Effect and mechanism of NS-398 on proIiferation and apoptosis of human coIorectaI carcinoma HCT-8 ceIIs

ZHANG Xiaoxian; SUN Jianjing; LIU Hua; LUO Qiang; ZHANG Linxi

doi:10.3969/j.issn.1002-266X.2016.25.003

Abstract：Objective To observe the effects of cyclooxygenase-2 (Cox-2)selective inhibitor NS-398 on proliferation and apoptosis of colorectal carcinoma HCT-8 cells and to investigate its mechanism.Methods HCT-8 cells in the logarith-mic phase were added with 0,10,20,40,80 and 160 μmol/L NS-398 to intervene.The inhibition rate of colorectal carci-noma HCT-8 cells was detected by CCK-8 kit,apoptosis rate was determined by flow cytometry and the cells were stained by Hoechst 33342 and observed under fluorescent inverted microscope further.After HCT-8 cells were treated by 0,40,80 and 160 μmol/L NS-398 for 24 hours,the protein expression of Cox-2 and Survivin were detected by immunocytochemical staining.ELISA analysis were performed to detect PGE2 concentration in the culture supernatant of HCT-8,and mean-while,the activities of Caspase-3 /7 were analyzed by automatic fluorescence enzyme-linked immunoassay detector.Results NS-398 inhibited the proliferation of HCT-8 cells in a time-and concentration-dependent manner,and there were signifi-cantly differences among the 40,80 and 160 μmol/L NS-398 concentration groups (all P <0.05).Flow cytometry re-vealed,the apoptosis rates were 12%,17% and 26% after treated by 40,80 and 160 μmol/L NS-398 for 24 hours,which was in a dose-dependent manner.Hoechst 33342 staining revealed,the apoptosis increased and cell nucleus showed high-density fluorescence with the increase of NS-398 concentration.The expression of Cox-2 and Survivin decreased significant-ly after treated by 40,80 and 160 μmol/L NS-398 for 24 hours,and the level of PGE2 production also significantly de-creased as compared with the group of 0 μmol/L NS-398.Meanwhile,the activity of Caspase-3 /7 was activated by NS-398 in a dose-dependent manner.Conclusion Cox-2 selective inhibitor NS-398 can inhibit proliferation and induce apoptosis of the colorectal carcinoma HCT-8 cells by down-regulating the expression of Cox-2 and Survivin,PGE2 production and up-regulating the activity of Caspase-3 /7.