EGCG对肝癌细胞HepG2凋亡及脂肪酸合酶表达的影响

Effect of epigallocatechin gallate on tumor cell apoptosis and fatty acid synthase expression in hepatocellular carcinoma cell line HepG2

目的观察表没食子儿茶素没食子酸酯(EGCG)对人肝癌HepG2细胞增殖抑制、凋亡诱导及对凋亡相关基因和脂肪酸合酶(FASN)表达的影响,明确其可能的抗肝癌作用机制。方法体外培养HepG2人肝癌细胞株,随机分为对照组(无药物干预)及80、120、160μmol/L EGCG组,作用48h后,荧光显微镜观察Hoechst33258染色结果并用流式细胞术定量分析细胞凋亡发生情况;用RT-PCR方法检测FASN及凋亡相关基因Bcl-2和Bax的表达。结果EGCG组Hoechst33258染色可见凋亡细胞核浓染,亮度明显加深或有染色质边集现象,亦可见典型的凋亡小体;流式细胞术检测发现,经160μmol/L EGCG作用48h后,肝癌细胞凋亡率最高可达28.6%;半定量RT-PCR结果显示,经EGCG作用48h后肝癌细胞中凋亡相关基因Bcl-2表达量明显下降,同时FASN表达量亦随EGCG浓度的增大而显著降低。Bax表达无明显变化。结论 EGCG可抑制人肝癌细胞HepG2的细胞增殖,并诱导凋亡发生,此作用可能与其抑制细胞凋亡相关基因Bcl-2以及内源性FASN的表达有关。

Objective To observe the proliferation-inhibiting and apoptosis-inducing effects of epigallocatechin gall （EGCG） on human hepatocellular carcinoma （HCC） cell line HepG2 and investigate the expressions of apop^t6sis, assOciated genes and fatty acid synthase （FASN） in order to explore the possible anti-cancer mechanism of EG,~G. ~tl3ods HCC cell line HepG2 was cultured in vitro and then randomly divided into blank control group, 80 t^mol~..!.EGCG-treated group, 120 t^mol/L EGCG-treated group and 160 t^mol/L EGCG-treated group. After 48 hours ~f treatment, cell apoptosis was observed by Hoechst33258 staining and detected with flow cytometry. RT-PCR was used to detect the expressions of Bcl-2 and Bax, two apoptosis-associated genes, and FASN gene. Results HCC cells treated with EGCG exhibited significant cell shrinkage, chromatin condensation, and the formation of apoptotic bodies with Hoechst 33258 staining. Flow cytometry showed that the highest apoptosis rate was 28.6% in 160 μmol/L EGCG-treated group. RT-PCR analysis indicated that Bcl-2 and FASN gene expressions were significantly decreased with the increase of EGCG concentration. Conclusion EGCG can inhibit cell proliferation and induce apoptosis of HCC cells. This effect may be related to inhibiting the expressions of endogenous FASN and cell apoptosis-associated gene Bcl-2.