二甲双胍对人肝癌细胞HepG2增殖及乙酰辅酶A羧化酶影响的实验研究

目的 探讨二甲双胍在人肝癌细胞HepG2中的抗肿瘤活性及其作用机制。方法 选取二甲双胍不同浓度（0、1、5、10、15 mmol／L）处理HepG2细胞24、48及72 h，用CCK-8法检测其对细胞增殖的影响。设二甲双胍不同浓度（0、5、10、15 mmol／L）处理HepG2细胞72 h，用Western blotting检测腺苷酸活化蛋白激酶（AMPK）、P-AMPK、乙酰辅酶A羧化酶（ACC）、P-ACC蛋白表达，Real-time PCR检测ACC mRNA的表达水平。结果 二甲双胍对HepG2细胞的增殖抑制作用呈时间和浓度依赖性。经不同浓度二甲双胍处理HepG2细胞72 h后，P-AMPK蛋白表达随药物浓度增高而上调，P-ACC蛋白表达随药物浓度增高而上升；与空白对照组（0 mmol／L）中P-AMPK、P-ACC表达比较，10、15 mmol／L组中两者的差异均有统计学意义（P＜0.01）。ACC mRNA表达随二甲双胍浓度的增加呈下降趋势，5、10、15 mmol／L组表达量均较空白对照组显著下降（P＜0.01）。结论 初步实验研究发现，二甲双胍能够抑制人肝癌细胞HepG2的增殖，并从蛋白磷酸化水平和基因水平抑制ACC的活性，其抗肿瘤作用可能与激活AMPK和抑制ACC有关。

Inhibition of metformin on acetyl coa carboxylase in human hepatocellular carcinoma cell line HepG2

Objective To determine the relationship between the antineopastic activity and the regulation on acetyl coa carboxylase （ACC） of metformin in human hepatocellular carcinoma cell（HCC） line HepG2. Methods HepG2 cells were treated with various concentrations of metformin（0，1，5，10，15 mmol／L） for 24 h， 48 h and 72 h respectively and cell growth was assessed by CCK 8 assay. After treated with different doses of metformin（0，5，10，15 mmol／L） for 72 h， protein expression levels of AMPKα，P-AMPKα，ACC1，P-ACC were measured by Western blotting method and ACC mRNA expression levels were measured by Real-time PCR. Results The growth of HepG2 cells were inhibited by metformin in dose dependent and time dependent manner. After treated with metformin for 72 h， metformin increased AMPK activation and decreased ACC activation respectively as metformin dose levels increased. Compared with control group， the protein expression levels of P-AMPKα and P-ACC were both significantly changed in 10mmol／L group and 15 mmol／L group（P＜0.01）. ACC mRNA expression levels were decreased significantly in all metformin-treated groups（P＜0.01）. Conclusion Metformin inhibits cellular proliferation of HepG2 cell line and suppresses ACC activation in both aspects of protein phosphorylation and gene expression. Metformin actitiviates AMPK and inhibits ACC， which may implicate with its antineopastic activity on HCC.