Exosomatic miR-1246 Promotes Hepatocellular Carcinoma Progression via FSTL5 and ERK/p38 MAPK Pathway.

Background: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Unfortunately, the effective targeted therapies for HCC are lacking at present. While the regulation of microRNA-1246 (miR-1246) has been identified in HCC, its specific mechanism in exosomes derived from HCC remains elusive. This study aimed to explore the regulation of tumor-derived exosome miR-1246 in HCC cell invasion, migration, proliferation, and epithelial-mesenchymal transition (EMT).

Methods: Exosomes secreted by HepG2 cells were characterized via Western blotting, nanoparticle tracking analysis, and transmission electron microscopy, followed by transfection with a miR-1246 inhibitor. RT-qPCR was employed for measuring the miR-1246 levels. Also, the impacts of the exosome miR-1246 inhibitor on HepG2 cell migration, invasion, proliferation, and EMT were evaluated.

Results: The findings revealed elevated miR-1246 levels in HCC tissues relative to adjacent non-cancerous tissues, with a greater enrichment of miR-1246 in HepG2-derived exosomes than in HepG2 cells. HCC cell invasion, migration, proliferation, and EMT were significantly enhanced by HCC-derived exosomes, while exosomes loaded with miR-1246 inhibitor inhibited these biological functions. Further mechanistic studies illustrated an association of the regulatory role of miR-1246 with FSTL5 and ERK/p38 MAPK signaling.

Conclusion: In conclusion, tumor-derived miR-1246 enters hepatocellular carcinoma cells in the form of exosomes and promotes cancer cell invasion, EMT, and migration. The potential mechanism of miR-1246 is potentially relevant to the targeted gene FSTL5 as well as the ERK/p38 signaling.