Medulate Effect Of Dihydroartemisinin On HSP70 Expression In Human Prostate Cancer PC-3 Cells And Its Mechanism

Objective: To investigate the effect of dihydroartemisinin(DHA) on HSP70 expression in human prostate cancer PC-3 cells and its underlying molecular mechanisms.Methods:Part1, PC-3 cells were treated with different concentrations(25, 50, and 100 μmol/L) of DHA for 48 h, while PC-3 cells without DHA treatment was used as the control group. Then the apoptosis and cell cycle distribution were detected by flow cytometry. Expression levels of HSP70 m RNA were determined by RT-q PCR.HSP70, Apaf-1and Caspase-3 protein expressions were determined by western blot.Part2, PC-3 cells were treated with different concentrations(25, 50, and 100 μmol/L) of DHA for 48 h,while PC-3 cells without DHA treatment was used as the control group. Then DNA fragments were detected by DNAladder.The expressions and locations of HSP70 and AIF were detected by immunofluorescence staining method.Expressions of AIF and HSP70 protein were determined by western blot. Two more groups were added in RT-q PCR and western blot, the 100 μmol/L HSP70 inhibitor group and the DMSO group.Results: DHA can significantly inhibit the expressions of HSP70m RNA and protein(P<0.05),induce the apoptosis of PC-3 cells(P<0.05),while the expressions of Apaf-1, Caspase-3 and AIF proteins were increased(P<0.05).Conclusion: DHA can significantly inhibit the expressions of HSP70,abrogate the antiapoptotic function of HSP70, induce the apoptosis of PC-3cells. These mechanisms may be due to the activity suppression of caspase pathway and non-caspase pathway.