MiR-30a-5p hampers proliferation of lung squamous cell carcinoma through targeting FBXO45.

Objective: Studies have elaborated the inhibition of miR-30a-5p on the proliferation of cancer cells. However, the regulatory mechanism of how miR-30a-5p works in lung squamous cell carcinoma (LUSC) cells is obscure.

Methods: Data of miRNAs/mRNAs in LUSC tissue (The Cancer Genome Atlas (TCGA)) were accessed. A differential upstream miRNA (miR-30a-5p) was obtained by differential analysis. Downstream target mRNAs were predicted and screened by several databases. The function pathways of target protein in cells were determined by gene set enrichment analysis (GSEA). Abnormal expression levels of FBXO45 and miR-30a-5p were evaluated in three LUSC cell lines. The expression levels of FBXO45 mRNA and miR-30a-5p were analyzed by qRT-PCR. Western blot method was employed to assess protein levels of FBXO45, Cyclin E1, Cdk4 and Cyclin D1. How the two researched genes interact was testified by dual-luciferase method. Cell proliferative ability was compared by CCK-8 and colony formation methods. Moreover, cell cycle was tested by flow cytometry.

Results: MiR-30a-5p was tested to be noticeably down-regulated in LUSC cell lines. Up-regulated FBXO45 in LUSC was targeted by miR-30a-5p. Overexpressing miR-30a-5p modulated proliferation and cell cycle in LUSC via inhibiting FBXO45.

Conclusion: MiR-30a-5p hindered FBXO45 expression to repress the proliferation of LUSC. FBXO45/miR-30a-5p may shed light on future molecular treatment of LUSC.