MiR-320a inhibits malignant phenotype of melanoma cells via targeting PBX3.

Purpose: To study the expression of micro ribonucleic acid-320a (miR-320a) in melanoma cells and its influence on the biological functions of these cells.

Methods: MiR-320a expression data and clinical data in melanoma tissues were downloaded from The Cancer Genome Atlas (TCGA) database. Real time-quantitative polymerase chain reaction (RT-qPCR) was used to detect miR-320a expression in melanoma tissues, malignant melanoma cell lines (A375, SKMEL-28 and A2058) and human epidermal melanoma (HEM) cells. The miR-320a mimic was transfected into A375 cells, and the functions of cells were detected. The luciferase reporter gene assay was employed to verify the miR-320a downstream target protein predicted by the biological information prediction software.

Results: The differential analysis of miRNAs in melanoma tissues from TCGA database showed that miR-320a expression in melanoma tissues was significantly lower than that in adjacent tissues, and low expression of miR-320a exhibited a severe poor prognosis (p<0.01). MiR-320a mimic could significantly enhance the expression level of miR-320a (p<0.01). The absorbance at 490 nm of A375 cells overexpressing miR-320a decreased remarkably and their proliferation ability was weakened (p<0.01). Overexpression of miR-320a in A375 cells inhibited cell migration to wound parts and epithelial-mesenchymal transition (EMT), invading malignant phenotype (p<0.05). Flow cytometry was employed and it was denoted that after transfecting with miR-320a, the apoptosis rate of A375 cells was elevated overtly (p<0.01). The dual luciferase report test indicated that the luciferase activity in wild type pre-B-cell leukemia transcription factor 3 (PBX3) was markedly lower than that of mutant type PBX 3 (p<0.05).

Conclusions: Targeted binding of miR-320a to PBX3 protein can inhibit the malignant phenotype of cells and affects the occurrence and development of melanoma.