Abstract:

Objective To investigate the effects of 17-allylamino-17-demethoxygeldanamycin (17-AAG), heat shock protein 90(HSP90) inhibitor, on the growth and expression of vascular endothelial growth factor (VEGF) in pheochromocytoma cell line PC12 in rats. Methods PC12 cells in experiment group were divided into experiment group 1 and experiment group 2. PC12 cells in experiment 1 were treated with different concentrations (0.005 μmol/L, 0.025 μmol/L, 0.05 μmol/L, 0.1 μmol/L, 0.25 μmol/L, 0.5 μmol/L, 1.0 μmol/L and 2.0 μmol/L) of 17-AAG culture fluid respectively, and those in experiment group 2 were treated with 150 μg/L VEGF culture fluid (VEGF group), 0.1 μmol/L 17-AAG culture fluid (17-AAG group) and 0.1 μmol/L17-AAG+150 μg/L VEGF culture fluid (17AAG+VEGF group) respectively. Besides, DMSO group (negative control group) and blank control group were also established. Cell survival rate was measured by MTT assay, cell morphology was observed by Wrights-Giemsa staining, cell apoptosis was detected by flow cytometry, and expression of VEGF-165 protein in cells was determined by Western blotting. Results 17-AAG significantly inhibited the growth of PC12 cells in time- and dose-dependent manners (P<0.05), with 50% inhibitory concentration (IC50) of 0.1 μmol/L. The apoptosis rates of PC12 cells after treatment with 0.1 μmol/L 17-AAG for 6 h, 12 h, 24 h and 48 h were significantly higher than that in blank control group (P<0.01). The expression of VEGF-165 protein gradually decreased with treatment of PC12 cells with 0.1 μmol/L 17-AAG for 6 h, 12 h, 24 h and 48 h, and the expression of VEGF-165 protein at each time point was significantly different from that in negative control group (P<0.05). Conclusion 17-AAG, HSP90 inhibitor, can inhibit the proliferation of PC12 cells, induce cell apoptosis and inhibit the expression of VEGF protein.

Key words: PC12 cells, pheochromocytoma, heat shock protein 90, 17-allylamino-17-demethoxygeldanamycin, vascular endothelial growth factor, apoptosis