VEGF level in ovarian tissues after heterotopic autotransplantation in ICR mice

Abstract

OBJECTIVE: Ovarian tissue banking is a promising technique for the preservation of fecundity in young female cancer patients. Revascularization plays a critical role in successful ovarian tissue transplantation, and vascular endothelial growth factor (VEGF) is a principal factor that promotes neovascularization. This study was designed to assess the VEGF levels in cryopreserved ovarian tissue after heterotopic autotransplantation in ICR mouse.DESIGN: Prospective study.MATERIALS AND METHODS: The ovarian tissues were obtained from 5 or 6 weeks aged ICR mouse. Ovarian tissues were divided into three groups: 1) ovarian tissue without cryopreservation (control, group I), 2) ovarian tissue vitrified with VFS-40 (vitrification, group II), and 3) ovarian tissue slowly frozen with DMSO (slow-freezing, group III). Thawing was carried out at room temperature. VEGF levels were checked in ovarian tissues of 3 groups recovered on day 7 after cryopreservation, also checked on day 14 after autotransplantation.RESULTS: In cryopreserved ovarian tissues, VEGF protein levels were significantly decreased in group II and III than group I (control) (p<0.05), whereas there were no significant difference between group II and III. In autotransplanted ovarian tissue, VEGF protein levels showed similar pattern in cryopreserved ovarian tissue. Primary and antral follicular density in autotransplanted ovarian tissue were significantly decreased in group II and III than group I (p<0.05). No significant differences were found in the density of primary and antral follicles in both groups.CONCLUSIONS: These result showed that VEGF may be damaged by cryopreservation. However method of cryopreservation showed no impact on the levels of VEGF damage in cryopreserved and autotransplanted ovarian tissues. Disruption of VEGF expression induced by cryopreservation seems to affect the angiogenesis and folliculogensis of the autotransplanted ovarian tissue. Future studies are needed to improve the preservation of VEGF after cryopreservation of ovarian tissues. OBJECTIVE: Ovarian tissue banking is a promising technique for the preservation of fecundity in young female cancer patients. Revascularization plays a critical role in successful ovarian tissue transplantation, and vascular endothelial growth factor (VEGF) is a principal factor that promotes neovascularization. This study was designed to assess the VEGF levels in cryopreserved ovarian tissue after heterotopic autotransplantation in ICR mouse. DESIGN: Prospective study. MATERIALS AND METHODS: The ovarian tissues were obtained from 5 or 6 weeks aged ICR mouse. Ovarian tissues were divided into three groups: 1) ovarian tissue without cryopreservation (control, group I), 2) ovarian tissue vitrified with VFS-40 (vitrification, group II), and 3) ovarian tissue slowly frozen with DMSO (slow-freezing, group III). Thawing was carried out at room temperature. VEGF levels were checked in ovarian tissues of 3 groups recovered on day 7 after cryopreservation, also checked on day 14 after autotransplantation. RESULTS: In cryopreserved ovarian tissues, VEGF protein levels were significantly decreased in group II and III than group I (control) (p<0.05), whereas there were no significant difference between group II and III. In autotransplanted ovarian tissue, VEGF protein levels showed similar pattern in cryopreserved ovarian tissue. Primary and antral follicular density in autotransplanted ovarian tissue were significantly decreased in group II and III than group I (p<0.05). No significant differences were found in the density of primary and antral follicles in both groups. CONCLUSIONS: These result showed that VEGF may be damaged by cryopreservation. However method of cryopreservation showed no impact on the levels of VEGF damage in cryopreserved and autotransplanted ovarian tissues. Disruption of VEGF expression induced by cryopreservation seems to affect the angiogenesis and folliculogensis of the autotransplanted ovarian tissue. Future studies are needed to improve the preservation of VEGF after cryopreservation of ovarian tissues.