Involvement of transcription factor activator protein-2α in doxazosin-induced HeLa cell apoptosis

Aim: To investigate the pro-apoptotic effects of alpha-1-adrenergic inhibitor doxazosin in HeLa cells and the potential involvement of transcription factor activator protein-2 alpha (AP-2 alpha) in doxazosin-induced apoptosis. Methods: The HeLa cells were exposed to various concentrations of doxazosin for 16 h. Apoptosis was detected using a DNA fragmentation assay, Hoechst 33258 staining, and flow cytometric analysis. The expression of AP-2 alpha and caspase-3 was detected by relative quantitative RT-PCR and Western blot assays, respectively. After the respective transfections of the HeLa cells with AP-2 alpha overexpressing constructs and an antisense oligonucleotide against AP-2 alpha, apoptosis was assessed by flow cytometric analysis, and the expression of AP-2 alpha and caspase-3 was detected by relative quantitative RT-PCR and Western blot assays. The colorimetric assay was performed to detect the caspase-3 activity. Results: Treatment with various concentrations of doxazosin for 16 h increased the apoptotic rate and total cell death rate of the HeLa cells in a dose-dependent manner and upregulated the expression of AP-2 alpha and caspase-3 in a dose-dependent manner. A dose-dependent increase was observed in the caspase-3 activity. Overexpressing AP-2 alpha led to the increased rate of doxazosin-induced apoptosis and the total cell death, whereas doxazosin-induced apoptosis and the total cell death in HeLa cells decreased by antisense AP-2 alpha. Furthermore, overexpressing AP-2 alpha increased the expression and activity of caspase-3, whereas antisense AP-2 alpha in part abolished the increased effects of doxazosin on caspase-3 expression and activity. Conclusion: Doxazosin induces apoptosis in HeLa cells in a dose-dependent manner, and transcription factor AP-2 alpha is functionally involved in doxazosin-induced HeLa cell apoptosis.