Akademik Veri Yönetim Sistemi
15th International Congress of Histochemistry and Cytochemistry, Antalya, Türkiye, 18 Mayıs 2017 - 21 Mayıs 2024, ss.382-383
Ovarian tissue cryopreservation in prepubertal girls before chemotherapy seems
to be efficient to preserve primordial follicle reserve as shown in a mouse model of
vitrification and re-transplantation
Soner Celik1, Sinan Ozkavukcu2, Dileyra Adiguzel1, Ciler Celik Ozenci1
1Department of Histology and Embryology, School of Medicine, Akdeniz University
2Department of Obstetrics and Gynecology, Centre for Assisted Reproduction, School of Medicine, Ankara University
Introduction & OBJECTIVES: Cyclophosphamide (CTX) is an alkylating agent that is commonly used in many chemotherapy protocols
and it is reported to cause irreversible loss of primordial follicles (PmF) in cancer survivals. Especially in prepubertal girls, ovarian tissue
cryopreservation (OTC) is the only option for fertility preservation and more than 80 live births have been reported after OTC and autotransplantation
so far. In this study, utilizing an animal model, we aim to investigate whether OTC before CTX therapy is efficient to preserve
fertility in prepubertal females.
Materials & METHODS: Control group (n=12): Whole ovaries from 8-weeks-old female mice were removed and fixed. CTX group (n=12):
Single dose of CTX was injected (200 mg/kg/I.P.) on postnatal day (PD) of 21. When these mice grew 8-weeks-old, their ovaries were also
removed and fixed. VIT+CTX+TR group (n=10): Ovaries were removed on PD18 (before puberty) and cryopreserved by vitrification. CTX
injection was applied on PD21 and ovaries were thawed and re-transplanted into the back muscle when mice grew 6-weeks-old. Grafts were
removed after 2 weeks. All tissues were fixed in Bouin’s solution and embedded into paraffin. Normal and atretic follicle counts were done in
serial sections from whole ovaries that were stained with HE.
RESULTS: Mean number of normal PmF count was 764.3±39.2, 14.5±4.8 and 325.2±39.1 in control, CTX, and VIT+CTX+TR groups,
respectively. The mean number of PmFs decreased significantly in CTX group when compared to control group. On the other hand, mean
number of PmFs was significantly higher in VIT+CTX+TR group when compared to CTX group (p<0.001)(Fig.1). Mean number of growing
follicles in CTX and VIT+CTX+TR groups were significantly lower than control group(p<=0.001) (Fig.2). No significant differences were
detected between any of the groups regarding atretic follicle numbers of PmFs and growing follicles(Fig.2). Representative images of HE
stained ovarian sections of each group are given in Fig.3.
CONCLUSIONS: Our findings indicate that PmF reserve was better protected by OTC before CTX treatment in mice. On contrary, number of
growing follicles was not affected. This model presents evidence for the first time that OTC in prepubertal girls before chemotherapy seems
to be efficient to preserve PmF pool.
Keywords: vitrification, transplantation, ovarian tissue, mouse,fertility preservation, follicle counting