miR‑24 regulates angiogenesis in gliomas

Area of Science:

• Oncology
• Molecular Biology
• Cell Biology

Background:

• Gliomas are aggressive central nervous system tumors.
• Tumor growth, including gliomas, relies on angiogenesis, a process regulated by microRNAs (miRNAs).
• The specific role of miR-24 in glioma-driven angiogenesis remains unclear.

Purpose of the Study:

• To determine if miR-24 dysregulation in glioma cells promotes microvascular proliferation in endothelial cells (ECs).
• To investigate the underlying molecular mechanisms of miR-24's role in glioma angiogenesis.

Main Methods:

• miR-24 was overexpressed or downregulated in U251 glioma cells using mimics or inhibitors.
• The effects of conditioned media from transfected cells on human umbilical vein endothelial cells (HUVECs) were assessed for viability, migration, and angiogenesis.
• Expression levels of key angiogenic factors (VEGF, bFGF, EGF, TGF-β, MMP-2, MMP-9) and intracellular signaling pathways (AKT, β-catenin) were analyzed using RT-qPCR and Western blot.

Main Results:

• Conditioned media from miR-24-overexpressing U251 cells significantly increased HUVEC viability, migration, and tube formation.
• Conversely, conditioned media from miR-24-inhibited U251 cells decreased these endothelial cell functions.
• miR-24 overexpression upregulated VEGF, TGF-β, and other angiogenic factors in U251 cells and HUVECs, involving AKT and β-catenin signaling.

Conclusions:

• Upregulated miR-24 in glioma cells promotes endothelial cell angiogenesis.
• miR-24 influences glioma angiogenesis potentially through VEGF and TGF-β signaling pathways.
• The AKT and β-catenin intracellular signaling pathways are implicated in miR-24-mediated angiogenesis.