OBJECTIVETo determine the expression level changes of survivin, a inhibitor of apoptosis protein, followed by activation of insulin receptors in human hepatocellular carcinoma HepG2 cell line, and to investigate the signalling pathway involved in the regulation.

METHODSHuman hepatocellular carcinoma HepG2 cells were treated with insulin alone or pre-treated with LY294002, a specific inhibitor of PI3K signalling pathway, to determine whether blocking PI3K signaling can attenuate the up-regulation of survivin expression. Real time RT-PCR and Western blot analysis were used to measure survivin mRNA and protein changes before and after treatment, respectively.

RESULTSWithout serum supplement, HepG2 cells expressed a small amount of survivin. Insulin induced survivin expression in a dose- and time-dependent fashion. Survivin expression was blocked if cells were pre-treated with LY294002 prior to insulin stimulation.

CONCLUSIONInsulin induces survivin expression via PI3K signalling pathway, suggesting that to interfere the key gene in this signalling pathway may block survivin expression, therefore, promoting apoptosis in hepatocellular carcinoma cells.