Jia Ke

Sun Yat-Sen University of Medical Sciences, Shengcheng, Guangdong, China

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Publications (18)69.39 Total impact

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    ABSTRACT: Hairy enhancer of split-1 (HES1) is a transcriptional target of the Notch pathway, and a high level of HES1 is regarded as a marker of activated Notch. The aim of the study was to investigate the role of HES1 in colorectal cancer progression. We used tissue microarrays to analyze the expression and clinical significance of HES1 in 320 colorectal cancer samples. Stable overexpression and knockdown of HES1 were established in three colorectal cancer cell (CRC) lines (RKO, HCT8 and LOVO). We investigated the differentially expressed genes and enriched pathways in HES1 overexpressing CRC cells by gene expression profiling. Also, the role of HES1 in invasion and migration were examined in vitro and in vivo. We found that high expression of HES1 was significantly correlated with distal metastasis (P = 0.037) at diagnosis, and HES1 could serve as an unfavorable prognostic factor for colorectal cancer patients (P = 0.034). Gene expression profiling and pathway enrichment analysis revealed that HES1 was related to cellular adherens junction loss. In addition, we showed that HES1 overexpression lead to depressed E-cadherin, and elevated N-cadherin, vimentin and Twist-1 levels. Functionally, HES1 enhanced invasiveness and metastasis of CRC cells. HES1 promotes cancer metastasis via inducing epithelial mesenchymal transition and serves as a poor prognosis factor of colorectal cancer patients.
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    ABSTRACT: Increasing evidence suggests that lineage specific subpopulations and stem-like cells exist in normal and malignant breast tissues. Epigenetic mechanisms maintaining this hierarchical homeostasis remain to be investigated. In this study, we found the level of microRNA221 (miR-221) was higher in stem-like and myoepithelial cells than in luminal cells isolated from normal and malignant breast tissue. In normal breast cells, over-expression of miR-221 generated more myoepithelial cells whereas knock-down of miR-221 increased luminal cells. Over-expression of miR-221 stimulated stem-like cells in luminal type of cancer and the miR-221 level was correlated with clinical outcome in breast cancer patients. Epithelial-mesenchymal transition (EMT) was induced by overexpression of miR-221 in normal and breast cancer cells. The EMT related gene ATXN1 was found to be a miR-221 target gene regulating breast cell hierarchy. In conclusion, we propose that miR-221 contributes to lineage homeostasis of normal and malignant breast epithelium.
    Oncotarget 01/2015; · 6.63 Impact Factor
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    ABSTRACT: Platelet activating factor (PAF), a potent pro-inflammatory phospholipid, has been found to trigger tumor growth and angiogenesis through its G-protein coupled receptor (PAFR). This study was aimed to investigate the potential role of PAF in azoxymethane (AOM)/dextran sulfate sodium (DSS) induced colitis-associated cancer (CAC), using PAFR antagonist Ginkgolide B (GKB). We found GKB up-regulated serum level of PAF-AH activity. As assessed by disease activity index (DAI), histological injury scores, leukocytes infiltration, and expression of pro-inflammatory cytokines, GKB ameliorated colonic inflammation and decreased tumor number and load in mice. GKB also decreased expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in tumor. These results suggest that PAFR antagonist might be a potential therapeutic strategy for CAC.
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    ABSTRACT: microRNAs are essential for self-renewal and differentiation of normal and malignant stem cells by regulating the expression of key stem cell regulatory genes. Here we report evidence implicating the microRNA100 (miR-100) in self-renewal of cancer stem-like cells (CSC). We found that miR-100 expression levels relate to the cellular differentiation state with lowest expression in cells displaying stem cell markers. Utilizing a tetracycline-inducible lentivirus to elevate expression of miR-100 in human cells, we found that increasing mir-100 levels decreased the production of breast CSCs. This effect was correlated with an inhibition of cancer cell proliferation in vitro and in mouse tumor xenografts due to attenuated expression of the CSC regulatory genes SMARCA5, SMARCD1 and BMPR2. Furthermore, miR-100 induction in breast CSC immediately upon their orthotopic implantation or intracardiac injection completely blocked tumor growth and metastasis formation. Clinically, we observed a significant association between miR-100 expression in breast cancer specimens and patient survival. Our results suggest that miR-100 is required to direct CSC self-renewal and differentiation.
    Cancer Research 09/2014; 74(22). DOI:10.1158/0008-5472.CAN-13-3710 · 9.28 Impact Factor
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    ABSTRACT: Chronic inflammation is an underlying risk factor for colorectal cancer. No direct evidence has proven that inflammation in the colon promotes carcinogenesis. STAT3 plays an important role in the development of colitis-associated colorectal cancer (CAC). There is crosstalk between the mammalian target of rapamycin complex 1 (mTORC1) and the STAT3 pathways. The aim of the present study was to confirm that colitis promotes CAC and if so, to explore the function of the STAT3 and mTORC1 pathways in CAC. C57BL/6 mice were treated with axozymethane (AOM) and dextran sulfate sodium (DSS) to induce CAC. By varying the concentration of DSS (0, 1 and 2% respectively), we mimicked the CAC model with different degrees of inflammation and determined the risk of carcinogenesis. Expression of the STAT3 and mTORC1 pathways was detected. Finally, rapamycin, an mTORC1 inhibitor, was used to treat the CAC model. Tumor load, protein and gene expression of chemokines were determined. The multiplicity and tumor load of the high inflammation group were higher than those of the low inflammation group. Immunohistochemical staining and western blot analysis revealed that activation of the STAT3 and mTORC1 pathways increased gradually in the inflammation tissues and tumors. When we treated the mice with rapamycin, the tumor incidence, multiplicity and tumor load decreased. In addition, rapamycin widely suppressed the expression of pro‑inflammatory and anti-inflammatory chemokines in the tissues, including tumor necrosis factor-α, interferon-γ, IL-6, IL-10 and IL-12α. In conclusion, inflammation promotes the development of CAC via the STAT3 and mTORC1 pathways, which may be a viable treatment strategy for the chemoprevention of CAC.
    Oncology Reports 08/2014; 32(5). DOI:10.3892/or.2014.3421 · 2.19 Impact Factor
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    ABSTRACT: To confirm that the severity of inflammation can promote the colitis-associated colorectal cancer(CAC) and explore the function of STAT3 signal pathway in CAC.
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    ABSTRACT: Background:About one in five patients with locally advanced rectal cancer (RC) suffers recurrence or distant metastasis after neoadjuvant therapy. We investigated how cancer stem cell markers change after neoadjuvant therapy and how these markers relate to recurrence.Methods:Pretreatment biopsies and postoperative specimens were taken from 64 patients with locally advanced rectal adenocarcinoma who received preoperative radiochemotherapy (RCT) between sampling. Samples were tested immunohistochemically for CD44, LGR5, ALDH1 and CD166; scores were dichotomised as high or low. The median follow-up period was 36 months.Results:High expression of CD44, LGR5, ALDH and CD166 was found in 38%, 5%, 48% and 10%, respectively, before RCT and 86%, 33%, 71% and 52%, respectively, after RCT. CD44 (P=0.001), LGR5 (P=0.049) and CD166 (P=0.003) were significantly upregulated after RCT. Whereas no recurrence was seen during the follow-up in the low ALDH group, 40% of the high ALDH group suffered recurrence. In multivariate COX analysis, postoperative ALDH1 independently predicted poor prognosis in patients with RC who received RCT (P=0.0095).Conclusion:Preoperative RCT upregulates expression of stem cell markers in patients with RC. High post-treatment ALDH1 expression predicts poor prognosis for these patients after neoadjuvant therapy.British Journal of Cancer advance online publication, 10 December 2013; doi:10.1038/bjc.2013.767 www.bjcancer.com.
    British Journal of Cancer 12/2013; 110(2). DOI:10.1038/bjc.2013.767 · 4.82 Impact Factor
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    ABSTRACT: To determine the role of the mammalian target of rapamycin (mTOR) signaling in sustaining cancer stem-like cells and its clinical values in colorectal cancer (CRC). mTOR expression in CRC patients was analyzed by immunohistochemistry and survival analysis was used to confirm the clinical value of mTOR. Colorectal cell lines were treated by mTOR inhibitors rapamycin and PP242, and sphere formation assay and aldehyde dehydrogenase (ALDH) assay were utilized to determine the impact of mTOR inhibition in CRC stem-like cells, combined or not combined with chemotherapeutic drug (fluorouracil and oxaliplatin). mTOR expression was associated with outcomes of CRC patients and predicted poor prognosis in stage II CRC patients. mTOR signaling was activated in stem-like colorectal cancer cells, and mTOR inhibitors (rapamycin and PP242) decreased the capacity of sphere formation as well as ALDH activity. Furthermore, mTOR inhibitors also were demonstrated to suppress the stimulation of stem-like cells by chemotherapy. mTOR shared predictive significance in stage II CRC patients' outcomes and played a vital role in the maintenance of colorectal cancer stem-like cells. mTOR inhibitors might hold the potential to become a therapeutic target against CRC stem cells.
    Annals of Surgical Oncology 08/2013; 21(1). DOI:10.1245/s10434-013-3146-8 · 3.94 Impact Factor
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    ABSTRACT: BACKGROUND: CCL18 has been shown to have an important role in the progression of gastric and breast cancers. However, the prognostic value of CCL18 in colorectal cancer (CRC) remains unknown. MATERIALS AND METHODS: We used immunohistochemistry to examine the expression of CCL18 in CRC patients. We applied both univariate and multivariate analysis to evaluate the prognostic value of CCL18 on CRC patients' survival. We used double staining to investigate the relationship between CCL18 and macrophages. RESULTS: A total 371 CRC patient samples were enrolled in immunohistochemical analysis. According to our criteria, 118 samples (31.8%) showed a high CCL18 expression level. Clinicopathologic analysis revealed an association between the expression level of CCL18 and the preoperative carcino embryonic antigen level (P = 0.001), and the preoperative carbohydrate antigen 19-9 level (P = 0.003). Survival analysis and multivariate analysis revealed that CCL18 was an independent favorable prognostic factor in patients with CRC (P = 0.033). Double staining implied that CCL18 was expressed by macrophages. CONCLUSIONS: A high CCL18 level might be an independent biomarker for predicting better survival of patients with CRC.
    Journal of Surgical Research 01/2013; 183(1). DOI:10.1016/j.jss.2013.01.017 · 2.12 Impact Factor
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    ABSTRACT: Breast cancer can be grouped by expression profiling into categories that differ in biological and clinical characteristics. Molecular characterization of these subtypes on the basis of stem cell markers has shown that basal and claudin-low tumor bear stem cell like characteristics with a higher population of CD44+/CD24- and CD49f+/EpCAM- cells, which also display characteristics of epithelial mesenchymal tumor transition (EMT). There are several genetic and epigenetic signaling pathways that regulate the stem cell like characteristics of these subtypes. We examined the role of microRNA221 (mir-221) in sub populations of normal breast cells isolated from reduction mammoplasties as well as in cancer cell lines from different molecular subtypes of breast cancer. We found that mir-221 drives cells towards more basal subtype and induces EMT in both normal mammary cells and breast cancer cell lines. On the basis of CD49f and ESA staining in the cells isolated from normal mammary tissue, we found high mir-221 expression in the CD49f+/EpCAM- population. Furthermore, we showed that ALDH+ cells from mammospheres expressed significantly higher mir-221 compared to ALDH- cells. In order to determine the effect of mir-221 on the stem cell population, we overexpressed mir-221 in cells from primary mammospheres and showed that overexpression of mir-221 increases the CD49f+/EpCAM- population with increased expression of mesenchymal biomarkers, an effect also seen in a non-transformed breast cell line MCF10A. Overexpression of mir-221 in luminal breast cancer cell lines MCF-7 and T47D cell lines increased the proportion of CD44+/CD24- cells. Furthermore, overexpression of mir-221 significantly stimulated the tumor growth of MCF7 xenographs in NOD/SCID mice. These studies suggest that mir-221 regulates breast CSCs by promoting EMT. This may play an important role in tumor behavior and treatment resistance.
    AACR; 06/2012
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    ABSTRACT: Recent studies have suggested similarities between cancer stem cells and the epithelial mesenchymal transition (EMT) state. In contrast, other studies suggest that these “states” are mutually exclusive. Our studies suggest that these divergent views may be explained by the existence of multiple stem cell states, which are regulated by microRNAs. Utilizing primary breast tissue and established cell lines, we demonstrate that both normal and malignant breast stem cells exist in distinct, inter-convertible states. The EMT-like state is characterized by expression of vimentin and N-cadherin, slug, snail and twist transcription factors. EMT-like CSCs have a mesenchymal morphology, are largely quiescent, invasive and characterized by expression of the CSC markers CD44+CD24- and are EpCAM-CD49f+. In contrast, the MET (mesenchymal epithelial transition) state of CSCs is characterized by an epithelial morphology and expression of E-cadherin and EpCAM. MET-like CSCs undergo self-renewal and express the CSC marker Aldehyde dehydrogenase (ALDH) and are EpCAM+CD49F+. A subpopulation of cells expressing both CD44+CD24- and ALDH may represent cells in transition between these states. This transition is regulated by signals in the microenvironment which in turn modulate microRNA networks. Expression induction of mir100 in MCF10A cells and several cancer cell lines resulted in a decrease of ALDH-positive CSC population with a concomitant increase in the CD24-CD44+ population accompanied by induction of EMT. We demonstrated mir100 effects are mediated by targeting BMPR2, SMARCA5 and SMARCD1, all of which may contribute to induction of EMT. Moreover, we show that mir100 overexpression induces cellular quiescence as shown by Ki67 and Brdu staining. Induction of mir100 expression immediately upon orthotopic implantation or after the tumors are established significantly reduced the subsequent tumor growth in NOD/SCID mice. In contrast of overexpression of mir100 stimulates cell invasion in vitro matrigel assay. The existence of multiple cancer stem cell states has important implications for understanding stem cell plasticity as well as tumor growth and metastasis. In addition, the existence of these states has implications for the development of CSC-targeting therapeutics.
    AACR; 06/2012
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    ABSTRACT: MicroRNAs (miRNAs) play important roles in normal cellular differentiation and oncogenesis. microRNA93 (mir-93), a member of the mir106b-25 cluster, located in intron 13 of the MCM7 gene, although frequently overexpressed in human malignancies may also function as a tumor suppressor gene. Using a series of breast cancer cell lines representing different stages of differentiation and mouse xenograft models, we demonstrate that mir-93 modulates the fate of breast cancer stem cells (BCSCs) by regulating their proliferation and differentiation states. In "claudin(low)" SUM159 cells, expression of mir-93 induces Mesenchymal-Epithelial Transition (MET) associated with downregulation of TGFβ signaling and downregulates multiple stem cell regulatory genes, including JAK1, STAT3, AKT3, SOX4, EZH1, and HMGA2, resulting in cancer stem cell (CSC) depletion. Enforced expression of mir-93 completely blocks tumor development in mammary fat pads and development of metastases following intracardiac injection in mouse xenografts. The effect of mir-93 on the CSC population is dependent on the cellular differentiation state, with mir-93 expression increasing the CSC population in MCF7 cells that display a more differentiated "luminal" phenotype. mir-93 also regulates the proliferation and differentiation of normal breast stem cells isolated from reduction mammoplasties. These studies demonstrate that miRNAs can regulate the states and fates of normal and malignant mammary stem cells, findings which have important biological and clinical implications.
    PLoS Genetics 06/2012; 8(6):e1002751. DOI:10.1371/journal.pgen.1002751 · 8.17 Impact Factor
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    ABSTRACT: The purpose of this study is to investigate the clinical/prognostic significance of tumor-infiltrating mast cells (TIMs) in patients with colorectal cancer (CRC). TIM infiltration in 325 stage I to III CRC specimens was detected by immunohistochemistry. The optimal cutpoint of TIM density was assessed by the X-tile program. TIM infiltration in CRC was significantly higher than in normal colorectal tissues. According to the X-tile program, the cutpoint for high TIM infiltration in CRC was determined when TIM density was more than 8.0 per high-power field. Correlation analysis between TIM density and clinicopathological variables demonstrated that TIM infiltration was significantly associated with gender, nodal status, and American Joint Committee on Cancer stage. Multivariate Cox regression analysis showed that high TIM infiltration was a risk factor for both overall survival and disease-free survival. Taken together, high TIM infiltration can be an independent and useful biomarker for predicting the poor survival of patients with CRC.
    International Journal of Surgical Pathology 05/2012; 21(2). DOI:10.1177/1066896912448836 · 0.96 Impact Factor
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    ABSTRACT: There is increasing evidence that many human cancers, including breast cancer, are driven and maintained by a cellular subcomponent that displays stem cell properties. These “cancer stem cells” (CSCs) may also mediate tumor metastasis and contribute to treatment resistance and relapse. Our group was the first to describe a subpopulation in breast cancer that displayed stem cell properties and was characterized by expression of the cell surface markers ESA and CD44 in the absence of expression of the marker CD24. These cells have been termed “breast cancer stem cells” (BCSCs). More recently, we have demonstrated that breast cancer cells contain subpopulations with stem cell properties that can be isolated by virtue of their expression of Aldehyde dehydrogenase (ALDH) as assessed by the Aldefluor assay. Interestingly, these markers identify overlapping, but not identical cell populations. Recently it has been suggested that the cell surface markers EpCAM and CD49f can be used to define heterogeneous population of normal mouse and human mammary cells. It has been suggested that EpCAM-CD49f+ cells represent mammary stem cells. However, more recent study suggest that in addition to luminal progenitors, a portion of EpCAM+CD49f+ cells may also contain a population with stem cell characteristics. More and more studies have linked the EMT state to cancer stem cells and EMT cells are largely quiescent. As described previously by our lab, CD24-CD44+ and ALDH identify overlapping, but not identical cell populations. Our data showed that EpCAM+CD49f+ cells (MET-like) contain much more ALDH+ cells than other populations, and CD24-CD44+ cells are mainly contained in EpCAM-CD49f+ population (EMT-like). We demonstrated, among microRNAs differently expressed in Aldefluor-positive and Aldefluor-negative populations of breast cancer cell lines we identified micrRNA100 (mir100). We found that mir100 is significantly increased in Aldefluor-negative compared to Aldefluor-positive populations in both normal breast cells and breast cancer cells. Utilizing a tetracycline inducible lentivirus driving mir100 expression, we found that induction of mir100 expression decreased the ALDH-positive population but increased CD24-CD44+ population along with either increasing EpCAM- cells or CD49f+ cells in both normal and cancerous breast cells in vitro, which is a character of EMT. Furthermore, induction of mir100 expression immediately upon orthotopic implantation or after the tumor established significantly blocked subsequent tumor growth. Induction of mir100 expression immediately upon intra-cardiac injection completely blocked metastasis formation. Moreover, we showed that mir100 overexpression increased the quiescent cells but decreased proliferative cells by Ki67 and BrDu staining. We further identified BMPR2, SMARCA5 and SMARCD1 as mir100 targets in ALDH+ cells. These studies indicats the existence of alternative CSC state and mir100 plays a functional role in modulating breast cancer stem cell EMT state, suggesting that the acquisition of stem cell markers may reflect transition of CSC states rather than generation of CSCs from non-CSC populations. In addition, the existence of multiple stem cell states suggests the necessity of developing of therapeutic strategies capable of effectively targeting CSCs in all of these states.
    AACR; 01/2012
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    ABSTRACT: There is increasing evidence that many human cancers, including breast cancer, are driven and maintained by a cellular subcomponent that displays stem cell properties. These “cancer stem cells” (CSCs) may also mediate tumor metastasis and contribute to treatment resistance and relapse. Our laboratory has identified cellular markers and developed in vitro and mouse models to isolate and characterize normal and malignant human mammary stem cells. We have previously demonstrated that breast cancer cell lines contain subpopulations with stem cell properties that can be isolated by virtue of their expression of Aldehyde dehydrogenase (ALDH) as assessed by the Aldefluor assay. We demonstrated, among microRNAs differently expressed in Aldefluor-positive and Aldefluor-negative populations of breast cancer cell lines we identified micrRNA100 (mir100). We found that mir100 is significantly increased in Aldefluor-negative compared to Aldefluor-positive populations. Utilizing a tetracycline inducible lentivirus driving mir100 expression, we found that induction of mir100 expression decreased the ALDH-positive population of SUM159 cells in vitro as well as in mouse xenografts where this reduction was associated with decreased tumor growth. Furthermore, induction of mir100 expression immediately upon orthotopic implantation or intracardiac injection completely blocked subsequent tumor growth and metastasis formation. These studies demonstrate that mir100 plays a functional role in the self-renewal and differentiation of breast cancer stem cells. Furthermore, the TET-inducible mir100 system allows for controlled regulation of the cancer stem cell population providing a valuable model to simulate the effects of CSC-directed therapies on breast cancer growth and metastasis.
    AACR; 07/2011
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    ABSTRACT: Crohn's disease is established in laparoscopic surgery due to partial bowel dissection and low postoperative complication rate. However, laparoscopic surgery for ulcerative colitis remains further discussed even if the trend of minimally invasive technique exists. This study is to figure out how laparoscopic surgery works for ulcerative colitis. Sixteen controlled trials were identified through the search strategy mentioned below. There was only one prospective randomized study among the studies selected. A meta-analysis pooled the outcome effects of laparoscopic surgery and open surgery was performed. Fixed effect model or random effect model was respectively used depending on the heterogeneity test of trials. Postoperative fasting time and postoperative hospital stay were shorter in laparoscopic surgery for ulcerative colitis (-1.37 [-2.15, -0.58], -3.22 [-4.20, -2.24], respectively, P < 0.05). Overall complication rate was higher in open surgery, compared with laparoscopic surgery (54.8% versus 39.3%, P = 0.004). However, duration of laparoscopic surgery for ulcerative colitis was extended compared with open surgery (weighted mean difference 69.29 min, P = 0.04). As to recovery of bowel function, peritoneal abscess, anastomotic leakage, postoperative bowel obstruction, wound infection, blood loss, and mortality, laparoscopic surgery did not show any superiority over open surgery. Re-operation rate was almost even (5.2% versus 7.3%). The whole conversion to open surgery was 4.2%. Laparoscopic surgery for ulcerative colitis was at least as safe as open surgery, even better in postoperative fasting time, postoperative hospital stay, and overall complication rate. However, clinical value of laparoscopic surgery for ulcerative colitis needed further evaluation with more well-designed and long-term follow-up studies.
    International Journal of Colorectal Disease 02/2010; 25(8):949-57. DOI:10.1007/s00384-010-0898-5 · 2.42 Impact Factor
  • Chinese medical journal 08/2009; 122(13):1591-4. · 1.02 Impact Factor

Publication Stats

71 Citations
69.39 Total Impact Points

Institutions

  • 2013–2015
    • Sun Yat-Sen University of Medical Sciences
      Shengcheng, Guangdong, China
  • 2010–2015
    • Sun Yat-Sen University
      • Proteomics Lab
      Shengcheng, Guangdong, China
  • 2012
    • University of Michigan
      • Comprehensive Cancer Center
      Ann Arbor, MI, United States