Fig. 2

Stat activation and apoptosis during tumor progression in parous mice and the effect of MT Oas2. A The phosphorylation of the indicated Stat proteins is shown by specific phospho-Stat IHC and DAB staining, within the lesions defined in Fig. 1. QuPath was used to quantify overall mammary gland pStat nuclear positivity in MT and WT glands. Error bars are standard error of the mean, MT Stat1 data is not Gaussian (KS p = 0.03) and so the Mann–Whitney U test is used to calculate the p value. Stat3 and Stat5 p values were calculated using Student’s t test. B. Cleaved caspase 3 (CC3) IHC was used to quantify the proportion of apoptotic cells (CC3% + cells, left hand panel), and the proportion of pixels positive for CC3 staining (CC3% + pixels, right hand panel), in the indicated lesion subtypes abbreviated as HYP.; hyperplasia, MIN; mammary intraepithelial neoplasia, ENG.; engorged, CAR.; carcinoma. All comparisons within lesion subtypes for CC3 between MT and WT are nonsignificant using Student’s t test