RESUMO
Objective To explore the inhibitory effects of miR-15 b-5 p on choroid melanoma cell line proliferation by targeting CDK4.Methods Dual-luciferase assay was used to verify the direct binding site between miR-15 b-5 p and CDK4 3'-UTR. MUM-2 B cells were cultured in vitro and transfected with negative control RNA, miR-15 b-5 p mimics, inhibitor normal control (nc) RNA, and miR-15 b-5 p inhibitor. qRT-PCR was used to detect miR-15 b-5 p expression, Western blotting was used to measure the expression levels of CDK4 in the cells, CCK-8 assay was used to detect proliferation capacity, and flow cytometry was used to detect cell cycle. Results Dual-luciferase assay verified that miR-15 b-5 p could bind to CDK4 mRNA 3'-UTR successfully. Compared to the negative control group, the mimics group showed significantly increased miR-15 b-5 p expression, decreased CDK4 levels, decreased cell proliferation rate, and increased proportion of G1-phase cells. Compared to the inhibitor nc group, the inhibitor group showed significantly decreased miR-15 b-5 p expression (t = 25.01, P ＜ 0.000 1), increased CDK4 protein level, increased cell proliferation rate, and decreased proportion of G1-phase cells.Conclusion miR-15 b-5 p can target CDK4, induce G1 phase arrest in cells, and thus, reduce the proliferation rate of choroid melanoma cells.