Vincristine induces sperm malformation and motility dysfunction in mice by downregulating Tssk4 and Ccdc159.

Vincristine (VCR), a cornerstone chemotherapeutic agent in B-cell acute lymphoblastic leukemia (B-ALL) treatment, has historically been classified as exhibiting low reproductive toxicity. However, its precise impact on testicular structure and spermatogenic function remains inadequately defined. This study utilized a clinically relevant patient-derived xenograft (PDX) mouse model of B-ALL to comprehensively evaluate VCR-induced gonadal injury. Our findings demonstrate that VCR administration resulted in significant testicular atrophy, manifested by a pronounced reduction in testis weight (approximately 48% of control levels), histopathological alterations including seminiferous tubule vacuolization, and a marked impairment of spermatogenic output. Detailed computer-assisted sperm analysis (CASA) revealed a multifaceted deleterious effect, characterized by a substantial decline in sperm density, a 5.8-fold increase in sperm morphological abnormalities, and a significant compromise in key kinematic parameters indicative of motility dysfunction. Integrated transcriptomic sequencing and bioinformatic analysis identified the coordinated downregulation of Tssk4 and Ccdc159, genes critically involved in sperm morphogenesis and flagellar structural assembly, as a core molecular event. This finding was subsequently confirmed at the mRNA level. In contrast, the expression of the sperm flagellar component gene Dnah1 remained unaltered. These results establish that VCR induces considerable reproductive toxicity, predominantly mediated through the suppression of Tssk4 and Ccdc159, thereby challenging its conventional low-risk categorization and providing a mechanistic foundation for refining fertility risk assessment and protective interventions in patients undergoing VCR-containing chemotherapy regimens.