Molecular Actions of Cyclophosphamide (CPA) in the Ovaries of Rats with Mammary Neoplasia

Introduction: Women diagnosed with cancer often undergo aggressive chemotherapy that can impair fertility and lead to long-term ovarian damage, significantly affecting their quality of life. Cyclophosphamide (CPA), a chemotherapeutic agent known for its gonadotoxic effects, has been shown to reduce ovarian follicle reserves, thereby contributing to the development of primary ovarian insufficiency in both humans and animal models. This study sought to identify the molecules and intracellular signaling pathways associated with CPA's effects on ovarian tissue of rats bearing mammary tumors. Methods: To address the objective of the study, transcriptomic (RNA-Seq) and proteomic (2D-DIGE/MS) methodologies were applied. The study was conducted on rats with N-methyl-N-nitrosourea (MNU)-induced mammary neoplasia, randomly assigned to control or cyclophosphamide (CPA)-treated groups. CPA was administered intraperitoneally (50 mg/kg on day 3, then 10 mg/kg weekly until day 31). Animals were euthanized on day 34, and ovaries were collected for RNA-Seq and 2D-DIGE/MS analyses. Results: Our results demonstrated that the crucial mechanism of CPA action during follicular depletion in the ovary may be linked to CPA-induced immune cell responses. Moreover, we found that CPA may trigger apoptosis or ferroptosis of follicular cells, ultimately leading to ovarian dysfunction. Conclusion: The obtained results highlight the importance of mechanisms contributing to ovarian toxicity from cancer chemotherapy, paving the way for developing targeted strategies for ovarian protection. Further functional experiments are needed to identify substances that could effectively preserve the fertility of female cancer survivors.