vascular-rich tumor models using a vascular endothelial growth factor-secreting tumor (SBC-3/VEGF). SBC-3/VEGF tumors exhibited a high degree of angiogenesis in comparison with the mock transfectant (SBC-3/Neo) tumors in a dorsal skinfold chamber model and grew much faster and larger than SBC-3/Neo tumors in the tumor growth study. The antitumor activity of antimicrotubule agents, including TZT-1027, was evaluated in both early- and advanced-stage SBC-3/Neo and SBC-3/VEGF tumor models to elucidate the relationship between the antitumor activity and anti-vascular effect of these agents. TZT-1027 exhibited potent antitumor activity against both early- and advanced-stage SBC-3/Neo and SBC-3/VEGF tumors, whereas combretastatin A4 phosphate did not. Vincristine and docetaxel exhibited potent antitumor activity against early-stage SBC-3/Neo and SBC-3/VEGF tumors, and advanced-stage SBC-3/Neo tumors, but did not exhibit activity against advanced-stage SBC-3/VEGF tumors. The difference in antitumor activity between these agents could be ascribed to differences in direct cytotoxicity and anti-vascular effect. Furthermore, a prominent accumulation of erythrocytes in the tumor vasculature, followed by leakage and scattering of these erythrocytes from the tumor vasculature, was observed after TZT-1027 administration to mice bearing advanced-stage SBC-3/VEGF tumors. These findings strongly suggest that TZT-1027 has a potent anti-vascular effect, in addition to direct cytotoxicity.
 
Article
TZT-1027 (soblidotin), an antimicrotubule agent, has previously been evaluated in terms of its antivascular effects. In this study, Evans blue perfusion, magnetic resonance imaging (MRI), and confocal laser scanning microscopy (CLSM) were utilized to further elucidate the antivascular effect of TZT-1027 in female nude mice and rats bearing human breast tumor MX-1, as well as in female Sprague-Dawley rats that developed breast tumors induced by dimethylbenz(a)anthracene (DMBA). Therapeutic doses of TZT-1027 caused nearly complete regression of implanted MX-1 tumors in nude mice and rats as well as DMBA-induced tumors in rats. The perfusion in MX-1 tumor implanted in nude mice was drastically reduced within 30 min after TZT-1027 administration and was completely inhibited after 6 h or more, although not reduced in normal tissue of kidney. The study using MRI demonstrated that rich blood flow within tumors was remarkably reduced 1-3 h after TZT-1027 administration both in nude rats bearing MX-1 tumors and in rats with DMBA-induced tumors. Furthermore, the study with CLSM in nude mice bearing MX-1 tumors revealed a disruption of tumor microvessels at 1 h and a destruction of tumor microvessel network at 3 h after TZT-1027 administration. In contrast, these types of vascular disorders were not observed in heart and kidney. These results suggest that TZT-1027 specifically damages tumor vasculatures, leading to extensive tumor necrosis within tolerable dose range, and confirms earlier observations that TZT-1027 exerts a considerable antivascular effect in addition to an excellent cytotoxic effect.
 
Article
Triple negative breast cancer (TNBC) is a heterogeneous, aggressive cancer for which there is no effective chemotherapy or targeted therapy. We aimed to evaluate L-type amino acid transporter (LAT) 1 and CD98 expression immunohistochemically in patients with breast cancer, especially TNBC. Out of 129 patients, LAT1 was positive in 56 patients (43.4%), and CD98 was positive in 41 patients (31.8%). The positive ratio of LAT1 expression in luminal A cases was 7.9%, 30.0% in luminal B cases, 71.4% in HER2 cases and 64.0% in TN cases. HER2 and TN subtypes expressed LAT1 and CD98 at higher levels than luminal A and B subtypes (both P < 0.001). LAT1 and CD98 expression correlated with tumor size (LAT1, P = 0.010; CD98, P = 0.007), nuclear grade (LAT1, P < 0.001; CD98, P < 0.001) and Ki67 labeling index (LAT1, P < 0.001; CD98, P = 0.001). LAT1 and CD98 expression was negatively associated with ER and PgR (both P < 0.001). In TNBC, the 5-year disease-free rate of CD98+ (63.6%) or LAT1+/CD98+ (61.9%) patients was significantly worse than that of CD98- (89.3%) patients or those with no co-expression of LAT1 and CD98 (89.7%), respectively (P = 0.014, P = 0.009). The 5-year survival rates of CD98 positive/negative patients were 77.3% and 100% (P = 0.050), respectively, whereas that of patients with LAT1+/CD98+ (76.2%) was significantly worse (100%) (P = 0.040). Multivariate analysis confirmed that CD98+ or LAT1+/CD98+ expression were risk factors for relapse in TNBC (P = 0.023, P = 0.019). Thus, in the present study we show that LAT1 and CD98 expression are prognostic factors. Inhibition of these proteins might provide a new therapeutic strategy in TNBC.
 
Article
Androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, this therapy is associated with several undesired side-effects, including increased risk of cardiovascular diseases. To study if termination of long-term androgen ablation and restoration of testosterone levels could suppress the growth of relapsed hormone-refractory prostate tumors, we implanted testosterone pellets in castrated nude mice carrying androgen receptor (AR)-positive LNCaP 104-R2 cells, which relapsed from androgen-dependent LNCaP 104-S cells after long-term androgen deprivation. 104-R2 tumor xenografts regressed after testosterone pellets were implanted. Of 33 tumors, 24 adapted to elevation of testosterone level and relapsed as androgen-insensitive tumors. Relapsed tumors (R2Ad) expressed less AR and prostate-specific antigen. We then studied the molecular mechanism underlying the androgenic regulation of prostate cancer cell proliferation. Androgen suppresses proliferation of 104-R2 by inducing G(1) cell cycle arrest through reduction of S-phase kinase-associated protein 2 (Skp2) and c-Myc, and induction of p27(Kip1). 104-R2 cells adapted to androgen treatment and the adapted cells, R2Ad, were androgen-insensitive cells with a slower growth rate and low protein level of AR, high levels of c-Myc and Skp2, and low levels of p27(Kip1). Nuclear AR and prostate-specific antigen expression is present in 104-R2 cells but not R2Ad cells when androgen is absent. Overexpression of AR in R2Ad cells regenerated an androgen-repressed phenotype; knockdown of AR in 104-R2 cells generated an androgen-insensitive phenotype. Overexpression of Skp2 and c-Myc in 104-R2 cells blocked the growth inhibition caused by androgens. We concluded that androgens cause growth inhibition in LNCaP 104-R2 prostate cancer cells through AR, Skp2, and c-Myc.
 
Article
Malignant pleural mesothelioma (MPM) is an asbestos-related malignancy that is highly resistant to current therapeutic modalities. We established four MPM cell lines (ACC-MESO-1, ACC-MESO-4, Y-MESO-8A and Y-MESO-8D) from Japanese patients, with the latter two from the same patient with biphasic-like characteristics of MPM, showing epithelial and sarcomatous phenotypes, respectively, in cell culture. These cells grew well in RPMI-1640 medium supplemented with 10% fetal bovine serum under 5% CO2. Mutation and expression analyses demonstrated that the tumor suppressor gene NF2, which is known to be one of the most frequently mutated in MPM, is mutated in ACC-MESO-1. We detected homozygous deletion of p16INK4A/p14ARF in all four MPM cell lines. However, mutations of other tumor suppressor genes, including TP53, and protooncogenes, including KRAS, NRAS, BRAF, EGFR and HER2, were not found in these cell lines. Polymerase chain reaction amplification of the simian virus 40 sequence did not detect any products. We also analyzed genetic alterations of six other MPM cell lines and confirmed frequent mutations of NF2 and p16INK4A/p14ARF. To characterize the biological differences between Y-MESO-8A and Y-MESO-8D, we carried out cDNA microarray analysis and detected genes that were differentially expressed in these two cell lines. Thus, our new MPM cell lines seem to be useful as new models for studying various aspects of the biology of human MPM as well as materials for the development of future therapies.
 
Tumor microenvironment. (a) Tumor tissue contains not only tumor cells, but also large numbers of normal cells, including tumor-associated macrophages, lymphocytes, blood vessels, and fibroblasts, that affect tumor development in various ways. The photographs show an example of a clinical case of human breast cancer (invasive ductal carcinoma). The relative distributions of the above-mentioned cell types differ by organ and tissue type as well as individual case. CK, cytokeratin. (b) Metastatic tumors contain a larger number of tumor-associated macrophages. The photographs show an example of a clinical case of human kidney cancer (clear cell renal cell carcinoma). The primary tumor tissues and the metastatic (lung) tumors are shown.
High numbers of CD68+ tumor-associated macrophages are correlated with clinical prognosis in human malignant tumors
Schema of the functional role of tumor-associated macrophages (TAMs). Tumor-associated macrophages are activated by macrophage colony-stimulating factor (M-CSF), interleukin (IL)-6, and other compounds secreted by tumor cells both to induce angiogenesis by producing angiogenic factors such as VEGF and platelet-derived growth factor, and to create immunosuppressive conditions by producing immunosuppressive factors such as IL-10 and prostaglandin E2 (PGE2). At the same time, growth factors that are secreted by TAMs, such as epidermal growth factor (EGF), directly promote cancer cell growth, whereas MMP and other compounds responsible for stroma remodeling promote tumor cell infiltration and metastasis. Activation of tumor cells and TAMs induced by direct cell–cell interactions may represent an extremely important event in relation to the development of malignant tumors. bFGF, basic fibroblast growth factor; CCL, chemokine (C-C motif) ligand; MDSC, myeloid-derived suppressor cell; PDGF, platelet-derived growth factor; Stat3, signal transducer and activator of transcription 3; TGF-β, transforming growth factor-β; TP, thymidine phosphorylase; Treg, regulatory T cell; VEGF, vascular endothelial growth factor.
Correlation between CD163+ or CD204+ tumor-associated macrophages and clinical prognosis in human malignant tumors
Article
The fact that various immune cells, including macrophages, can be found in tumor tissue has long been known. With the recent introduction of the novel concept of macrophage differentiation into a classically activated phenotype (M1) and an alternatively activated phenotype (M2), the role of tumor-associated macrophages (TAMs) is gradually beginning to be elucidated. Specifically, in human malignant tumors, TAMs that have differentiated into M2 macrophages act as "protumoral macrophages" and contribute to the progression of disease. Based on recent basic and preclinical research, TAMs that have differentiated into protumoral or M2 macrophages are believed to be intimately involved in the angiogenesis, immunosuppression, and activation of tumor cells. In this paper, we specifically discuss both the role of TAMs in human malignant tumors and the cell-cell interactions between TAMs and tumor cells. This article is protected by copyright. All rights reserved.
 
Article
Heat shock protein (HSP) 105 is overexpressed in various cancers, but is expressed at low levels in many normal tissues, except for the testis. A vaccination with HSP105-pulsed bone marrow-derived dendritic cells (BM-DC) induced antitumor immunity without causing an autoimmune reaction in a mouse model. Because Apc(Min/+) mice develop multiple adenomas throughout the intestinal tract by 4 months of age, the mice provide a clinically relevant model of human intestinal tumor. In the present study, we investigated the efficacy of the HSP105-pulsed BM-DC vaccine on tumor regression in the Apc(Min/+) mouse. Western blot and immunohistochemical analyses revealed that the tumors of the Apc(Min/+) mice endogenously overexpressed HSP105. Immunization of the Apc(Min/+) mice with a HSP105-pulsed BM-DC vaccine at 6, 8, and 10 weeks of age significantly reduced the number of small-intestinal polyps accompanied by infiltration of both CD4(+) and CD8(+) T cells in the tumors. Cell depletion experiments proved that both CD4(+) and CD8(+) T cells play a critical role in the activation of antitumor immunity induced by these vaccinations. These findings indicate that the HSP105-pulsed BM-DC vaccine can provide potent immunotherapy for tumors that appear spontaneously as a result of the inactivation of a tumor suppressor gene, such as in the Apc(Min/+) mouse model.
 
Article
Nucleoside analogues which show antimetabolic activity in cells have been successfully used in the treatment of various tumors. Nucleosides such as 1-beta-D-arabinofuranosylcytosine (araC), 6-mercaptopurine, fludarabine and cladribine play an important role in the treatment of leukemias, while gemcitabine, 5-fluorouracil and its prodrugs are used extensively in the treatment of many types of solid tumors. All of these compounds are metabolized similarly to endogenous nucleosides and nucleotides. Active metabolites interfere with the de novo synthesis of nucleosides and nucleotides or inhibit the DNA chain elongation after being incorporated into the DNA strand as terminators. Furthermore, nucleoside antimetabolites incorporated into the DNA strand induce strand-breaks and finally cause apoptosis. Nucleoside antimetabolites target one or more specific enzyme(s). The mode of inhibitory action on the target enzyme is not always similar even among nucleoside antimetabolites which have the same nucleoside base, such as araC and gemcitabine. Although both nucleosides are phosphorylated by deoxycytidine kinase and are also good substrates of cytidine deaminase, only gemcitabine shows antitumor activity against solid tumors. This suggests that differences in the pharmacological activity of these nucleoside antimetabolites may reflect different modes of action on target molecules. The design, in vitro cytotoxicity, in vivo antitumor activity, metabolism and mechanism of action of sugar-modified cytosine nucleosides, such as (2'S)-2'-deoxy-2'-C-methylcytidine (SMDC), 1-(2-deoxy-2-methylene-beta-D-erythro-pentofuranosyl)cytosine (DMDC), 1-(2-C-cyano-2-deoxy-1-beta-D-arabino-pentofuranosyl)cytosine (CNDAC) and 1-(3-C-ethynyl-beta-D-ribo-pentofura-nosyl)cytosine (ECyd), developed by our groups, are discussed here.
 
Article
We previously reported that heat shock protein 105 (HSP105), identified by serological analysis of a recombinant cDNA expression library (SEREX) using serum from a pancreatic cancer patient, was overexpressed in various human tumors and in the testis of adult men by immunohistochemical analysis. In the present study, to elucidate the biological function of the HSP105 protein in cancer cells, we first established NIH3T3 cells overexpressing murine HSP105 (NIH3T3-HSP105). The NIH3T3-HSP105 cells acquired resistance to apoptosis induced by heat shock or doxorubicin. The small interfering RNA (siRNA)-mediated suppression of HSP105 protein expression induced apoptosis in human cancer cells but not in fibroblasts. By a combination of siRNA introduction and doxorubicin or heat shock treatment, apoptosis was induced synergistically in a human colon cancer cell line, HCT116. In vivo, siRNA inoculation into the human gastric cancer cell line KATO-3 established in the flank of an NOD SCID mouse suppressed the tumor growth. This siRNA-induced apoptosis was mediated through caspases, but not the p53 tumor suppressor protein, even though the HSP105 protein was bound to wild-type p53 protein in HCT116 cells. These findings suggest that the constitutive overexpression of HSP105 in cancer cells is involved in malignant transformation by protecting tumor cells from apoptosis. HSP105 may thus be a novel target molecule for cancer therapy and a treatment regimen using synthetic siRNA to suppress the expression of HSP105 protein may provide a new strategy for cancer therapy.
 
Article
We established a variant of MIAPaCa-2 human pancreatic cancer cells that is resistant to 2',2'-difluorodeoxycytidine (gemcitabine, dFdCyd), MIAPaCa-2/dFdCyd, and elucidated the biochemical characteristics and mechanism of dFdCyd-resistance in these cells. We also evaluated 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)cytosine (ECyd, TAS-106, RNA polymerase inhibitor), a new anticancer ribonucleoside, for antitumor activity against the resistant cells in vitro and in vivo. MIAPaCa-2/dFdCyd cells were 2541-fold more resistant to dFdCyd than parental MIAPaCa-2 cells, and the major mechanism of the dFdCyd-resistance was found to be a decrease in the intracellular pool of dFdCyd and its active metabolites, which would result in a decrease in incorporation of dFdCyd triphosphate into DNA. This finding was confirmed by the discovery of decreased deoxycytidine kinase activity, increased cytidine deaminase and ribonucleotide reductase activity, and increased 5'-nucleotidase mRNA expression in the MIAPaCa-2/dFdCyd cells. The cytotoxicity of TAS-106 as an antitumor nucleoside analog was similar in both parental and dFdCyd-resistant cells, with IC(50) values of 6.25 and 6.27 nM, respectively, and this finding was supported by similar intracellular uptake and metabolism of TAS-106 in both cell lines. We also evaluated the in vivo antitumor activity of TAS-106 against MIAPaCa-2 and dFdCyd-resistant MIAPaCa-2/dFdCyd tumors implanted into nude mice. The tumor growth inhibition rate of weekly additions of TAS-106 (7 mg/kg, iv) against parental and dFdCyd-resistant tumors was 73% and 76%, respectively, while that of dFdCyd administered twice a week (240 mg/kg, iv) was 84% and 34%, respectively. These results suggest that TAS-106 would contribute to the treatment of patients with advanced pancreatic carcinomas in whom dFdCyd-based chemotherapy has failed.
 
Article
MicroRNAs are tiny RNA molecules which serve as important post-transcriptional regulators of gene expression. Dysregulated expression of microRNAs has been observed in human cancers, indicating that microRNAs may function as oncogenes or as tumor suppressors. To date, the microRNAs encoded by the oncogenic miR-17-92 cluster, and its paralog the miR-106b-25 cluster, are among those which are differentially expressed in human cancers. In this study, we examined and confirmed the over-expression of these clusters in hepatocellular carcinoma and in hepatoma-derived cells. At least 50% of the tumor samples showed a greater than two-fold increase in the expression for miR-18 and for the miR-106b-25 cluster when compared with the corresponding paired non-tumor samples. Knock-down studies for the miR-106b-25 cluster, which includes miR-106b, miR-93 and miR-25, showed that the expression of the cluster is necessary for cell proliferation and for anchorage-independent growth. In tumors with high expression of this cluster, reduced expression of the BH3-only protein Bim, a miR-25 target, was observed. We further identified the transcription factor E2F1 as a target gene for miR-106b and miR-93 and it is likely that one of the roles of the miR-106b-25 cluster is to prevent excessively high E2F1 expression, which may then cause apoptosis. We conclude that there is aberrant expression of microRNAs encoded by the oncogenic miR-17-92 cluster and the miR-106b-25 cluster in hepatocellular carcinoma. The consistent overexpression of the miR-106b-25 cluster and its role in cell proliferation and anchorage-independent growth points to the oncogenic potential of this cluster.
 
Effects of matrix metalloproteinase 2 (MMP2) on migration and invasion of breast cancer (BC) cells. (a) The siRNA of MMP2 was transfected into SUM1315-bo. This was confirmed at both the gene and protein levels. Si-M1, si-M2, and si-M3 represent the three different siRNA pairs of MMP2. Si-M1 and si-M2 were used in all the subsequent experiments. (b) The invasiveness of MMP2 knockdown SUM1315-bo and the negative control (si-NC) cells were assessed using transwell assays. The invasiveness through 8 μm pore transwells was significantly lower in MMP2 knockdown SUM1315-bo than in the negative control (P < 0.05). Original magnification ×100. (c) The constructed expression vector pEGFP-C2-MMP2 was stably transfected into MCF-7, which was MMP2-negative. Transfection was confirmed at the protein level. (d) The invasiveness of MMP2 overexpressing MCF-7 (MCF7-MO) and the control cells were assessed by transwell assays. The invasiveness through 8 μm pore transwells was found to be significantly higher in MMP2 over-expressing MCF-7 than in controls (P < 0.05). Original magnification ×100.
Matrix metalloproteinase 2 (MMP2) is the direct target of miR-106b. (a) Real-time polymerase chain reaction (PCR) analysis demonstrated higher levels of miR-106b expression in normal samples than in tumor cites. The endogenous expression of miR-106b was inversely correlated with MMP2 expression in MCF-7 and SUM1315-bo cells. (b) Expression of MMP2 decreased in SUM1315-bo cells after transfection of miR-106b mimic (miR-106b) compared with negative control (miR-NC) but increased in MCF-7 cells after transfection with miR-106b specific inhibitor (miR-106bI) compared with negative control (miR-NCI). (c, and d) The miR-106b binding site of MMP2 3′UTR was confirmed by luciferase assay on SUM1315-bo (c) and MCF7 (d) cells by cotransfection with the indicated reporters and miR-106b mimic or with the indicated reporters and miR-106b inhibitor. Data represent the mean ± standard deviation (SD) of at least three independent experiments. *P < 0.05, **P < 0.01.
Effects of miR-106b on aggressive behavior of SUM1315-bo and MCF-7 cells in vitro. (a) miR-106b mimic increased miR-106b level in SUM1315-bo cells. (b) Transwell invasion (n = 3) and migration (n = 3) assays showed that SUM1315-bo cells transfected with miR-106b mimic (200 nM) decreased the invasive and migratory ability of the cells. Cells were counted after staining with crystal violet. Representative images are shown at left. Graphs indicate the average number of cells per field 24 h after transfection. Data represent the mean ± standard deviation (SD) of at least three independent experiments. *P < 0.05, **P < 0.01. Magnification in b–c, ×100. (c) Suppression of miR-106b by specific inhibitor in MCF-7 cells. Mature miR-106b was quantified using miRNA-specific real-time polymerase chain reaction (PCR) using U6 RNA for normalization. (d) Transwell invasion and migration assays on MCF-7 cells indicated that the downregulation of miR-106b increased the invasive and migratory ability of the cells. Data represent the mean ± SD of at least three independent experiments *P < 0.05, **P < 0.01.
Effects of miR-106b on the proliferation and apoptosis of breast cancer cells. (a) The growth of cells over 3 days was measured using 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays. The proliferation rate of miR-106b treated SUM1315-bo cells was significantly decreased compared with negative control treated SUM1315 cells. *P < 0.05. (b) Apoptosis was measured using flow cytometry. The miR-106b treated SUM1315-bo cells had a higher apoptosis rate than the negative control treated SUM1315-bo cells. *P < 0.05. (c) The proliferation rate of miR-106bI treated MCF-7 cells was significantly increased compared with negative control treated MCF-7 cells. *P < 0.05. (d) The miR-106bI treated MCF-7 cells had a lower apoptosis rate than the negative control treated MCF-7 cells. *P < 0.05.
Effects of matrix metalloproteinase 2 (MMP2) on osteoclastogensis and removal of extracellular signal-regulated kinases (ERK) from tumor cells. (a) Western blot showing the level of ERK and p-ERK in the conditioned medium (CM) from SUM1315-bo cells. MiR-106b was shown to directly inhibit MMP2 and consequently decrease ERK and p-ERK expression. *P < 0.05. (b) Alteration of the RANKL/OPG abundance ratio in osteoblasts by MMP2 to favor osteoclast differentiation. RANKL and OPG were detected using immunoblotting in the culture media of HMSC-derived osteoblasts under different CM conditions. The RANKL/OPG ratio of the group of HMSC-derived osteoblasts cells (Os) (RANKL/OPG ratio = 0.28) and the group of HMSC-derived osteoblasts cultured using CM from MMP2 knockdown SUM1315-bo cells (MMP2i-Os) (RANKL/OPG ratio = 0.749) was significantly decreased when compared with the group of HMSC-derived osteoblasts cultured using CM from SUM1315 CM tumor cells (SUM1315-BO-Os) (RANKL/OPG ratio = 3.17). **P < 0.01.
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Breast cancer (BC) is one of the most common cancers in women, and it can often metastasize to the bone. The mechanism of BC bone metastasis remains unclear and requires in-depth investigation. In a previous study, we found the expression of matrix metalloproteinase 2 (MMP2) to be significantly more pronounced at metastatic bone sites than at orthotopic sites. MicroRNA expression profiling showed miR-106b to be markedly down-regulated during BC bone metastasis. However, the specific manner in which MMP2 and miR-106b are involved in the BC bone metastasis is still unclear. In the present study, we found MMP2 expression in orthotopic tumor tissue to be related to the risk of bone metastasis in BC patients. MiR-106b levels in orthotopic tumor tissue showed a negative correlation with MMP2 expression and breast cancer bone metastasis. MMP2 was shown to be a direct target of miR-106b. Both gain- and loss-of-function studies showed that MMP2 could promote the migration and invasion of BC cells and that miR-106b could suppress both. The blockage of MMP2 by RNA interference mimicked the anti-migration and anti-invasion effects of miR-106b, and introduction of MMP2 antagonized the function of miR-106b. MMP2 was also found to regulate the ERK signaling cascade and so adjust the bone microenvironment to favor osteoclastogenesis and bone metastasis. These results suggest that MMP2 upregulation plays an important role in BC bone metastasis through ERK pathways, and miR-106b directly regulates MMP2 expression. The miR-106b/MMP2/ERK pathway may be a promising therapeutic target for inhibiting BC bone metastasis. This article is protected by copyright. All rights reserved.
 
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Follicular lymphoma (FL) frequently transforms into diffuse large B-cell lymphoma (DLBCL). To clarify the associated clinicopathological prognostic parameters, we examined the correlation of 11 histopathological parameters with progression-free survival (PFS) and overall survival (OS) in 107 consecutive patients who had DLBCL with preexisting (asynchronous) or synchronous FL. The patients comprised 58 men and 49 women with a median age of 56 years. For DLBCL, the complete response rate was 81%, overall response rate was 88%, and 5-year PFS and OS rates were 55% and 79%, respectively. Immunohistochemical analysis of the DLBCL component revealed the following positivity rates: CD10, 64%; Bcl-2, 83%; Bcl-6, 88%; MUM1, 42%; GCB, 82%; cMyc index ≥80%, 17%; and Ki-67 index ≥90%, 19%. IGH/BCL2 fusion was positive in 57% of DLBCL cases. In univariate analyses, asynchronous FL and DLBCL (24%, P = 0.021), 100% proportion of DLBCL (29%, P = 0.004), Bcl-2 positivity (P = 0.04), and high Ki-67 index (P = 0.003) were significantly correlated with shorter PFS. Asynchronous FL and DLBCL (P = 0.003), 100% proportion of DLBCL (P = 0.001), and high Ki-67 index (P = 0.004) were significantly correlated with shorter OS. In a multivariate analysis, asynchronous FL and DLBCL (P = 0.035) and 100% proportion of DLBCL (P = 0.016) were significantly correlated with shorter OS. Thus, asynchronism and 100% proportion of DLBCL, that is, FL relapsed as pure DLBCL, or FL and DLBCL at different sites, were significant predictors of unfavorable outcome of patients with DLBCL transformed from FL.
 
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This randomized phase II study was intended to identify the optimal dose of TAS-108, a novel steroidal antiestrogen, for the treatment of breast cancer in postmenopausal Japanese women. The potential clinical effects of TAS-108 on the uterus, bone, serum lipids, and hormones were also investigated. Postmenopausal women with hormone receptor-positive metastatic breast cancer who had previously received one or two endocrine therapies were randomly assigned to one of the three possible dose levels of TAS-108 (40, 80 or 120 mg/day). Oral TAS-108 was given daily, and the efficacy and safety of the three doses were evaluated. A total of 97 patients (33, 32, and 32 in the 40-, 80-, and 120-mg groups, respectively) were treated with TAS-108. The clinical benefit rate was 30.3% for the 40-mg, 25.0% for the 80-mg, and 25.0% for the 120-mg group. The 40-mg group achieved the prespecified target threshold. TAS-108 at all dose levels was well tolerated and appeared to have no harmful effects in terms of the variables examined in this study. We conclude that the optimal dose of TAS-108 among the three doses is 40 mg, once daily, for further studies. JAPIC Clinical Trials Information number: Japic CTI - 121754.
 
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Intravascular large B-cell lymphoma (IVLBCL) is a rare disease entity with a high incidence of central nervous system (CNS) involvement at diagnosis. To evaluate CNS involvement, particularly recurrence including progression on therapy and relapse of IVLBCL, we retrospectively analyzed 109 patients with IVLBCL receiving chemotherapies with or without rituximab. In 82 patients (75%) without CNS involvement at initial diagnosis, risk of CNS recurrence at 3 years was 25% with a median follow-up in survivors of 39 months (range, 2-158 months). In 27 patients (25%) with CNS involvement at initial diagnosis, risk of CNS recurrence at 1 year was 25% with a median follow-up in survivors of 18 months (range, 10-77 months). Duration from diagnosis to CNS recurrence tended to be short in patients with CNS involvement at diagnosis. No significant difference in risk of CNS recurrence was found between patients receiving chemotherapies with or without rituximab. On multivariate analysis skin involvement at initial diagnosis was identified as a predictive factor for CNS recurrence in patients without CNS involvement at diagnosis (hazard ratio, 5.27; 95% confidence interval, 1.59-17.4; P = 0.007). Survival rate after CNS recurrence at 2 years was 12% in patients without CNS involvement at diagnosis. Central nervous system recurrence is a serious complication in IVLBCL patients and optimal strategies for CNS involvement should be established to obtain further improvements to clinical outcomes in the rituximab era.
 
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NY-ESO-1 is a cancer-testis antigen that elicits strong cellular and humoral immune responses against NY-ESO-1-expressing tumors. Although CD4(+) T cells play a critical role in inducing antitumor immunity, little is known about MHC class II-restricted helper epitopes of the NY-ESO-1 antigen compared with MHC class I-restricted epitopes. Here, we searched for new NY-ESO-1 helper epitopes presented by MHC class II molecules, especially those found frequently in the Japanese population. We established five NY-ESO-1-specific helper T-cell lines from healthy Japanese donors using NY-ESO-1 recombinant protein and peptide. Using MHC class II-specific antibodies and a panel of Epstein-Barr virus-transformed B-cell lines, it was demonstrated that four out of the five T-cell lines recognized a region within NY-ESO-1(119-143) in the context of HLA-DRB1*0802, DRB1*0901, DRB1*1502 or DRB1*0405/*0410. In addition, using a set of overlapping 15-mer synthetic peptides, we found that NY-ESO-1(122-138) was a promiscuous region that bound to four distinct HLA-DR molecules found in the Japanese population. These findings expand the usefulness of NY-ESO-1 as a tool for tumor vaccine therapy in eliciting NY-ESO-1-specific helper T-cell responses, especially in Japanese cancer patients.
 
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MicroRNAs (miRNAs) are frequently deregulated in human tumors, and play important roles in tumor development and progression. The pathological roles of miRNAs in neurofibromatosis type 1 (NF1) tumorigenesis are largely unknown. We demonstrated that miR-10b was up-regulated in primary Schwann cells isolated from NF1 neurofibromas and in cell lines and tumor tissues from malignant peripheral nerve sheath tumors (MPNSTs). Intriguingly, a significantly high level of miR-10b correlated with low neurofibromin expression was found in a neuroectodermal cell line: Ewing's sarcoma SK-ES-1 cells. Antisense inhibiting miR-10b in NF1 MPNST cells reduced cell proliferation, migration and invasion. Furthermore, we showed that NF1 mRNA was the target for miR-10b. Overexpression of miR-10b in 293T cells suppressed neurofibromin expression and activated RAS signaling. Antisense inhibition of miR-10b restored neurofibromin expression in SK-ES-1 cells, and decreased RAS signaling independent of neurofibromin in NF1 MPNST cells. These results suggest that miR-10b may play an important role in NF1 tumorigenesis through targeting neurofibromin and RAS signaling.
 
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We performed loss of heterozygosity (LOH) analysis on five chromosomal arms (1p, 3p, 9p, 10q, 17p) in hepatocellular carcinoma (HCC). Univariate analyses of 80 patients who underwent liver transplantation demonstrated significant correlations between cancer recurrence and the following variables: LOH on 3p26, LOH on 10q23, LOH on 17p13, tumor diameter > or = 5 cm, number of tumors > or = 4, histologic Grade 3, alpha-fetoprotein (AFP) > or = 400 ng/mL, American Joint Committee on Cancer (AJCC) pT classification, and portal invasion. Patients with LOH on 10q23 exhibited a significantly higher 3-year recurrence rate (38.9%vs 11.9%, P = 0.0009). Multivariate analysis identified LOH on 10q23, histologic Grade 3, tumor nodules > or = 4, and AFP > or = 400 ng/mL as the risk factors of advanced HCC recurrence. These results suggest that LOH on 10q23 is associated with metastatic recurrence of HCC.
 
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We treated elderly patients with relapsed or refractory peripheral T-cell lymphoma (PTCL) using a CMD (CPT-11, mitoxantrone [MIT], dexamethasone [DEX]) regimen and studied its safety and efficacy. The subjects were 70-79-year-old patients with relapsed or refractory PTCL. CPT-11 at 25 mg/m2 on days 1 and 2, MIT at 8 mg/m2 on day 3, and DEX at 40 mg/day on days 1-3 were administered once every 3 weeks, and this was performed for six cycles. Eleven (37%) of the 30 patients achieved complete remission and seven patients (23%) achieved partial remission. With a median follow-up period of 32 months, the 3-year survival rate was 28.2% and the 3-year progression-free survival rate was 17.5%. The main adverse drug reaction was hematological toxicity and there were no deaths related to the treatment. B-type natriuretic peptide and troponin T levels did not increase after the treatment and none of the patients showed electrocardiogram or echocardiogram abnormalities. Our results indicate that the CMD regimen is safe in elderly patients and no cardiotoxicities developed as a result of this regimen. In addition, it was effective in patients who had previously been treated with doxorubicin and good treatment results were obtained in elderly patients with relapsed PTCL.
 
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Recent studies have shown that genetically engineered stem cells (GESTECs) to produce suicide enzymes that convert non-toxic prodrugs to toxic metabolites selectively migrate toward tumor sites and reduce tumor growth. In the present study, we evaluated whether these GESTECs were capable of migrating to human ovarian cancer cells and examined the potential therapeutic efficacy of the gene-directed enzyme prodrug therapy against ovarian cancer cells in vitro. The expression of cytosine deaminase (CD) or carboxyl esterase (CE) mRNA of GESTECs was confirmed by RT-PCR. A modified transwell migration assay was performed to determine the migratory capacity of GESTECs to ovarian cancer cells. GESTECs (HB1.F3.CD or HB1.F3.CE cells) engineered to express a suicide gene (CD or CE) selectively migrated toward ovarian cancer cells. A [3H] thymidine incorporation assay was conducted to measure the proliferative index. Treatment of human epithelial ovarian cancer cell line (SKOV-3, an ovarian adenocarcinoma derived from the ascites of an ovarian cancer patient) with the prodrugs 5-fluorocytosine (5-FC) or camptothecin-11 (CPT-11) in the presence of HB1.F3.CD or HB1.F3.CE cells resulted in the inhibition of ovarian cancer cell growth. Based on the data presented herein, we suggest that GESTECs expressing CD/CE may have a potent advantage to selectively treat ovarian cancers. (Cancer Sci 2010; 101: 955–962)
 
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A randomized double-blind placebo-controlled phase II trial was conducted to evaluate the efficacy of a prophylactic quadrivalent vaccine targeting the Human Papillomavirus (HPV) types most frequently associated with cervical cancer (types 16/18) and genital warts (types 6/11) in Japanese women aged 18 to 26 years. Participants were randomly assigned to either quadrivalent HPV (types 6/11/16/18) L1 virus-like particle vaccine (GARDASIL(®) ) (n = 509) or placebo (n = 512). Participants underwent regular gynecological examinations, cervicovaginal sampling for HPV DNA, testing for serum neutralizing antibodies to HPV, and Pap testing. The primary endpoint was the combined incidence of persistent infection with HPV types 6, 11, 16, or 18 and cervical or external genital disease (ie, cervical intraepithelial neoplasia, cervical cancer, or external genital lesions related to HPV 6, 11, 16 or 18. Primary analyses were done per protocol. Combined incidence of persistent infection or disease with HPV 6, 11, 16, or 18 fell by 87.6% (95% CI: 59.2-97.6, p<0.001), with HPV 6 or 11 by 73.1% (95% CI: -41.1-97.3, p=0.0756) and with HPV 16 or 18 by 94.5% (95% CI: 65.2-99.9, p<0.001) in those assigned vaccine compared with those assigned placebo. Median duration of follow-up after month 7 in subjects was 23 months. In addition, the vaccine was well tolerated in Japanese women aged 18 to 26 years. Quadrivalent HPV vaccine could significantly reduce the acquisition of infection and clinical disease caused by HPV types 6, 11, 16, and 18.
 
Top-cited authors
Yusuke Nakamura
  • Tokai University
Hironobu Sasano
  • Tohoku University
Takahiro Ochiya
  • National Cancer Center, Japan
Yasuhiro Matsumura
  • National Cancer Center, Japan
Hideo Baba
  • Kumamoto University