Ovarian Growth Factor Protein Expression in Pediatric Patients before and after Cytotoxic Therapy
Author(s): Roni Prag Rosenberg, Maayan Maor, Benjamin Fisch, Irit Ben-Aharon, Galia Oron, Shifra Ash, Eli Anuka, Isaac Yaniv, Enrique Freud, Miriam Ben Arush, Fatme Mhameed, Avi Ben-Haroush, Yoel Shufaro, Ronit Abir
The improved survival of young cancer patients results often in follicle destruction. The infertility level varies by age, with alkylating agents considered the most gonadotoxic. One option for fertility preservation is ovarian cryostorage, often conducted post-chemotherapy. Large number of follicles remain in ovaries of pediatric patients post-chemotherapy. Anti-Mullerian hormone (AMH), growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) are ovarian markers. Their ovarian expression in post-chemotherapy girls might provide an indication of follicle normality, and if it is worthwhile to cryopreserve such tissue. AMH, GDF9 and BMP15 protein expression in human ovarian samples from 49 girls pre-and-post-chemotherapy was evaluated by regular immunohistochemistry (IHC) and immunofluorescence (IF) for confocal laser microscopy. Protein expression for the three growth factors in follicles of pediatric patients pre-and-post-chemotherapy (including alkylating agent exposure) was identified by both methods from primordial stages onwards in oocytes and granulosa cells, and in irregularly shaped follicles. In the pre-chemotherapy group, IHC AMH staining seemed strongest at age ≤ 8 years, and was more abundant in pubertal-than-pre-pubertal patients by IF. Post-chemotherapy patients had significantly more immunostaining for AMH and BMP15 in atretic follicles after exposure to alkylating agents. IHC immunostaining for all three proteins seemed fuller before than after chemotherapy; there were more follicles containing growth factor-expressing granulosa cells post-chemotherapy; BMP15 staining seemed stronger pre-than-post-chemotherapy. The growth factor distribution post-chemotherapy as well as the high numbers of remaining follicles, suggests that it is worthwhile to cryostore ovarian tissue from pediatric patients even after chemotherapy initiation, including alkylating agent exposure.