Fig. 4

Assessment of breast epithelium composition in TNBC. a Fractional composition of breast-tissue samples was assessed using a well-validated algorithm [37], based on our custom-designed DNAme reference profiles for breast epithelial cell subtypes (Materials and Methods). b There was a highly significant increase in luminal progenitor cell concentration in TNBC (compared to normal surrounding tissue in the same volunteers, n = 14), whereas c the mature luminal cell proportion was unchanged and the d basal cell fraction decreased. e Comparing normal tissues in the same volunteers (n = 31) to ER+ve/PR+ve breast cancers, there was a decrease in luminal progenitors and f a highly significant increase in mature luminal cells and g no changes were noted in basal cells; gold lines indicate increasing and blue decreasing values from surround normal to the cancer tissue in individual breast cancer patients (b-g). h RANKL and i RANK expression (respectively) were significantly correlated with mature luminal and luminal progenitor cell proportion in 38 healthy breast tissue samples from TCGA; j the mean of the normalised RANKL and RANK expression levels was significantly correlated with the WID-Breast29 index in the same 38 samples. Significances in b–g were assessed with the paired-sample t-test, and those in h–j were assessed with Pearson’s correlation test. F, Fat cells; I, Immune cells; E, Epithelial cells; S, Stromal cells; LP, Luminal Progenitors; LM, Luminal Mature; B, Basal