P-428 Impact of chemotherapy exposure using 4-hydroperoxycyclophosphamide on a male germ cell line (GC1-spg) and testes from prepubertal mouse

Abstract Study question What are the dynamics of toxicity from 4-hydroperoxycyclophosphamide (4-HC) on male germ cell line and prepubertal mouse testes? Summary answer Chemotherapy has dose- time- dependent harmful effects genes regulating apoptosis survival in two different models. is known already Fertility preservation strategies offered to boys during oncological treatment limited. The development a noninvasive pharmacological protection spermatogenic cells treatments would be major advancement field. Studies female gonad have shown that chemotherapy exposure alters expression profile miRNAs miRNA-mimics administration could used as an innovative tool protect gonadotoxic treatment. This project aims assess acute effect 4-HC proliferation spermatogonia order evaluate differential following insult. design, size, duration GC-1 spermatogonial (GC1-spg) were cultured for 48h exposed last 24h doses (20, 30 50µM) before assessing dose this agent. Cells then 4-HC-50µM apoptosis/proliferation evaluated after 1,4,8,12,16,20 establish timepoint gonadotoxicity. Similar experiments conducted post-natal day 3 testes culture 24h. (N = 3) Participants/materials, setting, methods Histological analyses performed detect early within using DDX4 Cleaved Caspase (CC3) co-immunostaining. DNA damages TUNEL assay. A large screening gene was with Taqman array (RT-qPCR). Apoptosis further assessed both models through CC3 Ki-67, respectively. Main results role chance After 24 hours vitro exposure, significant increase observed treated µM 50 4-HC, reflected by higher level those conditions compared control 4-HC-20 conditions. panel 20µM showed no difference between condition, sustaining absence at concentration our model. 50µM chemotherapy-induced occurs approximatively 20 initiation (p 0.014). Similarly, there control, while exposure. In models, change Ki-67 non-treated Finally, histological newborn previously or not revealed fragmentation control. Limitations, reasons caution use limitation because species barrier. direct (compared vivo models) can influence toxic damage. Wider implications findings Those data characterize spermatogonia. They will precise optimal temporal window modifications miRNA profiles sequencing, address alterations provide new targets reduce cyclophosphamide testicular cells. Trial registration number applicable