Fig. 2: Integrin β6-positive myoepithelial cells upregulate fibronectin expression.

a Representative images of integrin β6 by immunohistochemical staining in human DCIS tissue samples classified as low and high expression of integrin β6. Scale bar, 100 μm. b Bar graph showing the percent integrin β6-positive (β6⁺) myoepithelial (myo) cells (β4⁺EpCAM^-) in human DCIS samples (n = 4) (error bars, +s.e.m). c Bar graphs showing qRT-PCR analysis for FN1 using RNA isolated from DCIS myoepithelial cells with integrin β6-low (n = 2) and β6-high (n = 2) expression (error bars, +s.e.m). 3 technical replicates; ****P < 0.0001 (two-tailed t-test). d Immunoblots of integrin β6 and fibronectin (FN) in primary normal myoepithelial cells; 1989 and 1492, transfected with an empty vector (N-) or integrin β6 expression construct (β6-). HSC70 serves as loading control. Images are representative of three experiments. e Bar graphs showing qRT-PCR analysis for FN1 using RNA isolated from primary normal myoepithelial cells, generated as in (d) (error bars, +s.e.m). n = 3 biological replicates, 3 technical replicates; 1989 ***P = 0.0003 and ***P = 0.0009 (two-tailed t-test). f Immunoblots of integrin β6 and fibronectin in myoepithelial cell lines; N-1089 and β6-1089. HSC70 serves as loading control. Images are representative of three experiments. g Bar graphs showing qRT-PCR analysis for FN1 using RNA isolated from myoepithelial cell lines as in (f). n = 3 biological replicates, 3 technical replicates; ****P < 0.0001 (two-tailed t-test). h Representative images of integrin β6 (green) and fibronectin (FN, magenta) by immunofluorescent staining in myoepithelial cell lines as in (f). Nuclei were counterstained with DAPI (blue). Scale bar, 20 μm. Images are representative of three experiments.