The coenzyme A precursor pantethine enhances antitumor immunity in sarcoma

Area of Science:

• Oncology
• Immunology
• Metabolic pathways

Background:

• The tumor microenvironment involves complex interactions between stromal, cancer, and immune cells.
• The Vanin1 pathway, crucial for vitamin B5 and coenzyme A regeneration, acts as a tumor suppressor in sarcoma.
• Sarcoma cell lines lacking VNN1 expression provide a model to study Vanin1 pathway function.

Purpose of the Study:

• To investigate the therapeutic potential of pantethine, a vitamin B5 precursor, in an aggressive sarcoma model.
• To elucidate the mechanisms by which pantethine influences antitumor immunity.
• To assess the correlation between VNN1 expression and patient survival in human sarcomas.

Main Methods:

• Administration of pantethine to sarcoma-bearing immunocompetent and nude mice.
• Analysis of immune cell polarization, antigen presentation, and T cell metabolism.
• Comparison of pantethine efficacy with anti-PD1 treatment.
• Correlation analysis of VNN1 expression with survival and immune cell infiltration in human soft-tissue sarcomas and osteosarcomas.

Main Results:

• Pantethine attenuated tumor growth in immunocompetent mice but not in nude mice, indicating an immune-dependent mechanism.
• Pantethine enhanced antitumor immunity by promoting myeloid and dendritic cell polarization and improving CD8+ T cell metabolism.
• Immune cell exhaustion limited pantethine's efficacy at later stages, though it was comparable to anti-PD1 in sensitive tumors.
• In humans, VNN1 expression correlated with better survival and immune cell infiltration in soft-tissue sarcomas, but not osteosarcomas.

Conclusions:

• Pantethine acts as an immunomodulator, boosting antitumor immunity through vitamin B5-dependent pathways.
• The Vanin1-vitamin B5 axis represents a potential therapeutic target for enhancing anti-sarcoma immune responses.
• Pantethine may serve as a valuable immunoadjuvant in cancer therapy, particularly for specific sarcoma subtypes.