Association of downregulation of WWOX with poor prognosis in patients with intrahepatic cholangiocarcinoma after curative resection
Association of downregulation of WWOX with poor prognosis in patients with intrahepatic cholangiocarcinoma after curative resection
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WWOX 下调与肝内胆管癌根治性切除术后不良预后的关系
DOI：
10.1111/jgh.12722
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发表时间：
2015-02-01
影响因子：
4.1
通讯作者：
Li, Xiangcheng
中科院分区：
文献类型：
--
作者：
Huang, Changjun;Tian, Yuan;Li, Xiangcheng
背景与目的：研究表明，含有氧化还原酶WW结构域的蛋白表达下调与多种肿瘤的发生有关。本研究旨在探讨WWOX在肝内胆管癌（ICC）中的表达和作用。方法采用实时定量聚合酶链反应（PCR）、免疫印迹、免疫荧光和免疫组织化学方法检测WWOX的表达。Kaplan-Meier和考克斯回归分析其预后意义。通过使用慢病毒的WWOX再表达来评估WWOX在增殖、锚定非依赖性生长、基因表达调节和肿瘤发生中的作用。进行甲基化特异性PCR以评估WWOX基因调控区的甲基化状态。应用DNA甲基转移酶抑制剂5-氮杂-2-脱氧胞苷（5-aza-2-deoxycytidine，AZA）在体外和体内激活ICC细胞内源性WWOX基因。结果WWOX基因在ICC组织中的表达明显低于非肿瘤组织，且与细胞增殖状态呈负相关。WWOX表达的恢复通过激活内在凋亡信号通路导致WWOX缺陷型ICC细胞的生长受到抑制，但不影响WWOX充足的人肝内胆管上皮衍生的非癌细胞的生长。多变量分析显示，WWOX下调是总生存率和累积复发率的不利预测因素。WWOX基因调控区在ICC组织和细胞系中频繁甲基化，瘤内WWOX恢复，通过AZA注射，抑制肿瘤生长在nude mice.ConclusionDownregulation的WWOX可能发生由于过度甲基化，并意味着在ICC预后不良; WWOX的重新表达可能是一个潜在的分子治疗ICC的目标。
Background and AimDownregulation of the WW domain containing oxidoreductase (WWOX) has been reported to be involved in tumorigenesis in several neoplasms. This study sought to investigate the expression and role of WWOX in intrahepatic cholangiocarcinoma (ICC).MethodsWWOX expression was measured by quantitative real-time polymerase chain reaction (PCR), immunoblot, immunofluorescence, and immunohistochemistry. The prognostic significance was assessed by Kaplan-Meier and Cox regression analyses. The role of WWOX in proliferation, anchorage-independent growth, gene expression regulation, and tumorigenesis was assessed by WWOX re-expression using lentivirus. Methylation-specific PCR was performed to evaluate the methylation status of the WWOX gene regulatory region. A DNA methyltransferase inhibitor, 5-aza-2-deoxycytidine (AZA), was used to activate the endogenous WWOX gene in ICC cells both in vitro and in vivo.ResultsThe expression of WWOX in ICC tissues was much lower than that in nontumorous samples and showed reverse correlation with proliferative status. Restoration of WWOX expression resulted in suppression of the growth of WWOX-deficient ICC cells through activation of the intrinsic apoptotic signaling pathway, but did not affect growth of WWOX-sufficient human intrahepatic biliary epithelial derived non-cancer cells. Multivariate analyses revealed that downregulation of WWOX was an unfavorable predictor for overall survival and cumulative recurrence rates. The WWOX gene regulatory region was frequently methylated in ICC tissues and cell lines, and intratumoral WWOX restoration, through AZA injection, suppressed tumor growth in nude mice.ConclusionDownregulation of WWOX may occur as a result of hypermethylation and implies a poor prognosis in ICC; WWOX re-expression may be a potential molecular therapeutic target for ICC.