Fig. 6.
A single dose of radiation causes mammary hyperplasia in stromal PTEN-null mammary tissue and this effect that is abrogated by EGFR inhibition. a Donor (Ptenfl/fl or Fsp-cre;Ptenfl/fl) mice were treated daily with DMSO or erlotinib for 7 days. On day 6, the mice were irradiated (6 Gy whole-body). On day 7, after their final dose with erlotinib, the mammary glands were transplanted into wild-type FVB/N recipients. The mammary glands were harvested ~10 months post-radiation and evaluated histologically. b Quantification of hyperplasia at 10 months post-transplant in Ptenfl/fl or Fsp-cre;Ptenfl/fl mammary tissue that came from a donor mouse that was un-manipulated (no drug and no IR) or that was pre-treated (± erlotinib) and irradiated as shown in (a) (Ptenfl/fl: No IR n = 4, DMSO n = 9, Erlotinib n = 9; Fsp-cre;Ptenfl/fl: No IR n = 4, DMSO n = 9, erlotinib n = 8). P values determined by two-tailed Mann–Whitney. c PTEN and Ki67 immunohistochemistry and associated H&E in Fsp-cre;Ptenfl/fl mammary tissue in mice pre-treated with DMSO or erlotinib, irradiated (6 Gy whole-body), transplanted and evaluated 10 months post-radiation. Tissue pre-treated with DMSO displays lobuloalveolar hyperplasia with atypia. Scale bar = 20 μm