Effects of bleomycin A5 on caspase-3, P53, bcl-2 expression and telomerase activity in vascular endothelial cells

OBJECTIVE: The aim of this study was to investigate the molecular mechanism of bleomycin A5 in inducing the apoptosis of human umbilical vein endothelial cells (ECV304). MATERIALS AND METHODS: ECV304 cells were cultured and passaged, and then were divided into control group and three treatment groups. The later three groups were treated with 15, 75, and 150 μg/ml bleomycin A5 for 24 hours, respectively. The expressions of caspase-3, p53, and bcl-2 in ECV304 cells were detected by flow cytometry, and the activity of telomerase was determined using telomere repeat amplification protocol (TRAP)-silver staining method. RESULTS: After treatment with different concentrations of bleomycin A5, the expression of caspase-3 in ECV304 cells was increased. It was significantly decreased with the increase of bleomycin A5 concentration, but the difference between 75 μg/ml and 150 μg/ml groups was not significant. Bleomycin A5 could significantly increase the expression of p53, with concentration dependence. It had no obvious effect on bcl-2 expression. There was high expression of telomerase in control group. After treatment with different concentration of bleomycin A5, the telomerase activity was significantly decreased. CONCLUSION: Bleomycin A5 can increase caspase-3 and p53 levels and inhibit telomerase activity to induce ECV304 apoptosis.