Radiotherapy-associated changes in the miR-124/SP1 axis in a rat glioma model.

OBJECTIVES: Glioma is an aggressive brain tumor that frequently involves microRNA dysregulation. Rno-miR-124-3p is a brain-enriched miRNA involved in gene regulation, with Specificity Protein 1 (SP1) as its validated target. Radiotherapy remains a cornerstone of glioma treatment; however, its molecular effects on miRNA-transcription factor axes are not fully understood. We hypothesized that radiotherapy up-regulates Rno-miR-124-3p, thereby down-regulating SP1. Accordingly, this study evaluated their expression following radiotherapy in a rat glioma model. MATERIALS AND METHODS: C6 glioma cells were cultured, and an effective radiation dose was determined using an MTT assay. Sixty male Wistar rats were randomly assigned to six experimental groups: control, sham, glioma, and their corresponding radiotherapy-treated groups. Glioma was induced by stereotactic injection of C6 cells into the striatum. After radiotherapy, brain tissue was collected for histological and molecular analyses. Tumor expression of Rno-miR-124-3p and SP1 was quantified by real-time PCR. RESULTS: In glioma-bearing rats, Rno-miR-124-3p expression was significantly down-regulated, whereas SP1 was significantly up-regulated compared with control groups (P≤0.05 and P≤0.01, respectively). After radiotherapy, an inverse pattern was observed, with increased Rno-miR-124-3p and decreased SP1 in glioma tissues (P≤0.05 and P≤0.01). Histological evaluation suggested structural differences between the glioma and radiotherapy-treated glioma groups. CONCLUSION: Glioma development alters the Rno-miR-124-3p/SP1 regulatory axis. Radiotherapy modulates this molecular pattern, suggesting a potential role for Rno-miR-124-3p in glioma-related pathways. Further studies are needed to clarify its functional and clinical relevance.