S腺苷甲硫氨酸对肝癌细胞急性缺血/缺氧过程中的生物学作用

目的：研究S腺苷甲硫氨酸（SAMe）在急性缺血/缺氧过程中对肝癌细胞HepG2的生物学作用,并通过检测自噬的变化探讨其可能机制。方法：real time-PCR检测自噬特异性基因（Beclin 1）表达的变化;吖啶橙染色后,采用荧光显微镜定性观察自噬;CCK-8法检测HepG2细胞的成活率;用AnnexinⅤ/PI流式细胞仪检测细胞凋亡的变化。结果：SAMe可诱导HepG2细胞的自噬,在单纯缺血和缺血/缺氧处理因素下,HepG2自噬在荧光强度和Beclin 1基因水平分别比空白对照组增强约3.2倍和3.5倍。细胞成活率分别比空白对照组增加了约20%和30%。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,SAMe单独处理组和SAMe预处理结合缺血/缺氧组,其细胞成活率与空白对照组相比分别下降了约30%和70%。随着细胞成活率下降,细胞凋亡比例相应增加,与空白对照组相比,细胞经SAMe处理后凋亡比例增加约18%;细胞经SAMe预处理后再予以缺血/缺氧,凋亡比例增加约30%。结论：在SAMe抑制HepG2细胞生长过程中,自噬起着重要作用。

Effect of S-adenosylmethionine on hepatic cancer cell during acute ischemia/hypoxia

Objective To investigate the role of S-adenosylmethionine （SAMe） during acute ischemidhypoxia of hepatic cancer cell and its mechanism by analysis of autophagy. Methods The mRNA expression of Beclin 1 was measured by real time PCR. Quantitative analysis of autophagy was performed by fluorescent microscope on acridine orange staining. The cellular viability was detected by the CCK-8 method. The apoptosis was detected by Annexin V/PI flow cytometry. Results SAMe induced autophagy in hepatoma cell line HepG2. The cellular viability under ischemia and ischemia/hypoxia respectively increased about 20% and 30%. The level of autophagy in fluorescence intensity and mRNA of Beclin 1 expression increased about 3.2 and 3.5 times. SAMe significantly inhibited the proliferation of HepG2, especially in the environment of ischemia/hypoxia. The cellular viability under SAMe treatment only and SAMe-treatment followed by ischemia/hypoxia decreased about 30% and 70%, respectively. The cellular apoptosis increased about 18% and 30% compared to the blank control. Conclusions SAMe inhibits the proliferation of HepG2, in which autophagy may play an important role.