Skip to main content
. 2015 Sep 30;5:14723. doi: 10.1038/srep14723

Figure 6. MGMT repression facilitates DNA damage in ERp29-transfected MDA-MB-231 cells and MCF-7 cells.

Figure 6

(a) Reduction of MGMT in ERp29-overexpressed cells increased irradiation-induced expression of γ–H2AX. Note that irradiation induces significant increase of γ–H2AX in the mock-transfected MDA-MB-231 cells (column 2 vs. 1). Depletion of MGMT alone in the ERp29-overexpressed clone B cells only slightly increased the expression of H2AX (column 5 vs. 1). However, combination treatment (column 4) of irradiation/MGMT siRNA in these cells led to a significant induction of γ–H2AX relative to the cells treated with MGMT siRNA (column 5) or with the irradiation/control siRNA (column 3). The level of γ–H2AX was examined after 12 hours of post-irradiation. (b) Irradiation treatment significantly increased the expression of γ–H2AX in MGMT-knockdown MCF-7 cells. MCF-7 cells were transfected with MGMT siRNA or control siRNA for 48 hours and then irradiated with 4 Gy. The expression of γ–H2AX was assayed after 12 hours of post-irradiation. (c) MGMT depletion induced high expression of γ–H2AX and reduced double strand DNA breaks repair after irradiation. MB-231/ERp29 (clone B) cells were treated with MGMT siRNA or control siRNA for 48 hours, irradiated with 4 Gy and incubated for 2, 6, 12 and 24 hours. Phosphorylation of H2AX was examined by Western blot. **p < 0.01, ***p < 0.001, relative to control at the indicated doses/time.