Abstract 795: Acute and long-term effect of prepubertal chemotherapy on spermatogenesis, fertility and offspring health

Abstract Early detection and treatment of childhood cancers have improved the cure and the survival rates for more than a decade. However, long-term survivors of childhood cancers can experience fertility problems because of chemotherapy treatment. This is a major problem particularly for young boys, for whom no fertility preservation treatment is yet established. Here, we have determined the acute and long-term effect of cyclophosphamide (an alkylating drug commonly used in childhood cancers) on the germ cell development, fertility and on the health of their subsequent generations. We treated the prepubertal mice with clinically relevant dose of either cyclophosphamide (low dose- 100mg/kg and high dose- 200mg/kg), and vehicle control (sterile PBS), respectively. Acute exposure to both low and high doses of cyclophosphamide led to morphological changes in the prepubertal testis. Moreover, prepubertal treatment had long-term effect as the sperm concentration and motility in adult mice decreased in a dose dependent manner. Infertility and sub-fertility were observed in males exposed to high, but not in low dose of cyclophosphamide as compared to control males. There was no difference in the litter size born to cyclophosphamide exposed fathers as compared to controls. However, there was a sex specific increase in the litter weights of the female offspring born to fathers exposed to high dose of cyclophosphamide as compared to controls. Additionally, a high male to female birth sex ratio was found in the litters born to cyclophosphamide exposed fathers as compared to controls, suggesting that the cyclophosphamide exposure may be impacting the paternal X chromosome. We also investigated the adverse effect of paternal cyclophosphamide exposure on the metabolic health of F1 offspring. Female, but not male offspring of fathers exposed to cyclophosphamide, developed severe insulin resistance compared to controls. We have previously shown that sperm small non-coding RNAs contribute to the intergenerational transmission of paternally acquired metabolic disorders. Using small RNA sequencing, we found alterations in the population of small non-coding RNAs in the sperm of cyclophosphamide exposed fathers as compared to controls suggesting that sperm small non-coding RNAs may contribute to the adverse effect of pre-pubertal cyclophosphamide exposure. Overall, our results demonstrate that exposure to clinically relevant dose of cyclophosphamide in prepubertal mice not only affects the reproductive health of exposed mice but could also affect the health of their off-spring by altering the sperm small non-coding RNAs. Citation Format: Meghali Joshi, Duane G. Pereira, Sonia de Assis. Acute and long-term effect of prepubertal chemotherapy on spermatogenesis, fertility and offspring health [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 795.