The Effects Of MiR-30a On The Malignant Phenotype Of Lung Adencarcinoma Cells By Targeting EYA2

Lung cancer is the main cause of cancer mortality in China. Non-small-cell lung cancers (NSCLCs) are the main histological types of the lung cancer and account for nearly80%of the lung cancer. The overall five-year survival rate of NSCLC is still low at about15%. The pathogenesis of NSCLC remains unknown and more researches are needed to decipher the mechanism involved.MicroRNAs (miRNAs) are a class of conserved, non-coding small RNAs and act by fine-tuning gene expression through a post-transcriptional mechanism. Increasing evidences indicated that miR-30a act as an antioncogene to inhibit growth of various tumors. MiR-30a also showed the feature of an oncogene in some tumor cells. EYA2is a member of the EYA (eyes absent) family of proteins. Study had showed that EYA2promote proliferation, transformation, migration and invasion of breast cancer cells. However, the functions of miR-30a and EYA2in NSCLC are poorly understood.EYA2is a potential target of miR-30a predicted by TargetScan and miRanda. For further study, we evaluated the level of EYA2expression in three NSCLC cell lines by western blot and found EYA2is only up-regulated in A549cells; we evaluated the level of miR-30a expression in lung adenocarcinoma cells and tissues by qRT-PCR and found that miR-30a is significantly down-regulated in both A549cells and tissues samples from14patients; The direct regulation relationship between EYA2and miR-30a was also elucidated through dual-luciferase reporter assay and gain/lose of function assay. Results demonstrated that EYA2is a direct target of miR-30a in A549cells. In addition, we determined the functions of miR-30a and EYA2involve in migration, cell cycle process, proliferation, and invasion of A549cells by wound-healing assay, cell cycle analysis, cell proliferation assay and transwell invasion assay and found that overexpression of miR-30a in A549cells suppressed migration and invasion but not cell proliferation and cell cycle process, silencing of EYA2gene with specific siRNAs in A549cells inhibited migration, invasion, cell proliferation and cell cycle process. All these results indicated that miR-30a inhibited the expression of EYA2gene in lung adenocarcinoma A549cells and the regulatory relationship between miR-30a and EYA2 may be related to migration and invasion of A549cells but not cell proliferation and cell cycle.