MiR-124-3p Suppresses Glioma Cells Progression by Targeting STAT3/NAMPT and Inhibiting AKT/ERK Signaling

In our preliminary study, bioinformatics analyses identified differentially expressed miRNAs and mRNAs in glioma versus peritumoral samples, with functional validation of multiple miRNA-mRNA regulatory axes. MicroRNA-124-3p (miR-124-3p)/nicotinamide phosphoribosyltransferase (NAMPT) was among these axes and may critically regulate glioma malignant phenotypes, and this study aimed to validate their regulatory interactions.

We analyzed NAMPT expression in glioma tissues using clinical datasets from the Chinese Glioma Genome Atlas (CGGA). Functional effects of miR-124-3p and NAMPT were evaluated in U87 and U251 glioma cells using quantitative real-time PCR (qRT-PCR), Western blotting, colony formation assays, CCK-8 cell viability assays, Transwell invasion assays, and flow cytometry. The direct interaction between miR-124-3p and NAMPT was investigated using dual-luciferase reporter assays.

Clinical data revealed that elevated NAMPT expression correlated with poor prognosis, advanced pathological grade, and IDH-wild-type gliomas. MiR-124-3p overexpression significantly inhibited glioma cell proliferation, migration, and invasion while promoting apoptosis. Mechanistically, miR-124-3p downregulated NAMPT expression through regulation, leading to suppression of the p-AKT and p-ERK signaling pathways. Notably, NAMPT overexpression rescued the tumor-suppressive effects of miR-124-3p, confirming its critical role in this axis. However, dual-luciferase reporter assays ruled out a direct interaction between miR-124-3p and the NAMPT transcript, suggesting an indirect regulatory mechanism. Further investigation through WB and rescue experiments identified the transcription factor STAT3 as the key intermediary, serving as a functional bridge linking miR-124-3p to the regulation of NAMPT expression.

Accumulating evidence demonstrates that miR-124-3p functions as a potent tumor suppressor across diverse malignancies through distinct molecular mechanisms. STAT3, which is directly targeted by miR-124-3p, serves as the functional bridge linking miR-124-3p to NAMPT regulation. NAMPT, as a critical node in the NAD⁺ biosynthetic pathway, influences the malignant biological behavior of glioma through downstream PI3K/AKT and MEK/ERK signaling transduction pathways.

MiR-124-3p functions as a tumor suppressor in glioma by repressing STAT3/NAMPT-mediated AKT/ERK signaling, highlighting its potential as a diagnostic biomarker and therapeutic target for glioma management.