Fig. 3

Metabolic differences between the epithelium enriched and the stroma enriched breast tissue. To determine if the metabolic differences we saw between normal mammary tissue and tumors are indeed due to cancer progression, rather than the difference in cell type heterogeneity, we compared the mammary gland metabolome of stroma enriched tissue (adipocyte rich) and epithelium enriched tissue during normal mammary gland development. a Overview of experimental design. Stroma enriched and epithelium enriched tissue were collected at 3 weeks, at the time when the mammary epithelium invades only a part of the mammary fat pad. b Of the 1365 different features detected, only 48 metabolites had significantly different levels. c Major pathway distribution of adipocyte enriched and epithelium enriched metabolites. d Cloud plot of all metabolites with significantly different levels in the two tissue groups. Each circle indicates one metabolite, with the color indicating the tissue detected in (green: epithelial cells, red: stroma). The size of the circles indicates the fold of change (compared to background noise), and the color of the circles indicate P values (darker color indicating lower P value). The most significantly changed metabolites (with the lowest P values) in both tissues were presented on the right side of the plot