Clusterin促进肝癌侵袭转移的分子机制及其靶向干预研究

Clusterin (CLU) is abnormally high expressed in hepatocellular carcinoma (HCC). Our previous study found that CLU was significantly upregulated during cancer progression and metastasis using the isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach. However, the molecular mechanisms that CLU involved in HCC metastasis are still unclear. The role of CLU in the regulation of HCC metastasis will be investigated both in vitro and in vivo using shRNA-mediated down-regulation of CLU or ectopic expression of CLU in HCC cell lines with various metastatic potentials. This study will employ a tissue microarray containing samples from about 500 HCC patients to examine the expression of CLU and its correlation with the clinicopathological characteristics. Given the significant role of CLU as a chaperone, we will set out to identify CLU-binding partners by co-immunoprecipitation followed by nano-liquid chromatography / tandem mass spectrometry (LC-MS/MS). Metastasis PCR-Array will be used to study the targeted metastasis-related genes which were regulated by CLU. The network regulatory relationships between CLU-binding partners and targeted genes will be further explored. In addition, this project will also investigate the therapeutic activity and molecular mechanism of OGX-011, an antisense oligodeoxynucleotide (ODN) targeting clusterin, in HCC metastasis. This study may provide a novel and promising therapeutic approach to the treatment of HCC metastasis.

丛生蛋白（Clusterin, CLU）在肝癌组织中异常高表达，我们前期通过可视化肝癌转移模型结合蛋白质组学研究发现肝癌转移进展过程中CLU表达显著增高。目前关于CLU促进肝癌转移的分子机制尚不明确。本课题通过对肝癌细胞进行干扰或过表达，从细胞水平和动物水平研究CLU对肝癌细胞侵袭的影响，同时结合肝癌组织样本分析CLU表达与肝癌患者预后及临床病理特征之间的相关性。基于CLU作为分子伴侣的重要作用，采取免疫共沉淀-蛋白质组学分析CLU的相互作用蛋白谱；通过转移相关PCR-Array等高通量方法确定CLU发挥作用的下游靶分子，并进一步研究CLU相互作用蛋白与下游靶分子之间的网络调控关系，明确CLU调控肝癌侵袭转移的潜在分子机制。此外，本课题还将探讨CLU的分子靶向药物OGX-011对肝癌转移的抑制作用及相关分子机理,有望为肝癌转移的防治提供实验依据。

Clusterin作为一个应激性分子伴侣对肿瘤细胞增殖和存活具有重要调控作用。然而，关于Clusterin在肝癌转移中的作用和相关分子机制尚不明确。本研究中，我们通过肝癌组织芯片（n=198）分析Clusterin表达与肝癌患者临床参数的相关性，结果显示Clusterin高表达与患者的不良预后密切相关。体内体外功能实验表明，干扰Clusterin表达显著抑制肝癌细胞的侵袭和转移能力，过表达Clusterin则显著增强肝癌细胞的转移潜能。此外，我们还发现Clusterin可以通过结合真核翻译起始因子3亚基I（EIF3I）从而激活Akt信号通路，并进一步促进MMP13表达导致肝癌转移。在肝癌临床标本中Clusterin与p-Akt、MMP13和EIF3I的水平呈正相关趋势（n=198）。使用Clusterin靶向药物OGX-011可以有效抑制肝癌转移。以上研究结果表明Clusterin可以作为肝癌患者预后的独立预测指标，Clusterin可以通过EIF3I/Akt/MMP13信号通路促进肝癌细胞转移。使用OGX-011抑制肝癌细胞Clusterin表达可作为肝癌转移治疗的潜在手段。