Fig. 1: SOX10 is expressed in basal and luminal progenitor cells of the human mammary gland.
From: Epigenome erosion and SOX10 drive neural crest phenotypic mimicry in triple-negative breast cancer
a Representative SOX10 IHC analysis of reduction mammoplasty (RM) samples. Some terminal ducto-lobular units (TDLUs) had exclusive basal compartment expression (i) while others had expression in both basal and luminal compartments (ii). b (i) Analysis of SOX10 expression in ducts vs lobules of RM samples from 19 donors (whole sections). (ii) SOX10 expression in lobules was heterogeneous and more likely to occur in the luminal compartment (Mann–Whitney p = 0.011; n = 102 ducts and 102 lobules; median ± 95% confidence interval shown). c Representative immunofluorescent staining of SOX10 and CK8/18. Circled lobules and isolated cells (arrows) exhibited reciprocal expression of SOX10 (green) and CK8/18 (red) in structures with either (i) dual compartment (ii) or basal-restricted SOX10 expression. d IHC analysis of SOX10, c-kit, ER and Ki67 in serial RM sections. The three magnified regions represent major SOX10 staining patterns: (i) dual compartment, heterogeneous; (ii) dual compartment, homogeneous; and (iii) basal-restricted. Luminal SOX10 expression was directly associated with c-kit and inversely associated with ER, with no obvious relationship to Ki67 (e.g., cell cluster indicated with an arrow). e SOX10 mRNA levels in FACS-sorted human mammary epithelial cell (hMEC) subtypes15. Differentiation markers were analysed for comparison: basal markers CK14 and CK5; luminal progenitor (LP) markers KIT and ELF5; and markers enriched in mature luminal (ML) cells: CK18 and ESR1 (isolates with significantly different marker levels according to paired ANOVA tests are indicated and colour-coded: ****p < 0.00001; ***p < 0.0001; **p < 0.001). Data shown were means ± standard error of the mean from three donors. f Average methylation beta-values of SOX10 probes in FACS-sorted hMEC samples (DNAme), aligned with histone modification signals in a published ChIP-seq dataset42: H3K4me3, H3K27ac (activating) and H3K27me3 (repressive). Data were represented to scale on human chromosome 22. TSS transcription start site, UTR untranslated region. Indistinct = negative for CD45 (hematopoietic cells), CD31 (endothelia), CD140b (fibroblasts), EpCAM and CD49f (epithelia).
