miR-138-5p suppresses M2 macrophage polarization in esophageal squamous cell carcinoma via exosomes.

Over 90% of esophageal cancer are defined as esophageal squamous cell carcinoma (ESCC) in China, while no specific and efficient strategies for ESCC therapy. In recent years, the regulatory role and effect of macrophages in cancer have received wide attention. In this study, high expression of RHOC and low expression of miR-138-5p was found in cancer tissues of ESCC, which was identified to enhance malignant phenotypes of ESCC cells. Notably, miR-138-5p was turned out to inhibit RHOC expression, and the decreased level of miR-138-5p in ESCC cells was figured out to promote M2 macrophage polarization mediated by exosomes via activating STAT3. Finally, exosomes derived from ESCC cells with low expression of miR-138-5p enhance malignant phenotypes of ESCC cells and tumor growth. Therefore, M2 macrophage polarization mediated by miR-138-5p-RHOC-STAT3 signal axis via exosomes promote ESCC progression. This study provides insights into pathogenesis of ESCC from the perspectives of cell-cell communications and M2 macrophage polarization, which may provide new targets for diagnosis and treatment of ESCC.