Fig. 3. MGMT downregulation is required for cell cycle-dependent DNA damage induced by TMZ–POH.

A549 and SPC-A1 cells were treated with 0, 50, 100 μM TMZ–POH for 48 h with or without O⁶-BG pretreatment, respectively; H520 cells was infected by Ad-MGMT or control for 24 h followed by 100 μM TMZ–POH treatment for 48 h. a,b The cell cycle distributions of A549, SPC-A1, and H520 cells treated with above drugs were analyzed. c,d Western blot analysis demonstrated p-ATM, p-ChK1, p-ChK2, and ACTB expression in above drug-treated A549 and H520 cells