Tamoxifen prevents apoptosis and follicle loss from cyclophosphamide in cultured rat ovaries

Protective effects of Azilsartan against cyclophosphamide-induced ovarian toxicity in rats model

Background

Cyclophosphamide (CP) is an effective alkylating anticancer agent that is widely used in cancer chemotherapy, and it can cause ototoxicity and infertility in women.

Objectives

So, this study aimed to evaluate the protective effects of Azilsartan (AZ) as an antioxidant and anti-inflammatory agent in a rat model of CP-induced ovarian toxicity.

Materials and Methods

After receiving the 28 female Wister rats, they were acclimatized in proper environmental conditions for a week and then randomly divided into four groups based on the study protocol. After 15 days of the experiment, they were sacrificed, and organs were collected for biomarker detection (Using the ELISA technique) and histopathological analysis.

Results

The level of IL-10 was significantly (P < 0.05) decreased in all treated groups compared to control hostile groups, while the TNF-α level was significantly (P < 0.05) increased in AZ (220.67 ± 7.88 ng/mL) and AZ + CP groups (221.78 ± 9.11 ng/mL) compared to control negative/CP groups. Regarding the oxidative biomarker level, a significant increase was only found in the AZ + CP group (176.02 ± 6.71 nmol/mL) compared to the control negative group. On the other hand, histopathological findings revealed that ovarian sections in animals that received a single dose of CP had severe ovarian atrophy with significant follicular regression and deterioration, as well as depletion of stromal supportive tissues.

Conclusions

Azilsartan drastically reduced CP-induced ovarian toxicity in vivo by enhancing oxidative stress and inhibiting inflammatory effects in ovarian cells.

The Effect of Tamoxifen Citrate on Granulosa Cells of Ovarian Follicles in Adult Female Rats: Light Microscopic Study

Background

Tamoxifen is a drug that has been used extensively as a chemotherapeutic agent for breast cancer. It should be taken for a long period, from few weeks up to many years, so it can induce gynecological and nongynecological complications.

Aim

Present study was conducted to clarify the histopathological effects of tamoxifen intake on the ovarian follicles of rats and evaluate the promising recovery after drug withdrawal.

Materials and Methods

Adult female albino rats (n = 24) were randomly divided into four groups. Group I: Control rats without treatment. Group II: Rats received olive oil vehicle. Group III: Rats received 5 mg/kg daily of tamoxifen dissolved in olive oil by oral administration for 4 weeks. Group IV: Rats received tamoxifen as in Group III then will be kept for another 4 weeks without treatment for recovery. Then, the rats were anaesthetized and the ovaries were removed and prepared for histological assessment by light microscope.

Results

The ovarian histological findings in the ovary of Group III revealed an increase in atretic ovarian follicles, appearance of cystic ovarian follicles, and cystic corpus luteum. The granulosa cells of ovarian follicles were disorganized with vacuolation of their cytoplasm, increased number of pyknotic nuclei, fragmented nuclei, and apoptotic bodies. After the withdrawal of drug, the ovarian tissue showed slight improvement with the appearance of some atretic follicles with degenerated oocyte and stromal hyperplasia.

Conclusion

Based on the results, tamoxifen induced marked histological changes in the ovary. If tamoxifen is mandatory for the prevention of breast cancer, frequent gynecological examination should be carried out to detect any side effects.

Tamoxifen decreases ovarian toxicity without compromising cancer treatment in a rat model of mammary cancer

BACKGROUND

Premenopausal women diagnosed with breast cancer often face aggressive chemotherapy resulting in infertility. Tamoxifen (TAM) is a selective estrogen receptor modulator that was previously suggested as a protective agent against chemotherapy-induced ovarian failure. In the current study, we examined mechanisms of the protective action of TAM in the ovaries of tumor-bearing rats treated with the chemotherapy drug cyclophosphamide (CPA).

RESULTS

TAM prevented CPA-induced loss of ovarian follicular reserves. The protective TAM effect in the rat ovary partially resulted from decreased apoptosis. In addition, transcriptomic and proteomic screening also implicated the importance of DNA repair pathways as well as cell adhesion and extracellular matrix remodeling in the protective ovarian actions of TAM.

CONCLUSIONS

Tamoxifen shielded the ovary from the side effects of chemotherapy without lessening the tumoricidal actions of mammary cancer treatment.

Cyclophosphamide induced intestinal injury is alleviated by blocking the TLR9/caspase3/GSDME mediated intestinal epithelium pyroptosis

OBJECTIVES

Cyclophosphamide (CYC) was commonly used to treat autoimmune disorders, and it could also cause side effects such as intestinal damage. This study aimed to explore the mechanism of CYC-induced intestinal cytotoxicity and provide evidence for protecting from intestinal damage by blocking TLR9/caspase3/GSDME mediated pyroptosis.

METHODS

Intestinal epithelial cells (IEC-6) were treated with 4-hydroxycyclophosphamide (4HC), a key active metabolite of CYC. The pyroptotic rate of IEC-6 cells was detected by Annexin V/PI-Flow cytometry, microscopy imaging, and PI staining. The expression and activation of TLR9, caspase3 and GSDME in IEC-6 cells were detected by western blot and immunofluorescence staining. In addition, hydroxychloroquine (HCQ) and ODN2088 were used to inhibit TLR9 to investigate the role of TLR9 on caspase3/GSDME-mediated pyroptosis. Finally, mice lacking Gsdme or TLR9 or pretreating with HCQ were injected intraperitoneally with CYC, and the incidence and severity of intestinal damage were assessed.

RESULTS

CYC induced lytic cell death in IEC-6 cells and increased the expression of TLR9, activated caspase3, and GSDME-N. Besides, both ODN2088 and HCQ could inhibit CYC-induced pyroptosis in IEC-6 cells. In vivo, CYC-induced intestinal injury was characterized by a large amount of intestinal villi abscission and structural disordered. Gsdme or TLR9 deficiency, or pretreatment of HCQ effectively attenuated intestinal damage in CYC-induced model mice.

CONCLUSIONS

These results indicate an alternative mechanism for CYC-induced intestinal damage, which actives TLR9/caspase3/GSDME signaling pathway, leading to pyroptosis of intestinal epithelial cells. And targeting pyroptosis might be a potential therapeutic approach for CYC-induced intestinal damage.

Ovarian scaffolds promoted mouse ovary recovery from cyclophosphamide damage

There is growing evidence to suggest that scaffold of tissue can promote the tissue reparation. In this study, we investigate the effects of ovarian scaffolds on the reparation of cyclophosphamide (CPA) damaged mice ovaries. The mice were first administered with CPA, was then either transplanted an ovarian scaffold into each ovarian bursa for the experimental group (EG) or underwent sham surgery as the control (CG). To evaluate the extent of ovarian damage caused by CPA, a third group which did not undergo any treatment was included for the normal control (NG). Their ovaries were harvested for examination at day 30, 60, and 90 post CPA injection. We found that in EG, the number of all types of follicles in the ovaries remained almost the same throughout. The numbers of follicles were not significantly different from CG, except at day 60, where in CG the numbers of each type of follicle decreased to basal levels. The decrease in the number of ovarian follicles at day 60 in CG was mirrored by the significant increase in the number of apoptotic granulosa cells in the follicles, and was corroborated further by the basal levels of serum estradiol. Furthermore, we observed a significant decrease in collagen composition preceded by macrophage polarization, and elevation of inflammatory cytokine expression in the ovaries of the EG compared to the CG at day 60. We concluded that ovarian scaffolds can effectively protect primordial follicles from CPA-damage and promote the reparation of CPA-damaged ovaries. This research establishes a proof of concept for the future treatment of chemo-damaged ovaries.

An evaluation of the effects on the ovaries of hyperbaric oxygen therapy in a rat model of premature ovarian failure created with cyclophosphamide

Objective

To evaluate hyperbaric oxygen therapy (HBO) based on ovarian histology, total antioxidant status (TAS), total oxidant status (TOS), and anti-müllerian hormone (AMH), in the ovarian insufiency (POI) model created with cyclophosphamide (CYP).

Materials and Methods

The rats were separated into 3 groups of the control group (n=6), the CYP group (n=6), and the CYP+HBO group (n=6). The rats in the CYP group and the CYP+HBO group were injected intraperitoneally with 200 mg/kg CYP on day 1, followed by 8 mg/kg/day for 14 days to create POI. From the 15^th day onwards, the rats in the CYP+HBO group were placed in a hyperbaric cabin and exposed to 100% oxygen at 2.4 atm pressure for one h, and were then returned to their cages at the end of the hour.

Results

A statistically significant decrease was determined in the primordial and primary follicle counts in the CYP group compared with the control group (p<0.05). In the CYP+HBO group, a statistically significant increase was determined in the primordial and primary follicle counts (p<0.05). The serum AMH levels were seen to be significantly decreased in the CYP group compared with both the control group and the CYP+HBO groups. The HBO was seen to decrease TOS and increase TAS.

Conclusion

HBO could be an alternative treatment to minimize the effect of ovarian follicle loss caused by CYP, which is used for treating tumors that commonly occur in young females of reproductive age.

Identification of Common and Specific Genes Involved in Mouse Models of Age-Related and Cyclophosphamide-Induced Diminished Ovarian Reserve

Diminished ovarian reserve (DOR) is an etiologically heterogeneous disorder that usually leads to poor reproductive outcomes. Does a specific or common pathogenesis exist for DOR subtypes with different etiologies? Two frequently used mouse models, age-related DOR (AR-DOR) and cyclophosphamide (CTX)-induced DOR (CTX-DOR), were successfully established, and RNA sequencing was performed on ovarian tissue samples. Differentially expressed genes (DEGs) in each subtype and common DEGs (co-DEGs) in the two subtypes were identified. Subsequently, we performed comprehensive bioinformatics analyses, including an evaluation of immune cell infiltration. Finally, the genes of interest were further validated by performing RT-qPCR and immunohistochemistry. In AR-DOR mice, functional enrichment analyses showed that upregulated DEGs were mainly involved in the inflammatory/immune response, while downregulated DEGs were involved in DNA damage repair. In CTX-DOR mice, the inflammatory/immune response and cell apoptosis played significant roles. Meanwhile, 406 co-DEGs were identified from the two models. The biological functions of these co-DEGs were associated with inflammatory/immune responses. The analysis of immune cell infiltration showed reduced infiltration of Treg cells, as well as increased infiltration of M0 macrophages, NK resting, and T cells CD4 follicular in both DOR subtypes. The results of the validation experiments were consistent with the RNA sequencing data. In conclusion, the inflammatory/immune response might be the common pathogenesis for the two DOR subtypes, while DNA repair and cell apoptosis may have different roles in the two subtypes. These results may provide potential insights for mechanistic research and therapeutic targets of DOR.

Prevalence of Potential Pharmacological Interactions in Patients Undergoing Systemic Chemotherapy in a Tertiary Hospital

Introduction: Pharmacological interactions are frequently observed in patients with chronic diseases, and their occurrence is proportional to the amount of medication used daily. Patients undergoing chemotherapy treatment commonly have comorbidities, which favor a greater prevalence of polypharmacy, increasing the risk of drug interactions. Therefore, the aim of this study was to estimate the prevalence of drug interactions in patients undergoing intravenous chemotherapy treated at a hospital oncology service in southern Brazil. Methods: This was an observational study with a cross-sectional design that was carried out with the analysis of secondary data obtained through the review of medical records. The population assessed consisted of all cancer patients who received intravenous chemotherapy from October to December 2020. Results: Out of the 297 patients included in the study, 231 (77.8%) had at least 1 potential pharmacological interaction. In total, 1044 drug interactions were found that were classified according to severity, resulting in 18 (1.7%) contraindicated drug-drug interactions (DDI), 699 (67%) severe, 281 (26.9%) moderate, and 46 (4.4%) minor interactions. There was an association between polypharmacy and the prevalence of drug interactions. Conclusion: The results demonstrate that a large percentage of patients undergoing chemotherapy are susceptible to drug interactions. Thus, it is necessary that prescribers consider all drugs used by patients and, when possible, prescribe alternative drugs that have less potential for interaction in order to prevent drug interactions adverse effects and provide a better prognosis for patients.

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.

In vitro cytotoxic effects of 5-Fluorouracil on isolated murine ovarian preantral follicles

5 fluorouracil (5FU), an antineoplastic drug, is often utilized in the therapeutic regimen for several types of cancer, including the hepatoblastoma in children. The effects of 5FU on the population of ovarian preantral follicles, which is the largest oocyte reservoir, is still poorly understood. The integrity of the ovarian preantral follicle pool is important for lifelong fertility. The better understanding of such effects may favor intervention strategies to protect fertility in 5FU-treated children and women coping with cancer. To analyze the effects of 5FU on isolated murine secondary follicles in vitro, ovaries were collected from young mice (28-30 days old), and secondary follicles were isolated and cultured for 12 days in basic culture medium, with or without 5FU at concentrations of 0.3 mM, 1 mM, 3 mM, 10 mM, and 30 mM. In the in vitro study, we analyzed the percentage of morphologically normal follicles, antrum formation, follicular diameter, and hormone production. On day 12, oocytes were recovered for in vitro maturation. 5FU treatment did not alter the percentage of morphologically normal follicles. On day 12, only 1, 10, and 30 mM 5FU significantly reduced the percentage of antrum. From day 4 onwards, 5FU treatments significantly reduced follicle diameter. The meiosis resumption rate was significantly lower in all 5FU treatments. 5FU concentrations ≥3 mM reduced estradiol levels. In conclusion, 5FU does not affect follicular morphology. However, 5FU deleteriously affects follicular growth, estradiol production, and oocyte maturation in isolated ovarian follicles.

Melatonin Attenuates Cyclophosphamide-Induced Primordial Follicle Loss by Interaction with MT1 Receptor and Modulation of PTEN/Akt/FOXO3a Proteins in the Mouse Ovary

This study evaluated the protective effect of melatonin before cyclophosphamide administration on ovarian function and its potential mechanism in a mouse model. Two studies were performed. In the first, mice were pretreated with melatonin (10, 20, or 30 mg/kg body weight, i.p.) once daily for 3 days, followed by injection with a single dose of cyclophosphamide (200 mg/kg body weight, i.p.) 30 min after the last melatonin injection. The second study analyzed whether melatonin type 1 and/or 2 receptors mediate the effects of melatonin on the ovary through administration of non-selective MT₁/MT₂ antagonist (luzindole) or selective MT₂ antagonist (4-PPDOT) before the treatment with melatonin plus cyclophosphamide. After treatment groups, the ovaries were harvested and destined to histology, immunohistochemistry, and fluorescence analyses. Lastly, we examined the p-PTEN, p-Akt, and p-FOXO3a participation in the protective effect of melatonin in cyclophosphamide-induced ovarian damage. Results demonstrated that pretreatment with 20 mg/kg melatonin before cyclophosphamide administration showed more morphologically normal follicles, attenuated primordial follicle loss, decreased growing follicle atresia and mitochondrial damage, and increased GSH concentrations. Furthermore, treatment with luzindole blocked the protective effects of melatonin against the damage caused by cyclophosphamide. Additionally, pretreatment with 20 mg/kg melatonin regulated the PTEN/Akt/FOXO3a signaling pathway components after cyclophosphamide treatment. In conclusion, pretreatment with 20 mg/kg melatonin prevented primordial follicle loss and reduced apoptosis and oxidative damage in the mouse ovary during experimental chemotherapy with cyclophosphamide. Furthermore, the MT₁ receptor and PTEN/Akt/FOXO3a proteins mediated these cytoprotective effects.

Detrimental effect of Bisphenol S in mouse germ cell cyst breakdown and primordial follicle assembly

The female reproductive lifespan is largely determined by the size of primordial follicle pool, which is established in early life. Bisphenol S (BPS), frequently present in plastic products used in daily life, has been demonstrated as an exogenous estrogen-like endocrine disrupting chemical interfering with the endocrine and reproductive systems. However, the molecular mechanisms of its reproductive toxicity remain to be determined. In the present study, we focused on the effect of BPS on the early ovarian folliculogenesis of mice. Our in vivo experiments showed that the treatment with BPS at 2 and 10 μg/kg body weight/day for 3 days induced abnormal germ cell cyst breakdown and primordial follicle assembly in the mouse ovary, further affecting later ovarian differentiation and reducing oocyte quality. In addition, our in vitro study demonstrated that BPS could interact with estrogen receptors (ERs) to induce phosphorylation of JNKs, which is responsible for reducing oocyte adhesion in cysts. Meanwhile, BPS exposure up-regulated Notch signaling pathway to increase the proliferation of granulosa cells precursors. Our study provided new evidence for the adverse effects of BPS on female reproduction, especially after perinatal exposure, and elucidated how it works.

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.

Cilostazol protects against cyclophosphamide-induced ovarian toxicity in female rats: role of cAMP and HO-1

Purpose: Cancer rates have been increased among women of reproductive age nowadays. Hence, many young female will be exposed to chemotherapeutic agents as cyclophosphamide (CP), carrying the hazards on female fertility. Cilostazol is a selective phosphodiesterase-3 inhibitor drug which exhibits antioxidant, anti-inflammatory, and anti-apoptotic activities. We aimed in this study to explore the possible protective effects of cilostazol against CP-induced ovarian damage in female rats.Methods: Cilostazol (10 mg/kg/day) was administered orally for 10 days in presence and absence of CP (150 mg/kg IP single dose) treatment. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and anti-Müllerian hormone (AMH) levels were determined. Ovarian oxidative stress parameters along with inflammatory biomarkers were measured. 3,5-Cyclic adenosine monophosphate (cAMP) ovarian level was detected. Ovarian histopathological examination and caspase-3 immunohistochemical study were evaluated.Results: CP-treated rats showed a significant increase in serum levels of FSH and LH with decreased serum E2 and AMH levels with an increase in the ovarian inflammatory and oxidative stress biomarkers besides a significant decrease in cAMP ovarian level with an evident histopathological picture of ovarian damage and a high caspase-3 immunoexpression. Cilostazol pretreatment significantly restored the distributed hormonal levels, the oxidative stress and inflammatory biomarkers to their normal levels with marked improvement in histopathological picture of ovarian damage with a significant decrease in caspase-3 immunoexpression.Conclusions: These data suggest that cilostazol protects against CP- induced ovarian damage, which may be related to an increase in cAMP with subsequent anti-inflammatory, antioxidant, and anti-apoptotic properties.

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.

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.

Multiple dose treatment reduces cyclophosphamide-induced ovarian follicular loss in mice

This study compares the effects of single dose and multiple dose treatment of cyclophosphamide (CP) on oxidative stress-mediated follicular damage in mouse ovary. In the first experiment, adult female mice were administered with a single dose of CP (100 mg/kg body weight/mouse) and autopsied 72 hr after treatment. In the second experiment, adult female mice were injected with multiple doses of CP (40 mg/kg body weight/day/mouse for 10 consecutive days) and sacrificed on Day 11. There was a 58, 48, 53, and 51% loss of primordial, primary, preantral, and antral follicles, respectively, following the administration of a single dose of CP, whereas, multiple dose of CP caused only 35% reduction in primordial follicles coupled with 28, 23, and 38%, loss of primary, preantral, and antral follicles, respectively. There was a decrease in activities of the ovarian antioxidant enzymes and increase in reactive oxygen species (ROS) and malondialdehyde (MDA) concentrations following single dose CP, whereas multiple dose treatment caused an increase in activities of these enzymes and decrease in ROS and MDA concentrations. The serum concentration of estradiol was significantly decreased following single or multiple dose treatment. The ovarian damage caused by a single high dose of CP administration is higher than that by multiple doses of smaller amount, though the total amount of CP administered was higher with multiple treatment. The results of the current study reveal the benefit of metronomic chemotherapy in cancer treatment, for its effectiveness in reducing ovarian toxicity, a major side effect in young female patients.

Impact of Taxanes, Endocrine Therapy, and Deleterious Germline BRCA Mutations on Anti-müllerian Hormone Levels in Early Breast Cancer Patients Treated With Anthracycline- and Cyclophosphamide-Based Chemotherapy

Background: Limited evidence exists on the impact of adding a taxane, using endocrine therapy and carrying a deleterious germline BRCA mutation on ovarian reserve measured by anti-müllerian hormone (AMH) levels of young breast cancer patients receiving (neo)adjuvant cyclophosphamide- and anthracycline-based chemotherapy.

Methods: This is a biomarker analysis including young (≤ 40 years) early breast cancer patients with known germline BRCA mutational status and available prospectively collected frozen plasma samples before and after chemotherapy. Chemotherapy consisted of either six cycles of FEC (5 fluorouracil 500 mg/m², epirubicin 100 mg/m², cyclophosphamide 500 mg/m²) or three cycles of FEC followed by three cycles of docetaxel (D, 100 mg/m²). Endocrine therapy consisted of tamoxifen (±GnRH agonists). AMH levels at baseline, 1 and 3 years after diagnosis were compared according to type of chemotherapy (FEC only vs. FEC-D), use of endocrine therapy (yes vs. no) and deleterious germline BRCA mutations (mutated vs. negative).

Results: Out of 148 included patients, 127 (86%) received D following FEC chemotherapy, 90 (61%) underwent endocrine therapy, and 35 (24%) had deleterious germline BRCA mutations. In the whole cohort, AMH levels drastically dropped 1 year after diagnosis (p < 0.0001) with a slight but significant recovery at 3 years (p < 0.0001). One year after diagnosis, patients treated with FEC only had higher median AMH levels than those who received FEC-D (0.22 vs. 0.04 μg/L, p = 0.0006); no difference was observed at 3 years (0.06 and 0.18 μg/L, p = 0.47). Patients under endocrine therapy had significantly higher AMH levels than those who did not receive this treatment 1 year after diagnosis (0.12 vs. 0.02 μg/L; p = 0.008), with no difference at 3 years (0.11 and 0.20 μg/L, p = 0.22). AMH levels were similar between BRCA-mutated and BRCA-negative patients at baseline (1.94 vs. 1.66 μg/L, p = 0.53), 1 year (0.09 vs. 0.06 μg/L, p = 0.39) and 3 years (0.25 vs. 0.16 μg/L; p = 0.43) after diagnosis.

Conclusions: In breast cancer patients receiving FEC chemotherapy, adding D appeared to negatively impact on their ovarian reserve in the short-term; no further detrimental effect was observed for endocrine therapy use and presence of a deleterious germline BRCA mutation.

Impact of Taxanes, Endocrine Therapy, and Deleterious Germline BRCA Mutations on Anti-müllerian Hormone Levels in Early Breast Cancer Patients Treated With Anthracycline- and Cyclophosphamide-Based Chemotherapy

Background: Limited evidence exists on the impact of adding a taxane, using endocrine therapy and carrying a deleterious germline BRCA mutation on ovarian reserve measured by anti-müllerian hormone (AMH) levels of young breast cancer patients receiving (neo)adjuvant cyclophosphamide- and anthracycline-based chemotherapy. Methods: This is a biomarker analysis including young (≤ 40 years) early breast cancer patients with known germline BRCA mutational status and available prospectively collected frozen plasma samples before and after chemotherapy. Chemotherapy consisted of either six cycles of FEC (5 fluorouracil 500 mg/m², epirubicin 100 mg/m², cyclophosphamide 500 mg/m²) or three cycles of FEC followed by three cycles of docetaxel (D, 100 mg/m²). Endocrine therapy consisted of tamoxifen (±GnRH agonists). AMH levels at baseline, 1 and 3 years after diagnosis were compared according to type of chemotherapy (FEC only vs. FEC-D), use of endocrine therapy (yes vs. no) and deleterious germline BRCA mutations (mutated vs. negative). Results: Out of 148 included patients, 127 (86%) received D following FEC chemotherapy, 90 (61%) underwent endocrine therapy, and 35 (24%) had deleterious germline BRCA mutations. In the whole cohort, AMH levels drastically dropped 1 year after diagnosis (p < 0.0001) with a slight but significant recovery at 3 years (p < 0.0001). One year after diagnosis, patients treated with FEC only had higher median AMH levels than those who received FEC-D (0.22 vs. 0.04 μg/L, p = 0.0006); no difference was observed at 3 years (0.06 and 0.18 μg/L, p = 0.47). Patients under endocrine therapy had significantly higher AMH levels than those who did not receive this treatment 1 year after diagnosis (0.12 vs. 0.02 μg/L; p = 0.008), with no difference at 3 years (0.11 and 0.20 μg/L, p = 0.22). AMH levels were similar between BRCA-mutated and BRCA-negative patients at baseline (1.94 vs. 1.66 μg/L, p = 0.53), 1 year (0.09 vs. 0.06 μg/L, p = 0.39) and 3 years (0.25 vs. 0.16 μg/L; p = 0.43) after diagnosis. Conclusions: In breast cancer patients receiving FEC chemotherapy, adding D appeared to negatively impact on their ovarian reserve in the short-term; no further detrimental effect was observed for endocrine therapy use and presence of a deleterious germline BRCA mutation.

Transient inhibition of p53 homologs protects ovarian function from two distinct apoptotic pathways triggered by anticancer therapies

Platinum-based chemotherapies can result in ovarian insufficiency by reducing the ovarian reserve, a reduction believed to result from apoptosis of immature oocytes via activation/phosphorylation of TAp63α by multiple kinases including CHEK2, CK1, and ABL1. Here we demonstrate that cisplatin (CDDP) induces oocyte apoptosis through a novel pathway and that temporary repression of this pathway fully preserves ovarian function in vivo. Although ABL kinase inhibitors effectively block CDDP-induced apoptosis of oocytes, oocytic ABL1, and ABL2 are dispensable for damage-induced apoptosis. Instead, CDDP activates TAp63α through the ATR > CHEK1 pathway independent of TAp63α hyper-phosphorylation, whereas X-irradiation activates the ATM > CHEK2 > TAp63α-hyper-phosphorylation pathway. Furthermore, oocyte-specific deletion of Trp73 partially protects oocytes from CDDP but not from X-ray, highlighting the fundamental differences of two pathways. Nevertheless, temporary repression of DNA damage response by a kinase inhibitor that attenuates phosphorylation of ATM, ATR, CHEK1, and CHEK2 fully preserves fertility in female mice against CDDP as well as X-ray. Our current study establishes the molecular basis and feasibility of adjuvant therapies to protect ovarian function against two distinctive gonadotoxic therapeutics, CDDP, and ionizing radiation.

Role of SDF-1/CXCR4 and cytokines in the development of ovary injury in chemotherapy drug induced premature ovarian failure mice

OBJECTIVE

To explore the mechanism of chemotherapy drug induced ovarian injury in premature ovarian failure (POF) mice.

METHODS

C57BL/6 mice were treated with Cyclophosphamide and Busulfan by intraperitoneal injection. One week after treatment, the estrous cycles, folliculogenesis, ovarian endocrine function and ovarian histopathological changes were evaluated the ovarian function. The serum levels of cytokines, follicle stimulating hormone (FSH) and estradiol (E₂) were measured by enzyme-linked immunosorbent assay (ELISA). The protein levels of SDF-1/CXCR4 and FSHR in ovary were evaluated by immunohistochemistry and Western blot analysis. The ovarian cells apoptosis was measured by TUNEL Assay.

RESULTS

The ovaries from POF mice show the evidence of reduced ovarian function such as irregular estrous cycles, stromal hyperplasia, decreased follicle numbers, atresia follicles and less granular cell layer as well as corpora luteum. The lower levels of E₂ and higher levels of FSH in serum characterize the ovarian injury; a great number of granular apoptotic cells were observed in the POF mice; the serum concentrations of pro-inflammatory cytokines of IL-6, IL-8 and TNF-α level were increased but anti-inflammatory cytokine of IL-10 was decreased. SDF-1/CXCR4 and FSHR expressed in ovaries were detected in the cytoplasm of preantral and antral follicles; the expression of SDF-1/CXCR4 was increased and FSHR was decreased in POF mice.

CONCLUSION

Our data suggest that the inflammatory regulation, SDF-1/CXCR4 and cellular apoptosis in ovarian tissues are involved in the development of ovarian injury of POF. These data provide useful information to develop new therapeutic approach to treat POF disorders in the future.

Impact of tamoxifen therapy on fertility in breast cancer survivors

OBJECTIVE

To determine whether tamoxifen use is associated with decreased ovarian reserve and decreased likelihood of having a child after a breast cancer diagnosis, using data from the Furthering Understanding of Cancer, Health, and Survivorship in Adult (FUCHSIA) Women Study.

DESIGN

Population-based cohort study.

SETTING

Not applicable.

PATIENT(S)

Three hundred ninety-seven female breast cancer survivors aged 22-45 years whose cancer was diagnosed between ages 20 and 35 years and who were at least 2 years after diagnosis; 108 survivors also participated in a clinic visit.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Time to first child after cancer diagnosis, clinical measures of ovarian reserve (antimüllerian hormone [AMH] and antral follicle count [AFC]) after cancer.

RESULT(S)

Women who had ever used tamoxifen were substantially less likely to have a child after the breast cancer diagnosis (hazard ratio [HR] 0.29; 95% confidence interval [CI], 0.16, 0.54) than women who had never used tamoxifen. After adjusting for age at diagnosis, exposure to an alkylating agent, and race, the HR was 0.25 (95% CI, 0.14, 0.47). However, after adjusting for potential confounders, women who had used tamoxifen had an estimated geometric mean AMH level 2.47 times higher (95% CI, 1.08, 5.65) than women who had never taken tamoxifen. Antral follicle count was also higher in the tamoxifen group compared with the tamoxifen nonusers when adjusted for the same variables (risk ratio 1.21; 95% CI, 0.84, 1.73).

CONCLUSION(S)

Breast cancer survivors who had used tamoxifen were less likely to have a child after breast cancer diagnosis compared with survivors who never used tamoxifen. However, tamoxifen users did not have decreased ovarian reserve compared with the tamoxifen nonusers.

The comparison of animal models for premature ovarian failure established by several different source of inducers

The objective of this study was to compare premature ovarian failure animal models established by several different source of inducers. Female ICR mice, KM mice, and SD rats were treated by cyclophosphamide at 120 mg/kg, busulfan at 12 mg/kg, cisplatin at 3 or 4 mg/kg, 4-vinylcyclohexene diepoxide at 160 mg/kg, 35% galactose food pellet, and tripterygium glycosides at 50 mg/kg, respectively. Parameters were analyzed by body weight, serum concentration level of related hormones, ovarian and uterine pathological examination. The results indicated the body weight of mice increased very slowly following single dose of cyclophosphamide (p < 0.05) with damaged ovary; repeated doses of cisplatin could induce body weight significantly decreased (p < 0.01) with a rising trend of serum LH concentration, declining tendency of serum E2 concentration and injured ovary and uterus; 4-vinylcyclohexene diepoxide also hindered the mice growing (p < 0.05) with damaged ovary and uterus; the body weight of mice feed by 35% galactose food pellet increased slowly (p < 0.05) with dramatically higher serum concentration level of galactose, albumin, and total protein (p < 0.001) and injured ovary. Busulfan and tripterygium glycosides did not present obvious evidences. In conclusion, the inducers presented their respective features in such animal models and should be appropriately applied in preventive methods.

Challenges and Potential for Ovarian Preservation with SERMs

Tamoxifen (TAM) is a selective estrogen receptor modulator with tissue-specific effects on estrogen signaling used predominantly for treatment and chemoprevention of breast cancers. Recent studies have shown that TAM prevents infertility and decreases follicular loss from common cancer chemotherapy and radiation therapy in preclinical models. Here we review current and novel uses of selective estrogen receptor modulator s and advantages and challenges for translation of TAM for human fertility preservation.