Faculty Bibliography

Ovarian tissue cryopreservation and autotransplantation can restore ovarian endocrine function and fertility and recently were changed from experimental to fertility preservation procedures for medical indications by the American Society of Reproductive Medicine. Such advances have resulted in discussions around the utility of ovarian cryopreservation in healthy women to preserve fertility and delay menopause or as a hormone replacement approach. Such 'elective' use of ovarian tissue cryopreservation requires a risk-benefit assessment. Here, we review evidence for and against the utility of ovarian tissue harvesting in healthy women, scrutinize recent and needed advances to enhance the feasibility of such an approach, and provide practice and future research guidelines.

PURPOSE/OBJECTIVE:) pathogenic variants are associated with decreased ovarian reserve. MATERIALS AND METHODS/METHODS:four centers studied those affected with breast cancer (n = 161) and one studied unaffected individuals (n = 89). The data were adjusted for the center, age, body mass index, smoking, and oral contraceptive pill use before the final analysis. Anti-Müllerian hormone (AMH) levels in affected women were drawn before presystemic therapy. RESULTS:= .64). CONCLUSION/CONCLUSIONS:, have lower serum AMH levels compared with controls. They may need to be preferentially counseled about the possibility of shortened reproductive lifespan because of diminished ovarian reserve.

PURPOSE/OBJECTIVE:To investigate the differences concerning post-thawing/warming follicle survival, DNA damage and apoptosis in human ovarian tissues cryopreserved by slow freezing, open, or closed vitrification methods. METHODS:A total of 50 pieces of 5 × 5 × 1 mm ovarian cortical pieces were harvested (5 donor ovaries; mean age 31 ± 6.62 years). From each donor, one cortical piece was used as baseline; the remaining were randomly assigned to slow freezing (SF), vitrification using open device (VF-open), or closed device (VF-closed) groups. After 8-10 weeks of cryostorage, tissues were evaluated 4 h after thawing/warming. Histological analysis was evaluated for follicle survival (primordial and primary follicle densities) by H&E staining. The percentages of primordial and primary follicles with DNA double-strand breaks (γH2AX) and apoptotic cell death pathway activation (AC3) were immunohistochemically assessed. Data were analysed using one-way ANOVA and LSD post hoc comparison. RESULTS:Compared to the baseline, primordial follicle (pdf) densities significantly declined in all cryopreserved groups (SF, VF-open, and VF-closed, P < 0.05). However, the total and non-apoptotic pdf densities were similar among SF, VF-open, and VF-closed. SF and VF with either open or closed devices did not increase the percentages of primordial or primary follicles with DNA double-strand breaks (DSBs) or apoptosis compared to the baseline or among the freezing methods in the present study. CONCLUSION/CONCLUSIONS:Based on the intact primordial follicle survival, DNA damage, and apoptosis rates after thawing/warming, SF vs VF with either open or newly developed closed devices appear to be comparable.

PURPOSE/OBJECTIVE:To determine the longitudinal impact of adjuvant chemotherapy and tamoxifen-only treatments on the reproductive potential of women with breast cancer by using a sensitive ovarian reserve marker anti-Mullerian hormone (AMH) as a surrogate. METHODS:One-hundred-and-forty-two women with a primary diagnosis of breast cancer were prospectively followed with serum AMH assessments before the initiation, and 12, 18 and 24 months after the completion of adjuvant chemotherapy or the start of tamoxifen-only treatment. The chemotherapy regimens were classified into Anthracycline-Cyclophosphamide-based (AC-based) and Cyclophosphamide-Methotrexate + 5-Fluorouracil (CMF). Longitudinal data were analyzed by mixed effects model for treatment effects over time, adjusting for baseline age and BMI. RESULTS:Both chemotherapy regimens resulted in significant decline in ovarian reserve compared to the tamoxifen-only treatment (p < 0.0001 either regimen vs. tamoxifen for overall trend). AMH levels sharply declined at 12 months but did not show a significant recovery from 12 to 18 and 18 to 24 months after the completion of AC-based or CMF regimens. The degree of decline did not differ between the two chemotherapy groups (p = 0.53). In contrast, tamoxifen-only treatment did not significantly alter the age-adjusted serum AMH levels over the 24-month follow up. Likewise, the use of adjuvant tamoxifen following AC-based regimens did not affect AMH recovery. CONCLUSIONS:Both AC-based regimens and CMF significantly compromise ovarian reserve, without a recovery beyond 12 months post-chemotherapy. In contrast, tamoxifen-only treatment does not seem to alter ovarian reserve. These data indicate that the commonly used chemotherapy regimens but not the hormonal therapy compromise future reproductive potential.

The loss of fertility and early menopause are common after gonadotoxic therapies and radical pelvic surgery. The strategy of ovarian tissue cryopreservation and auto-transplantation was introduced to prevent this significant quality of health issue. Ovarian transplantation with cryopreserved tissue has gone through remarkable evolution in the last 20 years. In this review, we detail the history and evolution of ovarian transplantation with cryopreserved tissue from its origins to the present. Ovarian cryopreservation and transplantation approach was first tested with animal models. The approach was then validated in human ovarian xenografting models before being applied to patients in pioneering clinical studies. The first orthotopic and heterotopic approaches to ovarian transplantation was developed by Oktay et al. who reported the first successful restoration of ovarian function with these approaches beginning in 2000 with first embryo development in 2004. Controversy remains on when the first live birth occurred after orthotopic ovarian transplantation with cryopreserved tissue as the patient was ovulating with elevated progesterone levels in the case reported in 2004; first live birth is likely to be the one reported by Meirow et al. in 2005. Nevertheless, the technique has evolved to reach a level where most recent live birth rates are exceeding 35% and the procedure is no longer considered experimental by many.

Among the investigated mechanisms of chemotherapy-induced damage to human primordial follicle reserve are induction of DNA double-strand breaks (DSBs) and resultant apoptotic death, stromal-microvascular damage and follicle activation. Accumulating basic and translational evidence suggests that acute exposure to gonadotoxic chemotherapeutics, such as cyclophosphamide or doxorubicin, induces DNA DSBs and triggers apoptotic death of primordial follicle oocytes within 12-24 h, resulting in the massive loss of ovarian reserve. Evidence also indicates that chemotherapeutic agents can cause microvascular and stromal damage, induce hypoxia and indirectly affect ovarian reserve. While it is possible that the acute reduction of the primordial follicle reserve by massive apoptotic losses may result in delayed activation of some primordial follicles, this is unlikely to be a predominant mechanism of loss in humans. Here, we review these mechanisms of chemotherapy-induced ovarian reserve depletion and the potential reasons for the discrepancies among the studies. Based on the current literature, we propose an integrated hypothesis that explains both the acute and delayed chemotherapy-induced loss of primordial follicle reserve in the human ovary.

BACKGROUND:Oocyte aging has significant clinical consequences, and yet no treatment exists to address the age-related decline in oocyte quality. The lack of progress in the treatment of oocyte aging is due to the fact that the underlying molecular mechanisms are not sufficiently understood. BRCA1 and 2 are involved in homologous DNA recombination and play essential roles in ataxia telangiectasia mutated (ATM)-mediated DNA double-strand break (DSB) repair. A growing body of laboratory, translational and clinical evidence has emerged within the past decade indicating a role for BRCA function and ATM-mediated DNA DSB repair in ovarian aging. OBJECTIVE AND RATIONALE:Although there are several competing or complementary theories, given the growing evidence tying BRCA function and ATM-mediated DNA DSB repair mechanisms in general to ovarian aging, we performed this review encompassing basic, translational and clinical work to assess the current state of knowledge on the topic. A clear understanding of the mechanisms underlying oocyte aging may result in targeted treatments to preserve ovarian reserve and improve oocyte quality. SEARCH METHODS:We searched for published articles in the PubMed database containing key words, BRCA, BRCA1, BRCA2, Mutations, Fertility, Ovarian Reserve, Infertility, Mechanisms of Ovarian Aging, Oocyte or Oocyte DNA Repair, in the English-language literature until May 2019. We did not include abstracts or conference proceedings, with the exception of our own. OUTCOMES:Laboratory studies provided robust and reproducible evidence that BRCA1 function and ATM-mediated DNA DSB repair, in general, weakens with age in oocytes of multiple species including human. In both women with BRCA mutations and BRCA-mutant mice, primordial follicle numbers are reduced and there is accelerated accumulation of DNA DSBs in oocytes. In general, women with BRCA1 mutations have lower ovarian reserves and experience earlier menopause. Laboratory evidence also supports critical role for BRCA1 and other ATM-mediated DNA DSB repair pathway members in meiotic function. When laboratory, translational and clinical evidence is considered together, BRCA-related ATM-mediated DNA DSB repair function emerges as a likely regulator of ovarian aging. Moreover, DNA damage and repair appear to be key features in chemotherapy-induced ovarian aging. WIDER IMPLICATIONS:The existing data suggest that the BRCA-related ATM-mediated DNA repair pathway is a strong candidate to be a regulator of oocyte aging, and the age-related decline of this pathway likely impairs oocyte health. This knowledge may create an opportunity to develop targeted treatments to reverse or prevent physiological or chemotherapy-induced oocyte aging. On the immediate practical side, women with BRCA or similar mutations may need to be specially counselled for fertility preservation.

Recent data suggest that paternal age can have major impact on reproductive outcomes, and with increased age, there is increased likelihood of chromosomal abnormalities in the sperm. Here, we studied DNA damage and repair as a function of male aging and assessed whether sphingosine-1-phosphate (S1P), a ceramide-induced death inhibitor, can prevent sperm aging by enhancing DNA double-strand breaks (DSB) repair. We observed a significant increase in DNA damage with age and this increase was associated with a decline in the expression of key DNA DSB repair genes in mouse sperm. The haploinsufficiency of BRCA1 male mice sperm showed significantly increased DNA damage and apoptosis, along with decreased chromatin integrity when compared to similar age wild type (WT) mice. Furthermore, haploinsufficiency of BRCA1 male mice had lower sperm count and smaller litter size when crossed with WT females. The resulting embryos had a higher probability of growth arrest and reduced implantation. S1P treatment decreased genotoxic-stress-induced DNA damage in sperm and enhanced the expressions of key DNA repair genes such as BRCA1. Co-treatment with an ATM inhibitor reversed the effects of S1P, implying that the impact of S1P on DNA repair is via the ATM-mediated pathway. Our findings indicate a key role for DNA damage repair mechanism in the maintenance of sperm integrity and suggest that S1P can improve DNA repair in sperm. Further translational studies are warranted to determine the clinical significance of these findings and whether S1P can delay male reproductive aging. There is mounting evidence that sperm quality declines with age, similar to that of the oocyte. However, the reasons behind this decline are poorly understood and there is no medical intervention to improve sperm quality. Our study suggests a strong role for DNA damage repair in maintenance of sperm quality, and for the first time, a potential pharmaceutical approach to prevent sperm aging.