Effect of sorafenib induced apoptosis and autophagy on drug resistance in HeLa cells

Abstract

Objective To explore the effect of sorafenib on HeLa cell proliferation by inducing cell apoptosis and autophagy and its impact on drug resistance. Methods The drug-resistant cell strains were constructed through intermittent induction method, with concentrations of 0, 2.5, 5.0, 7.5, 10.0, 15.0, 20.0 μmol/L. HeLa cells were incubated with increasing concentrations of sorafenib with each concentration for 1 week. The drug-resistant cell strains with stable passages were collected. MTT assay was used to detect the effect of sorafenib on cell proliferation. Cell cycle distribution was analyzed by flow cytometry. The change in the expression of drug-resistant and apoptotic genes in the parents and drug-resistant cell strains under different drug concentrations was examined by semi-quantitative PCR. The changes of apoptotic related marker proteins LC3-Ⅰ and LC3-Ⅱ were detected by Westernblot. Results Stable drug-resistant strains were successfully obtained; Drug-treated cells were more blocked in the G1 phase. In drug-resistant cells, the expression of apoptosis suppressor gene Bcl-2 was significantly decreased and the apoptotic gene Bax as well as the drug-resistant genes were all significantly increased(P＜0.05). The LC3-Ⅱ/LC3-Ⅰ ratio of drug-resistant cells was significantly higher than that of parent cells(P＜0.05). Conclusions Sorafenib may block the cell cycle, suppress malignant cell proliferation and promote autophage. On one hand, autophagy participates in the development of cell drug resistance and promotes cell survival. On the other hand, drug-induced autophagy may activate some of apoptotic signaling pathway in drug-resistant cells and promote the reversal of cell drug resistance.

Keywords

• sorafenib|cervical cancer|cell drug resistance|apoptosis|autophagy|cell cycle