ZBP1-mediated sensing of genomic stress in cancer therapy
Z-nucleic acid-binding protein 1 (ZBP1) is a cytosolic innate immune sensor that detects left-handed Z-DNA and Z-RNA, structures arising from endogenous retroelements, splicing stress, R-loops, viruses, or viral mimicry. Originally viewed as an antiviral receptor, ZBP1 has emerged as a sentinel of genomic and transcriptomic instability. Upon ligand binding, ZBP1 recruits receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and receptor-interacting serine/threonine-protein kinase 3 (RIPK3) via RIP homotypic interaction motif domains; in humans, RIPK1 acts as an essential scaffold to form the necrosome, which phosphorylates mixed lineage kinase domain-like pseudokinase (MLKL) and triggers necroptosis, a lytic, immunogenic cell death. This pathway is intimately regulated by reactive oxygen species (ROS): oxidative stress promotes RIPK1 activation, and necroptosis further drives a mitochondrial ROS burst, establishing a feed-forward amplification loop. In cancer, therapeutic induction of viral mimicry (e.g., using curaxins or splicing inhibitors) combined with tumor-localized ROS generation activates ZBP1-driven necroptosis, leading to the release of damage-associated molecular patterns and tumor antigens. This process converts immunosuppressive “cold” tumors into inflamed “hot” tumors, enhancing dendritic cell maturation, CD8+ T cell infiltration, and sensitivity to immune checkpoint blockade. Integrating epigenetic priming, nanomedicine, and patient stratification according to ZBP1/RIPK3/MLKL pathway status holds promise for overcoming therapeutic resistance. Thus, ZBP1-mediated nucleic acid surveillance represents a central innate checkpoint bridging genomic stress to antitumor immunity.