Tumor-suppressive role of miR-129-5p in gliomas through downregulation of CCND1

Introduction
Gliomas are among the most aggressive brain tumors, with limited treatment options and poor patient outcomes. Recent studies suggest that miRNAs play a crucial role in tumor development and progression. This study aimed to leverage transcriptomics data to identify critical miRNAs involved in glioma, which may serve as potential therapeutic targets.

Material and methods
GO and KEGG analyses were used to investigate target genes. Protein-protein interaction analysis identified CCND1 as a key gene, and miR-129-5p was selected for its interaction with CCND1. The expression levels of miR-129-5p and CCND1 in glioma samples and cells were measured. Dual-luciferase assays confirmed their targeting relationship. Functional assays (CCK-8, wound healing, Transwell) were conducted in U87 cells, and the impact on the PI3K/AKT pathway was analyzed by western blot. In vivo studies were performed in nude mice.

Results
miR-129-5p expression was significantly reduced in glioma tissues and U87 cells compared to normal tissues or cells, while CCND1 was markedly increased. Dual-luciferase reporter assays confirmed that miR-129-5p directly targets CCND1. Overexpression of miR-129-5p reduced U87 cell proliferation, migration, and invasion, and inhibited the PI3K/AKT pathway. In vivo, miR-129-5p suppressed tumor growth and improved mouse survival.

Conclusions
miR-129-5p may exert a tumor-suppressive effect in glioma by targeting CCND1 and suppressing the PI3K/AKT signaling pathway.