Epithelial-to-mesenchymal transition lowers the cholesterol pathway, which influences colon tumors differentiation

ABSTRACT Colorectal cancer (CRC) is the second cause of death worldwide. Up to 70% of CRC patients will metastasize. Identify new biomarkers of progression to prevent/delay disease evolution is urgent. Epithelial-to-mesenchymal transition (EMT) is a major program engaged during metastasis. We aim at identifying a combination of new genes that further identify signs of EMT in cancer tissues. We treated HT-29 cells grown in 3D with an EMT Inducing cocktail, and collect them before during and after treatment. For each condition, pan-transcriptomic analyses were done. Genes that were both induced upon EMT induction and inhibited upon EMT release (mesenchymal-to-epithelial transition or MET) were selected. We identified new genes for EMT-MET programs. These genes were used to build a metagene that, when applied to a database of transcriptomic data from primary colorectal tumors (n= 2,239), had an independent prognosis value. Finally, we submitted this metagene to CMap and identified drugs that might affect EMT-MET programs. Statins, well-known inhibitors of cholesterol synthesis, were among them and effectively delayed MET. These data show that cholesterol and EMT pathways are opposite regulators and impact differently tumor differentiation and outcome. TRANSLATIONAL RELEVANCE Metastases are the main cause of death of colorectal cancer (CRC) and the major issue in CRC management. Understanding the chain of events that lead to metastasis occurrence is urgent to identify new biomarkers of progression and/or new potential targets. Epithelial to mesenchymal transition (EMT) is a major player in cancer dissemination that remains non-targetable due to its broad involvement in tissue homeostasis. Here, we used a relevant in vitro dynamic model to identify the pathways triggered during EMT in CRC and how this might improve tumors classification, prognosis and open therapeutic avenue for this deadly disease. The cholesterol pathway surprisingly popped-out from this model and turned out to be a good prognosis factor of disease-free survival for CRC. Altogether, our results showed that an active EMT program lowers the cholesterol pathway, which further influence the differentiation of colon tumor toward the most aggressive subtypes.