IQGAP1通过mTOR信号通路促进肝癌细胞增殖  

IQGAP1 Promotes Hepatic Carcinoma Cell Proliferation through the mTOR Signal Transduction Pathway

作　　者：刘志辉[1] 宋明旭[1] 周希科[1] 李莉华[1] 

机构地区：[1]苏州大学附属第四医院肿瘤研究所,江苏省无锡市214062

出　　处：《中国肿瘤临床》2011年第20期1247-1250,共4页Chinese Journal of Clinical Oncology

摘　　要：目的:研究IQGAP1(IQ domain GTPase-activating proteins,IQGAP1)对肝癌细胞株增殖及mTOR信号转导通路的影响,阐述其诱导细胞增殖的机制。方法:Western blot检测IQGAP1在肝癌细胞株HepG2、Huh-7中的表达。选择高表达IQGAP1的细胞株,针对IQGAP1基因的mRNA序列合成siRNA,采用脂质体转染法将其转入HepG2细胞;采用MTT法分析细胞的增殖;流式细胞仪检测细胞周期变化;免疫印迹法观测IQGAP1、mTOR和p-mTOR蛋白表达的变化。结果:IQGAP1在HepG2和Huh-7细胞中均表达,且在HepG2细胞中表达高于Huh-7细胞。IQGAP1 siRNA转染HepG2细胞后,抑制细胞的增殖;DNA合成前期(G_0/G_1期)细胞比例上升,合成期(S期)细胞比例下降;mTOR表达变化不明显,而p-mTOR的表达下降。结论:IQGAP1促进肝癌细胞的增殖,其机制可能是通过mTOR相关信号通路实现的。Objective： To investigate the effect of the IQ domain of GTPase-actwatmg proteins （ lt2tJAVi ） on me promcetauu, of hepatic carcinoma cells and the mTOR signal transduction pathway, and to explain the mechanism of cell proliferation. Methods： The IQGAP 1 expression in HepG2 and Huh-7 cells were detected using Western blot analysis. IQGAP 1 siRNA was synthesized accord- ing to the mRNA sequence of the human IQGAP1 gene and was transfected into HepG2 cells. The effects of IQGAP1 on HepG2 proliferation was analyzed by MTT assay. The effect of IQGAPI on the cell cycle was analyzed by flow cytometry. The expression levels of IQGAP1, mTOR, and p-mTOR were measured through Western blot analysis. Results： The HepG2 and Huh-7 cells showed detectable levels of IQGAP 1, whereas the HepG2 cell line showed higher expression than that in the Huh-7 cells. IQGAP 1 siRNA not only inhibit- ed cell proliferation but also increased the number of cells in the G0/G~ phase, with a concomitant decrease in the number of ceils in the S phase of the cell cycle, mTOR expression did not significantly change, whereas IQGAP 1 and proTOR expression were downregulated. Conclusion： These findings suggest that IQGAP 1 promotes the proliferation of HepG2 ceils, the mechanisms of which may be related to the roTOR pathways.

关 键 词：IQGAP1 肝癌细胞 MTOR 

分 类 号：R735.7[医药卫生—肿瘤]