Figure 1. Pro-apoptotic effects of doxazosin in human glioblastoma cells.

(A–D) Fluorescence microphotographs corresponding to terminal deoxyribonucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays. Increased green nuclear fluorescence reflects DNA degradation and apoptosis of LNT-229 glioblastoma cells treated with doxazosin for 24 h, compared to solvent controls. (E, F) Microscopic findings after treatment of LNT-229 cells with vehicle (E) or 30 µM doxazosin (F) further illustrate doxazosin-associated cell death. Scale bars, 100 µm. (G) Concentration-response relationship obtained from 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT) cell viability assays reveals an EC₅₀ value of 35.3 µM in LNT-229 cells. (H) Time course of doxazosin-associated apoptosis. Cell death was determined using the XTT-based assay (n = 3 to 6 assays). Data are represented as mean ± SEM.