MicroRNA-9-5p Facilitates Lung Adenocarcinoma Cell Malignant Progression via Targeting STARD13.

We aimed to elucidate binding of microRNA-9-5p and STARD13 in lung adenocarcinoma (LUAD) cells and discuss their impact on malignant progression of LUAD, so as to provide evidence for identifying new therapeutic targets for LUAD. Bioinformatics analysis was introduced for analysis of differentially expressed miRNAs in LUAD tissue, and potential downstream target gene was predicted with TargetScan and other databases. MicroRNA-9-5p and STARD13 mRNA levels at cellular level was analyzed with qRT-PCR assay. Lipofectamine 2000 was applied for cell transfection. Proliferation, migration and invasion of LUAD cells were assayed with CCK-8, wound healing and Transwell assays, respectively. Protein expression of STARD13 was assessed with western blot. Binding of microRNA-9-5p and STARD13 was identified with dual-luciferase assay. Compared with normal human bronchial cells, microRNA-9-5p level in LUAD cells was noticeably increased, and STARD13 level was noticeably decreased. MicroRNA-9-5p could significantly promote malignant progression of LUAD cells, while forced STARD13 level markedly repress malignant progression of LUAD cells. Dual-luciferase gene assay showed that microRNA-9-5p had a direct targeting relationship with STARD13, and it was also found that microRNA-9-5p enhanced malignant behaviors of LUAD cells through modulating STARD13. STARD13 was a target of microRNA-9-5p in LUAD. MicroRNA-9-5p fostered malignant behaviors of LUAD cells by targeting STARD13. Therefore, microRNA-9-5p may become a new target for LUAD, and microRNA-9-5p inhibition may be a new treatment method.