Effects of Cetrorelix on Ovary and Endometrium Prior to Anti-PD-L1 Antibody in Murine Model

Background: Recent anti-cancer agents, immune checkpoint inhibitors (ICIs), have emerged as effective agents targeting the programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway. While the administration of gonadotropin-releasing hormone (GnRH) analogs before cytotoxic agents is known to preserve female reproductive organ function, the potential effects of ICIs and the protective impact of GnRH analogs on female reproductive organs, especially concerning ovarian reserve and endometrial receptivity, remain unknown. In this study, we attempted to elucidate the protective or regenerative effect on the female reproductive organ of cetrorelix prior to anti-PD-L1 antibody administration. Method: Using a murine model, we examined the effects of Anti-PD-L1 antibody treatment on ovarian and uterine morphology, compared them with controls, and further assessed any potential protective effect of cetrorelix, a GnRH analog. Histological examinations and quantitative reverse transcription polymerase chain reaction were employed to study the morphological changes and associated gene expression patterns. Results: Anti-PD-L1 treatment led to a significant depletion of primordial/primary ovarian follicles and impaired decidualization in uterine stromal cells. However, while pretreatment with cetrorelix could restore normal decidualization patterns in the uterus, it did not significantly ameliorate ovarian follicular reductions. Gene expression analysis reflected these observations, particularly with marked changes in the expression of key genes like Prl and Igfbp1 , pivotal in uterine decidualization. Conclusion: Our study underscores the potential reproductive implications of cetrorelix treatment prior to Anti-PD-L1 therapy, shedding light on its short-term protective effects on the uterus. Further studies are necessary to understand long-term and clinical implications.