Here, we identified microRNA-27b (miR-27b) as a key regulator for the generation of a side-population in breast cancer cells that showed CSC properties, and also found that the anti-type II diabetes (T2D) drug metformin reduced this side-population via miR-27b-mediated repression of ectonucleotide pyrophosphatase/phosphodiesterase family member 1 (ENPP1), which is involved in T2D development.
It was possible to identify a selective group of phosphatases upregulated only in the ER- ERBB2+ subgroup and not in ER+ (like DUSP6, DUSP10 and PPAPDC1A among others), suggesting a role of these phosphatases in specific BC subtypes, unlike other differentially expressed phosphatases (DUSP4 and ENPP1) that seemed to have a role in multiple BC subtypes.