Fig. 5

ErbB4 loss compensates for ErbB3 loss in aMECs during pregnancy and lactation. a HC11 cells serum and EGF-starved for 48 h were treated with PRL for 24 h, in the presence of NRG1 (2 ng/ml), neratinib (250 nM), and/or BKM120 (500 nM) as indicated. Whole cell lysates assessed by western blot analysis for proteins indicated at the left. b HC11 cells harvested for analysis 72 h after transfection with three distinct siRNA sequences targeting ErbB3, or a scrambled siRNA sequence (siScr). Western blot analysis using antibodies listed at the left. Representative images are shown, repeated three times. c HC11-shErbB3 and HC11-shScr cells serum and EGF-starved for 24 h, followed by treatment ± PRL for 24 h. Whole cell RNA assessed by RT-qPCR for expression of Erbb4 and quantitated as described for Fig. 4b. d Samples stained using IHC for P-ErbB4 Tyr1056. Representative images are shown, and original magnification is 400×. N = 12. e, f HC11-shErbB3 and HC11-shScr cells transduced with Ad.ErbB4 or Ad.GFP. At 48 h after transduction, cells were serum and EGF-starved, and then treated with PRL for 24 h. e Cells assessed by western blot analysis using antibodies shown at the left. f Whole cell RNA assessed for expression of Stat5a and Csn2 and quantitated as described in Fig. 4b. g HC11-shErbB3 and HC11-shScr cells were transfected with control siRNA sequences (siCtrl) or siRNA sequences targeting ErbB4 (siErbB4). At 72 h after transfection, cells were serum and EGF-starved, then treated with PRL for 24 h. Cells assessed by western blot analysis using antibodies shown at the left. dpc days post coitus, Lact d lactation day, PRL prolactin