Fig. 2.

H₂O₂ induces cell cycle arrest and minor apoptosis in TE7 cells after treatment with 250 μM H₂O₂. (A) H₂O₂ induces S and G2 arrests 24 hrs after H₂O₂ treatment. Cell cycle profiles were determined by fluorescence-activated cell sorting (FACS) analysis, and the percentage of cells in the different cell cycle phases was calculated. The data are representative of three independent experiments. (B) H₂O₂ exposure induces an upregulation of p21^WAF1, downregulation of cyclin D1 and p-H3^Ser10 and activation of Chk1. Cells were cultured with H₂O₂ and grown for 0.25, 0.5, 1, 3, 6, 12 and 24 hrs. Lysates were immunoblotted and probed with anti-p21^WAF1, -cyclin D1, -H3, -p-H3^Ser10, -Chk1 and -p-Chk1^Ser317 antibodies. β-actin was used as a loading control. Fold expression changes are given below the blots. (C) H₂O₂ initiates apoptosis pathways. Cells were incubated with H₂O₂ and lysates were immunoblotted for Bax, Bcl-2, caspases 8, 9 and 3 after 0.25, 0.5, 1, 3, 6, 12 and 24 hrs. The ratio of Bax/Bcl-2 is shown. β-actin was used as a loading control. Fold expression changes are given below the blots.