NS398 induces apoptosis of COX-2 negatively expressed human prostate cancer cell line PC-3 in vitro

To determine whether the cyclooxygenase-2 (COS-2) selective inhibitor,｛N-[2-(cyclohexyloxy)-4-nitrophenyl]-methane sulfonamide｝ (NS398),can inhibit proliferation of COX-2 negatively expressed human prostate cancer cell line PC-3 and induce its apoptosis in vitro.Methods The expression of COX-2 in cultured PC-3 cells was examined by RT-PCR and Western blot for mRNA and protein respectively.The proliferative inhibition of PC-3 cells by NS398 was observed by methyl thiazolyl tetrazolium (MTT) rapid photocolorimetric assay.PC-3 cells cultured in 100 μmol/L NS398 medium for 24 h was marked with AnnexinV-FITC and PI for the cell apoptosis assay by flow cytometry.Results COX-2 was not expressed in PC-3 cell line at either mRNA or protein level.The inhibitory rate of NS398 on proliferation micreased with the increasing concentration but was not time-dependent.Compared with the controls (10.563±2.582)%,PC-3 cells cultured in 100 μmol/L NS398 medium for 24 h had significantly higher incidence (19.307±3.773)% Ⅰ of early apoptosis (P=0.01).Conclusion NS398 can inhibit proliferation of COX-2 negatively expressed human prostate cancer cell line PC-3 and induce its apoptosis in vitro,which suggests its COX-2 independent pathway.10 refs,2 tabs.