Fig. 5.

Effects of Hx and Reox on A431 cell proliferation and cell cycle arrest. A, cells were subjected to the indicated conditions, and proliferation was subsequently analyzed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell proliferation was found to be suppressed by both Hx and Reox treatments but to a lesser extent in the latter case. B, induction of cell cycle arrest in G₀G₁ phase by Hx. Cells were treated with the fluorescent dye propidium iodide, and measurements of DNA content were performed via flow cytometry. The distribution of cells based on cell cycle stage is shown. Hx induced severe arrest in G₀G₁ phase that was released by Reox, evidenced by cells entering both S and G₂ phases. 48N, 48-h normoxia; 48H, 48-h hypoxia; 48H-24R, 48-h hypoxia followed by 24-h normoxia.