Additional file 2: of Estrogen promotes estrogen receptor negative BRCA1-deficient tumor initiation and progression

Figure S2. p18-/-;Brca1MGKO and p16-/-;Brca1MGKO tumor cells generate reproducible ER-negative Brca1-deficient mammary tumors. (A) A primary mammary tumor (donor tumor A) developed in a 15-month-old p16-/-;Brca1MGKO mouse was analyzed by FACS. As a control, tumor-free mammary glands from age-matched p16-/- mice were analyzed. Note a predominant CD24?+?CD29high population in the tumor. (B, C) We transplanted 6?×?104 FACS-sorted Lin- cells from a p16-/-;Brca1MGKO tumor (donor tumor B) into MFPs of four NSG mice. Representative tumors generated were analyzed by IHC (B) and western blot (C). (D, E) Representative p18-/- and p18-/-;Brca1MGKO tumor cells were cultured and analyzed. MCF7 cells were used as a positive control of ERa expression. (F, G) We transplanted 1?×?106 cultured p18-/-;Brca1MGKO tumor (donor tumor A) cells into MFPs of four NSG mice. Representative tumors generated were analyzed by IHC (F) and western blot (G). p18-/- tumors were used as control in (C) and (G).