Effect of compound Chinese traditional medicine PC-SPES Ⅱ in inhibiting proliferation of human prostate cancer cell LNCaP and on expressions of AR and PSA

Abstract

To investigate the effect of compound Chinese traditional medicine PC-SPES II I in inhibiting proliferation of human prostate cancer cell LNCaP based on the androgen receptor (AR) signaling pathway. The effect of PC-SPES II on LNCaP cell proliferation was detected by MTT assay. According to the findings, at the mass concentration of 180-1 440 mg x L(-1), PC-SPES II significantly inhibited the proliferation of LNCaP cells; the IC50 of PC-SPES II at 24 h and 48 h were 311.48, 199.01 mg x L(-1), respectively. The flow Cytometry detection showed 240 mg x L(-1) PC-SPES II arrested cells in G2/M phase, and an obvious apoptotic peak appeared before G0/G1 peak and rose over time. Meanwhile, Hoechst 33258 staining revealed apoptotic cellular morphology. Annexin V-FITC/PI staining manifested an increase in apoptotic cell ratio at the PC-SPES II concentration of 480 mg x L(-1) in a dose dependent manner. The prostate specific antigen (PSA) secretion of LNCaP cells was tested by PSA ELISA kit. Besides, compared with 25 mg x L(-1) Bic, 480 mg x L(-1) PC-SPES II significantly reduced the cell secretion of PSA. The AR and PSA mRNA and protein expressions were detected by qRT-PCR and Western blot. According to the results, after the induction of LNCaP cells with synthetic androgen 25 μg x L(-1) R1881, 240-480 mg x L(-1) PC-SPES II notably down-regulated the AR and PSA mRNA and protein expressions and inhibited the translocation of AR from cytoplasm to nucleus. In summary, PC-SPES II significantly can inhibit the in vitro proliferation of LNCaP cells and arrest cell cycle arrest in G2/M phase. Its mechanism may be associated with the down-regulation of the AR and PSA expressions and the inhibition of AR nuclear translocation.