Evaluation of the structure and ultrastructure of fresh and frozen/thawed ovarian tissue in cancer patients, after chick embryo chorioallantoic membrane

Background: With the improvement in diagnosis and treatment, the survival rate of cancer patients is increasing. But, ovarian tissue (OT) that contains irreplaceable resources is susceptible to cytotoxic effects of chemotherapy drugs. The ovarian cryopreservation is a promising alternative in fertility preservation programs. Ovarian cortex can be obtained by using laparoscopic surgery at any stage of the menstrual cycle before starting cancer treatment.Objective: The aim of this study was evaluation of the structure including follicle morphology and stroma and ultrastructure of fresh and frozen/thawed OT after two methods of vitrification and slow freezing, in cancer patients, after 5 and 10 days grafted onto chick embryo chorioallantoic membrane (CAM) And determining the best freezing method for ovarian tissue in patients who are seeking fertility preservation and also ensuring that the metastasis cell is not frozen in the tissue.Materials and Methods: Small pieces of the OT from 10 cancer patients, under 30 yr, were included in the study after obtaining written informed consent. These pieces were divided into three general groups of fresh (control), vitrification and slow freezing. These components were controlled by the presence of metastatic cells with stained slides, by an experienced pathologist. After grafted onto the CAM, they were removed after 5 and 10 days. These components were divided into two groups based on the addition of activin to the culture medium. Structural and ultrastructural studies were done for assessment of follicular integrity.Results: The mean age for participant was 26.7 and none of the OT had metastatic cells. After 5 days of culture, follicogenesis occurred in the presence of activin (p˂0.05), but in the long-term culture, it was independent (p˂0.05). The quality of follicles in the non-transplanted tissue was better than the two freezing groups (p˂0.05). Long-cultured transplantation had a negative impact on follicle and stromal quality. Expression of PCNA in granulosa cells was started at intermediate follicles stage. The vitrification was more successful in transplantation than slow freezing (65% vs. 59%). In the ultrastructure study, better follicle quality was obtained in slow freezing and better stroma in vitrification group. Activin was identified as a follicle activator and also anti-angiogenic factor.Conclusion: At the end of a 10-days culture, the follicles had better morphology in the tissue from slow freezing and better stromal cells in vitrification. CAM is suitable environment for short-term tissue transplantation. Also, activvin did not improve the culture condition for OT.

کلیدواژه ها:

Fertility preservation ، Human ovary ، Transplantation