Altered propionate metabolism contributes to tumor progression and aggressiveness

The alteration of metabolic pathways is a critical strategy for cancer cells to attain the traits necessary for metastasis in disease progression. We found that dysregulation of propionate metabolism occurs through TGFbeta- and ERK2-driven downregulation of methylmalonyl-CoA epimerase (MCEE). MCEE downregulation occurs through a transcription factor Sp1/EGR1 switch at its promoter region, resulting in reduced flux through this anapleurotic pathway and leading to accumulation of methylmalonic acid (MMA), a byproduct of the propionate metabolism. MMA accumulation through alteration of propionate metabolism produces a pro-aggressive signature in breast and lung cancer cells and increases their metastatic potential. Altogether, we present a previously uncharacterized dysregulation of propionate metabolism as a novel contributor to cancer and a valuable potential target in the therapeutic treatment of metastatic carcinomas. Global analysis of RNA levels to determine transcriptional reprogramming in A549 cells with shMUT expression for 3 days, in triplicate