Tumor promoting effects of exosomal microRNA-210 derived from lung cancer cells on lung cancer through the RUNX3/PI3K/AKT signaling pathway axis

Abstract

Exosomes are involved in a range of processes in lung cancer such as cell proliferation, metastasis, and angiogenesis. Tumor-derived exosomes participate in the formation and progression of lung cancer by delivering functional biomolecules, including microRNAs (miRNA). The purpose of the present study was to determine the role of lung cancer cell-derived exosomal miR-210 in the proliferation and invasion of lung cancer cells and its underlying mechanism. Initially, exosomes were isolated from A549 cells and characterized by transmission electron microscopy and assessment of exosomal marker expression. RT-qPCR determined that miR-210 expression was elevated in exosomes as well as lung cancer cells. As reflected by dual-luciferase reporter assay, miR-210 negatively regulated RUNX3 expression. Following loss- and gain- function assay, it was found that miR-210 inhibition suppressed biological properties of A549 and H460 cells, which could be reversed by the silencing of RUNX3. miR-210 elevation induced the p-PI3K/PI3K and p-AKT/AKT levels, suggesting the activation of PI3K/AKT signaling pathway. Collectively, exosomal miR-210 targeted and negatively regulated RUNX3 expression to promote malignant properties of lung cancer cells by potentiating PI3K/AKT signaling pathway.