Abstract: Objective To study the effect of human insulin on cell cycle progression and apoptosis in rat liver cell line BRL-3A in vitro. Methods MTT method was used to observe the effect of insulin on cell activity, and flow cytometry was used to detect cell apoptosis and cell cycle. Then qRT-PCR was used to evaluate the expression of related genes. Results Human insulin induced the proliferation of BRL-3A cells in a dose-dependent manner (P<0.05或P<0.01); After 3 days treated by human insulin (500 nmol/L), the proportion of cells in G0/G1 phases remarkably decreased (P<0.05). Moreover, pro-apoptotic BAX was down-regulated (P<0.05), while cell proliferation-related gene CCNA2 was up-regulated (P<0.05). Conclusions Human insulin could inhibit the apoptosis of BRL-3A cell line and induce its proliferation due to the down-regulated expression of BAX and up-regulated expression of CCNA2.

Key words: Key Words: human insulin, BRL-3A cells, apoptosis, cell cycle