Anti-tumor activity of curcumin against androgen-independent prostate cancer cells via inhibition of NF-κB and AP-1 pathway in vitro.

The anti-tumor activity of curcumin against androgen-independent prostate cancer cells in vitro and the possible mechanism were investigated. After curcumin treatment, the effect of curcumin on the proliferation of prostate cancer PC-3 cells was assessed by CFSE staining. Flow cytometery (FCM) was performed to analyze the cell cycle and the induction of apoptosis of tumor cells. A luciferase reporter gene assay was used to determine the effects of curcumin on the activities of intracellular NF-κB and AP-1 signaling pathways. The results showed curcumin could effectively inhibit the proliferation of PC-3 cells in vitro (P<0.05). Cells were arrested at G(2)/M phase. After curcumin treatment, the percentage of apoptotic cells was significantly higher than in control group (P<0.05). The results of the luciferase assay revealed that curcumin selectively inhibited the activities of the NF-κB and AP-1 signaling pathways in PC-3 cells significantly. It was suggested that curcumin could exert anti-tumor activity against androgen-independent prostate cancer cells in vitro by inhibiting cellular proliferation and inducing apoptosis, which was probably contributed to the inhibition of transcription factors NF-κB and AP-1.