Immunohistochemical localization of growth factors after cryopreservation and 3 weeks' xenotransplantation of human ovarian tissue

Objective: To compare early follicular growth after fresh and frozen-thawed human ovarian tissue xenografting and to investigate whether expression of c-kit, kit ligand (KL), and growth differentiation factor-9 (GDF-9) is maintained after freezing and xenografting of human ovarian tissue. Design: Prospective experimental study. Setting: Gynecology research unit in a university hospital. Animal(s): Ten nude (Swiss nu/nu) 6-week-old female mice. Intervention(s): The ovarian biopsy samples were obtained from six women, aged 20 to 30 years. Fresh and frozen-thawed ovarian fragments intraperitoneally grafted into nude mice for 3 weeks. Main Outcome Measure(s): Histologic analysis and immunohistochemical evaluation of c-kit, KL, and GDF-9 expression before and after grafting. Result(s): The integrity and proportion of growing follicles increased similarly in both fresh (64%) and frozen-thawed (59%) xenografts compared with non-grafted tissue (fresh: 40%; frozen-thawed: 21%). Both C-kit and KL staining were detected in the oocytes and granulosa cells of preantral follicles, and GDF-9 expression was observed in the oocytes of preantral follicles in all groups. Conclusion(s): Freezing does not appear to have a major impact on early follicular growth after transplantation. This study shows, for the first time, expression of c-kit, KL, and GDF-9 in human preantral follicles after ovarian tissue cryopreservation and xenotransplantation. (Fertil Steril (R) 2011;95:1241-6. (C) 2011 by American Society for Reproductive Medicine.)