JMJD6 regulates lipid metabolism in MCF7 cells. A) Immunohistochemistry staining for ANXA1 (brown) combined with Oil red-O staining (pink) for lipid droplets visualization in wild-type MCF7 cells B) Gene set enrichment plot for 'Hallmark of Adipogenesis' found to be significantly downregulated in JMJD6 KO MCF7 cells compared to scramble control. C) List of 'Reactome Pathways' found to be regulated by the genes included in the gene set enrichment pathway of 'Hallmark of Adipogenesis' and present in the DEGs list of JMJD6 KO versus scramble MCF7 cells.
ARTICLE ABSTRACTBreast cancer is the most common type of cancer in women worldwide, with the luminal subtype being the most widespread. Although characterized by better prognosis compared with other subtypes, luminal breast cancer is still considered a threatening disease due to therapy resistance, which occurs via both cell- and non–cell-autonomous mechanisms. Jumonji domain-containing 6, arginine demethylase and lysine hydroxylase (JMJD6) is endowed with a negative prognostic value in luminal breast cancer and, via its epigenetic activity, it is known to regulate many intrinsic cancer cell pathways. So far, the effect of JMJD6 in molding the surrounding microenvironment has not been explored.Here, we describe a novel function of JMJD6 showing that its genetic inhibition in breast cancer cells suppresses lipid droplet formation and ANXA1 expression, via estrogen receptor alpha and PPARα modulation. Reduction of intracellular ANXA1 results in decreased release in the tumor microenvironment (TME), ultimately preventing M2-type macrophage polarization and tumor aggressiveness.
Our findings identify JMJD6 as a determinant of breast cancer aggressiveness and provide the rationale for the development of inhibitory molecules to reduce disease progression also through the remodeling of TME composition.