Bortezomib prevents acute doxorubicin ovarian insult and follicle demise, improving the fertility window and pup birth weight in mice

Ultrasonographic and histopathological investigation of the effect of N-acetylcysteine on doxorubicin-induced ovarian and uterine toxicity in rats

BACKGROUND

This study aimed to investigate the mitigating effect of N-acetylcysteine (NAC) on doxorubicin (DOX)-induced ovarian and uterine toxicity in rats using laboratory tests, ultrasonographic (US) imaging, and histopathology analysis.

METHODS

Forty-eight rats were divided into six groups (n = 8) as follows: Group A (control) (0.5 mL saline administered intraperitoneally [IP]), Group B (a single 10 mg/kg dose of DOX administered IP on day 1), Group C (a single 10 mg/kg dose of DOX administered IP 24 h before sacrifice), Group D (100 mg/kg of NAC administered IP for 21 days), Group E ( a single 10 mg/kg dose of DOX administered IP on day 1 and 100 mg/kg of NAC administered IP for 21 days), and Group F (100 mg/kg of NAC administered IP for 21 days and a single 10 mg/kg dose of DOX administered IP 24 h before sacrifice). The ovaries were examined using B-mode US on days 1, 14, and 21, and the histopathological examinations of the ovaries and the uterus were undertaken after sacrifice on day 22.

RESULTS

Histomorphological analyses showed that ovarian weight decreased after DOX administration in Group B but not in Group E. US revealed a transient increase in ovarian size in Group B and E, reverting to baseline levels over time, as well as a progressive increase in peritoneal fluid in Groups B and E. Group B exhibited a significant decrease in the thickness of the endometrium and myometrium and uterine cornual length, which was not observed in Group E. Histopathological examination showed that DOX caused a decline in follicular count, especially in primordial, secondary, and Graafian follicles, and resulted in follicular atresia, predominantly in Group B. Destructive degeneration/necrosis and vascular changes were most prominently seen in the corpus luteum of Groups C and B. In NAC-treated rats (Groups E and F), although germ cell damage was present, atretic follicles and vascular changes, such as hyperemia and congestion, were reduced. The anti-müllerian hormone (AMH) level was the highest in Group F.

CONCLUSIONS

NAC, an antioxidant, attenuated DOX-induced gonadotoxicity in rats.

Gynotoxic Effects of Chemotherapy and Potential Protective Mechanisms

Chemotherapy is one of the leading cancer treatments. Unfortunately, its use can contribute to several side effects, including gynotoxic effects in women. Ovarian reserve suppression and estrogen deficiency result in reduced quality of life for cancer patients and are frequently the cause of infertility and early menopause. Classic alkylating cytostatics are among the most toxic chemotherapeutics in this regard. They cause DNA damage in ovarian follicles and the cells they contain, and they can also induce oxidative stress or affect numerous signaling pathways. In vitro tests, animal models, and a few studies among women have investigated the effects of various agents on the protection of the ovarian reserve during classic chemotherapy. In this review article, we focused on the possible beneficial effects of selected hormones (anti-Müllerian hormone, ghrelin, luteinizing hormone, melatonin), agents affecting the activity of apoptotic pathways and modulating gene expression (C1P, S1P, microRNA), and several natural (quercetin, rapamycin, resveratrol) and synthetic compounds (bortezomib, dexrazoxane, goserelin, gonadoliberin analogs, imatinib, metformin, tamoxifen) in preventing gynotoxic effects induced by commonly used cytostatics. The presented line of research appears to provide a promising strategy for protecting and/or improving the ovarian reserve in the studied group of cancer patients. However, well-designed clinical trials are needed to unequivocally assess the effects of these agents on improving hormonal function and fertility in women treated with ovotoxic anticancer drugs.

Doxorubicin and other anthracyclines in cancers: Activity, chemoresistance and its overcoming

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action. The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

Protective Effect of Cimicifuga racemosa (L.) Nutt Extract on Oocyte and Follicle Toxicity Induced by Doxorubicin during In Vitro Culture of Mice Ovaries

This study evaluated the potential of Cimicifuga racemosa (L.) Nutt extract (CIMI) to reduce the deleterious effects of doxorubicin (DOXO) in oocytes, follicles and stromal cells in mice ovaries cultured in vitro. In experiment 1, mice ovaries were cultured in DMEM⁺ alone or supplemented with 5, 50 or 500 ng/mL CIMI, while in experiment 2, mice ovaries were cultured in DMEM⁺ alone or supplemented with 5 ng/mL CIMI (better concentration), 0.3 μg/mL DOXO or both. Thereafter, the ovaries were processed for histological (morphology, growth, activation, extracellular matrix configuration and stromal cell density), immunohistochemical (caspase-3) analyses. Follicle viability was evaluated by fluorescence microscopy (ethidium homodimer-1 and calcein) while real-time PCR was performed to analyses the levels of (mRNA for SOD, CAT and nuclear factor erythroid 2-related factor 2 (NRF2) analyses. The results showed that DOXO reduces the percentage of normal follicles and the density of stromal cells in cultured ovaries, but these harmful effects were blocked by CIMI. The DOXO reduced the percentage of primordial follicles, while the presence of CIMI alone did not influence percentage of primordial follicles. A higher staining for caspase-3 was seen in ovaries cultured in control medium alone or with DOXO when compared with those cultured with CIMI alone or both CIMI and DOXO. In addition, follicles from ovaries cultured with both CIMI and DOXO were stained by calcein, while those follicles cultured with only DOXO were stained with ethidium homodimer-1. Furthermore, ovaries cultured with CIMI or both CIMI and DOXO had higher levels of mRNA for SOD and CAT, respectively, than those cultured with only DOXO. In conclusion, the extract of CIMI protects the ovaries against deleterious effects of DOXO on follicular survival and ovarian stromal cells.

Development of protective agents against ovarian injury caused by chemotherapeutic drugs

BACKGROUND

Chemotherapy is one of the causes of ovarian injury and infertility. Although assisted reproductive technology helps young female patients with cancer become pregnant, preventing chemotherapy-induced ovarian injury will often possess even more significant benefits.

OBJECTIVE

We aimed at demonstrating the hazardous effects and mechanisms of ovarian injury by chemotherapeutic agents, as well as demonstrating agents that protect the ovary from chemotherapy-induced injury.

RESULTS

Chemotherapeutic agents cause death or accelerate activation of follicles and damage to the blood vessels in the ovary, resulting in inflammation. These often require drug development to protect the ovaries from injury.

CONCLUSIONS

Our findings provide a basis for the development of drugs to protect the ovaries from injury. Although there are many preclinical studies on potential protective drugs, there is still an urgent need for a large number of clinical experiments to verify their potential use.

Effects of bortezomib on mouse preimplantation embryo development in vitro

BACKGROUND

Bortezomib, a selective inhibitor of 26S proteasome, is commonly used as a chemotherapeutic agent against different types of human cancer cells. While cancer during pregnancy is a rare condition, the trends in becoming pregnant at an advanced age increase the risk of cancer associated with pregnancy. Cancers need to be treated carefully without harming the fetus during pregnancy for the patients who desire to continue their pregnancy. The aim of this study is to demonstrate the potential side effects of bortezomib as this drug has so far not been investigated during preimplantation embryo development.

MATERIALS AND METHODS

Two cell stage embryos were flushed from mated female CD1 mice and were cultured. Two-cell, eight-cell, and morula stage embryos were exposed to different concentrations of bortezomib in vitro. Morphologic alterations of the embryos were evaluated and the data were statistically analyzed.

RESULTS

Our study showed that bortezomib exposure caused a statistically significant decrease in embryo survival and developmental competence and potential rate. We detected those early stages of embryos are more susceptible to bortezomib exposure than later stages.

CONCLUSION

We indicated that bortezomib adversely affects preimplantation embryo development in a dose, time, and developmental stage dependent manner. Moreover, bortezomib treatment inhibits preimplantation embryo development and induces cytoplasmic fragmentation and cell-cycle arrest on embryos.

Can Some Anticancer Treatments Preserve the Ovarian Reserve?

BACKGROUND

Preventing premature ovarian failure (POF) is a major challenge in oncology. With conventional regimens, cytotoxicity-associated POF involves primordial follicles (PF) pool depletion by apoptosis or overactivation mechanisms, notably mediated by the ABL/TAp63 and PI3K/Akt/mTOR pathways. New anticancer treatments have been designed to target pathways implicated in tumor growth. Although concerns regarding fertility arise with these targeted therapies, we hypothesized that targeted therapies may exert off-tumor effects on PF that might delay POF. We provide an overview of evidence concerning these off-tumor effects on PF. Limitations and future potential implications of these findings are discussed.

DESIGN

PubMed was searched by combining Boolean operators with the following keywords: fertility, ovarian, follicle, anti-tumoral, cancer, targeted, cytotoxic, and chemotherapy.

RESULTS

Cisplatin-related PF apoptosis via the ABL/TAp63 pathway was targeted with a tyrosine kinase inhibitor, imatinib, in mice, but effects were recently challenged by findings on human ovarian xenografts in mice. In cyclophosphamide-treated mice, PI3K/Akt/mTOR pathway inhibition with mTOR inhibitors and AS101 preserved the PF pool. Proteasome and GSK3 inhibitors were evaluated for direct and indirect follicle DNA damage prevention. Surprisingly, evidence for cytotoxic drug association with PF pool preservation was found. We also describe selected non-anticancer molecules that may minimize gonadotoxicity.

CONCLUSION

Not all anticancer treatments are associated with POF, particularly since the advent of targeted therapies. The feasibility of associating a protective drug targeting PF exhaustion mechanisms with cytotoxic treatments should be evaluated, as a way of decreasing the need for conventional fertility preservation techniques. Further evaluations are required for transfer into clinical practice.

IMPLICATIONS FOR PRACTICE

Anticancer therapies are associated with infertility in 10%-70% of patients, which is the result of primordial follicles pool depletion. Alone or associated with gonadotoxic treatments, some targeted therapies may exert favorable off-targets effects on the primordial follicle pool by slowing down their exhaustion. Current evidence of these effects relies on murine models or human in vitro models. Evaluation of these protective strategies in humans is challenging; however, if these results are confirmed with clinical and biological data, it not only could be a new approach to female fertility preservation but also would change standard fertility strategies.

The role of microRNAs in ovarian function and the transition toward novel therapeutic strategies in fertility preservation: from bench to future clinical application

BACKGROUND

New therapeutic approaches in oncology have converted cancer from a certain death sentence to a chronic disease. However, there are still challenges to be overcome regarding the off-target toxicity of many of these treatments. Oncological therapies can lead to future infertility in women. Given this negative impact on long-term quality of life, fertility preservation is highly recommended. While gamete and ovarian tissue cryopreservation are the usual methods offered, new pharmacological-based options aiming to reduce ovarian damage during oncological treatment are very attractive. In this vein, advances in the field of transcriptomics and epigenomics have brought small noncoding RNAs, called microRNAs (miRNAs), into the spotlight in oncology. MicroRNAs also play a key role in follicle development as regulators of follicular growth, atresia and steroidogenesis. They are also involved in DNA damage repair responses and they can themselves be modulated during chemotherapy. For these reasons, miRNAs may be an interesting target to develop new protective therapies during oncological treatment. This review summarizes the physiological role of miRNAs in reproduction. Considering recently developed strategies based on miRNA therapy in oncology, we highlight their potential interest as a target in fertility preservation and propose future strategies to make the transition from bench to clinic.

OBJECTIVE AND RATIONALE

How can miRNA therapeutic approaches be used to develop new adjuvant protective therapies to reduce the ovarian damage caused by cytotoxic oncological treatments?

SEARCH METHODS

A systematic search of English language literature using PubMed and Google Scholar databases was performed through to 2019 describing the role of miRNAs in the ovary and their use for diagnosis and targeted therapy in oncology. Personal data illustrate miRNA therapeutic strategies to target the gonads and reduce chemotherapy-induced follicular damage.

OUTCOMES

This review outlines the importance of miRNAs as gene regulators and emphasizes the fact that insights in oncology can inspire new adjuvant strategies in the field of onco-fertility. Recent improvements in nanotechnology offer the opportunity for drug development using next-generation miRNA-nanocarriers.

WIDER IMPLICATIONS

Although there are still some barriers regarding the immunogenicity and toxicity of these treatments and there is still room for improvement concerning the specific delivery of miRNAs into the ovaries, we believe that, in the future, miRNAs can be developed as powerful and non-invasive tools for fertility preservation.

New insights into the activities and toxicities of the old anticancer drug doxorubicin

The anthracycline drug doxorubicin is among the most used—and useful—chemotherapeutics. While doxorubicin is highly effective in the treatment of various hematopoietic malignancies and solid tumours, its application is limited by severe adverse effects, including irreversible cardiotoxicity, therapy‐related malignancies and gonadotoxicity. This continues to motivate investigation into the mechanisms of anthracycline activities and toxicities, with the aim to overcome the latter without sacrificing the former. It has long been appreciated that doxorubicin causes DNA double‐strand breaks due to poisoning topoisomerase II. More recently, it became clear that doxorubicin also leads to chromatin damage achieved through eviction of histones from select sites in the genome. Evaluation of these activities in various anthracycline analogues has revealed that chromatin damage makes a major contribution to the efficacy of anthracycline drugs. Furthermore, the DNA‐damaging effect conspires with chromatin damage to cause a number of adverse effects. Structure–activity relationships within the anthracycline family offer opportunities for chemical separation of these activities towards development of effective analogues with limited adverse effects. In this review, we elaborate on our current understanding of the different activities of doxorubicin and their contributions to drug efficacy and side effects. We then offer our perspective on how the activities of this old anticancer drug can be amended in new ways to benefit cancer patients, by providing effective treatment with improved quality of life.

Ovarian damage from chemotherapy and current approaches to its protection

BACKGROUND

Anti-cancer therapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicle reserve is extremely sensitive to the effects of chemotherapy and radiotherapy. While oocyte, embryo and ovarian cortex cryopreservation can help some women with cancer-induced infertility achieve pregnancy, the development of effective methods to protect ovarian function during chemotherapy would be a significant advantage.

OBJECTIVE AND RATIONALE

This paper critically discusses the different damaging effects of the most common chemotherapeutic compounds on the ovary, in particular, the ovarian follicles and the molecular pathways that lead to that damage. The mechanisms through which fertility-protective agents might prevent chemotherapy drug-induced follicle loss are then reviewed.

SEARCH METHODS

Articles published in English were searched on PubMed up to March 2019 using the following terms: ovary, fertility preservation, chemotherapy, follicle death, adjuvant therapy, cyclophosphamide, cisplatin, doxorubicin. Inclusion and exclusion criteria were applied to the analysis of the protective agents.

OUTCOMES

Recent studies reveal how chemotherapeutic drugs can affect the different cellular components of the ovary, causing rapid depletion of the ovarian follicular reserve. The three most commonly used drugs, cyclophosphamide, cisplatin and doxorubicin, cause premature ovarian insufficiency by inducing death and/or accelerated activation of primordial follicles and increased atresia of growing follicles. They also cause an increase in damage to blood vessels and the stromal compartment and increment inflammation. In the past 20 years, many compounds have been investigated as potential protective agents to counteract these adverse effects. The interactions of recently described fertility-protective agents with these damage pathways are discussed.

WIDER IMPLICATIONS

Understanding the mechanisms underlying the action of chemotherapy compounds on the various components of the ovary is essential for the development of efficient and targeted pharmacological therapies that could protect and prolong female fertility. While there are increasing preclinical investigations of potential fertility preserving adjuvants, there remains a lack of approaches that are being developed and tested clinically.

Response of preantral follicles exposed to quinoxaline: A new compound with anticancer potential

The culture of preantral follicles as an in vitro model to evaluate the toxicity of new anticancer drug has being established. Therefore, the aim of this study was to evaluate the effect of quinoxaline derivative the 2 2- (XYZC 6H 3 -CH=N-NH)-quinoxaline, 1 (QX) on caprine preantral follicles. We evaluate the follicular morphology and activation, proliferation and apoptosis of granulosa cells and finally the protein (ABCB1) and genes expression (cyclin/Cdks), respectively involved in multidrug resistance and cell cycle progression. Ovarian fragments containing primordial and developing follicles were exposed (in vitro culture) to different concentrations of QX (QX1.5, QX3.0 or QX6.0 μM/mL) during 6 days. To evaluate the effect of QX, the ovarian tissue was exposed to Paclitaxel 0.1 μg/mL (PTX - negative control) or in culture media without QX (MEM). At the end of exposure time, we realized that the QX (all concentrations) increased (P < .05) the normal morphology of preantral follicles compared to control (not treated ovarian tissue) or MEM. However, QX6.0 showed a enhanced (P < .05) on follicular activation (burnout) and apoptosis than QX1.5 and QX3.0. Expression of ABCB1 was similar between QX1.5 and QX6.0 and both were lower than control, MEM and PTX. Interestingly, the apoptosis rate in QX3.0 was similar to control and MEM and lower then QX1.5; QX6.0 and PTX. We conclude that quinoxaline may be a promising chemotherapeutic agent, however, other concentrations within a defined range (2-5.5 μM) could be widely investigated.

Single and combined effects of cisplatin and doxorubicin on the human and mouse ovary in vitro

Chemotherapy drugs are administered to patients using combination regimens, and as such the possibility of multiplicative effects between drugs need to be investigated. This study examines the individual and combined effects of the chemotherapy drugs cisplatin and doxorubicin on the human ovary. Although cisplatin and doxorubicin are known to affect female fertility, there is limited information about their direct effects on the human ovary, and none examining the possibility of combined, multiplicative effects of co-exposure to these drugs. Here, human ovarian biopsies were obtained from 14 women at the time of caesarean section, with 38 mouse ovaries also obtained from neonatal C57Bl/6J mice. Tissue was cultured for 6 days prior to analyses, with chemotherapy drugs added to culture medium on the second day of culture only. Treatment groups of a single (5 μg/mL human; 0.5 μg/mL mouse) or double (10 μg/mL human; 1.0 μg/mL mouse) dose of cisplatin, a single (1 μg/mL human; 0.05 μg/mL mouse) or double (2 μg/mL human; 0.1 μg/mL mouse) dose of doxorubicin or a combination of a single dose of both drugs together were compared to controls without drug exposure. Exposure to cisplatin or doxorubicin significantly decreased follicle health in human and mouse, supporting the suitability of the mouse as a model for the human ovary. There was also a significant reduction of mouse follicle number. Human ovarian stromal tissue exhibited increased apoptosis and decreased cell proliferation. Crucially, there was no evidence indicating the occurrence of multiplicative effects between cisplatin and doxorubicin.

The Impact of Chemotherapy on the Ovaries: Molecular Aspects and the Prevention of Ovarian Damage

Cancer treatment, such as chemotherapy, induces early ovarian follicular depletion and subsequent infertility. In order to protect gametes from the gonadotoxic effects of chemotherapy, several fertility preservation techniques—such as oocyte or embryo cryopreservation with or without ovarian stimulation, or cryopreservation of the ovarian cortex—should be considered. However, these methods may be difficult to perform, and the future use of cryopreserved germ cells remains uncertain. Therefore, improving the methods currently available and developing new strategies to preserve fertility represent major challenges in the area of oncofertility. Animal and ovarian culture models have been used to decipher the effects of different cytotoxic agents on ovarian function and several theories regarding chemotherapy gonadotoxicity have been raised. For example, cytotoxic agents might (i) have a direct detrimental effect on the DNA of primordial follicles constituting the ovarian reserve and induce apoptosis; (ii) induce a massive growth of dormant follicles, which are then destroyed; or (ii) induce vascular ovarian damage. Thanks to improvements in the understanding of the mechanisms involved, a large number of studies have been carried out to develop molecules limiting the negative impact of chemotherapy on the ovaries.

Ovarian Follicle Depletion Induced by Chemotherapy and the Investigational Stages of Potential Fertility-Protective Treatments-A Review

Ovarian follicle pool depletion, infertility, and premature menopause are all known sequelae of cancer treatment that negatively impact the quality of life of young cancer survivors. The mechanisms involved in this undesired iatrogenic ovarian damage have been intensively studied, but many of them remain unclear. Several chemotherapeutic drugs have been shown to induce direct and indirect DNA-damage and/or cellular stress, which are often followed by apoptosis and/or autophagy. Damage to the ovarian micro-vessel network induced by chemotherapeutic agents also seems to contribute to ovarian dysfunction. Another proposed mechanism behind ovarian follicle pool depletion is the overactivation of primordial follicles from the quiescent pool; however, current experimental data are inconsistent regarding these effects. There is great interest in characterizing the mechanisms involved in ovarian damage because this might lead to the identification of potentially protective substances as possible future therapeutics. Research in this field is still at an experimental stage, and further investigations are needed to develop effective and individualized treatments for clinical application. This review provides an overview of the current knowledge and the proposed hypothesis behind chemotherapy-induced ovarian damage, as well as current knowledge on possible co-treatments that might protect the ovary and the follicles from such damages.

Epigallocatechin-3-gallate inhibits doxorubicin-induced inflammation on human ovarian tissue

Chemotherapy protocol can destroy the reproductive potential of young cancer patients. Doxorubicin (DOX) is a potent anthracycline commonly used in the treatment of numerous malignancies. The purpose of the study was to evaluate the ovarian toxicity of DOX via inflammation and the possible protective effect of the green tea polyphenol epigallocatechin-3-gallate (EGCG). Ovarian tissue of three patients was cultured with 1 µg/ml DOX and/or 10 µg/ml EGCG for 24 and 48 h. Levels of inflammatory factors were determined by quantitative Real-Time PCR, western blot, zimography, and multiplex bead-based immunoassay. Morphological evaluation, damaged follicle count and TUNEL assay were also performed. DOX influenced inflammatory responses by inducing a significant increase in the expression of pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and cyclooxigenase-2 (COX-2), of inflammatory interleukins (IL), such as interleukin-6 (IL-6) and interleukin-8 (IL-8), and the inflammatory proteins mediators metalloproteinase-2 and metalloproteinase-9 (MMP2 and MMP9). IL-8 secretion in the culture supernatants and MMP9 activity also significantly raised after DOX treatment. Moreover, a histological evaluation of the ovarian tissue showed morphological damage to follicles and stroma after DOX exposure. EGCG significantly reduced DOX-induced inflammatory responses and improved the preservation of follicles. DOX-induced inflammation could be responsible for the ovarian function impairment of chemotherapy. EGCG could have a protective role in reducing DOX-mediated inflammatory responses in human ovarian tissue.

In vitro culture systems as an alternative for female reproductive toxicology studies

Studies have shown that daily exposure to different products, whether chemical or natural, can cause irreversible damage to women’s reproductive health. Therefore it is necessary to use tests that evaluate the safety and efficacy of these products. Most reproductive toxicology tests are performedin vivo. However, in recent years, various cell culture methods, including embryonic stem cells and tissues have been developed with the aim of reducing the use of animals in toxicological tests. This is a major advance in the area of toxicology, as these systems have the potential to become a widely used tool compared within vivotests routinely used in reproductive biology and toxicology. The present review describes and highlights data onin vitroculture processes used to evaluate reproductive toxicity as an alternative to traditional methods usingin vivotests.

Doxorubicin Has Dose-Dependent Toxicity on Mouse Ovarian Follicle Development, Hormone Secretion, and Oocyte Maturation

Doxorubicin (DOX), one of the most commonly used anticancer medications, has been reported to affect fertility by damaging ovarian follicles; however, the dose-dependent toxicity of DOX on the dynamic follicle development and oocyte maturation has not been well-defined. Our objective is to determine the effects of human-relevant exposure levels of DOX on follicular functions across developmental time. In vitro cultured multilayered secondary mouse follicles were treated with DOX at 0, 2, 20, 100, and 200 nM for 24 h, and follicle development, hormone secretion, and oocyte maturation were analyzed. DOX caused dose-dependent toxicity on follicle growth, survival, and secretion of 17β-estradiol (E2). At 200 nM, DOX induced DNA damage and apoptosis in follicle somatic cells first and then in oocytes, which was correlated with the uptake of DOX first to the somatic cells followed by germ cells. Follicles treated with DOX at 0, 2, and 20 nM showed similar oocyte metaphase II (MII) percentages after in vitro oocyte maturation; however, 20 nM DOX significantly increased the number of MII oocytes with abnormal spindle morphology and chromosome misalignment. In an effort to harmonize the in vitro study to in vivo treatment, dose-dependent toxicity on oocyte meiotic maturation was found in 16-day-old CD-1 mice treated with DOX at 0, 0.4, 2, and 10 mg/kg, consistent with the in vitro oocyte maturation outcomes. Our study demonstrates that DOX has dose-dependent toxicity on ovarian follicle development, hormone secretion, and oocyte maturation, which are three key factors to support the female reproductive and endocrine functions.

Pediatric and Teen Ovarian Tissue Removed for Cryopreservation Contains Follicles Irrespective of Age, Disease Diagnosis, Treatment History, and Specimen Processing Methods

PURPOSE

Fertility preservation in a pediatric and teen female population is challenging because standard technologies of egg and embryo freezing may not be possible due to premenarcheal status. Ovarian tissue cryopreservation (OTC) with the intent of future ovarian tissue transplantation or in vitro follicle growth may be the only option to preserve fertility. The purpose of this study was to add to the general understanding of primordial follicle dynamics in young patients.

METHODS

First, the unique infrastructure of the Oncofertility Consortium National Physicians Cooperative (OC-NPC) is described, which simultaneously drives clinical fertility preservation and basic research to explore and expand the reproductive options for those in need. Then, the OC-NPC research resource is used to perform a histological evaluation of ovarian tissue from 24 participants younger than 18 years of age.

RESULTS

Primordial follicles, which comprise the ovarian reserve, were observed in all participant tissues, irrespective of variables, including age, diagnosis, previous treatment history, tissue size, and tissue processing methods. Primordial follicles were present in ovarian tissue, even in participants who had a previous history of exposure to chemotherapy and/or radiation treatment regimens, which placed them at risk for iatrogenic infertility or premature ovarian failure.

CONCLUSION

Primordial follicles were observed in ovarian tissue from all participants examined, despite population and tissue heterogeneity. These results increase the understanding of human follicle dynamics and support OTC as a promising fertility preservation modality in the young female population. Future studies to evaluate follicle quality within these tissues are warranted.

An ovarian bioreactor for in vitro culture of the whole bovine ovary: a preliminary report

Background

Improved cancer therapeutics and enhanced cancer survivorship have emphasized the severe long-term side effects of chemotherapy. Specifically, studies have linked many chemotherapy agents with primary ovarian insufficiency, although an exact insult model has not yet been determined. To investigate and ultimately solve this problem, a novel device for extended study of mammalian ovaries in vitro was developed.

Methods

A bioreactor was fabricated for bovine ovarian culture that provides intravascular delivery of media to the ovary through isolation and cannulation of a main ovarian artery branch. Whole ovaries were cultured in vitro using three methods: (1) continuously supplied fresh culture media, (2) recirculated culture media, or (3) continuously supplied fresh culture media supplemented with 500 nM doxorubicin for 24 or 48 h. TUNEL assay was used to assess apoptotic cell percentages in the three groups as compared to uncultured baseline ovaries.

Results

The ovary culture method was shown to maintain cell viability by effectively delivering nutrient-enriched pH-balanced media at a constant flow rate. Lower apoptosis observed in ovaries cultured in continuously supplied fresh culture media illustrates that this culture device and method are the first to sustain whole bovine ovary viability for 48 h. Meanwhile, the increase in the percentage of cell apoptosis with doxorubicin treatment indicates that the device can provide an alternative model for testing chemotherapy and chemoprotection treatments to prevent primary ovarian insufficiency in cancer patients.

Conclusions

An ovarian bioreactor with consistent culture media flow through an ovarian vasculature-assisted approach maintains short-term whole bovine ovary viability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-016-0249-4) contains supplementary material, which is available to authorized users.

Doxorubicin and cisplatin induce apoptosis in ovarian stromal cells obtained from cryopreserved human ovarian tissue

AIM

To investigate mechanisms by which doxorubicin (DOX) and cisplatin (CIS) cause human ovarian stroma injury.

PATIENTS & METHODS

Stromal cells from human cryopreserved ovarian tissue were cultured in the presence of 1 µM DOX and 10 µM CIS. Ovarian damage induced by treatments was evaluated by 'Live/Dead' and sulforhodamine-B assays, the expression of different apoptosis markers.

RESULTS

Stromal cell growth was inhibited by DOX and CIS, and this effect was accompanied by apoptosis through mitochondrial pathway activation: Bax, cleaved-caspase 9, cleaved-PARP1 induction and Akt1, Bcl2, phospho-44/42-MAPK/ERK1/2 reduction were observed.

CONCLUSION

DOX and CIS induced apoptosis in human ovarian stromal cells. Knowledge of mechanisms by which the drugs act is important to identify possible ways to counteract side effects of chemotherapy on ovaries.

Dexrazoxane Diminishes Doxorubicin-Induced Acute Ovarian Damage and Preserves Ovarian Function and Fecundity in Mice

Advances in cancer treatment utilizing multiple chemotherapies have dramatically increased cancer survivorship. Female cancer survivors treated with doxorubicin (DXR) chemotherapy often suffer from an acute impairment of ovarian function, which can persist as long-term, permanent ovarian insufficiency. Dexrazoxane (Dexra) pretreatment reduces DXR-induced insult in the heart, and protects in vitro cultured murine and non-human primate ovaries, demonstrating a drug-based shield to prevent DXR insult. The present study tested the ability of Dexra pretreatment to mitigate acute DXR chemotherapy ovarian toxicity in mice through the first 24 hours post-treatment, and improve subsequent long-term fertility throughout the reproductive lifespan. Adolescent CD-1 mice were treated with Dexra 1 hour prior to DXR treatment in a 1:1 mg or 10:1 mg Dexra:DXR ratio. During the acute injury period (2-24 hours post-injection), Dexra pretreatment at a 1:1 mg ratio decreased the extent of double strand DNA breaks, diminished γH2FAX activation, and reduced subsequent follicular cellular demise caused by DXR. In fertility and fecundity studies, dams pretreated with either Dexra:DXR dose ratio exhibited litter sizes larger than DXR-treated dams, and mice treated with a 1:1 mg Dexra:DXR ratio delivered pups with birth weights greater than DXR-treated females. While DXR significantly increased the "infertility index" (quantifying the percentage of dams failing to achieve pregnancy) through 6 gestations following treatment, Dexra pretreatment significantly reduced the infertility index following DXR treatment, improving fecundity. Low dose Dexra not only protected the ovaries, but also bestowed a considerable survival advantage following exposure to DXR chemotherapy. Mouse survivorship increased from 25% post-DXR treatment to over 80% with Dexra pretreatment. These data demonstrate that Dexra provides acute ovarian protection from DXR toxicity, improving reproductive health in a mouse model, suggesting this clinically available drug may provide ovarian protection for cancer patients.

Hydrogel Based 3-Dimensional (3D) System for Toxicity and High-Throughput (HTP) Analysis for Cultured Murine Ovarian Follicles

Various toxicants, drugs and their metabolites carry potential ovarian toxicity. Ovarian follicles, the functional unit of the ovary, are susceptible to this type of damage at all stages of their development. However, despite of the large scale of potential negative impacts, assays that study ovarian toxicity are limited. Exposure of cultured ovarian follicles to toxicants of interest served as an important tool for evaluation of toxic effects for decades. Mouse follicles cultured on the bottom of a culture dish continue to serve an important approach for mechanistic studies. In this paper, we demonstrated the usefulness of a hydrogel based 3-dimensional (3D) mouse ovarian follicle culture as a tool to study ovarian toxicity in a different setup. The 3D in vitro culture, based on fibrin alginate interpenetrating network (FA-IPN), preserves the architecture of the ovarian follicle and physiological structure-function relationship. We applied the novel 3D high-throughput (HTP) in vitro ovarian follicle culture system to study the ovotoxic effects of an anti-cancer drug, Doxorobucin (DXR). The fibrin component in the system is degraded by plasmin and appears as a clear circle around the encapsulated follicle. The degradation area of the follicle is strongly correlated with follicle survival and growth. To analyze fibrin degradation in a high throughput manner, we created a custom MATLAB® code that converts brightfield micrographs of follicles encapsulated in FA-IPN to binary images, followed by image analysis. We did not observe any significant difference between manually processed images to the automated MATLAB® method, thereby confirming that the automated program is suitable to measure fibrin degradation to evaluate follicle health. The cultured follicles were treated with DXR at concentrations ranging from 0.005 nM to 200 nM, corresponding to the therapeutic plasma levels of DXR in patients. Follicles treated with DXR demonstrated decreased survival rate in greater DXR concentrations. We observed partial follicle survival of 35% ± 3% (n = 80) in 0.01nM treatment and 48% ± 2% (n = 92) in 0.005nM, which we identified as the IC50 for secondary follicles. In summary, we established a 3D in vitro ovarian follicle culture system that could be used in an HTP approach to measure toxic effects on ovarian follicles.

Dexrazoxane abrogates acute doxorubicin toxicity in marmoset ovary

Preservation of ovarian function following chemotherapy for nonovarian cancers is a formidable challenge. For prepubescent girls, the only option to prevent chemotherapy damage to the ovary is ovarian tissue cryopreservation, an experimental procedure requiring invasive surgeries to harvest and reimplant tissue, which carries the risk of cancer reintroduction. Drugs that block the primary mechanism of chemotherapy insult, such as dexrazoxane (Dexra) in the context of anthracycline chemotherapy, provide a novel approach for ovarian protection and have the potential to overcome current limitations to oncofertility treatment. Dexra is a catalytic topoisomerase 2 inhibitor that protects the mouse ovary from acute doxorubicin (DXR) chemotherapy toxicity in vitro by preventing DXR-induced DNA damage and subsequent gammaH2AX activation. To translate acute DXR ovarian insult and Dexra protection from mouse to nonhuman primate, freshly obtained marmoset ovarian tissue was cultured in vitro and treated with vehicle or 20 μM Dexra 1 h prior to 50 nM DXR. Cultured ovarian tissue was harvested at 2, 4, or 24 h post-DXR treatment. Dexra prevented DXR-induced DNA double-strand breaks as quantified by the neutral comet assay. DXR treatment for 24 h increased gammaH2AX phosphorylation, specifically increasing the number of foci-positive granulosa cells in antral follicles, while Dexra pretreatment inhibited DXR-induced gammaH2AX phosphorylation foci formation. Additionally, Dexra pretreatment trended toward attenuating DXR-induced AKT1 phosphorylation and caspase-9 activation as assayed by Western blots of ovarian tissue lysates. The combined findings suggest Dexra prevents primary DXR-induced DNA damage, the subsequent cellular response to DNA damage, and may diminish early apoptotic signaling in marmoset ovarian tissue. This study provides initial translation of Dexra protection against acute ovarian DXR toxicity from mice to marmoset monkey tissue.