Study On The Apoptosis Mechanisms Of Human Hepatoma Cell Line HepG2 Induced By Triacsin C, A Selective Inhibitor Of FACL4

Objective: On the basis of the effect of Triacsin C, a selective inhibitor of fatty acid-CoA ligase 4(FACL4), to induce apoptosis in human hepatoma cell line HepG2, to investigate and explore the mechanism of the apoptoticprocess further.Methods: Human hepatoma cells line HepG2 were cultured in vitro, after treated by various concentration of Triacsin C at different times ,then,Flow cytometry coupled with fluorescent dyes Rhodamine 123 were used to detect the changes of mitochiondrial transmembrane potential of HepG2; the expression of apoptosis-associated genes wp53,bcl-2,bax were detected with Streptavidin-peroxidase immunocytochemical dying methods; the activity of caspase-3,caspase-8 and caspase-9, three proteinases related to apoptosis ,were detected by colorimetry.Results: 1,Flow cytometry coupled with Rhodamine 123 dying showed that MTP of HepG2 treated with Triacsin C declined, which was dose- and time-dependent; 2,S-P immunocytochemical dying results revealed that in control groups the expression of Bcl-2 and p53 were high, the expression of bax was low relatively;after treated with Triacsin C, the expression of Bcl-2 and p53 reduced, the expression of bax increased ,The expression of p53 reduced more remarkably than Bcl-2, which were all dose-dependent. there were significant difference by statistical analysis compared with control groups. 3,The results detected by colorimetry suggested that during apoptosis induced by Triacsin C, three Caspase proteinases increased, which were dose- and time-dependent. Among them, Caspase-9 and Caspase-3 increased more remarkably than Caspase-8.there were significant difference by statistical analysis compared with control groups(P<0.01).Conclusions: 1,After treated by Triacsin C, mitochiondrial transmembrane potential of HepG2 declined remarkly,suggested that the main apoptosis mechanism is probably the pathway by mitochondrion,which to induce apoptosis by injury to mitochondrion or functional disorder of mitochondrion. 2,The apoptosis-associated proteins Bcl-2, Bax and p53 were probabaly significant regulation factors of apoptosis-induced by Triacsin C on HepG2. 3,At the process of apoptosis-induced by Triacsin C on HepG2, it's mainly by way of activation of Caspase-9 to start cascade reaction of caspase proteinases.