关键词: 肝癌, 积雪草酸, SMMC-7721细胞, 增殖, 自噬, mTOR, p53

Abstract: Objective To investigate the effects of asiatic acid（AA） on cell proliferation and autophagy of human hepatoma SMMC-7721 cells. Methods The human hepatoma SMMC-7721 cells were exposed to different concentrations of AA alone or combined with autophagy inhibitor 3-MA for 24 h，after that，the cell viability was examined by MTT method，the formation of autophagic vacuoles were detected by MDC staining，the expression of the autophagy-related proteins including LC3-Ⅰ，LC3-Ⅱ，p62，mTOR，p-mTOR，and p53 were detected by Western-blot. Results  MTT assay results showed that different concentrations of AA could inhibit the proliferation of human hepatocarcinoma SMMC-7721 cells in a concentration-dependent manner（F＝46.790，P＝0.006） with IC₅₀= 37.313 μmon/L.When combined with autophagy inhibitor 3-MA，the cell proliferation inhibition rate （%） of AA to SMMC-7721 cells was significantly reduced compared with the group treated with 40 μmol/L AA alone［（22.000±3.391）% vs （46.400±9.099） %，P<0.001）］. AA increased the amount of autophagic vacuoles detected by MDC staining. Compared with the control group，40 μmol/L AA significantly down-regulated the protein expression level of LC3-I while up-regulated the protein expression of LC3-Ⅱ（1.744±0.108 vs 1.529±0.065，t=2.928，P=0.043；0.113±0.031  vs 0.380±0.036，t=-9.754，P<0.001），but down-regulated the p62 protein expression（0.522±0.024 vs 0.123±0.019，t=22.565，P<0.001）.　Besides，AA significantly reduced the protein expression level of p-mTOR（1.252±0.039 vs 0.353±0.028，t=30.775，P<0.001），but had no influence on the protein expression of mTOR and p53（1.713±0.111 vs 1.556±0.076，t=1.555，P=0.190；0.671±0.040 vs 0.726±0.055，t=-1.555，P=0.210）. Conclusions AA can inhibit the proliferation of human hepatoma SMMC-7721 cells，which may be related to the AA-inducted autophagy via the suppression of mTOR signaling pathway in a p53-indepandent manner.

Key words: Hepatic carcinoma, Asiatic acid, SMMC-7721 cells, Proliferation, Autophagy, mTOR, p53