Ovarian tissue cryopreservation and transplantation: a review

AMH prevents primordial ovarian follicle loss and fertility alteration in cyclophosphamide-treated mice

The follicular ovarian reserve, constituted by primordial follicles (PMFs), is established early in life, then keeps declining regularly along reproductive life. The maintenance of a normal female reproductive function implies the presence of a vast amount of dormant PMFs. This process involves a continuous repression of PMF activation into early growing follicle through the balance between factors activating the initiation of follicular growth, mainly actors of the PI3K signaling pathway, and inhibiting factors such as anti-Müllerian hormone (AMH). Any disruption of this balance may induce follicle depletion and subsequent infertility. It has been recently proposed that cyclophosphamide (Cy), an alkylating agent commonly used for treating breast cancer, triggers PMF activation, further leading to premature ovarian insufficiency. Preventing chemotherapy-induced ovarian dysfunction might represent an interesting option for preserving optimal chances of natural or medically assisted conceptions after healing. The aim of the present study was to evaluate, in a model of Cy-treated pubertal mice, whether AMH administration might restrain PMF depletion. The counting of the total PMF number within mouse ovaries showed that recombinant AMH prevented Cy-induced PMF loss. Western blot analysis revealed activation of PI3K signaling pathway after Cy administration. After AMH injection, FOXO3A phosphorylation, a main actor of PMF activation, was significantly decreased. Taken together, these results support a protective role of AMH against Cy-induced follicular loss. We also provide evidence for a possible role of autophagy in the preservation of follicular pool reserve. Therefore, concomitant recombinant AMH administration during chemotherapy might offer a new option for preserving young patients' fertility.-Sonigo, C., Beau, I., Grynberg, M., Binart, N. AMH prevents primordial ovarian follicle loss and fertility alteration in cyclophosphamide-treated mice.

Fertility Preservation: Current and Future Perspectives for Oncologic Patients at Risk for Iatrogenic Premature Ovarian Insufficiency

Progress in recent years in the efficacy of oncologic treatment and early diagnosis of cancer has determined an increase in life expectance in cancer patients. About 10% of all cancer cases affect women younger than 45 years; therefore nowadays approximately 5-6% of the population in childbearing age consists in cancer survivors. A crucial issue is the high risk of premature ovarian insufficiency due to possible gonadotoxic effects of oncologic treatments. Considering combined chemotherapy, radiation therapy, and bone marrow transplantation, this risk can reach 92-100%, depending on the age and ovarian reserve of the patient, as well as the schedule and type of therapy. International guidelines recommend addressing all the patients diagnosed with a neoplasia treatable with potentially gonadotoxic therapies to fertility preservation. Moreover, fertility preservation also seems to reserve fascinating implications for women who want to delay childbearing for social reasons or women affected with endometriosis, who could receive unexpected opportunities. At present, the most widespread techniques to preserve fertility in adult women are embryo or oocyte cryopreservation, depending on the presence of a partner or according to legislative issues, but these procedures require time for ovarian stimulation. In prepubertal patients or when there is no possibility of delaying chemotherapy, ovarian tissue cryopreservation and subsequent transplantation represent the main strategy.

Fertility preservation in Hodgkin's lymphoma patients that undergo targeted molecular therapies: an important step forward from the chemotherapy era

In total, 80%-90% of Hodgkin's lymphoma (HL) patients are curable with combination chemoradiotherapy. Due to improvements in therapeutic strategies, 50% of all relapsed/refractory patients may undergo complete clinical responses and have long-term survival. Treatment options for HL are effective, but may have a negative impact on post-chemotherapy fertility. Thus, cryopreservation of semen prior to treatment is recommended for male patients. For female patients, assisted reproductive techniques (ART) consult and fertility preservation should be offered as a therapeutical option. In the last years, new targeted molecules have been available for HL treatment. These new drugs showed a high rate of overall responses in the setting of heavily pretreated patients, most of them in relapse after autologous stem cell transplantation, a group previously considered very poor risk. Up to 50% of patients have a complete response and an improved overall survival. Future studies will address the usefulness of novel molecules as a frontline therapy. Considering the high response and survival rates with monoclonal antibody-based therapeutics, fertility has become a concerning issue for long-term HL survivors. As progress has been made regarding ART, with the rigorous steps planned for HL patients, more survivors will become parents.

Effects of vitrification on the viability of alginate encapsulated isolated bovine pre-antral follicles

PURPOSE

Individual follicle cryopreservation techniques, without hydrogel support, are labor-intensive and a substantial proportion of isolated follicles are lost during handling and after warming. Therefore, the viability and morphology of isolated bovine (as a model for human) pre-antral follicles after vitrification and warming, when encapsulated in alginate beads, were investigated.

METHODS

Bovine pre-antral follicles were mechanically isolated and divided into four different groups: (1) culture in 2% alginate beads (3D system) and vitrification in beads using mesh cups (3DVIT), (2) culture in 2% alginate beads (3DCUL), (3) culture in 96-well plates (2D system) and vitrification using High Security Vitrification straws® (2DVIT), (4) culture in a 2D system (2DCUL). The same vitrification and warming protocols were used for embedded (3DVIT) and non-embedded follicles (2DVIT).

RESULTS

No differences were observed in follicle viability between group 2DCUL and 3DCUL. Group 3DVIT showed the lowest viability (45.9%) according to calcein and neutral red staining among all groups. Group 2DVIT displayed the highest viability (87.5%) and largest percentage of follicles with a well-preserved morphology.

CONCLUSIONS

Our results show that, using a vitification protocol optimized for non-embedded follicles, 2D culture is more effective in vitrifying isolated follicles. However, embedding in alginate allow to handle follicles more efficiently, i.e., without excessive manipulation and thus less labor-intensive in combination with a reduced loss of follicles during the procedure. Based on the increased work efficiency, but lower viability and higher proportion of follicles showing impaired morphology, we consider it advantageous to optimize the protocol for the vitrification of embedded follicles to increase survival and maintain morphology after vitrification.

The Growth of Preantral Follicles and the Impact of Different Supplementations and Circumstances: A Review Study with Focus on Bovine and Human Preantral Follicles

One of the most important concerns cancer survivors face is fertility. Current treatment modalities often result in damage to the reproductive system. Different options have been proposed to preserve the fertility of affected women, and many attempts have been made to improve their chance of childbearing after therapy. Cryopreservation of ovarian tissue and follicles before the onset of cancer treatment and then either transplantation of ovarian tissue or culture of ovarian tissue and individual follicles in vitro is a commonly cited approach. Extensive research is being done to design an optimal condition for the culture of ovarian follicles. Improving follicle culture systems by understanding their actual growth needs might be a crucial step toward fertility preservation in cancer patients. This review article will try to provide a summary of the role of different factors and conditions on growth of human and bovine preantral follicles in vitro.

Current perspectives on in vitro maturation and its effects on oocyte genetic and epigenetic profiles

In vitro maturation (IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years. Although IVM has the specific advantages of low cost and minor side effects over controlled ovarian stimulation, the prevalence of IVM is less than 1% of routine in vitro fertilization and embryo transfer techniques in many reproductive centers. In this review, we searched the MEDLINE database for all full texts and/or abstract articles published in English with content related to oocyte IVM mainly between 2000 and 2016. Many different aspects of the IVM method may influence oocyte potential, including priming, gonadotrophin, growth factors, and culture times. The culture conditions of IVM result in alterations in the oocyte or cumulus cell transcriptome that are not observed under in vivo culture conditions. Additionally, epigenetic modifications, such as DNA methylation or acetylation, are also different between in vitro and in vivo cultured oocytes. In sum, current IVM technique is still not popular and requires more systematic and intensive research to improve its effects and applications. This review will help point our problems, supply evidence or clues for future improving IVM technique, thus assist patients for fertility treatment or preservation as an additional option.

Transplantation of frozen-thawed ovarian tissue: an update on worldwide activity published in peer-reviewed papers and on the Danish cohort

PURPOSE

The purpose of the study is to review all peer-reviewed published reports of women receiving ovarian tissue transplantation (OTT) with frozen/thawed tissue (OTC) with respect to age, diagnosis, transplantation site, fertility outcome, and potential side effects, including data from all women in the Danish program.

METHODS

A systematic review of the literature was performed in PubMed combined with results from all patients who had received OTT in Denmark up to December 2017.

RESULTS

OTT has been reported from 21 different countries comprising a total of 360 OTT procedures in 318 women. In nine women, malignancy was diagnosed after OTT; none were considered to be directly caused by the OTT. Despite a potential under reporting of cancer recurrence, there is currently no evidence to suggest that OTT causes reseeding of the original cancer. Renewed ovarian endocrine function was reported in 95% of the women. Half of all children born following OTT resulted from natural conception, and newborns were reported to be healthy except for one neonate with a chromosome anomaly with a family disposition. Women who conceived after OTT were significantly younger than those who failed.

CONCLUSION

This study found no indications of sufficient numbers of malignant cells present in the ovarian tissue to cause recurrence of cancer after OTT. Further, it is unlikely that OTC affects the well-being of children born. OTC is now an established method of fertility preservation in Denmark with public reimbursement. The current data encourage that women who require gonadotoxic treatment should be offered an individual evaluation considering fertility preservation.

Is oxygen availability a limiting factor for in vitro folliculogenesis?

Transplantation of ovarian tissue for the preservation of fertility in oncological patients is becoming an accepted clinical practice. However, the risk of re-introducing tumour cells at transplantation has stirred an increased interest for complete in vitro folliculogenesis. This has not yet been achieved in humans possibly for the lack of knowledge on the environmental milieu that orchestrates folliculogenesis in vivo. The main aim of this study was to investigate the effect of oxygen availability on follicle health and growth during in vitro culture of ovarian tissue strips. To this end, a model was developed to predict the dissolved oxygen concentration in tissue under varying culture conditions. Ovarian cortical strips of bovine, adopted as an animal model, and human tissue were cultured in conventional (CD) and gas permeable (PD) dishes under different media column heights and gaseous oxygen tensions for 3, 6 and 9 days. Follicle quality, activation of primordial follicles to the primary stage, and progression to the secondary stage were analysed through histology. Follicle viability was assessed through a live-dead assay at the confocal scanning laser microscope. Findings showed a higher follicle quality and viability after culture of bovine ovarian strips in PD in adequate medium height and oxygen tensions. The best culture conditions found in the bovine were adopted for human ovarian strip culture and promoted a higher follicle quality, viability and progression. Overall, data demonstrated that modulation of oxygen availability in tissue plays a key role in maintaining follicles' health and their ability to survive and progress to the secondary stage during ovarian tissue in vitro culture. Such culture conditions could increase the yield of healthy secondary follicles for subsequent dissection and individual culture to obtain competent oocytes.

Recent advances in fertility preservation and counseling for female cancer patients

INTRODUCTION

Ensuring quality of life for increasing numbers of women surviving cancer has become a key challenge. Patients need to be counseled on potential fertility loss resulting from gonadotoxic treatments, and referred to fertility specialists to discuss existing options and available results. Areas covered: Fertility preservation options have existed for over twenty years. The proposed fertility preservation approach depends on patient age, the urgency of required chemotherapy, and psychosocial factors such as financial concerns, especially in countries where techniques are not covered by social security. Efficacy in terms of pregnancy rates has been demonstrated with frozen-thawed embryos, oocytes and re-implanted ovarian tissue. Appropriate counseling by oncologists is on the increase, despite persistently low rates of referral to fertility specialists. Expert commentary: Access to oncofertility services is steadily improving, facilitated by the growing involvement of public healthcare systems and sustained efforts all over the world to establish specific oncofertility programs. Early referral to reproductive specialists before initiation of chemo/radiotherapy is crucial to success in the field of female fertility preservation. In the near future, efforts should focus on increasing patient referrals and establishing international registries on short- and long-term outcomes of fertility preservation strategies.

Follicle activation is a significant and immediate cause of follicle loss after ovarian tissue transplantation

PURPOSE

Extensive follicle loss has been demonstrated in ovarian grafts post transplantation, reducing their productivity and lifespan. Several mechanisms for this loss have been proposed, and this study aims to clarify when and how the massive follicle loss associated with transplantation of ovarian tissue graft occurs. An understanding of the mechanisms of follicle loss will pinpoint potential new targets for optimization and improvement of this important fertility preservation technique.

METHODS

Frozen-thawed marmoset (n = 15), bovine (n = 37), and human (n = 46) ovarian cortical tissue strips were transplanted subcutaneously into immunodeficient castrated male mice for 3 or 7 days. Histological (H&E, Masson's trichrome) analysis and immunostaining (Ki-67, GDF9, cleaved caspase-3) were conducted to assess transplantation-associated follicle dynamics, with untransplanted frozen-thawed tissue serving as a negative control.

RESULTS

Evidence of extensive primordial follicle (PMF) activation and loss was observed already 3 days post transplantation in marmoset, bovine, and human tissue grafts, compared to frozen-thawed untransplanted controls (p < 0.001). No significant additional PMF loss was observed 7 days post transplantation. Recovered grafts of all species showed markedly higher rates of proliferative activity and progression from dormant to growing follicles (Ki-67 and GDF9 staining) as well as higher growing/primordial (GF/PMF) ratio (p < 0.02) and higher collagen levels compared with untransplanted controls.

CONCLUSIONS

This multi-species study demonstrates that follicle activation plays an important role in transplantation-induced follicle loss, and that it occurs within a very short time frame after grafting. These results underline the need to prevent this activation at the time of transplantation in order to retain the maximal possible follicle reserve and extend graft lifespan.

Determination of Follicular Localization in Human Ovarian Cortex for Vitrification

PURPOSE

To determine the optimal follicle localization for ovarian vitrification in adolescent and young adult (AYA)-aged (between 15 and 39 years of age) patients with cancer or primary ovarian insufficiency (POI).

METHODS

In total, ovaries from 24 women were included in our study. These include women who received ovariectomy for fertility preservation before gonadotoxic treatments for cancer (n = 4), or for the treatment of POI by the in vitro activation method (n = 8), and other women and infants (0-3 years of age) whose ovaries were autopsied (n = 12). Before cryopreservation, a portion of the ovary sampled from cancer and POI patients was used for histological analysis. Depths of follicles from the surface of ovarian cortices were then measured by using digital imaging software. The locations of the follicles at different developmental stages in the ovarian cortex were noted.

RESULTS

The mean depth at which the primordial and primary follicles were located was 271 μm in infants. This was deeper in women in their twenties, thirties, and forties (501, 462, and 493 μm, respectively). The majority of secondary follicles were located <1000 μm from the ovarian surface (mean depth, 639 μm). In regard to patients with POI, the mean depth of primordial and primary follicles was 566 μm, whereas 70% of secondary follicles were located >1000 μm deep.

CONCLUSION(S)

These findings suggest that <1 mm is a potential optimum thickness of normal ovarian tissue for vitrification and a requirement that thicker ovarian cortices include secondary follicles in POI patients.

Expectations and limitations of ovarian tissue transplantation

Constant progress in the diagnosis and treatment of cancer disease has increased the number and prognosis of cancer survivors. However, the toxic effects of chemotherapy and radiotherapy on ovarian function have resulted in premature ovarian failure. Patients are, therefore, still expecting methods to be developed to preserve their fertility successfully. Several potential options are available to preserve fertility in patients who face premature ovarian failure, including immature or mature oocyte and embryo cryopreservation. However, for children or prepubertal women needing immediate chemotherapy, cryopreservation of ovarian tissue is the only alternative. The ultimate aim of this strategy is to implant ovarian tissue into the pelvic cavity (orthotopic site) or in a heterotopic site once oncological treatment is completed and the patient is disease free. Transplantation of ovarian tissue with sufficiently large numbers of follicles could potentially restore endocrine function and allow multiple cycles for conception. However, the success of ovarian tissue transplantation still has multiple challenges, such as the low number of follicles in the graft that may affect their longevity as well as the survival of the tissue during ex vivo processing and subsequent transplantation. Therefore, this review aims to summarize the achievements of ovary grafting and the potential techniques that have been developed to improve ovarian graft survival.

The Effect of Erythropoietin in Preventing Ischemia-Reperfusion Injury in Ovarian Tissue Transplantation

Condensation Erythropoietin improved the survival of follicles in ovarian grafts most likely by reducing ischemic injury, by improving neoangiogenesis, and by its antioxidant effects.

OBJECTIVE

Ovarian tissue cryopreservation and transplantation are the only options accepted for prepubertal girls and women requiring immediate chemotherapy. Ischemia-reperfusion injury is the main obstacle for ovarian tissue transplantation. In the present study, we aimed to evaluate the effects of recombinant human erythropoietin (EPO) on tissue viability in autotransplanted rat ovaries.

STUDY DESIGN

Seventeen female rats were randomized into 3 groups as sham control group (n = 5), EPO-treated group (n = 6), and EPO-untreated group (n = 6). Both ovaries were excised and transplanted into a subcutaneous pouch formed at the anterior abdominal wall in the EPO-treated and untreated groups. In the EPO group, 5000 U/kg EPO was applied as local injection to the site that ovarian tissue was placed and the dose was repeated with the same route at the end of the fourth week. After 2 months, ovaries were removed and blood samples were obtained. Levels of estradiol (E₂), vascular endothelial growth factor (VEGF), VEGF-C, and lipid hydroperoxidase (LPO) and the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) were measured both in blood and tissue samples. Histopathological and morphometric analyses were also performed on tissue samples.

RESULTS

Considering serum levels, mean CAT was significantly higher ( P = .003) and mean SOD ( P = .033), LPO ( P = .050), VEGF ( P = .001), and VEGF-C ( P = .024) were significantly lower in the EPO-treated group than in the untreated group. Mean serum GPX levels were similar. Significantly higher levels of E₂ were determined in the EPO group than in the untreated group. Highest serum E₂ levels were found in the sham group ( P = .001). Tissue levels of GPX (1.23) and CAT (53.17) were significantly higher in the EPO group ( P = .002 and P = .001, respectively). However, tissue levels of SOD and LPO, VEGF, and VEGF-C levels were significantly lower in the EPO group than those in the untreated group ( P = .033, P = .050, P = .002, and P = .003, respectively). In tissue examination, the highest values of x, y axis and epithelial height were in the sham group. Mean value of the EPO group was found statistically significantly higher than that of the untreated group ( P ≤ .05). In terms of antral follicle count, ordering was found as sham > EPO-treated > EPO-untreated group. Follicle counts in the EPO group were significantly higher than those in the untreated group ( P ≤ 0.05).

CONCLUSION

Erythropoietin improved the survival of follicles in ovarian grafts most likely by reducing ischemic injury, by improving neoangiogenesis, and by its antioxidant effects.

In vitro maturation of human immature oocytes for fertility preservation and research material

Aim

In recent years, the importance of fertility preservation (FP) has increased. In vitro maturation (IVM), an important technique in FP, has started to be used in the clinic, but controversies persist regarding this technique. Here, a survey of IVM for FP is provided.

Methods

Based on a literature review, the applications of FP, methods of FP, IVM of oocytes that had been collected in vivo and ex vivo, maturation of oocytes after IVM for FP, cryopreservation of oocytes for FP, explanation of the procedures to patients, and recent research on FP using IVM were investigated.

Results

Although IVM for FP remains controversial, the application of FP is expected to expand. Depending on the age and disease status of the patient, various methods of oocyte collection and ovarian stimulation, as well as various needle types and aspiration pressures, have been reported. The maturation rate of IVM in FP ranges widely and requires optimization in the future. In regard to cryopreservation for matured oocytes, the vitrification method is currently recommended.

Conclusion

Regarding FP for patients with cancer, the treatment of cancer is prioritized; thus, the time and use of medicines are often constrained. As several key points regarding IVM remain unclear, well‐designed and specific counseling for patients is necessary.

The promise of organ and tissue preservation to transform medicine

The ability to replace organs and tissues on demand could save or improve millions of lives each year globally and create public health benefits on par with curing cancer. Unmet needs for organ and tissue preservation place enormous logistical limitations on transplantation, regenerative medicine, drug discovery, and a variety of rapidly advancing areas spanning biomedicine. A growing coalition of researchers, clinicians, advocacy organizations, academic institutions, and other stakeholders has assembled to address the unmet need for preservation advances, outlining remaining challenges and identifying areas of underinvestment and untapped opportunities. Meanwhile, recent discoveries provide proofs of principle for breakthroughs in a family of research areas surrounding biopreservation. These developments indicate that a new paradigm, integrating multiple existing preservation approaches and new technologies that have flourished in the past 10 years, could transform preservation research. Capitalizing on these opportunities will require engagement across many research areas and stakeholder groups. A coordinated effort is needed to expedite preservation advances that can transform several areas of medicine and medical science.

Complete protection against cryodamage of cryopreserved whole bovine and human ovaries using DMSO as a cryoprotectant

Purpose

This study aims to determine the optimal cryopreservation protocol for whole ovaries intended for preservation of fertility in women.

Methods

We investigated the optimal cryopreservation procedure for whole ovaries in a bovine model. The following parameters were investigated to determine their effect on ovarian tissue viability: type of cryoprotectant, administration route of the cryoprotectant (perfusion and/or submersion), and the maximum tolerable interval between death of the animal and start of the cryopreservation process. The resulting optimal cryopreservation procedure for bovine ovaries was subsequently tested on human ovaries. In vitro glucose uptake, histology, and immunohistochemistry were used to assess the integrity of the ovarian tissue.

Results

Starting the cryopreservation procedure (including perfusion with and submersion in DMSO) within 10–15 min after death of the animal proved critical, resulting in a 90–100% protection level against cryodamage. When cryopreserving human ovaries using the same protocol, over 95% protection against cryodamage was observed on all tissue levels. In addition, no apparent morphological damage to either the follicles or the vascular endothelium was observed.

Conclusion

Our findings suggest that using the optimized protocol presented in this paper allows good cryopreservation of whole human ovaries and represents an important step in considering whole ovary autotransplantation for clinically applied fertility preservation.

Recent advances in the field of ovarian tissue cryopreservation and opportunities for research

PURPOSE

The purpose of this study was to summarize the latest advances and successes in the field of ovarian tissue cryopreservation while identifying gaps in current knowledge that suggest opportunities for future research.

METHODS

A systematic review was performed according to PRISMA guidelines for all relevant full-text articles in PubMed published in English that reviewed or studied historical or current advancements in ovarian tissue cryopreservation and auto-transplantation techniques.

RESULTS

Ovarian tissue auto-transplantation in post-pubertal women is capable of restoring fertility with over 80 live births currently reported with a corresponding pregnancy rate of 23 to 37%. The recently reported successes of live births from transplants, both in orthotopic and heterotopic locations, as well as the emerging methods of in vitro maturation (IVM), in vitro culture of primordial follicles, and possibility of in vitro activation (IVA) suggest new fertility options for many women and girls. Vitrification, as an ovarian tissue cryopreservation technique, has also demonstrated successful live births and may be a more cost-effective method to freezing with less tissue injury. Further, transplantation via the artificial ovary with an extracellular tissue matrix (ECTM) scaffolding as well as the effects of sphingosine-1-phosphate (SIP) and fibrin modified with heparin-binding peptide (HBP), heparin, and a vascular endothelial growth factor (VEGF) have demonstrated important advancements in fertility preservation. As a fertility preservation method, ovarian tissue cryopreservation and auto-transplantation are currently considered experimental, but future research may pave the way for these modalities to become a standard of care for women facing the prospect of sterility from ovarian damage.

Oncologic and obstetric outcomes of conservative surgery for borderline ovarian tumors in women of reproductive age

Objective

To compare the oncologic and obstetric outcomes in reproductive-age females with borderline ovarian tumors (BOTs) treated with cyst enucleation (CE) or unilateral salpingo-oophorectomy (USO).

Methods

The medical records of patients with BOTs treated between 1998 and 2014 were retrospectively reviewed. The recurrence rates in the USO and CE groups were compared, and the postoperative obstetric outcomes were assessed via telephone survey.

Results

Eighty-nine patients with BOTs underwent USO, and 19 underwent CE. Of these, six patients had recurrent BOTs. The recurrence rate was significantly lower in the USO group (3/89, 3.4%) than in the CE group (3/19, 15.8%) (P=0.032). All patients with recurrent disease were successfully treated with further surgery. Of the 76 patients interviewed by telephone, 71 (93.4%) resumed regular menstruation after surgery. Twenty-six of the 32 patients (81.3%) who attempted to conceive had successful pregnancies. USO (19/24, 79.2%), like CE (7/8, 87.5%), resulted in favorable pregnancy rates for patients with BOTs.

Conclusion

USO is a suitable fertility-preserving surgery for women with BOTs. CE is also an acceptable option for select patients.

Optimal FSH usage in revascularization of allotransplanted ovarian tissue in mice

Backgroud

Ovarian transplantation is a useful method for preserving the fertility of young women with cancer who undergo radiotherapy and chemotherapy. Follicle-stimulating hormone (FSH) is use to protect transplanted ovarian tissues from ischemia injury through promoting revascularization after transplantation, but the side effect of high level FSH is ovarian overstimulation leading to substantial follicular loss. In this study, we investigated the optimal usage of FSH on revascularization in the in vitro cultured ovarian tissues before and after transplantation.

Results

FSH mainly exhibited an additive response in the gene and protein expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and follicle stimulating hormone receptor (FSHR) with its raised concentrations (0.15 IU/ml, 0.30 IU/ml and 0.60 IU/ml) and prolonged treatment (3 h, 6 h, 12 h, 24 h). The concentrations with 0.60 IU/ml FSH could obviously promoted the expression of VEGF, bFGF and FSHR, but under this concentration FSH could also overstimulated the ovarian tissue leading to follicular loss. With the increase of culture time, the gene and protein expression of VEGF and bFGF both were up-regulated in all of the FSH added groups, but FSHR expression decreased when culture time exceeded 12 h. So we chose 0.30 IU/ml FSH added concentration and 6 h culture time as the FSH usage condition in functional revascularization verification experiment, and found that under this condition FSH promoted 2.5 times increase of vascular density in treated group than in control group after ovarian tissues transplantation.

Conclusion

Ovarian intervention with 0.30 IU/ml FSH for 6 h is an optimal FSH usage condition which could accelerate the revascularization in the allotransplanted ovarian tissue and can not produce ovarian overstimulation.

Effects of Angiopoietin-2 on Transplanted Mouse Ovarian Tissue

Transplantation of ovarian tissue (OT) is currently the only clinical option to restore fertility with cryopreserved OT. However, follicle loss caused by ischemia and slow revascularization occurs in transplanted OT. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been used. Angiopoietin-2 (Ang2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in ischemic and/or hypoxic environment. This study was performed to investigate the effects of Ang2 on follicle integrity and revascularization of transplanted mouse OT. Five-week-old B6D2F1 female mice were divided into a control group and two Ang2 groups, followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without Ang2 injection (50 or 500 ng/kg), and then the mice were sacrificed at days 2, 7, 21, and 42 after transplantation. A total 2,437 follicles in OT grafts were assessed for follicular density, integrity, and classification by using hematoxylin and eosin staining. Apoptosis and revascularization were evaluated by using TUNEL assay and CD31 immunohistochemistry, respectively. Serum follicle-stimulating hormone (FSH) levels were measured by using enzyme-linked immunosorbent assay. Both Ang2 groups showed remarkable increase in morphologically intact follicle ratio across all grafting durations except D21. The numbers of CD31(+) vessels were significantly increased in both Ang2 groups compared with the control group at all durations, except in the 50 ng Ang2 group at D42. However, the mean numbers of follicles of the grafts, apoptosis ratios, and serum FSH levels showed no significant differences among the groups. Our results show that Ang2 treatment significantly increased the intact follicle ratios and the number of blood vessels of the mouse OT grafts. However, further studies performed with large animal or human OT are necessary before clinical application for fertility preservation in cancer patients, and the reliability of the systemic effects of Ang2 should be verified.

Cryopreservation and xenografting of human ovarian fragments: medulla decreases the phosphatidylserine translocation rate

BACKGROUND

Phosphatidylserine is the phospholipid component which plays a key role in cell cycle signaling, specifically in regards to necrosis and apoptosis. When a cell affected by some negative factors, phosphatidylserine is no longer restricted to the intracellular side of membrane and can be translocated to the extracellular surface of the cell. Cryopreservation can induce translocation of phosphatidylserine in response to hypoxia, increasing intracellular Ca²⁺, osmotic disruption of cellular membranes, generation of reactive oxygen species and lipid peroxidation. As such the aim of this study was to test the level of phosphatidylserine translocation in frozen human medulla-contained and medulla-free ovarian tissue fragments.

METHODS

Ovarian fragments from twelve patients were divided into small pieces of two types, medulla-free cortex (Group 1, n = 42, 1.5-3.0 × 1.5-3.0 × 0.5-0.8 mm) and cortex with medulla (Group 2, n = 42, 1.5-3.0 × 1.5-3.0 × 1.5-2.0 mm), pre-cooled after operative removal to 5 °C for 24 h and then conventionally frozen with 6 % dimethyl sulfoxide, 6 % ethylene glycol and 0.15 M sucrose in standard 5-ml cryo-vials. After thawing at +100 °C and step-wise removal of cryoprotectants in 0.5 M sucrose, ovarian pieces were xenografted to SCID mice for 45 days. The efficacy of tissues cryopreservation, taking into account the presence or absence of medulla, was evaluated by the development of follicles (histology with hematoxylin-eosin) and through the intensity of translocation of phosphatidylserine (FACS with FITC-Annexin V and Propidium Iodide).

RESULTS

For Groups 1 and 2, the mean densities of follicles per 1 mm³ were 9.8, and 9.0, respectively. In these groups, 90 and 90 % preantral follicles appeared morphologically normal. However, FACS analysis showed a significantly decreased intensity of translocation of phosphatidylserine (FITC-Annexin V positive) after cryopreservation of tissue with medulla (Group 2, 59.6 %), in contrast with tissue frozen without medulla (Group 1, 78.0 %, P < 0.05). In Groups 1 and 2 it was detected that 21.6 and 40.0 % cells were viable (FITC-Annexin V negative, Propidium Iodide negative).

CONCLUSION

The presence of medulla in ovarian pieces is beneficial for post-thaw development of cryopreserved human ovarian tissue.

Fertility preservation through gonadal cryopreservation

Fertility preservation is an area of immense interest in today's society. The most effective and established means of fertility preservation is cryopreservation of gametes (sperm and oocytes) and embryos. Gonadal cryopreservation is yet another means for fertility preservation, especially if the gonadal function is threatened by premature menopause, gonadotoxic cancer treatment, surgical castration, or diseases. It can also aid in the preservation of germplasm of animals that die before attaining sexual maturity. This is especially of significance for valuable, rare, and endangered animals whose population is affected by high neonatal/juvenile mortality because of diseases, poor management practices, or inbreeding depression. Establishing genome resource banks to conserve the genetic status of wild animals will provide a critical interface between ex-situ and in-situ conservation strategies. Cryopreservation of gonads effectively lengthens the genetic lifespan of individuals in a breeding program even after their death and contributes towards germplasm conservation of prized animals. Although the studies on domestic animals are quite promising, there are limitations for developing cryopreservation strategies in wild animals. In this review, we discuss different options for gonadal tissue cryopreservation with respect to humans and to laboratory, domestic, and wild animals. This review also covers recent developments in gonadal tissue cryopreservation and transplantation, providing a systematic view and the advances in the field with the possibility for its application in fertility preservation and for the conservation of germplasm in domestic and wild species.

Ethico-legal issues related to ovarian tissue transplantation

Ovarian tissue transplantation (OTT) is a promising experimental method which may soon become well-established. In cases of minor oncology, where patients' fertility is seriously threatened by treatment, it may be applied as a unique fertility preservation option. OTT has a dual nature ('organ' and 'gamete'). Many stakeholders are involved, including donor, recipient, child, health-care providers and society at large. There is considerable uncertainty about the long-term consequences of the application of OTT and OT cryopreservation (OTC). Thus, application of OTT gives rise to a number of very different ethico-legal issues and dilemmas which are hard to solve coherently through a principlism-based bioethical approach. This study focuses on such dilemmas and attempts to review them. The role of virtue ethics, which may be combined with principlism, is essential to solve such dilemmas coherently and reasonably. Dealing with conflicts of ethical principles equivalent between them, or moral dilemmas without available answers and mind-sharing in a difficult interpersonal process of decision making, requires a virtue-based ethical approach. Besides, ethico-legal issues related to OTC/OTT are complex issues requiring a multidisciplinary approach (ethical considerations, medical, psychological and social evaluations etc.). We stress the crucial role of multidisciplinary Ethics Committee which is considered indispensable for each reproductive health-care unit practicing OTC/OTT.

New advances in ovarian autotransplantation to restore fertility in cancer patients

Human ovary autotransplantation is a promising option for fertility preservation of young women and girls undergoing gonadotoxic treatments for cancer or some autoimmune diseases. Although experimental, it resulted in at least 42 healthy babies worldwide. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature review was performed for all relevant full-text articles published in English from 1 January 2000 to 01 October 2015 in PubMed to explore the latest clinical and research advances of human ovary autotransplantation. Human ovary autotransplantation involves ovarian tissue extraction, freezing/thawing, and transplantation back into the same patient. Three major forms of human ovary autotransplantation exist including (a) transplantation of cortical ovarian tissue, (b) transplantation of whole ovary, and (c) transplantation of ovarian follicles (artificial ovary). According to the recent guidelines, human ovary autotransplantation is still considered experimental; however, it has unique advantages in comparison to other options of female fertility preservation. Human ovary autotransplantation (i) does not need prior ovarian stimulation, (ii) allows immediate initiation of cancer therapy, (iii) can restore both endocrine and reproductive ovarian functions, and (iv) may be the only fertility preservation option suitable for prepubertal girls or for young women with estrogen-sensitive malignancies. As any other fertility preservation option, human ovary autotransplantation has both advantages and disadvantages and may not be feasible for all cases. The major challenges facing this option are how to avoid the risk of reintroducing malignant cells and how to prolong the lifespan of ovarian transplant as well as how to improve artificial ovary results.

Physiological basis for low-temperature survival and storage of quiescent larvae of the fruit fly Drosophila melanogaster

The cryopreservation techniques proposed for embryos of the fruit fly Drosophila melanogaster are not yet ready for practical use. Alternative methods for long-term storage of D. melanogaster strains, although urgently needed, do not exist. Herein, we describe a narrow interval of low temperatures under which the larvae of D. melanogaster can be stored in quiescence for up to two months. The development of larvae was arrested at the pre-wandering stage under fluctuating thermal regime (FTR), which simultaneously resulted in diminishing the accumulation of indirect chill injuries. Our physiological, metabolomic, and transcriptomic analyses revealed that compared to larvae stored at constant low temperatures, the larvae stored under FTR conditions were able to decrease the rates of depletion of energy substrates, exploited brief warm episodes of FTR for homeostatic control of metabolite levels, and more efficiently exerted protection against oxidative damage.

Female fertility preservation strategies: cryopreservation and ovarian tissue in vitro culture, current state of the art and future perspectives

In the present review, the main strategies of female fertility preservation are covered. Procedures of fertility preservation are necessary for women who suffer from diseases whose treatment requires the use of aggressive therapies, such as chemotherapy and radiotherapy. These kinds of therapy negatively influence the health of gametes and their progenitors. The most commonly used method of female fertility preservation is ovarian tissue cryopreservation, followed by the retransplantation of thawed tissue. Another approach to female fertility preservation that has been actively developed lately is the ovarian tissue in vitro culture. The principal methods, advantages and drawbacks of these two strategies are discussed in this article.

N-acetylcysteine leads to greater ovarian protection than enoxaparin sodium in a rat ovarian torsion model

This study evaluated the effects of N-acetylcysteine (NAC) and enoxaparin on ovarian tissue preservation, ovarian reserve and oxidative damage following ovarian torsion/detorsion injury. Rats were divided into four groups (n = 6/group): control; ischaemia/reperfusion (I/R); I/R + NAC; I/R + enoxaparin. Twenty-four hours after detorsion, ovarian tissues were collected for histopathological analysis and measurement of tissue 8-OHdG, GSH, MDA, MPO and SOD concentrations, as well as pre- and post-operative circulating AMH concentrations. Administration of NAC resulted in more pre-antral follicles compared with enoxaparin treatment and haemorrhage and follicle cell degeneration were more pronounced in I/R + enoxaparin group than I/R + NAC group. Both NAC and enoxaparin led to a significant reduction in ovarian tissue 8-OHdG (P = 0.004 and P = 0.01, respectively) and MPO (P = 0.013 and P = 0.023, respectively) concentrations compared with I/R group, indicating a protective effect against I/R oxidative damage. Only NAC-treated animals showed a significant increase in GSH and SOD concentrations and decrease in MDA concentrations compared with I/R group (P = 0.007, P = 0.024 and P = 0.026, respectively). These results indicate that NAC is more effective than enoxaparin in minimizing ovarian damage and preserving ovarian reserve following ovarian torsion.

[Fertility preservation in women of the childbearing age: Indications and strategies]

Advances on cryopreservation techniques now allow considering oocyte, embryo or ovarian tissue freezing for female fertility preservation. Originally developed for patients suffering from cancer, fertility preservation has rapidly invaded others medical fields, and represents now the standard of care for all young patient diagnosed with a disease that could impair fertility or having to receive possibly gonadotoxic treatment. As a result, autoimmune diseases, some genetic pathologies or iterative pelvic surgeries, at risk of premature ovarian failure, have become common indications of fertility preservation. In addition, the social egg freezing aiming at preventing the age-related fertility decline is still debated in France, although authorized in numerous countries. This review will discuss the different strategies of fertility preservation in young girls and women of reproductive age, regarding different medical or non-medical indications.

Heterotopic ovarian transplantation results in less apoptosis than orthotopic transplantation in a minipig model

Background

Ovarian autotransplantation has shown increasing promise as a clinical method for the preservation of fertility and hormonal function. However, information regarding the success rate of this type of transplantation is limited. We hypothesized that results vary according to the site of the ovarian transplantation. To test this hypothesis, fresh or cryopreserved ovarian strips were autotransplanted to orthotopic or heterotopic sites. The strips were later collected, and the morphology and expression of selected markers of apoptosis were evaluated. We compared the Bax, Bcl-2 and cleaved caspase-3 staining levels and the morphometric aspects of autotransplanted fresh and cryopreserved ovarian strips placed at orthotopic and heterotopic sites in minipigs.

Methods

Forty female minipigs were allocated to the following five groups: group 1 (control), ovarian tissue removed during oophorectomy; group 2, transplantation of fresh ovarian strips to a heterotopic site; group 3, transplantation of fresh ovarian strips to an orthotopic site; group 4, transplantation of cryopreserved ovarian strips to a heterotopic site; and group 5, transplantation of ovarian trips to an orthotopic site. On day 7 after transplantation, ovarian strips were collected, and the morphology and expression of apoptosis markers were evaluated.

Results

In all groups, follicles across all stages of development were detected. The numbers of primordial, primary and secondary follicles were similar in all groups, but the numbers of antral follicles were lower in the cryopreserved groups in comparison with freshly derived ovarian tissue, with no significant differences observed between fresh and cryopreserved transplants. In all transplanted groups, Bcl-2 expression was lower and Bax expression was higher than in the control group. Furthermore, increased expression of apoptosis markers was detected in fresh intraperitoneal transplants. Lastly, the expression of cleaved caspase-3 was higher in the cryopreserved orthotopic group compared with the heterotopic group.

Conclusions

Orthotopic and heterotopic ovarian strip transplantations are feasible options using these techniques. Importantly, we found that heterotopic transplantation preserves ovarian follicle integrity to a greater degree (i.e., lower expression of apoptosis markers) than orthotopic transplantation, and cryopreservation does not exacerbate expression of apoptosis’s markers. These findings have major clinical applications and enhance the discussion regarding the heterotopic transplantation of ovarian tissue.

History of ABVD alters the number of oocytes vitrified after in vitro maturation in fertility preservation candidates

AIM

This retrospective case-control study aimed at analyzing the results of in vitro maturation (IVM) of oocytes, used for fertility preservation (FP), in patients with history of ABVD (adriamycin, bleomycin, vinblastine and dacarbazine) for classical Hodgkin lymphoma.

PATIENTS & METHODS

A total of 22 candidates for FP, having received ABVD at least 2 years before IVM for FP were studied. IVM results were compared with those of 44 breast cancer patients, without history of chemotherapy, matched for ovarian reserve parameters.

RESULTS

The number of cumulo-oocyte complexes recovered and the total number of matured oocytes vitrified was lower in patients having received AVBD (5.5 ± 4.8 vs 8.5 ± 4.4 oocytes; p = 0.03 and 3.5 ± 3.7 vs 6 ± 3.0 oocytes; p < 0.04, respectively).

CONCLUSION

In light of these results, FP should be discussed before ABVD.

Vitrification of embryos and oocytes for fertility preservation in cancer patients

As survival rates and the life expectancy of those with malignancy have increased, more women in their reproductive years are referred for fertility preservation. Chemotherapy and radiotherapy can severely affect ovarian function, and the effect is irreversible. Therefore, it is optimal to attempt fertility preservation before chemotherapy and radiotherapy are initiated. Oocyte and embryo cryopreservation is the most common option for fertility preservation in women. Several reports have proven that embryo and oocyte cryopreservation can achieve a successful pregnancy. This review discusses the impact of chemotherapy and radiotherapy on ovarian function, and the importance of oocyte and embryo cryopreservation for fertility preservation. In addition, the current status of pregnancy outcomes and potential for cryopreserved oocytes to result in live births in cancer patients was reviewed. This may provide useful information for decision-making in cancer patients regarding oocyte and embryo cryopreservation and fertility preservation.

Human single follicle growth in vitro from cryopreserved ovarian tissue after slow freezing or vitrification

STUDY QUESTION

What is the effect of human ovarian tissue cryopreservation on single follicular development in vitro?

SUMMARY ANSWER

Vitrification had a greater negative effect on growth and gene expression of human ovarian follicles when compared with fresh follicles.

WHAT IS KNOWN ALREADY

For human ovarian cortex cryopreservation, the conventional option is slow freezing while more recently vitrification has been demonstrated to maintain good quality and function of ovarian tissues.

STUDY DESIGN, SIZE, DURATION

Ovarian tissues were collected from 11 patients. For every patient, the ovarian cortex was divided into three samples: Fresh, slow-rate freezing (Slow) and vitrification (Vit). Tissue histology was performed and follicles were isolated for single-cell mRNA analysis and in vitro culture (IVC) in 1% alginate for 8 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Follicle morphology was assessed with hematoxylin-eosin analysis. Follicles were individually embedded in alginate (1% w/v) and cultured in vitro for 8 days. Follicle survival and growth were assessed by microscopy. Follicle viability was observed after Calcein-AM and ethidium homodimer-I (Ca-AM/EthD-I) staining. Expression of genes, including GDF9 (growth differentiation factor 9), BMP15 (bone morphogenetic protein 15) and ZP3 (zona pellucida glycoprotein 3) in oocytes and AMH (anti-Mullerian hormone), FSHR (FSH receptor), CYP11A (cholesterol side-chain cleavage cytochrome P450) and STAR (steroidogenic acute regulatory protein) in GCs, was evaluated by single-cell mRNA analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 129 follicles were separated from ovarian cortex (Fresh n = 44; Slow n = 40; Vit n = 45). The percentage of damaged oocytes and granulosa cells was significantly higher in both the Slow and Vit groups, as compared with Fresh control (P< 0.05). The growth of follicles in vitro was significantly delayed in the Vit group compared with the Fresh group (P< 0.05). Both slow freezing (P< 0.05) and vitrification (P< 0.05) down-regulated the mRNA levels of ZP3 and CYP11A compared with Fresh group, while there was no significant difference between the Slow and Vit groups (P> 0.05). Vitrification also down-regulates AMH mRNA levels compared with Fresh group (P< 0.05).

LIMITATIONS, REASONS FOR CAUTION

Only short-term IVC studies (8 days) are reported. Further study should be performed to examine and improve follicular development in a long-term culture system after cryopreservation.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first comparison of gene expression and growth of single human ovarian follicles in vitro after either slow freezing or vitrification. With the decreased gene expression and growth during IVC, damage by cryopreservation still exists and needs to be minimized during the long-term IVC of follicles in the future for eventual clinical application.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the National Natural Science Foundation of China (31230047, 81571386, 81471508, 31429004 and 81501247), National Natural Science Foundation of Beijing (7142166) and Mega-projects of Science Research for the 12th five-year plan (2012ba132b05). There are no conflicts of interest to declare.

Ovarian tissue freezing: current status

PURPOSE OF REVIEW

This article aims to carefully evaluate a number of critical points related to ovarian tissue freezing and presents factual data in terms of live birth rates and risks.

RECENT FINDINGS

Reimplantation of frozen-thawed ovarian tissue remains an experimental procedure according to the American Society for Reproductive Medicine, despite almost 40 live births reported in the literature. Recent literature on the topic has focused on the risk of reimplanting malignant cells, so the present review assesses the risks according to disease.

SUMMARY

This manuscript emphasizes the crucial importance of not only preserving fertility in young women but also clearly explaining to patients the different available options and their respective success rates. Some previously published reviews have reported inaccurate reimplantation success rates. In this review, we report the true picture, with a live birth rate of 25%. Ovarian tissue freezing may be combined with pickup of immature oocytes (at the time of ovarian biopsy and tissue removal) or mature oocytes (if chemotherapy can be delayed).

Similar in vitro maturation rates of oocytes retrieved during the follicular or luteal phase offer flexible options for urgent fertility preservation in breast cancer patients

STUDY QUESTION

Are in vitro maturation (IVM) rates of cumulus-oocyte complexes (COCs), retrieved from breast cancer patients seeking urgent fertility preservation (FP) before neoadjuvant chemotherapy, different between those recovered in the follicular or in the luteal phase of the cycle?

SUMMARY ANSWER

The present investigation reveals no major difference in the number of COCs recovered or their IVM rates whatever the phase of the cycle at which egg retrieval is performed, suggesting that IVM is a promising tool for breast cancer patients seeking urgent oocyte cryopreservation.

WHAT IS KNOWN ALREADY

FP now represents a standard of care for young cancer patients having to undergo gonadotoxic treatment. Mature oocyte cryopreservation after IVM of COCs has been proposed for urgent FP, especially in women, who have no time to undergo ovarian stimulation, or when it is contraindicated.

STUDY DESIGN, SIZE, DURATION

From January 2011 to December 2014, we prospectively studied 248 breast cancer patients awaiting neoadjuvant chemotherapy, aged 18-40 years, candidates for oocyte vitrification following IVM, either at the follicular or the luteal phase of the cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serum anti-Müllerian hormone and progesterone levels and antral follicle count (AFC) were measured prior to oocyte retrieval. Patients were sorted into two groups according to the phase of the cycle during which eggs were harvested (Follicular phase group, n = 127 and Luteal phase group, n = 121). Number of COCs recovered, maturation rates after 48 h of culture and total number of oocytes cryopreserved were assessed. Moreover, the oocyte retrieval rate (ORR) was calculated by the number of COCs recovered ×100/AFC.

MAIN RESULTS AND THE ROLE OF CHANCE

In the Follicular and the Luteal phase groups, women were comparable in terms of age, BMI and markers of follicular ovarian status. There was no significant difference in the number of COCs recovered (mean ± SEM), 9.3 ± 0.7 versus 11.1 ± 0.8, and ORR (median (range)) 43.1 (1-100) versus 47.8 (7.7-100)%. Moreover, maturation rates after 48 h of culture (median (range)) were comparable in the follicular and luteal phase groups, 66.7 (20-100) versus 64.5 (0-100)%. Finally, the total number of oocytes cryopreserved (mean ± SEM) was similar in both groups (6.2 ± 0.4 versus 6.8 ± 0.5).

LIMITATIONS, REASONS FOR CAUTION

Despite the intact meiotic competence of immature oocytes recovered during the follicular or the luteal phase, there is a dramatic lack of data regarding the outcome of IVM oocytes cryopreserved in cancer patients.

WIDER IMPLICATIONS OF THE FINDINGS

IVM of oocytes may be an interesting method of FP in urgent situations. Improving the culture conditions will be needed to increase the maturation rates and the overall potential of in vitro matured oocytes.

STUDY FUNDING/COMPETING INTERESTS

None.

TRIAL REGISTRATION NUMBER

N/A.

Fertility issues in patients with hematologic malignancies

An essential component of a cancer patient's comprehensive care is addressing potential threats to his or her reproductive health. Providers should discuss the risk of infertility with newly diagnosed patients and offer the chance to consult with a reproductive specialist as early as possible. Standard fertility preservation options include embryo or oocyte cryopreservation for women and sperm banking for men; all options for pre-pubertal children are experimental. Patients with hematologic malignancies are a distinct population in whom standard options may present special challenges, and alternative management strategies are being explored. Unique approaches in hematologic malignancy patients include experimental techniques, such as hormonal therapy, referrals to reproductive specialists after cancer treatment, or discontinuation of tyrosine kinase inhibitor therapy in appropriate chronic myelogenous leukemia patients. Importantly, expedited communication between hematologists and reproductive specialists may greatly enhance the quality of care for these patients. Facilitation of referrals will both improve the quality-of-life and expand the prospect of parenthood in survivors. There are ample opportunities to advance the field of oncofertility through additional research, especially in hematologic malignancy patients.

The past, present and future of fertility preservation in cancer patients

Fertility preservation strategies have been developed for men and women whose fertility is compromised for medical reasons, especially in case of cancer therapy. At present, many reliable options for preserving fertility are available. However, a part of these fertility preservation methods, despite being promising, are still considered experimental. Nevertheless, there are still situations where no methods can be offered. Remarkable scientific progress is currently underway to improve available techniques and to develop new technologies to solve problems with current fertility strategies. These new options may drastically change reproductive options for young patients facing germ cell loss and hence sterility. Therefore, oncofertility counseling by a specialist is recommended for all young cancer patients having to undergo treatment that may reduce fertility potential.

The beneficial effects of polyethylene glycol-superoxide dismutase on ovarian tissue culture and transplantation

PURPOSE

Reducing the ischemic damage from free radicals that is inflicted on ovarian tissue is critical for successful ovarian tissue transplantation. Polyethylene glycol-superoxide dismutase (PEG-SOD) is mimetic of superoxide dismutase (SOD) and powerful free radical scavenger acts by reducing superoxide anions. The objective of study was to evaluate effects of PEG-SOD on mouse ovarian tissues in in vitro culture and in autotransplantation.

METHODS

Ovaries were collected and randomly divided into four groups that received different doses of PEG-SOD. To assess effects of PEG-SOD on in vitro cultures, four different doses of PEG-SOD were applied to in vitro culture media during in vitro culturing following ovarian tissue vitrification and warming. To evaluate effects of PEG-SOD on ovarian tissue transplantation, four different doses of PEG-SOD were applied for 2, 7, and 21 days to mice following vitrified-warmed mouse ovarian tissue autotransplantation.

RESULTS

The percentage of primordial follicles was maintained at the highest dose of PEG-SOD for 2 h in vitro, and there was a significant decrease in the percentage of apoptotic follicles at 2 h, but not at later time points. The highest dose of PEG-SOD also maintained primordial, primary, and secondary follicles 2 days post-transplantation, but only primordial follicles were maintained up to 21 days after transplantation.

CONCLUSIONS

PEG-SOD is protective mainly toward primordial follicles only for a short interval in vitro, presumably via antioxidant effects. PEG-SOD may be a promising additive for preserving ovarian tissue integrity, at least for primordial follicles, up to 21 days post-transplantation.

Transplantation of ovarian tissue

Since the first live birth after orthotopic transplantation of frozen-thawed ovarian tissue, >40 babies have been born. It is time to consider fertility preservation in women as one of the foremost challenges of the next decade and to offer women facing the risk of induced or iatrogenic premature menopause the best chances of becoming mothers. Heterotopic transplantation has also been attempted, with consistent restoration of endocrine function; nonetheless, its clinical value remains questionable as it may not provide an optimal environment for follicular development, possibly because of differences in temperature, pressure, paracrine factors and blood supply. Finally, orthotopic allo-transplantation of fresh human ovarian tissue has been successfully attempted between monozygotic twins and also between genetically different sisters. The next step in this field will be the development of an artificial ovary, using, as a support, a biodegradable scaffold made of an alginate matrigel matrix onto which isolated preantral follicles and ovarian cells can be grafted.

Anticancer treatment and fertility: Effect of therapeutic modalities on reproductive system and functions

The significant improvement of cancer treatments entailed a longer life in cancer survivors and raised expectations for higher quality of life with minimized long-term toxicity. Infertility and gonadal dysfunction are adverse effects of anticancer therapy or may be related to specific tumors. In female cancer survivors, premature ovarian failure is common after antineoplastic treatments resulting in infertility and other morbidities related to oestrogen deficiency such as osteoporosis. In male cancer survivors, infertility and persistent a zoospermia is a more common long-term adverse effect than hypogonadism because germ cells are more sensitive to chemotherapy and radiotherapy than leydig cells. Gonadal toxicity and compromise of reproductive functions will be more efficiently prevented and treated if addressed before treatment initiation. This review focuses on these issues in young cancer survivors of childbearing age, where methods of protecting or restoring endocrine function and fertility need to be considered.

Impact of the cryopreservation technique and vascular bed on ovarian tissue transplantation in cynomolgus monkeys

PURPOSE

The aim of this study was to determine the best combination in terms of cryopreservation techniques and vascular bed preparation before grafting in order to obtain functional ovarian tissue after transplantation.

METHODS

Five cynomolgus monkeys were used. Strips from 10 ovaries were cryopreserved, 5 by vitrification (V), and 5 by slow-freezing (SF). Pieces of fresh ovarian tissue were used for controls. After 1 month, the strips were autografted to two different vascular beds, healed (HB) or freshly decorticated (FDB), constituting four study groups: SF-HB, SF-FDB, V-HB, and V-FDB. These were compared to fresh tissue. After 6 months, the ovaries were removed and several parameters analyzed: follicle quality, stage, density, proliferation, apoptosis, functionality, vascularization, and fibrosis. Mixed effect linear regression models were built to assess the impact of cryopreservation and vascular bed preparation on ovarian tissue viability and functionality. p values were adjusted for multiple testing using the Benjamini-Hochberg method, and q values < 0.20 were considered significant in order to achieve a 20% false discovery rate.

RESULTS

Compared to fresh tissue, no difference was observed in the percentage of morphologically normal follicles, while a significant increase was noted in the follicle proliferation rate (41%, q = 0.19), percentage of antral follicles (12%, q = 0.14), and number of vessels per area (3.3 times, q = 0.07) in the V-FDB group.

CONCLUSIONS

Vitrification associated with FDB vascular bed preparation is the best combination to obtain functional autografted ovarian tissue. Further studies are nevertheless required, with confirmed pregnancies and live births before introducing the procedure into clinical practice.

The effects of tacrolimus on the activity and expression of tissue factor in the rat ovary with ischemia-reperfusion induced injury

In the present study, the effects of tacrolimus on the activity and expression of tissue factor (TF) were investigated in the ovarian ischemia-reperfusion induced injury in rats. Twenty-eight female rats (8-12 weeks, 300-350 g) were divided into four groups: control, ischemia-reperfusion (IR), tacrolimus treated before ischemia (TBI), and tacrolimus treated before reperfusion (TBR) groups (n=7/per group). TF activity was measured using Quick's method, whereas TF expression was examined immunohistochemically. TF activity was significantly higher in all treated groups compared with the control group. Strong ovarian TF expression was demonstrated in the IR and TBR groups. Moreover, tacrolimus decreased TF activity in the TBI group compared with the IR group. The decreased activity of TF in the ovarian IR model may prevent IR-related inflammation during transplant procedure.