中文摘要：

目的研究S腺苷蛋氨酸（SAMe）对急性缺血／缺氧过程中肝癌细胞HepG2生物学特性的作用，并通过应用氯喹（CQ）抑制自噬探讨其可能机制。方法用实时PCR检测自噬特异性基因（Beclin1）表达的变化。吖啶橙染色后，采用荧光显微镜对自噬进行定性观察。CCK8法检测HepG2细胞生存率。Westernblot检测蛋白LC3的变化。用AnnexinV／PI流式细胞仪检测细胞凋亡的变化。结果缺血／缺氧可以促进HepG2细胞生长，细胞生存率比空白对照组增加了20％～30％。sAMe可诱导HepG2细胞自噬的表达，自噬在荧光强度和Beclin1基因水平分别比空白对照组增强约3．2倍和3．5倍。SAMe对HepG2细胞具有显著的抑制作用，这种抑制作用在缺血／缺氧环境中更加明显。经SAMe处理后，正常和缺血／缺氧环境的细胞生存率与空白对照组相比分别下降了30％和70％。与空白对照组相比，细胞经SAMe处理后，凋亡比例增加约24％。细胞经SAMe预处理，再进行缺血缺氧后，凋亡比例增加约40％。抑制自噬后，细胞生存率下降15％～30％，细胞凋亡增加7％～16％。结论在SAMe抑制HepG2细胞生长过程中，自噬对细胞有一定的保护作用。

英文摘要：

Objective To investigate the role of S-adenosylmethionine （SAMe） during ischemi- a/hypoxia in hepatocellular carcinoma and its underlying mechanism through autophagy inhibition by chloroquine （CQ）. Methods Real-time PCR measured the expression of Beclin 1, and quantitative a- nalysis of autophagy was performed with fluorescent microscope on acridine orange staining. The cel- lular viability was detected by the CCK8 method, the LC3 protein was detected by Western blot, and apoptosis was detected by AnnexinV/PI flow cytometry. Results The cellular viability under ischemi- a/hypoxia increased about 20% - 30%. SAMe induced autophagy in the hepatoma cell line HepG2, and the level of autophagy in fluorescent intensity and real-time PCR of Beclin 1 increased about 3.2 and 3.5 times, respectively. SAMe significantly inhibited the proliferation of HepG2, especially in the environment of ischemia/hypoxia. The cellular viability under SAMe treatment only and SAMe-treat- ment followed by ischemia/hypoxia decreased about 30 % and 70 %, respectively, and cellular apopto- sis increased about 24o//00 and 40%, respectively, over blank control. After autophagy inhibition, the proliferation of HepG2 decreased about 15 % - 30 % and cellular apoptosis increased about 7 % - 16 %. Conclusions SAMe inhibited the proliferation of HepG2, and autophagy may be a protective factor during acute ischemic hypoxia.