Context-dependent functions of pattern recognition receptors in cancer

The immune system plays a critical role in shaping all facets of cancer, from the early initiation stage through to metastatic disease and resistance to therapy. Our understanding of the importance of the adaptive arm of the immune system in antitumour immunity has led to the implementation of immunotherapy with immune checkpoint inhibitors in numerous cancers, albeit with differing efficacy. By contrast, the clinical utility of innate immunity in cancer has not been exploited, despite dysregulated innate immunity being a feature of at least one-third of all cancers associated with tumour-promoting chronic inflammation. The past two decades have seen innate immune pattern recognition receptors (PRRs) emerge as critical regulators of the immune response to microbial infection and host tissue damage. More recently, it has become apparent that in many cancer types, PRRs play a central role in modulating a vast array of tumour-inhibiting and tumour-promoting cellular responses both in immune cells within the tumour microenvironment and directly in cancer cells. Herein, we provide a comprehensive overview of the fast-evolving field of PRRs in cancer, and discuss the potential to target PRRs for drug development and biomarker discovery in a wide range of oncology settings. This Review provides an overview of cancer-related actions of pattern recognition receptors, including both immune and non-immune functions that influence cancer mechanisms as well as the potential to target pattern recognition receptors for cancer drug development and biomarker discovery.

Automated summary

The immune system plays a critical role in cancer, and while the importance of adaptive immunity has been recognized and utilized in immunotherapy, the potential of innate immunity has not been fully exploited. Pattern recognition receptors (PRRs) have emerged as key regulators in the immune response to cancer, both in immune cells and cancer cells. Targeting PRRs shows promise in cancer drug development and biomarker discovery.