Fig. 5.

ATF2 knockdown combined with H₂O₂ induces a switch from cell cycle arrest to enhanced apoptosis in TE7 cells. Cells were transfected with ATF2 siRNA and transfection reagent (TFR) for 7 hrs prior to H₂O₂ treatment (250 μM). (A) H₂O₂ treatment combined with ATF2 knockdown reduces the G2/M arrest. After transfection and treatment, cells were grown for 24 hrs, and cell cycle analysis was performed. Differentially gated cell populations were counted; their percentage in the total cell populations was calculated and presented in the diagram. The data are representative of three independent experiments. (B) Combined treatment of H₂O₂ and ATF2 siRNA transfection reinforces apoptosis induction. Apoptotic, necrotic and live cell populations were measured after 24 hrs using Annexin-V and PI staining. Mean values are shown ± SD. (C) ATF2 knockdown induced elevated caspase 3 cleavage in H₂O₂-treated cells. The lysates were immunoblotted for caspase 3 after 12 and 24 hrs. β-actin was used as loading control. Fold expression changes are given below the blots.