MicroRNA-331 Inhibits Proliferation and Invasion of Melanoma Cells by Targeting Astrocyte-Elevated Gene-1.

Melanoma is characterized by aggressive invasion, early metastasis, and resistance to existing chemotherapeutic agents. Accumulated studies have reported that microRNA (miRNA) is a potentially robust molecular tool for developing future therapeutic technologies. Therefore, examining the expression patterns, biological roles, and associated mechanisms of cancer-related miRNAs in melanoma is essential for developing novel therapeutic targets for patients with this disease. In this study, miRNA-331 (miR-331) was underexpressed in melanoma tissues and cell lines. Functional assays revealed that the enforced expression of miR-331 inhibited cell proliferation and invasion. In addition, astrocyte-elevated gene-1 (AEG-1) was identified as a novel target of miR-331 through bioinformatics analysis, reverse transcription quantitative polymerase chain reaction analysis, Western blot analysis, dual-luciferase reporter assay, and Spearman's correlation analysis. Furthermore, reintroduction of AEG-1 partially abrogated the inhibitory effects of miR-331 overexpression on the proliferation and invasion of melanoma cells. Moreover, miR-331 suppressed the activation of the PTEN/AKT signaling pathway in melanoma by inhibiting AEG-1. In short, miR-331 may play tumor-suppressive roles in melanoma by directly targeting AEG-1 and regulating the PTEN/AKT signaling pathway, suggesting that miR-331 could be investigated as a therapeutic strategy for patients with this malignancy.