Current Advances in PARP1-Targeted Theranostics

Poly (ADP-ribose) polymerase 1 (PARP1) plays critical roles in DNA repair, chromatin regulation, and cellular equilibrium, positioning it as a pivotal target for therapeutic interventions in cancer and central nervous system (CNS) disorders. PARP1 responds to oxidative stress and DNA damage through PARylation, influencing energy depletion, survival, inflammation, and genomic regulation in many biological scenarios. PARP inhibitors (PARPis) have demonstrated efficacy against cancers harboring defective homologous recombination repair pathways, notably those linked to BRCA mutations. PARP1-targeted PET imaging enables patient stratification, treatment assessment, and PARPi pharmacodynamic evaluation in cancers and other pathophysiological conditions. Importantly, PARP1-targeted theranostics have emerged for both diagnostic imaging and therapeutic applications in multiple types of cancers, representing a pivotal advancement in personalized oncology. However, its application in brain tumors is limited by the heterogeneous integrity of the blood brain barrier (BBB) and the blood-tumor barrier. Thus, the development of BBB-penetrant PARP1 tracers remains an unmet need for imaging brain cancers. This review summarizes the current landscape of radiopharmaceuticals and radioligands targeting PARP1, detailing their pharmacological characteristics and potential clinical uses. Furthermore, this review discusses PARP1 tracers that can cross the BBB, underscoring their potential applications in neurooncology and other neurological disorders.