The effect of calycosin for PC-3 apoptosis and PI3K/Akt signaling pathway

Objectives To explore the effect and mechanism of calycosin promoting PC-3 cells apoptosis. Methods MTT assay was applied to evaluate the effect of calycosininhibitting the PC-3 cells proliferation rate after treated with different final concentrations: 0, 25, 50, 100, 200μmol/L, solvent control (DMSO) for 48h. Flow cytometric analysis was used to evaluate the apoptosis of PC-3 cells treated with 0, 25, 50, 100, 200μmol/L calycosin for 48 h. The expression levels of Akt, p-Akt, Bax, Bcl-2 and Caspase-3 protein in 0μmol/L group, 200μmol/L calycosin group, 200μmol/L calycosin + PI3K specific inhibitor(Wortmannin) group were detected by Western Blot. Results MTT assay showed that calycosinwas able to inhibit the PC-3 cells proliferation in a dose-dependent manner (P<0.05); Flow cytometry experiments displayed the apoptosis rate of PC-3 cells after treated with 0, 25, 50, 100, 200μmol/L calycosin for 48h were (0.1±0.04)%, (6.8±0.6)%, (9.2±0.2)%, (11.5±0.27)%, (59.2±0.36)% (P<0.05). Western blot experiment showed that the expression level of p-Akt and Bcl-2 in the 200 μmol/L calycosin group decreased compared with the 0μmol/L group (P<0.05), when adding Wortmanninin in the 200μmol/L calycosin group, this result was strengthened again. Compared with the 0μmol/L group, the expression level of Bax and Caspase-3 in the 200 μmol/L calycosin group increased (P<0.05), when adding Wortmanninin in the 200μmol/L calycosin group, this result was strengthened again. Conclusions Calycosin is able to inhibit the PC-3 cells proliferation and induce its apoptosis. The relative mechanisms are down-regulating of the PI3K/Akt signaling pathway and activation of the mitochondrion pathway of apoptosis. Key words: Prostatic Neoplasms; Isoflavones; Apoptosis