Epithelial ovarian carcinoma is usually present at the advanced stage, during which the patients generally have poor prognosis. Our study aimed to evaluate the correlation of gene methylation and the clinical outcome of patients with advanced-stage, high-grade ovarian serous carcinoma. The methylation status of eight candidate genes was first evaluated by methylation-specific PCR and capillary electrophoresis to select three potential genes including DAPK, CDH1, and B LU (ZMYND10) from the exercise group of 40 patients. The methylation status of these three genes was further investigated in the validation group consisting of 136 patients. Patients with methylated BLU had significantly shorter progression-free survival (PFS; hazard ratio (HR) 1.48, 95% CI 1.01–2.56, P=0.013) and overall survival (OS; HR 1.83, 95% CI 1.07–3.11, P=0.027) in the multivariate analysis. Methylation of BLU was also an independent risk factor for 58 patients undergoing optimal debulking surgery for PFS (HR 2.37, 95% CI 1.03–5.42, P=0.043) and OS (HR 3.96, 95% CI 1.45–10.81, P=0.007) in the multivariate analysis. A possible mechanism of BLU in chemoresistance was investigated in ovarian cancer cell lines by in vitro apoptotic assays. In vitro studies have shown that BLU could upregulate the expression of BAX and enhance the effect of paclitaxel-induced apoptosis in ovarian cancer cells. Our study suggested that methylation of BLU could be a potential prognostic biomarker for advanced ovarian serous carcinoma.
Ying-Cheng Chiang, Ming-Cheng Chang, Pao-Jen Chen, Meei-Maan Wu, Chang-Yao Hsieh, Wen-Fang Cheng and Chi-An Chen
Han-Wei Lin, Ying-Cheng Chiang, Nai-Yun Sun, Yu-Li Chen, Chi-Fang Chang, Yi-Jou Tai, Chi-An Chen and Wen-Fang Cheng
The role of chitinase-3-like protein 1 (CHI3L1) in ovarian cancer and the possible mechanisms were elucidated. CHI3L1 is a secreted glycoprotein and associated with inflammation, fibrosis, asthma, extracellular tissue remodeling and solid tumors. Our previous study showed CHI3L1 could be a potential prognostic biomarker for epithelial ovarian cancer and could protect cancer cells from apoptosis. Therefore, clinical data and quantitation of CHI3L1 of ovarian cancer patients, tumor spheroid formation, side-population assays, Aldefluor and apoptotic assays, ELISA, RT-PCR, immunoblotting and animal experiments were performed in two ovarian cancer cells lines, OVCAR3 and CA5171, and their CHI3L1-overexpressing and -knockdown transfectants. High expression of CHI3L1 was associated with poor outcome and chemoresistance in ovarian cancer patients. The mRNA expression of CHI3L1 in CA5171 ovarian cancer stem-like cells was 3-fold higher than in CA5171 parental cells. CHI3L1 promoted the properties of ovarian cancer stem-like cells including generating more and larger tumor spheroids and a higher percentage of ALDH+ in tumor cells and promoting resistance to cytotoxic drug-induced apoptosis. CHI3L1 could induce both the Akt (essential) and Erk signaling pathways, and then enhance expression of β-catenin followed by SOX2, and finally promote tumor spheroid formation and other properties of ovarian cancer stem-like cells. OVCAR3 CHI3L1-overexpressing transfectants were more tumorigenic in vivo, whereas CA5171 CHI3L1-knockdown transfectants were not tumorigenic in vivo. CHI3L1 critically enhances the properties of ovarian cancer stem-like cells. CHI3L1 or CHI3L1-regulated signaling pathways and molecules could be potential therapeutic targets in ovarian cancer.