Fig. 1: Myoepithelial expression of integrin β6 and periductal fibronectin deposition correlates with human DCIS progression.

a GSEA of transcriptional profiles from GEO series GSE21422 showing upregulated extracellular matrix (ECM) remodelling and integrin interaction gene set terms associated DCIS (n = 9) compared to normal breast (n = 5). b Scatter plot of p-value (-log10) vs. log fold change (logFC) for gene expression from the GO_extracellular_matrix_constituent gene set for microarray data for IDC (n = 5) compared to DCIS (n = 9). c Cartoon depicting a normal duct, a DCIS duct without (pure DCIS) and with co-existent invasion (DCIS/IDC). d Haematoxylin and eosin (H&E) staining of human breast tissue samples featuring adjacent normal ducts, DCIS and DCIS/IDC. Scale bar, 100 μm. e–g Representative images of smooth-muscle actin (SMA) (e), integrin β6 (f) and fibronectin (g) by immunohistochemical staining in human breast tissue samples featuring adjacent normal ducts, DCIS and DCIS/IDC. h, i Bar graphs showing the mean and individual percentage of ducts positive for integrin β6 (h) or fibronectin (i) in adjacent normal (n = 40), DCIS (n = 20) and DCIS/IDC (n = 20) patient samples (error bars, +s.e.m). ****P < 0.0001 (h, ordinary one-way ANOVA and i, Kruskal–Wallis one-way ANOVA). See Supplementary Table 1 for patient information. j, Scatter plot depicting the linear regression of the percentage of positive DCIS ducts for integrin αvβ6 (β6) and fibronectin (FN) in serial human tissue sections as in (f,g) (n = 40). k, l, mRNA expression of ITGB6 and FN1 in normal breast tissues (n = 5), DCIS (n = 9) and IDC (n = 5) (error bars, +s.e.m). *P = 0.019 (k) and **P = 0.0023 (l) (ordinary one-way ANOVA).