Cancer cell-derived exosomes promote NSCLC progression via the miR-199b-5p/HIF1AN axis

Background: Exosomes are mediators of intercellular communication. Cancer cell-secreted exosomes allow exosome donor cells to promote cancer growth, as well as metastasis. Methods: Here, exosomes were isolated from the serum of non-small cell lung cancer (NSCLC) patients and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot analysis. NSCLC cell proliferation and migration were assessed using CCK-8, 5-ethynyl-2 '-deoxyuridine (EdU) and Transwell assays. H1299 tumor formation and pulmonary metastasis were examined in a xenograft model in nude mice. Results: We found that exosomes derived from NSCLC (NSCLC-Exos) promoted NSCLC cell migration and proliferation, and that NSCLC-Exo-mediated malignant progression of NSCLC was mediated by miR-199b-5p. Inhibition of miR-199b-5p decreased the effects of NSCLC-Exos on NSCLC malignant progression. HIF1AN was identified as a downstream target of miR-199b-5p. Furthermore, overexpression of HIF1AN reversed the effects of miR-199b-5p on NSCLC malignant progression. Conclusion: In summary, our findings demonstrated that exosomal-specific miR-199b-5p promoted proliferation in distant or neighboring cells via the miR-199b-5p/HIF1AN axis, resulting in enhanced tumor growth.