Tetrandrine suppresses proliferation, induces apoptosis, and inhibits migration and invasion in human prostate cancer cells.

Tetrandrine (TET), a traditional Chinese medicine, exerts remarkable anticancer activity on various cancer cells. However, little is known about the effect of TET on human prostate cancer cells, and the mechanism of function of TET on prostate cancer has not yet been elucidated. To investigate the effects of TET on the suppression of proliferation, induction of apoptosis, and inhibition of migration and invasion in human prostate cancer cell lines, DU145 and PC-3. Inhibition of growth was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and clone formation assay, and flow cytometry analysis was performed to detect the induction of apoptosis. Activation of poly (ADP-ribose) polymerase, caspase-3, Akt, phospho-Akt, Bcl-2, and Bax was analyzed by Western blotting. Wound healing assay and transwell migration assay were used to evaluate the effect of TET on migration and invasion of cancer cells. TET inhibited the growth of DU145 and PC-3 cells in a dose- and time-dependent manner. Cell cloning was inhibited in the presence of TET in DU145 and PC-3 cells. TET suppressed the migration of DU145 and PC-3 cells. Transwell invasion assay showed that TET significantly weakened invasion capacity of DU145 and PC-3 cells. TET exhibited strong inhibitory effect on proliferation, migration, and invasion of prostate cancer cells. In addition, TET induced apoptosis in a dose-dependent manner by activating the caspase cascade and inhibiting phosphoinositide 3-kinase-Akt signal pathway. The accumulating evidence suggests that TET could be a potential therapeutic candidate against prostate cancer in a clinical setting.

Silibinin inhibits prostate cancer invasion, motility and migration by suppressing vimentin and MMP-2 expression.

AIM: Silibinin is known to exert growth inhibition and cell death together with cell cycle arrest and apoptosis in human prostate cancer cells. Whether silibinin could inhibit the invasion, motility and migration of prostate cancer cells remains largely unknown. This study was designed to evaluate this efficacy and possible mechanisms using a novel highly bone metastatic ARCaP(M) cell model. METHODS: Four prostate cancer cell lines, LNCaP, PC-3, DU145, and ARCaP(M), were used in this study. These cells were treated with increasing concentrations of silibinin (50, 100, and 200 micromol/L) for different periods of time. After treatment, cell viabilities of four prostate cancer cells were compared by MTT assay. Alterations of ARCaP(M) cell invasion, motility and migration were assessed by cell invasion, motility and wound healing assays. The changes of vimentin expression were observed by Western blotting and immunofluorescence staining, and the expression of MMP-2, MMP-9, and uPA was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: ARCaP(M) cells showed less sensitivity to the growth inhibition of pharmacological doses of silibinin than LNCaP, PC-3, and DU145 cells. However, silibinin exerted significant dose- and time-dependent inhibitory effects on the invasion, motility and migration of ARCaP(M) cells. Furthermore, the expression of vimentin and MMP-2, but not MMP-9 or uPA, was down-regulated in a dose- and time-dependent manner after treatment of silibinin. CONCLUSION: This study shows that silibinin could inhibit the invasion, motility and migration of ARCaP(M) cells via down-regulation of vimentin and MMP-2 and therefore may be a promising agent against prostate cancer bone metastasis.