Genome instability and crosstalk with the immune response.

Genome instability, tumour-promoting inflammation, and immune escape are three distinct hallmarks of cancer. However, accumulating scientific and clinical evidence over the past decade have uncovered a multifaceted interplay of complex dynamic network of interactions between genome instability, the DNA damage response (DDR), and tumour immunogenicity. Fuelled by the clinical successes of immune checkpoint blockers (ICB), growing interest for immuno-oncology and recent cancer biology discoveries have allowed a better understanding of the underlying biology and clinical opportunities brought by this interplay-which is yet, still only in its infancy. The cooperative nature of tumour cell-intrinsic and -extrinsic mechanisms involved suggests that harnessing genomic instability in cancer does not only hamper cancer cells fitness but also stimulate the anti-tumour immune response, thereby paving the way to the development of DDR-based immunomodulatory therapeutic strategies applicable to a variety of molecular and histological cancer types. Here, we review the various aspects of this crosstalk between genome instability and tumour immunogenicity, including feedforward and feedback mechanisms affecting either side of this interplay, as well as the specific consequences of chromosomal instability. We further discuss emerging DDR-based predictive biomarkers of response to ICB therapies, and finally examine the latest clinical developments of therapeutic combinations that exploit the DDR-immunity interplay in immuno-oncology.