DNA Repair Deficiency Regulates Immunity Response in Cancers: Molecular Mechanism and Approaches for Combining Immunotherapy

SIMPLE SUMMARY: DNA repair pathways play a crucial role in maintaining the stability of a cell’s genetic material. When these pathways are defective, it can lead to genomic instability in cancer cells, which can increase their ability to stimulate an immune response. Inhibiting DNA damage response, the process that helps repair DNA damage, has been shown to increase the effectiveness of anticancer immunotherapies. In this review, we will explore how deficits in the DNA repair pathway can affect the immune system’s ability to fight cancer. We will also examine clinical trials that have combined inhibition of DNA damage response with immune-oncology treatments. A better understanding of these pathways could help improve the effectiveness of cancer immunotherapies and other treatments for various types of cancer. ABSTRACT: Defects in DNA repair pathways can lead to genomic instability in multiple tumor types, which contributes to tumor immunogenicity. Inhibition of DNA damage response (DDR) has been reported to increase tumor susceptibility to anticancer immunotherapy. However, the interplay between DDR and the immune signaling pathways remains unclear. In this review, we will discuss how a deficiency in DDR affects anti-tumor immunity, highlighting the cGAS-STING axis as an important link. We will also review the clinical trials that combine DDR inhibition and immune-oncology treatments. A better understanding of these pathways will help exploit cancer immunotherapy and DDR pathways to improve treatment outcomes for various cancers.