Gynecologic Cancer Center, Department of Obstetrics and Gynecology, Cathay General Hospital, Taipei, Taiwan.
Mol Cancer. 2012 Aug 8;11:53. doi: 10.1186/1476-4598-11-53.
This study is to analyze promoter methylation of various tumor suppressor genes in different types of ovarian carcinoma and to identify potential therapeutic targets of ovarian clear cell adenocarcinoma (OCCA).
The promoter methylation statuses of 40 genes in primary ovarian carcinomas including 47 clear- and 63 non-clear-cell type tissues, 6 OCCA cell lines, 29 benign ovarian endometriotic cysts, and 31 normal controls were analyzed by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). The MS-MLPA results were correlated with clinicopathological features and outcomes of 47 OCCA patients. Functions of the target genes were further explored by Western Blot Analysis, apoptosis assay, and caspase-3/7 activity analysis.
Frequencies of methylated RASSF1A, CDH13, CACNA1A, HIN-1, and sFRP5 genes in OCCA tissues were significantly higher than those in non-OCCA cancerous tissues and benign endometriotic cysts. The expected OS for patients with methylated promoters of HIN-1 was significantly worse than those for patients without methylated HIN-1 (30% vs. 62%, p = 0.002). The HIN-1 gene was over-expressed in ES2 cells, a significant reduction in cell growth and induction of apoptosis, and increasing paclitaxel sensitivity by reducing phosphorylation of Akt were observed.
Methylation of HIN-1 promoter is a novel epigenetic biomarker associated with poor outcomes in OCCA patients. Ectopic expression of the HIN-1 gene increased paclitaxel sensitivity which is partly through Akt pathway.
本研究旨在分析不同类型卵巢癌中各种肿瘤抑制基因的启动子甲基化情况，以确定卵巢透明细胞腺癌（OCCA）的潜在治疗靶点。
采用甲基化特异性多重连接探针扩增（MS-MLPA）技术分析 47 例 OCCA 组织（包括 47 例透明细胞型和 63 例非透明细胞型）、6 株 OCCA 细胞系、29 例良性卵巢子宫内膜异位囊肿和 31 例正常对照组织中 40 个基因的启动子甲基化状态。将 MS-MLPA 结果与 47 例 OCCA 患者的临床病理特征和预后进行相关性分析。进一步通过 Western blot 分析、细胞凋亡检测和 caspase-3/7 活性分析来探索靶基因的功能。
OCCA 组织中 RASSF1A、CDH13、CACNA1A、HIN-1 和 sFRP5 基因的甲基化频率明显高于非 OCCA 癌组织和良性子宫内膜异位囊肿。HIN-1 启动子甲基化患者的预期总生存期明显短于无 HIN-1 甲基化患者（30% vs. 62%，p=0.002）。HIN-1 基因在 ES2 细胞中过表达，观察到细胞生长减少、细胞凋亡增加以及通过降低 Akt 磷酸化增加紫杉醇敏感性。
HIN-1 启动子甲基化是 OCCA 患者预后不良的新型表观遗传标志物。HIN-1 基因的异位表达增加了紫杉醇的敏感性，部分是通过 Akt 通路。
