ABSTRACT
Aim To explore the effect of survivin in PC12 cells against injuries induced by cobalt chloride(CoCl_2).Methods PC12 cells were exposed to CoCl_2 at different doses in different time to set up the chemical hypoxia induced PC12 cells injuries model.Cell viability was tested by using cell counter kit-8.Dose-effect(200～1 000 μmol·L~(-1))and time-effect(0～48 h)relationship between hypoxia induced by CoCl_2 and the expression of survivin was evaluated by western blot.Results PC12 cells viability was inhibited significantly by CoCl_2 in a dose and time dependent manners;At the concentrations from 200 to 600 μmol·L~(-1) CoCl_2 for 24 h,survivin expression was upregulated in a dose dependent manner,peaking at 600 μmol·L~(-1) CoCl_2 treatment,exceeding this concentration of CoCl_2,with dose increasing,survivin expression decreased.At the dose of CoCl_2 up to 1 000 μmol·L~(-1),survivin did not express basically;Treatment with 600 μmol·L~(-1) CoCl_2 in different time,within the range of 0～36 h,the expression of survivin enhanced in time dependent manner.But with the extension of time,survivin expression was declining; 17-allylamino-17-demethoxygeldanamycin (2 μmol·L~(-1)),an inhibitor of Hsp90,not only decreased survivin overexpression but also obviously enhanced the injuries of PC12 cells induced by CoCl_2,which didn't damage PC12 cells alone.Conclusion Upregulation of survivin expression may be one of the endogenous defense mechanisms for PC12 cells against chemical hypoxia.
ABSTRACT
Objective:To study the anti-proliferation effects of a heat shock protein 90(Hsp90) inhibitor,17-allylamino-17-demethoxygeldanamycin(17-AAG),on a human breast cancer cell line,SKBr3,and related mechanism.Methods:MTT assay was used to detect the growth inhibition of SKBr3 cells.Cell cycle and apoptosis were analyzed by flow cytometry.Alteration of human epidermal growth factor receptor 2(HER2) in SKBr3 cells being treated with 17-AAG were measured by immunohistochemistry.Results:17-AAG significantly inhibited growth of SKBr3 cells in vitro in a dose-dependent manner with an IC_(50) value at 3.09 ?g/ml.Under concentrations of 0,0.625,1.250,2.500,5.000 and 10.000(?g/ml,)the percentages of cell apoptosis were(1.03?0.08)%,(3.68?0.67)%,(7.06?1.12)%,(11.23?1.36)%,(20.32?1.98)%,and(31.65?2.96)%;the percentages of cells at G_(0)/G_(l) phase were 58.61%,54.34%,49.55%,43.73%,35.52%,and 27.46%;the percentages of cells at S phase were 29.57%,25.21%,19.65%,22.98%,19.71%,and 15.46%;the percentages of cells at G_(2) /M phase were 11.82%,20.45%,30.18%,33.29%,44.77%,and 57.08%,respectively.The level of HER2 expression in SKBr3 cells being treated with 17-AAG,compared to that in control cells,was reduced significantly.Conclusion:17-AAG can inhibit the growth of human breast cancer cell and enhance its apoptosis.It may be a promising anti-tumor drug.