中文摘要：

目的：分析TLR4在肝癌细胞H7402的表达水平,研究其活化对肿瘤细胞生物学功能、炎症应答以及对化疗药物治疗的影响。方法：RT-PCR方法检测肝癌细胞TLR4基因、细胞凋亡和细胞周期相关基因的表达水平。LPS作用于肝癌细胞后,利用MTT法检测细胞增殖,AnnexinV/PI双染法检测细胞凋亡,荧光定量PCR法检测肿瘤相关细胞因子的表达水平,流式细胞术检测肿瘤细胞表面淋巴细胞受体的配体及CyclinD1表达,Western blot检测Bcl-xl表达水平。结果：TLR4在人肝癌细胞系HepG2、H7402、PLC/PRF/5中都有表达,LPS能促进肝癌细胞系的增殖,抵抗顺铂的抗肿瘤作用。进一步的机制研究表明,LPS能上调肝癌细胞周期相关分子CyclinD1、凋亡相关分子Bcl-xl的表达,并下调Fas的表达、上调肿瘤相关的炎症因子的表达。结论：LPS诱导肝癌细胞H7402表达炎症因子、促进肿瘤细胞的增殖,导致肿瘤细胞对化疗药顺铂产生抵抗作用。

英文摘要：

Objective：To analyze the expression levels of TLR4 expressed on hepatocellular carcinoma cell line H7402,and investigate the effect of LPS on the tumor characterizations,including proliferation ability,inflammatory response and sensitivity to chemotherapy.Methods：The expression of TLR4,molecules associated with apoptosis and cell cycle on hepatocellular carcinoma cells was detected by RT-PCR.The proliferation of tumor cells was detected by MTT assay.Cell apoptosis was analyzed by AnnexinV/PI assay.The expression of inflammatory factors was determined by quantitative real-time PCR.FACS was used to detect the expression of the molecules expressed on cell surface and CyclinD1.The expression of Bcl-xl was detected by Western blot.Results： TLR4 was expressed on human hepatocellular carcinoma cell line HepG2,H7402,PLC/PRF/5.LPS could promote the proliferation of hepatocellular carcinoma cells and protect tumor cells from chemotherapy drug.Further investigation indicated that the molecules associated with cell cycle and apoptosis,CyclinD1 and Bcl-xl,were up-regulated,whereas Fas was down-regulated.Additionally,the inflammatory cytokines were also up-regulated by LPS.Conclusion：LPS could induce the expression of inflammatory cytokines,promote the proliferation of hepatocellular carcinoma cell H7402 and protect tumor cells from chemotherapy drug.