[Bortezomib enhances the sensitivity of prostate cancer cells to natural killer cell-mediated cytotoxicity].

ABSTRACT

OBJECTIVE: To investigate whether bortezomib can enhance the sensitivity of human prostate cancer (PCa) cells to natural killer (NK) cell-mediated cytotoxicity, and whether it produces the same effect on different PCa cell lines. METHODS: We treated androgen-dependent PCa LNCaP cells and androgen-independent PCa DU145 cells with bortezomib at the concentrations of 0, 5, 10, 15, 20 and 25 nmol/L for 24, 48 and 72 hours, and then detected the proliferation and apoptosis of the tumor cells by CCK-8 and Annexin V/PI, respectively. RESULTS: The proliferation rates of the DU145 cells treated with 15, 20 and 25 nmol/L bortezomib were (82.79 +/-2.04)%, (73.59+/- 2.95)% and (74.16+/- 6. 16)% at 48 hours and (71.24+/- 5.30)%, (51.20+/- 2.91)% and (38.02+/- 2.67)% at 72 hours, and those of the LNCaP cells were (77.04+/- 7.74)% , (42.61 +/- 6.62)% and (23.85 +/-6.04)% at 48 hours and (36.45 +/-7.02)%, (14.94 +/-5.76)% and (11.65 +/-5. 87)% at 72 hours, both significantly inhibited as compared with the control group (P <0.05). At 24 hours, the apoptosis rates of the DU145 cells treated with 15, 20 and 25 nmol/L bortezomib were (14.41 +/- 1.32)% , (16.13 +/- 1.55)% and (14.48 +/- 1.42)% , and those of the LNCaP cells treated with 20 and 25 nmol/L bortezomib were (12.77 +/- 1.28)% and (14. 84 +/- 1.65)% , significantly higher than those of the control group (P <0.05) , and the DU145 cells showed an even higher sensitivity to bortezomib than the LNCaP cells. Bortezomib failed to sensitize these two cell lines to NK cell-mediated cytotoxicity in short-term assay, while long-term assay manifested that the apoptosis rates of DU145 and LNCaP cells after treated with 20 nmol/L bortezomib + NK cells were (41.83 +/- 5.06)% and (30.31 +/- 3.62)% , respectively, significantly higher CONCLUSION: Bortezomib enhances the sensitivity of than those after treated with either bortezomib or NK cells alone (P <0.05). PCa cells to NK cell-mediated cytotoxicity and adds to the effect of current cancer therapies, and it is more efficacious for androgen-independent prostate cancer.