Targeting pattern recognition receptors for cancer therapy: Mechanisms and strategies

Pattern recognition receptors (PRRs) play a crucial role in immune responses, acting as primary sensors for microbial and host-derived signals. PRRs, which include Toll-like receptors (TLRs), retinoic acid-inducible gene 1-like receptors, nucleotide-binding oligomerization domain-like receptors, C-type lectin receptors, and various cytoplasmic DNA sensors, are essential for initiating immune responses that regulate both inflammation and tumor immunity. Recent studies have highlighted their dual roles in cancer, where they can either suppress or promote tumor progression by influencing the tumor microenvironment and modulating responses to immunotherapy. In the context of cancer, PRRs not only activate immune cells but also contribute to immune evasion mechanisms within tumors. Therapeutically, targeting PRRs represents a promising approach for cancer treatment, with related drugs showing potential to enhance the efficacy of existing immunotherapies. Numerous PRR-based agents, particularly TLR agonists, are currently under clinical investigation for their ability to augment antitumor immunity and overcome resistance to immune checkpoint inhibitors. This review examines the molecular mechanisms by which PRRs influence cancer, with a focus on recent advancements in PRR-targeted therapies and their integration with contemporary immunotherapeutic strategies.