Fertility In Young Cancer Survivors Research Articles

Effects of needle puncturing on re-vascularization and follicle survival in xenotransplanted human ovarian tissue

BackgroundOvarian tissue transplantation can restore fertility in young cancer survivors, however the detrimental loss of follicles following transplantation of cryopreserved ovarian tissue is hampering the efficiency of the procedure. This study investigates whether needle puncturing prior to transplantation can enhance revascularization and improve follicle survival in xenotransplanted human ovarian cortex.MethodsCryopreserved human ovarian cortex pieces (N = 36) from 20 women aged 24–36 years were included. During the thawing process, each piece of tissue was cut in halves; one half serving as the untreated control and the other half was punctured approximately 150–200 times with a 29-gauge needle. The cortex pieces were transplanted subcutaneously to immunodeficient mice for 3, 6 and 10 days (N = 8 patients) and for 4 weeks (N = 12 patients). After 3, 6 and 10 days, revascularization of the ovarian xenografts were assessed using immunohistochemical detection of CD31 and gene expression of angiogenic factors (Vegfα, Angptl4, Ang1, and Ang2), and apoptotic factors (BCL2 and BAX) were performed by qPCR. Follicle density and morphology were evaluated in ovarian xenografts after 4 weeks.ResultsA significant increase in the CD31 positive area in human ovarian xenografts was evident from day 3 to 10, but no significant differences were observed between the needle and control group. The gene expression of Vegfα was consistently higher in the needle group compared to control at all three time points, but not statistically significant. The expression of Ang1 and Ang2 increased significantly from day 3 to day 10 in the control group (p < 0.001, p = 0.0023), however, in the needle group this increase was not observed from day 6 to 10 (Ang2 p = 0.027). The BAX/BCL2 ratio was similar in the needle and control groups. After 4-weeks xenografting, follicle density (follicles/mm3, mean ± SEM) was higher in the needle group (5.18 ± 2.24) compared to control (2.36 ± 0.67) (p = 0.208), and a significant lower percentage of necrotic follicles was found in the needle group (19%) compared to control (36%) (p = 0.045).ConclusionsNeedle puncturing of human ovarian cortex prior to transplantation had no effect on revascularization of ovarian grafts after 3, 6 and 10 days xenotransplantation. However, needle puncturing did affect angiogenic genes and improved follicle morphology.

Extended adverse effects of cyclophosphamide on mouse ovarian function

PurposeMost patients with cancer undergo multiple administrations of anticancer drugs during treatment, resulting in chronic impairment of their reproductive health. As improved treatment options increase cancer survival, it has become increasingly important to address fertility issues in cancer survivors. In this study, we examined the pathophysiological effects of multiple exposures to cyclophosphamide (Cy) on the ovaries of mice and their underlying molecular mechanism.MethodsFemale C57BL/6 mice were intraperitoneally injected with 100 mg/kg Cy six times over 2 weeks; 4 weeks later, the mice were sacrificed and their ovaries, sera, and oocytes were collected for histological observation, measurement of anti-Müllerian hormone levels, and assessment of oocyte quantity and quality in response to hormonal stimulation. Gene expression changes in Cy-treated ovaries were examined by microarray and bioinformatics analyses.ResultsAfter repeated Cy exposure, the anti-Müllerian hormone level was decreased, and follicle loss and impairments in the quality of oocyte were irreversible. The expression levels of genes involved in folliculogenesis, oogenesis, and zona pellucida glycoprotein transcription displayed sustained alterations in Cy-exposed ovaries even after 4 weeks.ConclusionThe adverse effects of Cy on ovarian function and oocytes remained even after chemotherapy was complete. Therefore, strategies to prevent ovarian damage or restore ovarian function after treatment are required to safeguard the fertility of young cancer survivors.

Role of stem cells in fertility preservation: current insights.

While improvements made in the field of cancer therapy allow high survival rates, gonadotoxicity of chemo- and radiotherapy can lead to infertility in male and female pre- and postpubertal patients. Clinical options to preserve fertility before starting gonadotoxic therapies by cryopreserving sperm or oocytes for future use with assisted reproductive technology (ART) are now applied worldwide. Cryopreservation of pre- and postpubertal ovarian tissue containing primordial follicles, though still considered experimental, has already led to the birth of healthy babies after autotransplantation and is performed in an increasing number of centers. For prepubertal boys who do not produce gametes ready for fertilization, cryopreservation of immature testicular tissue (ITT) containing spermatogonial stem cells may be proposed as an experimental strategy with the aim of restoring fertility. Based on achievements in nonhuman primates, autotransplantation of ITT or testicular cell suspensions appears promising to restore fertility of young cancer survivors. So far, whether in two- or three-dimensional culture systems, in vitro maturation of immature male and female gonadal cells or tissue has not demonstrated a capacity to produce safe gametes for ART. Recently, primordial germ cells have been generated from embryonic and induced pluripotent stem cells, but further investigations regarding efficiency and safety are needed. Transplantation of mesenchymal stem cells to improve the vascularization of gonadal tissue grafts, increase the colonization of transplanted cells, and restore the damaged somatic compartment could overcome the current limitations encountered with transplantation.

Morphological study of isolated ovarian preantral follicles using fibrin gel plus platelet lysate after subcutaneous transplantation.

Ovarian and follicle transplantation may preserve fertility in young cancer survivors. In this study, we have transplanted preantral follicles using fibrin gel as a carrier and fibrin gel supplemented with platelet lysate (PL) as a rich source of angiogenic and growth factors. The purpose of this study was to evaluate the role of fibrin gel and PL in follicle transplantation. In this experimental study, ovaries were taken from 14-day- old Naval Medical Research Institute (NMRI) mice. Preantral follicles were dissected from the ovaries and encapsulated into fibrin gel supplemented with 5, 10, 15 or 20% PL, then transplanted back into the same donor mice. Fibrin gels supplemented with PL that contained preantral follicles were placed in a subcutaneous pocket in the back of the neck of the recipient, donor mouse (the same mouse that follicles were collected). After 14 days the grafts were processed and embedded in paraffin blocks, then serially sectioned for histological evaluation. We counted the follicles and classified them according to stage (preantral or antral). Data were presented as mean ± standard error of mean (SEM) and analysed by analysis of variance (ANOVA) and the Kruskal-Wallistest. The mean percentage of recovered follicles encapsulated and transplanted in each group were 33.30 ± 2.47 (fibrin gel), 31.96 ± 1.90 (fibrin gel+5% PL), 34.02 ± 2.44 (fibrin gel+10% PL), 48.31 ± 2.06 (fibrin gel+15% PL) and 17.60 ± 2.79 (fibrin gel+20% PL). There was a significant increase in the recovery rate of grafted follicles with fibrin gel+15% PL (48.31%; p<0.001). The percentage of preantral follicles showed no significant difference in all groups (p<0.05). The percentage of antral follicles showed a significant decrease in follicles grafted with fibrin gel+20% PL when compared to the other groups (11.77%; p<0.005) but no significant difference was observed in the other groups. The use of PL in follicle transplantation can improve ovarian follicular survival rate.