The Radiosensitivity Index Gene Signature Identifies Distinct Tumor Immune Microenvironment Characteristics...

Area of Science:

• Oncology
• Immunology
• Genomics

Background:

• Radiation therapy (RT) is a cornerstone of cancer treatment.
• The interplay between RT and the immune system is increasingly recognized.
• Understanding tumor immune contexture in relation to RT sensitivity is crucial for optimizing treatment.

Purpose of the Study:

• To investigate the relationship between tumor immune microenvironment and radiation sensitivity.
• To characterize tumor immune contexture using the radiation sensitivity index (RSI) gene signature.
• To analyze over 10,000 primary tumors for RSI and immune microenvironment correlations.

Main Methods:

• Gene expression profiles of 10,469 primary tumors across 31 types were analyzed.
• Radiation sensitivity index (RSI) was calculated to estimate RT sensitivity.
• Differential gene expression, gene set enrichment analysis, and deconvolution algorithms were employed to assess immune cell infiltrates and regulatory molecules.

Main Results:

• A wide spectrum of RSI values was observed across tumor types.
• High RT sensitivity correlated with distinct enrichment of interferon-associated signaling pathways.
• Tumors with high RSI showed increased infiltration of CD8+ T cells, activated NK cells, and M1 macrophages.

Conclusions:

• The RSI gene signature effectively characterizes tumor biology in relation to RT sensitivity.
• RT sensitivity is associated with specific immune microenvironment features, including immune cell infiltrates and interferon signaling.
• This study provides a framework for understanding tumor immune contexture and its implications for radiation oncology.