目的：观察表没食子儿茶素没食子酸酯\[(-)-epigallocatechin-3-gallate， EGCG\]对体外培养的人肝癌细胞株生物学特性的影响，研究其作用效果与血红素氧合酶-1（hemeoxygenase-1， HO-1）及相关信号分子的关系，探讨其作用机制。方法：利用MTT法检测EGCG对HepG2、Sk-hep1、SMMC7721等肝癌细胞增殖的影响，并用吖啶橙/溴化乙锭（AO/EB）双染法观察肝癌细胞的形态学变化，流式细胞术检测EGCG作用后Sk-hep1细胞周期的变化，Real-time PCR和Western blotting法检测EGCG作用后Sk-hep1细胞中HO-1、IL-10及TNF-α等信号分子表达的变化。结果：EGCG作用后，3株肝癌细胞贴壁细胞数量显著少于对照组，凋亡细胞数增多\[HepG2:（16.33±3.51) vs (3.67±1.15)个，P<0.01），Sk-hep1:（18.33±2.31) vs (2.33±208)个，P<0.01），SMMC7721: （15.33±3.06) vs (3.33±2.08)个，P<0.01）\]。实验组Sk-hep1细胞G2/M期比例明显高于对照组\[（34.33±8.09）% vs （3.07±2.32）%，P<0.01\]。设对照组基准值为1.00，实验组Sk-hep1细胞中HO-1、IL-10、及TNF-α的mRNA相对表达水平依次为（0.58±0.15）、（5.91±1.11）、（5.29±1.14），差别均有统计学意义(P<001）；与对照组相比，实验组HO-1蛋白表达水平明显下调（0.16±0.04 vs 0.33±0.08，P<0.05），IL-10（0.42±0.06 vs 0.24±0.08, P=0034，P<0.05）和TNF-α蛋白（0.95±0.17 vs 0.58±008，P<0.05）表达水平明显上调。结论：EGCG可抑制肝癌细胞增殖及诱导细胞凋亡，并将Sk-hep1细胞阻滞在G2/M期，其机制可能与HO-1、IL-10、TNF-α等炎症信号分子表达的变化有关。

Objective :To investigate the effect of Epigallocatechin-3-gallate (EGCG) on hepatocellular carcinoma cell growth and the molecular mechanisms underlying the effect in vitro. Methods: Three human hepatocellular carcinoma cell lines (i.e., HepG2, Sk-hep1 and SMMC7721) were used in this study. Cells were cultured in the presence of 0, 40, 80 or 120 μg/ml EGCG. At 24, 48 and 72 h after EGCG treatment, cell viability was assessed by MTT assay, apoptosis by AO/EB staining, cell cycle progression by flow cytometer, and mRNA and protein levels of HO11, IL-10 and TNF-α by Realtime PCR and Western blotting respectively. Results: EGCG treatment significantly induced cell attachment (P<005), increased the proportion of apoptotic cells (P<0.01), and induced G2/M arrest (P<0.01) in all three cell lines tested as compared with the control. HO-1, IL-10 and TNF-α mRNA levels were 0.58±0.15, 5.91±1.11 and 529±1.14 in EGCG-treated Sk-hep1 cells, significantly different from the levels in the control cells (P＝0.008, P＝0002, P＝0.003). EGCG resulted in a significant decrease in HO-1 protein content as compared with the control (0.16±0.04 vs 0.33±0.08, P<0.05). In contrast, EGCG significantly increased levels of IL-10 protein (0.42± 006 vs 0.24±0.08, P<0.05) and TNF-α protein (0.95±0.17 vs 0.58±0.08, P<0.05). Conclusions: EGCG may inhibit proliferation and block cell cycle progression and induce apoptosis in hepatocellular carcinoma cells. The mechanism(s) underlying these effects of EGCG may involve modulation of HO-1, IL-10 and TNF-α expression.

广西医科大学青年科学基金项目(No. 02602211011)；广西自然科学青年基金项目(No. 2013GXNSFBA019186)；广西科学研究与技术开发计划课题(No.1140003A-32)