A-to-I edited miR-411-5p targets MET and promotes TKI response in NSCLC-resistant cells

Non-small cell lung cancer (NSCLC) patients carrying an epidermal growth factor receptor (EGFR) mutation have an initial favorable clinical response to the tyrosine kinase inhibitors (TKIs). Unfortunately, rapid resistance occurs mainly because of genetic alterations, including amplification of the hepatocyte growth factor receptor (MET) and its abnormal activity. The RNA post-transcriptional modifications that contribute to aberrant expression of MET in cancer are largely under-investigated and among them is the adenosine-to-inosine (A-to-I) RNA editing of microRNAs. A reduction of A-to-I editing in position 5 of miR-411-5p has been identified in several cancers, including NSCLC. In this study, thanks to cancer-associated gene expression analysis, we assessed the effect of the edited miR-411-5p on NSCLC cell lines. We found that edited miR-411-5p directly targets MET and negatively affects the itogen-activated protein kinases (MAPKs) pathway. Considering the predominant role of the MAPKs pathway on TKI resistance, we generated NSCLC EGFR mutated cell lines resistant to TKI inhibitors and evaluated the effect of edited miR-411-5p overexpression. We found that the edited miR-411-5p reduces proliferation and induces apoptosis, promoting EGFR TKI response in NSCLC-resistant cells\ H1299 and H520 were transfected with ed.miR-411-5p and Scr as control, and, after 48h hours, cells were collected and RNA isolated.