Pancreatic cancer-derived exosomal miR-510 promotes macrophage M2 polarization and facilitates cancer cell aggressive phenotypes.

Abstract

Extensive tumor microenvironment (TME) and tumor-associated macrophages (TAMs) contribute to the initiation and progression of pancreatic cancer (PC). Cancer cell-derived exosomal miRNAs that stimulate macrophage M2 polarization might play an important role in the process. In the current study, we observed significant upregulation of miR-510 in PC cell lines in comparison to normal HPDE cell line, with PANC-1 exhibiting the highest and MIA PaCa-2 the lowest miR-510 levels. Functional assays demonstrated that miR-510 overexpression enhanced, while its inhibition reduced, PC cell viability, migration, invasion, and EMT. In vivo, miR-510 mimics promoted tumor growth and macrophage M2 polarization, whereas miR-510 inhibition had the opposite effect. Exosomes from PANC-1 and MIA PaCa-2 cells, characterized by nanoparticle tracking analysis and TEM, contained significantly higher miR-510 levels than those from HPDE cells. Macrophages incubated with conditioned media from these PC cells showed increased M2 polarization markers, a process inhibited by the exosome inhibitor GW4869. The delivery of miR-510 via PC cell-derived exosomes facilitated macrophage M2 polarization and regulated the STAT signaling pathway, suggesting that exosomal miR-510 plays a crucial role in the tumor microenvironment of PC by modulating macrophage M2 polarization.