Autophagic apoptosis induced by paclitaxel in cervical cancer HeLa cells

Objective To observe autophagic apoptosis induced by paclitaxel in cervical cancer HeLa cells in vitro,and to explore its potential molecular mechanism.Methods Cervical cancer HeLa cells in vitro were treated with paclitaxel at different concentrations(1.2,6,12,24,36 mg/L) and different time(6,12,24,48,72 hours).The paclitaxel-induced cytoxity on cervical cancer HeLa cells was observed with the methyl thiazolyl tetrazolium(MTT) assay.Inverted microscope and electron microscopy were used to observe cell morphological changes.The apoptosis ratio and cell cycle were determined by flow cytometry.The expression of autophagy gene Beclin 1 was examined by reverse transcriptase polymerase chain reaction(RT-PCR) technique.Results Paclitaxel inhibited the proliferation of cervical cancer HeLa cells in a dose-dependent and time-dependent manner.Analysis indicated that after treatment with 12 mg/L of paclitaxel for 24 hours,HeLa cells showed typical morphology of autophagy by inverted microscope and electron microscopy.Using flow cytometry,it was observed that the number of apoptotic cells were greatly increased,and G2/M phase was blocked.Moreover,detected by RT-PCR,expression of autophagy gene Beclin 1 was enhanced in cervical cancer cells.Conclusions Paclitaxel can inhibit proliferation and induce autophagic apoptosis in cervical cancer HeLa cells.The autophagic apoptosis induced by paclitaxel is related to upregulation of the expression of autophagy gene Beclin 1.