NF-κB induces miR-148a to sustain TGF-β/Smad signaling activation in glioblastoma

Area of Science:

• Oncology
• Molecular Biology
• Gene Regulation

Background:

• Glioblastoma exhibits hyperactivation of nuclear factor-κB (NF-κB) and transforming growth factor-β (TGF-β) signaling pathways.
• MicroRNA-148a (miR-148a) is overexpressed in glioblastoma.
• miR-148a directly suppresses Quaking (QKI), a known negative regulator of TGF-β signaling.

Purpose of the Study:

• To investigate the role of miR-148a in glioblastoma.
• To elucidate the mechanism by which NF-κB and TGF-β signaling are co-activated in glioblastoma.
• To identify potential therapeutic targets for glioblastoma treatment.

Main Methods:

• NF-κB and TGF-β/Smad signaling activity were assessed using luciferase reporter assays.
• RNA-induced silencing complex association with target mRNAs was analyzed via immunoprecipitation and real-time PCR.
• Glioblastoma xenograft models were established in nude mice for in vivo studies.

Main Results:

• Suppression of QKI by miR-148a promoted an aggressive glioblastoma cell phenotype in vitro and in vivo.
• NF-κB activation was found to induce miR-148a expression, leading to enhanced and prolonged TGF-β/Smad signaling.
• A significant correlation was observed between miR-148a levels, NF-κB hyperactivation, and activated TGF-β/Smad signaling in human glioblastoma specimens.

Conclusions:

• A mechanism involving NF-κB-induced miR-148a sustains TGF-β/Smad activation in glioblastoma.
• This miR-148a-mediated pathway represents a potential novel therapeutic target for human cancers, particularly glioblastoma.