Exosomal Mirna Confers Chemo Resistance Via Targeting Cav1/p-gp/M2-Type Macrophage Axis in Ovarian Cancer

Abstract

Circulating miRNAs are known to play important roles in intercellular communication.However, the effects of exosomal miRNAs on cells are not fully understood. In this study, substantial expression of oncogenic miR-1246 in sensitive as well as chemoresistant (paclitaxel and multidrug) ovarian cancer (OC) exosomes was found. We showed that Cav1 gene, which is the direct target of miR-1246, is involved in the process of exosomal transfer. A significantly worse overall prognosis were found for OC patients with high miR-1246 and low Cav1 expression based on TCGA data. miR-1246 expression were significantly higher in paclitaxel-resistant OC exosomes than in their sensitive counterparts. Overexpression of Cav1 and anti-miR-1246 treatment significantly sensitized OC cells to paclitaxel. We showed that Cav1 and multi drug resistance (MDR) gene is involved in the process of exosomal transfer. Our proteomic approach also revealed that miR-1246 inhibits Cav1 and acts through PDGFI² receptor at the recipient cells to inhibit cell proliferation. miR-1246 inhibitor treatment in combination with chemotherapy led to reduced tumor burden in vivo. Finally, we demonstrated that when OC cells are co-cultured with macrophages, they are capable of transferring their oncogenic miR-1246 to M2-type macrophages, but not M0-type macrophages. Our results suggest that cancer exosomes may contribute to oncogenesis by manipulating neighboring infiltrating immune cells. This study provide a new mechanistic therapeutic approach to overcome chemosensitization and tumor progression through exosomal miR-1246 in OC patients. Funding: This study was funded by the NIH Common Fund (UH3 TR000943), through the Office of Strategic Coordination/Office of the NIH Director and MD Anderson’s Cancer Center Support Grant (CCSG) (CA016672) to G. Lopez-Berestein, A.K. Sood, G.A. Calin,, the American Cancer Society Research Professor Award to A.K. Sood, and The Center for RNA Interference and Non-Coding RNA to G.A. Calin, A.K. Sood, and G. Lopez-Berestein and CA166228 from the National Cancer Institute of the NIH to MLG. Declaration of Interest: We have no conflicts of interest to disclose. Ethical Approval: All animal work was approved by the Institutional Animal Use and Care Committee of MD Anderson.