Fig. 4

Depletion of Gata3 or Brca1 promotes estrogen-induced DNA damage in mammary tumorigenesis. a, b Representative IHC analysis of regenerated p18^−/−;Gata3^+/−, p18^−/−;Brca1^+/−, and p18^−/− mammary tumors treated with or without E2. Typical γH2AX-positive tumor cells are indicated. c The H-scores for γH2AX in a and b were calculated. The results represent the mean ± SD of four individual tumors per group. The asterisk (*) denotes a statistical significance from E2 and placebo-treated samples determined by the T-test. The asterisk (**) denotes a statistical significance from E2-treated p18^−/− and p18^−/−;Gata3^+/− or p18^−/−;Brca1^+/− samples determined by the T-test. Note since p18^−/− tumor cells did not generate tumors when transplanted without exogenous E2, we calculated γH2AX H scores from primary tumors as an alternative control for placebo-treated p18^−/− tumors (indicated by #)