Figure 4.

In response to IR, ZEB1 KO delays resolution of γH2AX foci and increases the average number of cells with high levels of RAD51 foci. (A) Top: IF staining time course of appearance, post-1Gy, and resolution of γH2AX foci, in either wt, or ZEB1-depleted (via CRISPR KO) 293T cells; Bottom, left: quantitation of staining results (200 cells from each condition were scored in a blinded fashion). Bottom right: WB shows virtual absence of ZEB1 protein in the KO line. (B) wt or ZEB1 KO U2OS cells were subjected to either Mock (Control) or 2 Gy, and, 2 h later stained for RAD51 (see Materials and Methods); below, at least 200 cells from each condition were scored (blinded) for presence of RAD51 foci and resulting percentages categorized as shown. Data shown in all panels is a representative example of three independent experiments. Asterisks indicate statistically significant differences by Student's t test, Error bars are S.E.M.; ns, not significant: P > 0.05; *P ≤ 0.05, **P ≤ 0.01,***P ≤ 0.005.