Fig. 4: ZEB1 induces ATM expression by stimulating transcription of the ATM gene

a MDA-MB-231 cells were co-transfected with the ZEB1 expression plasmid and different wild-type ATM promoter luciferase reporter constructs. Extract luciferase activities were determined 36 h after transfection using a Betascope analyzer. Luciferase values were normalized to Renilla activities. **P < 0.01 vs respective control in Student’s t test. b Overexpression of ZEB1 significantly enhanced its recruitment to the endogenous ATM promoter as confirmed by a quantitative ChIP assay. *P < 0.05 vs respective control in Student’s t test. c The interactions among ZEB1, p300 and PCAF protein were analyzed by co-immunoprecipitation in ZEB1/231 cells. Cropped blots are shown (full-sized blots are presented in Supplementary Fig. S11). d Overexpression of ZEB1 significantly enhanced the recruitment of p300 and PCAF to the endogenous ATM promoter as confirmed by a quantitative ChIP assay. **P < 0.01, ***P < 0.001 vs respective control in Student’s t test. e, f MDA-MB-231 cells were transiently transfected with the ZEB1 expression plasmid or vector control. At the indicated time points, expression of ZEB1 and ATM were verified by (e) quantitative PCR and (f) immunoblotting and normalized to the levels of β-actin. Cropped blots are shown (full-sized blots are presented in Supplementary Fig. S12). **P < 0.01, ***P < 0.001 vs respective control in one-way ANOVA followed by Tukey’s honestly significant difference test. g, h The non-negative percentage analysis for ATM indicates a positive correlation with ZEB1 expression in primary breast cancer. i, j The non-negative percentage analysis for p-ATM indicates a positive correlation with ZEB1 expression in primary breast cancer. k Representative images of immunohistochemical staining of ZEB1, ATM, and p-ATM in tumors from three cases are shown. Scale bars, 50 μm