Fig. 1
Characterization of human mammary epithelial cells. a Schematic representation of steps for the derivation of two human mammary epithelial cell types, breast primary epithelial cells (BPECs) and human mammary epithelial cells (HMECs). b Images of BPECs and HMECs showing: I BPECs that have been grown in WIT medium and on tissue culture plates with a modified attachment surface (Primaria); II HMEC that have been grown in mammary epithelial growth medium-basal (MEpiCM) and on regular culture plates; III and IV detection of luminal-specific Claudin-4 (green) and myoepithelial specific CD-10 (red) proteins in BPECs and HMECs by immunofluorescence. c Paraffin section of a breast sample after immunofluorescent detection of Claudin-4 (green) and CD-10 (red). d Western blot for detection of Claudin-4, p16INK4a, basal p53 and human telomerase reverse transcriptase (hTERT) in BPECs at an early, a mid and a late population doubling (PD) and in HMECs at pre-stasis and post-stasis; glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as loading control. e Sorting of BPEC and HMEC cultures for CD-227 and CD-10. f Immunofluorescent detection of keratins 14 (K14) and 19 (K19) on BPEC and HMEC cultures. In the BPEC cultures, we found cells positive for K14 and positive for K19 (i and ii). But in the HMEC culture (iii), we only observed K14-positive cells. g mRNA levels of K19 in 12BPECs, 14BPECs and HMECs, as obtained by qRT-PCR. h Western blot for detection of basal p53 and the s15 phosphorylated form of p53 in irradiated and non-irradiated BPECs. DAPI 4',6-diamidino-2-phenylindole