NAD Synthesis Pathway Interference Is a Viable Therapeutic Strategy for Chondrosarcoma

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Chondrosarcoma is a bone tumor with identified driver mutations in IDH1/2.
• IDH1/2-mutant cells exhibit vulnerability to NAD+ depletion.
• Nicotinamide phosphoribosyltransferase (NAMPT) and nicotinic acid phosphoribosyltransferase (NAPRT) are key enzymes in NAD+ synthesis.

Purpose of the Study:

• To investigate the efficacy of NAMPT inhibitors as a treatment for chondrosarcoma.
• To explore the relationship between NAMPT/NAPRT expression, promoter methylation, and chondrosarcoma response to NAMPT inhibitors.

Main Methods:

• Treatment of 11 chondrosarcoma cell lines with NAMPT inhibitors.
• Assessment of cell viability, colony formation, and 3D collagen invasion.
• Analysis of NAMPT and NAPRT transcript levels and NAPRT promoter methylation status.

Main Results:

• NAMPT inhibitors significantly reduced chondrosarcoma cell viability, invasion, and colony formation.
• Nearly 50% of cell lines showed low nanomolar IC50 values.
• Higher NAPRT expression and lower promoter methylation correlated with increased sensitivity.
• No correlation was found between IDH1/2 mutation status and drug sensitivity.
• High-grade chondrosarcomas exhibited higher NAPRT promoter methylation.

Conclusions:

• NAMPT is a potential therapeutic target for chondrosarcoma treatment.
• Patients with high-grade chondrosarcoma and specific NAPRT methylation patterns may benefit from NAD+ synthesis pathway inhibition.