miR-1284靶向调控EIF4A1对胃癌进展的影响

The most basic characteristic of malignant tumor cells is the uncontrolled proliferation of cells and the fundamental reason is the failure of gene regulation mechanism. MicroRNA plays an important role in gene regulation so that it is closely associated with tumor progression. Our preliminary experiments showed that miR-1284 expression in human gastric cancer tissues was lower than that in adjacent normal tissues. Moreover, miR-1284 overexpression inhibited growth, proliferation, invasion and metastasis of gastric cancer cells. The bioinformatics softwares and the dual luciferase reporter assay system have confirmed that eukaryotic translation initiation factor 4A1 (EIF4A1) is the target gene of miR-1284. In order to further analyze the action of miR-1284, we first test interacting of miR-1284 and EIF4A1 by GST pull-down method. Also, we construct miR-1284 vectors and transfect these vectors into gastric cancer cells to observe the effects of miR-1284 on the growth, proliferation, invasion, metastasis and EIF4A1-related genes expression of human gastric cancer cells in vitro. Finally, we detect the expression of miR-1284/EIF4A1 signal pathway and related molecules by establishing subcutaneous tumor model of gastric cancer in nude mice and collecting clinical specimens of human gastric cancer so as to reveal the action of miR-1284 targeting EIF4A1 on the progression of gastric cancer.

恶性肿瘤细胞的最基本特征是细胞的失控性增殖，其根本原因是基因调控机制的破坏。microRNA在基因调控中具有重要作用，因此与肿瘤进展关系密切。我们的前期研究发现，人胃癌组织miR-1284表达低于癌旁正常组织，且miR-1284过表达抑制胃癌细胞的生长增殖、侵袭转移；生物信息学软件和双荧光素酶报告实验证实，真核翻译起始因子4A1(EIF4A1)是miR-1284的靶基因。为了进一步分析miR-1284的作用，本项目首先应用GST pull-down实验验证miR-1284和EIF4A1的相互作用；然后构建miR-1284载体转染胃癌细胞，在体外观察miR-1284对胃癌生长增殖、侵袭转移及EIF4A1相关基因等的影响；最后建立裸鼠胃癌皮下瘤模型及收集临床人胃癌标本，观察miR-1284/EIF4A1信号通路及相关分子的表达，从而阐明miR-1284靶向调控EIF4A1在胃癌进展中的作用。

恶性肿瘤细胞的最基本特征是细胞的失控性增殖，其根本原因是基因调控机制的破坏。microRNA在基因调控中具有重要作用，因此与肿瘤进展关系密切。本研究构建了miR-1284过表达载体并转染胃癌细胞，结果发现miR-1284过表达在体外或体内环境中均能抑制胃癌细胞生长、侵袭和转移能力，促进细胞凋亡。检测胃癌患者的临床标本，结果发现肿瘤体积越大或远处转移的胃癌患者miR-1284表达量较低，淋巴结转移阳性与真核翻译起始因子4A1（EIF4A1）的蛋白过表达相关。通过染色质免疫共沉淀（ChIP）-PCR 检测和双荧光素酶报告实验，证实miR-1284与EIF4A1靶向直接结合。全基因表达谱芯片检测和Western Blot相关实验，初步阐明了miR-1284靶向调控EIF4A1基因影响胃癌细胞生物学行为的相关分子机制。本研究为今后探索miR-1284在胃癌中的调控作用、早期诊断和预后判断奠定了实验及理论基础。