RAGE/SNAIL signaling drives Epithelial-Mesenchymal plasticity in metastatic Triple-Negative Breast Cancer

Epithelial-Mesenchymal plasticity plays a fundamental role both in embryogenesis and in tumor cell dissemination during tumor progression. The receptor for advanced glycation end products (RAGE) is a driver of cell plasticity in fibrotic diseases; however, its role and molecular mechanism in triple-negative breast cancer (TNBC) remains unclear. Here, we demonstrate that RAGE signaling maintains the mesenchymal phenotype of aggressive TNBC cells by enforcing the expression of SNAIL. We uncover a crosstalk mechanism between the TGF-ß and RAGE pathways that is required for the acquisition of mesenchymal traits in TNBC cells. Consistently, RAGE inhibition elicits epithelial features that block migration and invasion capacities. Since RAGE is a sensor of the tumor microenvironment (TME) and the highly glycolytic rate of tumors induces an acidic TME, we modeled acute acidosis in TNBC cells and showed it promotes enhanced production of RAGE ligands and the activation of RAGE-dependent invasive properties. Furthermore, acute acidosis increases SNAIL levels and tumor cell invasion in a RAGE-dependent manner. Finally, we demonstrate that in vivo inhibition of RAGE reduces metastasis incidence and expands survival, consistent with molecular effects that support the relevance of RAGE signaling in EMT plasticity. These results uncover new molecular insights on the regulation of EMT phenotypes in cancer metastasis and provide rationale for pharmacological intervention of this signaling axis. Overall design: Gene expression profiling analysis of RNA-seq data to identify genes over and under-expressed in MDA-MB-231 cells treated with/or without DMSO or Azeliragon (AZ). Three replicates of each condition were performed.