Figure 1.

MMEC model. (A) Western blot analysis of E1A, p53DD, β-catenin, E-cadherin, CK8/18, Ep-CAM, ERα, β-casein, and actin in independently derived wild-type iMMEC cell lines (WTA-D) in regular growth medium. (B) Western blot analysis of β-casein and actin in iBMKs, immortalized mouse prostate epithelial cells (iMPECs), and iMMECs (WTA) in regular growth medium. (C) Phase contrast. (D) IF of WTA cells for tight junction proteins. (E) IF of WTA cells for luminal (CK8) and basal/myoepithelial (CK14, CK5, SMA) markers. (F) Lactogenic stimulation of WTA cells. (Top panel) Phase contrast. (Middle panel) β-casein IF counterstain. (Bottom panel) DAPI counterstain. (G) Red oil O staining. (H) Confocal cross-section through the center of WTA acinus grown for 12 d in regular 3D morphogenesis medium, stimulated for 2 d with lactogenic hormones, and immunostained with β-casein (red) and β-catenin (green). Domes formed upon lactogenic stimulation of WTA cells are encircled by a yellow line in F and G.