RESUMO
The inhibitory effects of two kinds of selective cyclooxygenase-2 inhibitors on the proliferation of human carcinoma of larynx Hep-2 in vitro and their corresponding mechanisms were investigated. Hep-2 cells were cultured with two kinds of selective cyclooxygenase-2 inhibitors (Sc58125 and Celecoxib) at various concentrations for 24 h. Morphological changes were observed under the phase microscopy and the growth suppression was detected by using MTT colorimetric assay. Apoptotic DNA fragments were observed by agarose gel electrophoresis, and the cell cycle andapoptotic rate were detected by flow cytometry (FCM) respectively. Hep-2 cells became roundedand detached from the culture dish after being treated with Celecoxib for 24 h, however, they remained morphologically unchanged with Sc-58125. Sc-58125 could increase G2 phase cells, whereas, Celecoxib rose G1 phase cells. Both of the two effects were dose-dependent. Moreover, the Hep-2 cells cultured with 50μmol/L and 100 μmol/L Celecoxib showed obvious apoptosis, with the nuclear DNA of cells exhibiting characteristic DNA ladder. So Sc-58125 could inhibit the proliferation of Hep-2 cells by altering the G2 phase cells. However, Celecoxib had the same effect by changing the G1 phase cells and inducing apoptosis at higher concentration.
RESUMO
AIM: To clarify the effect of SC58125 on cell proliferation and apoptosis in HepG-2 cells and explore the molecular mechanisms. METHODS: Cell culture, MTT, TUNEL, DNA ladder, flow cytometry and Western blot analysis were employed in the present study. RESULTS: SC58125 inhibited the growth of HepG-2 cells and induced the apoptosis. Furthermore, it arrested G_0/G_1 phase and inhibited S phase in HepG-2 cells. Depressed expression of P33 cdk2 ,P34 cdc2 ,cyclin B_1,cyclin E ,Mpm-2,Rb ,PCNA proteins were found in HepG-2 cells treated with SC58125. CONCLUSION: SC58125 inhibits cell proliferation and induces apoptosis, which may be related to the altered low protein levels of P33 cdk2 ,P34 cdc2 ,cyclin B_1,cyclin E ,Mpm-2,Rb,PCNA