Reduced miR-3127-5p expression promotes NSCLC proliferation/invasion and contributes to dasatinib sensitivity via the c-Abl/Ras/ERK pathway

miR-3127-5p is a primate-specific miRNA which is down-regulated in recurrent NSCLC tissue vs. matched primary tumor tissue (N = 15) and in tumor tissue vs. normal lung tissue (N = 177). Reduced miR-3127-5p expression is associated with a higher Ki-67 proliferation index and unfavorable prognosis in NSCLC. Overexpression of miR-3127-5p significantly reduced NSCLC cells proliferation, migration and motility in vitro and in vivo. The oncogene ABL1 was a direct miR-3127-5p target and miR-3127-5p regulated the activation of the Abl/Ras/ERK pathway and transactivated downstream proliferation/metastasis-associated molecules. Overexpression of miR-3127-5p in A549 or H292 cells resulted in enhanced resistance to dasatinib, an Abl/src tyrosine kinase inhibitor. miR-3127-5p expression levels were correlated with dasatinib sensitivity in NSCLC cell lines without K-Ras G12 mutation. In conclusion, miR-3127-5p acts as a tumor suppressor gene and is a potential biomarker for dasatinib sensitivity in the non-mutated Ras subset of NSCLC.