Abstract: Objective To study the apoptosis mechanism of HeLa cells induced by berberine (BR). Methods HeLa cells were treated by different concentration of BR，with different times. CCK-8 assay was used to detect the Hela cells proliferation activity. Detecting the expression of STAT3 in control HeLa cells and BR treated Hela cells. HeLa cell cycles were detected by flow cytometry(FCM). The relative expressions of STAT3, CYCLIN B1, CDC2 and C-MYC were examined by real-time PCR. The relative expressions of STAT3, CYCLIN B1, CDC2 and C-MYC proteins were examined by Western blot analysis. Results BR can effectively inhibit the proliferation of HeLa cells in vitro, which exhibits a dose-dependent and time-dependent manner. The FCM showed that the the proportion of BR-treated cells in G2/M phase was higher than control group. Real–time PCR results showed that relative expressions of STAT3, CYCLIN B1, CDC 2and C-MYC genes in HeLa cells treated with BR were lower than the control group. Western blot results showed that relative expressions of STAT3, CYCLIN B1, CDC 2and C-MYC proteins in HeLa cells treated with BR were lower than the control group. Conclusions BR can induce apoptosis of cervical cancer by targeting STAT3.

Key words: Berberine, STAT3, cell cycle, apoptosis