STAT3及其竞争性内源RNAs调控网络在肝内胆管癌进展中的功能研究

Transcription signal transducer and activator of 3 (STAT3) is an important cancer gene widely expressed in a variety of cells and tissues, and is an important part of the JAK-STAT signaling pathway. Its expression and activation has been confirmed within several type of cancers, including gastric cancer, hepatocellular carcinoma, lung cancer and laryngeal cancer, whereas the role of STAT3 during bile duct cancer progression and development has not been reported clearly. This study was designed to take advantage of the large sample of intrahepatic cholangiocarcinoma clinical and pathological data, combined with the cellular level and the animal level experiments, affect STAT3 expression by the STAT3-competing endogenous RNAs(STAT3-ceRNAs) regulating net and cell internal/external environmental non-coding RNA, and to provide a new method for the clinical treatment of intrahepatic bile duct cancer, prognosis and ideas. In our previous studies, we found the over-expression of STAT3 in human ICC tissues. We also observed the enhanced expression of STAT3 by one of its potential ceRNAs ETS1 in a ICC cell line. Our project here plans : (1)to further confirm the STAT3-ceRNAs as the predictive biomarker or treatment target of ICC by using a larger samples firstly; (2)to intensively explore the role of STAT3-ceRNAs during the development and progression of ICC(especially for the modulation cell self renewal, proliferation, chemoresistance, tumorigenicity, migration and invasion); (3)to thoroughly investigate the mechanisms involving in the STAT3-ceRNAs and their cross-talk with each other(probably through microRNAs-dependant regulation); (4) to establish an integrated STAT3-ceRNAs regulation net (STAT3-ceRNET). We expect that such information along with established clinical and demographic prognostic factors would have the potential to lead to personalized risk stratifications and interventions that could benefit the public's health and millions of patients around the world.

2010年提出的竞争性内源RNA（ceRNA）假说，认为ceRNA之间通过miRNA应答元件竞争结合miRNA实现互相调控形成庞大的转录调控网络对肿瘤进展具有重要作用。STAT3是一类重要的癌基因，其表达和活化被证实与多种肿瘤发生发展密切相关，然而STAT3及其ceRNA的交互调节尚无报道。我们前期研究发现STAT3信号通路在肝内胆管细胞癌（ICC）中异常活化，并与肿瘤的较差预后显著相关。本研究拟通过建立STAT3-ceRNAs表达网络分析筛选STAT3相关ceRNAs，细胞、动物水平明确关键ceRNA生物学功能,MS2-RIP和TALEN基因敲除技术筛选节点microRNAs，阐明STAT3-ceRNAs网络调节ICC恶性表型的分子机制和下游效应基因。最后结合临床大样本ICC病理资料和预后数据回归分析,明确STAT3-microRNA-ceRNAs在肿瘤转归预测和干预治疗中的潜在作用。

本研究首次发现STAT3在肝内胆管癌中显著表达，STAT3的高表达与肿瘤体积、病理性卫星灶、血管侵犯、肿瘤分化以及淋巴结转移呈正相关。同时细胞学和动物实验发现过表达STAT3能促进肝内胆管癌的转移侵袭能力。结合数据库和实验验证我们确认候选ceRNAs （LncRNA-NEAT1）与肿瘤组织中STAT3的表达水平呈显著正相关（P＜0.001）。进一步LncRNA-NEAT1作为STAT3的竞争性内源RNA可以调控STAT3在胆管癌中的活化表达。结合之前的肝内胆管癌组织中microRNA规模化筛选我们还发现和正常胆管组织相比，let-7a/7b在ICC中显著降低，STAT3 3’UTR野生型及其突变型报告基因质粒实验还发现Let7b过表达能使野生型STAT报告基因活性下降而不能影响突变型报告基因活性。而LncRNA-NEAT1可能通过影响let-7a/7b表达从而稳定STAT3蛋白水平促进肝内胆管癌细胞恶性表型。本研究已在Gut（2016），Gut（2015，并列第一作者），Gastroenterology（2017），Cancer Letter（2016），Cancer Letter（2015），Oncotarget（2017，通讯作者）发表标注项目资助号SCI文章6篇，其中影响因子大于10分的文章3篇，大余5分的文章3篇。