Cisplatin-Induced Peripheral Neuropathy Is Associated With Neuronal Senescence-Like Response

Background. Cisplatin-induced peripheral neuropathy (CIPN) is a frequent serious dose-dependent adverse event that can determine dosage limitations for cancer treatment. CIPN severity correlates with the amount of platinum detected in sensory neurons of the dorsal root ganglia (DRG). However, the exact pathophysiology of CIPN is poorly understood, so the chance of developing neuroprotective treatment is reduced.The aim of this study was to determine the exact mechanisms involved in CIPN development.Methods. By single-cell RNA-sequencing (scRNAseq), we have studied the transcriptomic profile of DRG sensory neurons from a well-characterized neurophysiological mouse model of CIPN.Results. Gene Ontology analysis of the scRNAseq data indicated that cisplatin treatment induces the upregulation of biological pathways related to DNA damage response (DDR) in the DRG neuronal population. Moreover, DRG neurons also upregulated the Cdkn1a gene, confirmed later by the measurement of its protein product p21. While apoptosis activation pathways were not observed in DRG sensory neurons of cisplatin-treated mice, these neurons did express several senescence hallmarks, including senescence-associated beta-galactosidase, phospho-H2AX, and nuclear factor kappa B (Nfkb)-p65 proteins.Conclusions. In this study, we determined that after cisplatin-induced DNA damage, p21 appears as the most relevant downstream factor of the DDR in DRG sensory neurons in vivo, which survive in a nonfunctional senescencelike state.