Effect of berberine on radiosensitivity of cervical cancer cells

Objective To investigate the effect of berberine on the radiosensitivity of cervical cancer cells. Methods 5, 10, 15, 20 μmol/L of berberine were used to treat cervical cancer cell lines of Siha, HeLa, Caski. DMSO was applied as control of drug treatment. Cell proliferation was detected by the CCK-8 method, and then the half inhibitory concentration of berberine was calculated. Cell apoptosis and cell cycle distribution were detected by flow cytometry. Protein expressions of Cleaved Caspase-3, Cyclin B1, CDK1, STAT3 and p-STAT3 were detected by Western blot. Cervical cancer cells of Siha were treated by berberine with a half inhibitory concentration for 24 h and then irradiated with 0, 2, 4, 6, 8 Gy of X-rays. Cell clone assay was used to detect cell survival. Results Berberine could inhibit the growth of cervical cancer cells with a half inhibition concentration of(16.84±3.52), (23.54±8.67), (21.86±6.35)μmol/L for Siha, Caski, and HeLa cells, respectively. The berberine at 17 μmol/L could induce apoptosis(t=56.847, P<0.01)and G2/M phase arrest(t=47.251, P<0.01)in Siha cells, which also inhibited the expressions of Cyclin B1, CDK1 and p-STAT3 and promoted the expression of cleaved Caspase-3, but did not influence the expression of STAT3 in cervical cancer cells. Treatment of cells with 17 μmol/L berberine increased the radiosensitivity of cervical cancer cells with a sensitivity enhancement ratio of 1.55. Conclusions Berberine can inhibit cell proliferation, promote apoptosis, block cell cycle, and increase radiosensitivity of cervical cancer cells. Key words: Cervical cancer; Berberine; Radiosensitivity; Signaling pathway; Cell apoptosis