Identification of exosomal miR-484 role in reprogramming mitochondrial metabolism in pancreatic cancer through Wnt/MAPK axis control

Abstract

The microRNAs (miRNAs) are potent regulators of tumorigenesis in various cancers, especially pancreatic cancer. The abnormal expression of miRNAs can be observed in tumor cells. Noteworthy, miRNAs could be transferred by exosomes as small extracellular vesicles in regulation of carcinogenesis. This research focused on exploring the roles and mechanisms of exosomal miR-484, derived from human bone marrow mesenchymal stem cells (hBMSCs), in the context of molecular interactions and regulation of mitochondrial metabolism. Exosomes were isolated for the examination of miR-484 expression. The impacts of hBMSCs-derived exosomal miR-484 on pancreatic cancer cells were studied using various assays. Evaluation of mitochondrial function and metabolism was performed. Wnt/MAPK pathway-related protein expression was assessed, and an in vivo tumor xenograft model was utilized to examine the functions. Our findings demonstrated a decreased miR-484 expression in pancreatic cancer cells. However, hBMSCs-derived exosomal miR-484 inhibited the proliferation and migration of these cells, while inducing apoptosis. Moreover, miR-484 led to an upsurge in reactive oxygen species production, a decrease in ATP levels, and a disruption in mitochondrial metabolism. In vivo analyses showed that hBMSCs-derived exosomal miR-484 lessened tumor size and weight, while also suppressing the expression of mitochondrial biomarkers. Further, there was a decline in β-catenin and p-p38 protein levels both in vitro and in vivo. The addition of LiCl restored the disrupted mitochondrial metabolism. Conclusively, our results suggest that hBMSCs-derived exosomal miR-484 mitigates the malignant transformation and mitochondrial metabolism of pancreatic cancer by deactivating the Wnt/MAPK pathway.

Keywords: Exosomes; Mesenchymal stem cells; MiR-484; Mitochondria; Pancreatic cancer.