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

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).

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.

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.

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.