Cancer Cell-Intrinsic Type I Interferon Signaling Promotes Antitumor Immunity in Head and Neck Squamous Cell...

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• The cyclic GMP-AMP synthase (cGAS)-type I interferon (IFN-I) pathway is crucial for detecting cytoplasmic DNA and initiating immune responses.
• Cancer cells often suppress the cGAS-IFN-I pathway to evade immune surveillance, limiting therapeutic strategies.
• Understanding the therapeutic potential of this pathway in cancer is critical for developing new treatments.

Purpose of the Study:

• To investigate the role of the cGAS-IFN-I pathway in immune-unresponsive oral squamous cell carcinoma (OSCC) models.
• To explore the potential of reactivating the cGAS-IFN-I pathway as a therapeutic strategy for head and neck squamous cell carcinoma (HNSCC).

Main Methods:

• Utilized mouse oral squamous cell carcinoma (OSCC) models (MOC1 and MOC2).
• Employed flow cytometry, Western blot, ELISA, and PCR for molecular and cellular analysis.
• Assessed the impact of cGAS-IFN-I pathway activation on tumor cells and the tumor microenvironment.

Main Results:

• Immune-unresponsive MOC2 tumors showed suppressed cGAS-IFN-I pathway, reduced antigen-presenting cells, and cytotoxic T lymphocytes compared to MOC1 tumors.
• MOC2-conditioned medium impaired dendritic cell (DC) differentiation and reduced MHC molecule expression.
• Activating the cGAS-IFN-I pathway in MOC2 cells enhanced MHC class I expression, antigen presentation, induced apoptosis, and upregulated immune-attracting chemokines (CXCL9, CXCL10).
• IFNB1 expression in MOC2 cells suppressed tumor growth in vivo by recruiting DCs and T cells, an effect potentiated by GM-CSF.

Conclusions:

• Enhancing cancer cell-intrinsic cGAS-IFN-I signaling can improve tumor immune surveillance.
• Reactivating this pathway holds therapeutic potential for immune-cold HNSCC tumors.
• Targeting the cGAS-IFN-I pathway offers a novel strategy to control tumor progression in resistant cancers.