Targetable T-type Calcium Channels Drive Glioblastoma

Area of Science:

• Neuro-oncology
• Cancer Biology
• Pharmacology

Background:

• Glioblastoma stem-like cells (GSCs) drive tumor growth, progression, and resistance to therapy.
• The T-type calcium channel Cav3.2 is implicated in cancer, but its role in GSCs is not fully understood.

Purpose of the Study:

• To investigate the role of Cav3.2 in GSCs and evaluate mibefradil as a targeted therapy for glioblastoma.

Main Methods:

• Analysis of Cav3.2 expression in human GBM specimens and databases.
• In vitro and in vivo studies using mibefradil and RNAi to inhibit Cav3.2.
• Proteomic and transcriptomic analyses to identify downstream signaling pathways.
• Evaluation of GSC growth, survival, stemness, and response to chemotherapy.

Main Results:

• Cav3.2 is highly expressed in GBM and enriched in GSCs, correlating with poor prognosis.
• Mibefradil treatment or Cav3.2 inhibition suppressed GSC growth, survival, and stemness.
• Cav3.2 inhibition modulated cancer signaling pathways, including AKT/mTOR, survivin, and BAX.
• Mibefradil treatment inhibited GSC-derived xenograft growth and sensitized tumors to temozolomide in vivo.

Conclusions:

• Cav3.2 is a critical target in GSCs, and its inhibition represents a promising therapeutic strategy for glioblastoma.
• Repurposing the FDA-approved drug mibefradil offers a mechanism-based approach for glioblastoma treatment.