Fig. 4

The aberrant expression of basal/EMT-like genes in luminal progenitors of Brca1/p53-deficient mice is reduced by Itga6 deletion. A Hematoxylin and Eosin staining of juxta-tumoral mammary gland sections from Brca1p53-KO and α6KO/Brca1p53-KO mice (bearing a tumor in another gland) and a control littermate. Scale bar: 100 µm. B Immunofluorescent staining with anti-K8 (white), and anti-Ki67 (red) antibodies. Nuclear DAPI staining is shown in blue. Scale bar: 20 µm. The graph shows the percentage of Ki67 + cells (mean ± SEM) obtained from 4 controls, 6 Brca1p53-KO and 6 α6KO/Brca1p53-KO mice. C, D Representative FACS analysis of juxta-tumoral glands from Brca1p53-KO and α6KO/Brca1p53-KO mice. C separation of basal (green) and luminal (orange) populations. Right: graph showing the percentage of basal and luminal cells in the Lin- population in 5 independent cell sorting experiments. D Analysis of ICAM1 expression gated in the luminal cells. Right: graph showing the percentage of luminal ICAM1⁺ and ICAM1- cells relative to the total luminal population in five independent cell sorting experiments. E RT-qPCR analysis of the ICAM1 + LP from Brca1p53-KO and α6KO/Brca1p53-KO juxta-tumoral glands and control glands (5 animals per group) The graphs present mean ± SEM. F Immunofluorescent staining with anti-K8 (green), and anti-K14 (red) antibodies of control normal gland and normal-looking ducts (upper panels), or of mammary hyperplasic lesions (lower panels) developed in Brca1p53-KO and α6KO/Brca1p53-KO mice. In normal ducts, dashed rectangles indicate magnifications shown in the right panels. Note the presence of numerous cells co-expressing K8 and K14, indicated by white arrowheads in normal ducts, or marked in yellow in lesions (lower panels). Nuclear DAPI staining is shown in blue. Scale bar: 20 µm (12 µm in magnifications). G Western blot analysis of ICAM1 + LP isolated from Brca1p53-KO and α6KO/Brca1p53-KO juxta-tumoral glands. Control cells are shown for comparison. In B–E, *P < 0.05, **P < 0.01, ***P < 0.001, n.s., non-significant