LKB1通过负调控MMP1的转录抑制肺癌细胞侵袭的分子机制

项目名称： LKB1通过负调控MMP1的转录抑制肺癌细胞侵袭的分子机制

项目编号： No.31301160

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 孙琳琳

作者单位： 天津医科大学

项目金额： 20万元

中文摘要： 抑癌基因LKB1在非小细胞肺癌中的失活突变率高达20%-30%。小鼠肺癌模型研究显示LKB1的缺失显著促进肺癌转移，但分子机制不明。我们发现，将LKB1表达下调，导致非小细胞肺癌细胞的侵袭能力增强，而且基质金属蛋白酶1（MMP1）的mRNA水平和蛋白水平显著升高。我们推测LKB1通过负调控MMP1的转录，降低MMP1表达，从而抑制肺癌的侵袭和转移。为证实该假说, 本课题在前期工作基础上，利用基因点突变、RNA干扰、双荧光素酶报告基因、Transwell等技术，进一步论证LKB1对MMP1转录的负调控，从LKB1对MMP1转录因子的调控以及LKB1与MMP1相关信号通路的crosstalk这两个层次，深入探讨LKB1负调控MMP1转录的分子机制，并阐明MMP1作为下游重要分子，介导LKB1缺失导致的肺癌细胞侵袭能力增强，从而赋予LKB1作为抑癌基因新的视角，为将来的分子靶向治疗提供新的思路。

中文关键词： 肺癌；细胞侵袭；细胞信号通路；抑癌基因；抗肿瘤药物

英文摘要： Loss-of-function mutations of tumor suppressor gene LKB1 occur in 20%-30% non-small cell lung cancers. Study of mouse model of lung cancer indicated that LKB1 loss greatly promotes lung cancer invasion and metastasis, but the molecular mechanism remains largely unclear. Based on our previous finding that isogenic LKB1 stable knockdown lung cancer line showed higher invasiveness and increased mRNA and protein levels of Matrix Metalloproteinase 1(MMP1), we hypothesize that LKB1 inhibits lung cancer cell invasion through negatively regulating MMP1 transcription and decreasing its expression level. To test the hypothesis, using site-directed mutagenesis system, RNA interference, dual-luciferase reporter gene and Transwell assay, etc, the project will attempt to further confirm the negative regulation of MMP1 transcription mediated by LKB1 and focus on the in-depth investigations of its molecular mechanisms from the respects of modulation of MMP1 transcription factors by LKB1 and the crosstalk between LKB1 and MMP1 related signaling pathway, and illustrate that MMP1 functions as a key downstream molecule and mediates the higher lung cancer cell invasiveness promoted by LKB1 loss, thus providing new insights into the role of LKB1 as a tumor suppressor gene and future molecular target therapy.

英文关键词： Lung cancer；Cell invasion；Cell signaling pathway；Tumor suppressor；Anti-tumor drug