Effects of hydroxycamptothecine and pingyangmycin alone or in combination on the proliferation and telomerase activity of human tongue carcinoma cells / 实用口腔医学杂志

ABSTRACT

Objective:To study the effects of hydroxycamptothecine(HC PT ) and pingyangmycin(PYM) alone or in combination(HCPT/PYM) on the proliferation and telomerase activity of human tongue carcinoma Tca 8113 cells.Methods:The growth inhibitary effects of HCPT or PYM on Tca 8113 cells were stu died by MTT assay and the IC 30 values of the two drugs were obtained. Then the cells were exposed to HCPT or PYM at IC 30 , or to their combination. T he clonogenecity, cell cycle distribution, morphological change and telomerase a ctivity were studied by clonogenic assay, flow cytometry,transmision electron mi croscopy and telomeric repeat amplification protocol (TRAP) respectively.Results:IC 30 (ng/ml) of HCPT and PYM was 109 and 416 respectivel y, when in combination(HCPT/PYM) the IC 30 of HCPT and PYM was 35 and 100 r espectively. The clonogenecity(%) of the control, HCPT,PYM and HCPT/PYM treated cells was 31.7,11.6,15.2 and 4.1 respectively. PYM decreased S and G 2 phase ce lls,increased G 1 phase cells.HCPT or HCPT/PYM decreased G 1 phase cells and i ncreased S and G 2 phase cells.Drug treatment resulted in cell organ degenerati on and decrese of telomerase activity.The A value at A 450 of telomerase in control,HCPT,PYM and HCPT/PYM treated cells was 1.89?0.03,0.82?0.02,0.77?0.0 2 and 0.53?0.02 respectively(P