Combating radiation therapy-induced damage to the ovarian environment

Evaluation of the protective effect of coenzyme Q10 against x-ray irradiation-induced ovarian injury

AIM

This study focused on the anti-oxidant and anti-apoptotic effects of CoQ10 in ovaries exposed to pelvic radiation.

METHODS

Thirty-two female rats were randomly assigned into four groups. Group I (control group), Group II: Only 2 Gy pelvic x-ray irradiation (IR) was administered as a single fractioned dose. Group III: 30 mg/kg CoQ10 was administered by oral gavage +2 Gy pelvic IR. Group IV: 150 mg/kg CoQ10 was administered by oral gavage +2 Gy pelvic IR. CoQ10 treatment was started 7 days before pelvic IR and completed 7 days later. The rats in Group III and IV were treated with CoQ10 for a total of 14 days.

RESULTS

Histopathological analysis showed severe damage to the ovarian tissue in the radiation group, while both doses of CoQ10 showed normal histological structure. Likewise, while there was a high level of staining in the IR group for necrosis and apoptosis, the CoQ10 treated ones were like the control group. Tissue Malondialdehyde (MDA) levels were like the control group in the low-dose CoQ10 group, while the MDA levels of the high dose CoQ10 group were similar to the radiation group.

CONCLUSION

Usage of low-dose CoQ10 has a radioprotective effect on radiation-induced ovarian damage. Although the use of high doses is morphologically radioprotective, no antioxidative effect was observed in the biochemical evaluation.

Is motherhood still possible after pelvic carbon ion radiotherapy? A promising combined fertility-preservation approach

INTRODUCTION

Preserving the endocrine and reproductive function in young female cancer patients undergoing pelvic radiation is a significant challenge. While the photon beam radiation's adverse effects on the uterus and ovaries are well established, the impact of pelvic carbon ion radiotherapy on women's reproductive function is largely unexplored. Strategies such as oocyte cryopreservation and ovarian transposition are commonly recommended for safeguarding future fertility.

METHODS

This study presents a pioneering case of successful pregnancy after carbon ion radiotherapy for locally advanced sacral chondrosarcoma.

RESULTS

A multidisciplinary approach facilitated the displacement of ovaries and uterus before carbon ion radiotherapy, resulting in the preservation of endocrine and reproductive function.

CONCLUSION

The patient achieved optimal oncological response and delivered a healthy infant following the completion of cancer treatment.

Fertility preservation is an imperative goal in the clinical practice of radiation oncology: a narrative review

With reduced cancer mortality in recent years, increased efforts must be put into safeguarding cancer survivors' long-term quality of life (QOL). Fertility preservation is recognised as a key component of QOL in survivorship. Concerns about fertility have been seen to significantly impact cancer patients' emotional and mental health as, generally, both malignancy and its treatment may cause a temporary or permanent reduction in infertility. This article reviews the primary effects of radiation therapy on male and female gonads and has further highlighted procedures through which the functioning of these organs can be protected before or during radiation treatment. We have also emphasised the importance of the establishment of multidisciplinary tumour boards and patient education regarding future reproductive function which is an important component of the care of individuals with cancer. This article highlights that infertility is a persistent and major concern that can add to long-term stress in cancer survivors, and education about fertility preservation before the initiation of any treatment is especially important.

Unlaid Eggs: Ovarian Damage after Low-Dose Radiation

The total body irradiation of lymphomas and co-irradiation in the treatment of adjacent solid tumors can lead to a reduced ovarian function, premature ovarian insufficiency, and menopause. A small number of studies has assessed the radiation-induced damage of primordial follicles in animal models and humans. Studies are emerging that evaluate radiation-induced damage to the surrounding ovarian tissue including stromal and immune cells. We reviewed basic laboratory work to assess the current state of knowledge and to establish an experimental setting for further studies in animals and humans. The experimental approaches were mostly performed using mouse models. Most studies relied on single doses as high as 1 Gy, which is considered to cause severe damage to the ovary. Changes in the ovarian reserve were related to the primordial follicle count, providing reproducible evidence that radiation with 1 Gy leads to a significant depletion. Radiation with 0.1 Gy mostly did not show an effect on the primordial follicles. Fewer data exist on the effects of radiation on the ovarian microenvironment including theca-interstitial, immune, endothelial, and smooth muscle cells. We concluded that a mouse model would provide the most reliable model to study the effects of low-dose radiation. Furthermore, both immunohistochemistry and fluorescence-activated cell sorting (FACS) analyses were valuable to analyze not only the germ cells but also the ovarian microenvironment.

Sexual function in reproductive-aged women following radiotherapy: a cross sectional study

Background While female sexual dysfunction post-radiation therapy has been previously described, much of the literature is focused on older, often postmenopausal, women; and neglects the experiences of younger populations. Our study aims to describe the changes in sexual functioning following radiotherapy among women of a reproductive age. Methods A cross-sectional survey was conducted on reproductive-aged women post-radiation therapy. Information on sexual frequency, pleasure, discomfort and habit was collected and compared to responses from healthy women of comparable ages. Results Reproductive-aged women post-radiotherapy experienced decreased pleasure, more discomfort and had less sexual activity than healthy controls. However, sexual habit was comparable. Conclusions Our findings illustrated that most domains of sexual function are negatively affected in our study population. Understanding the sexual sequelae of radiation therapy may help guide clinicians in counselling their patients and planning their future needs.

Molecular Mechanism and Prevention Strategy of Chemotherapy- and Radiotherapy-Induced Ovarian Damage

Fertility preservation is an emerging discipline, which is of substantial clinical value in the care of young patients with cancer. Chemotherapy and radiation may induce ovarian damage in prepubertal girls and young women. Although many studies have explored the mechanisms implicated in ovarian toxicity during cancer treatment, its molecular pathophysiology is not fully understood. Chemotherapy may accelerate follicular apoptosis and follicle reservoir utilization and damage the ovarian stroma via multiple molecular reactions. Oxidative stress and the radiosensitivity of oocytes are the main causes of gonadal damage after radiation treatment. Fertility preservation options can be differentiated by patient age, desire for conception, treatment regimen, socioeconomic status, and treatment duration. This review will help highlight the importance of multidisciplinary oncofertility strategies for providing high-quality care to young female cancer patients.

Premature Ovarian Insufficiency (POI) Induced by Dynamic Intensity Modulated Radiation Therapy via P13K-AKT-FOXO3a in Rat Models

This study is aimed to investigate the mechanisms of radiation-induced mouse models of premature ovarian insufficiency (POI). Wistar female rats were grouped into the control, 3.2 Gy, 4.0 Gy, and 4.8 Gy groups. Overall ovarian functions were assessed with the H&E staining and ELISA. Proinflammatory cytokine secretion was analyzed ELISA, and the reactive oxygen species (ROS) levels were analyzed with immunohistochemistry. Protein expressions were analyzed by Western blot analysis. The 4.0 Gy and 4.8 Gy groups had significantly lower ovarian weight coefficients than the control and 3.2 Gy groups (after only one irradiation therapy). The 3.2 Gy radiation group induced periodic disturbance and hormone change at 4 weeks after radiation. In the 4.0 Gy and 4.8 Gy groups, the preantral follicles and antral follicles were decreased, while Atresia follicles were increased. E2 was decreased, while FSH and LH secretions were increased. The ovaries in the 4.0 Gy group were not completely atrophied, and some preantral follicles remained. Ovarian atrophy and follicular Atresia were found in the 4.8 Gy group. Inflammatory and oxidative markers were upregulated. PI3K and AKT were downregulated in the 4.0 Gy and 4.8 Gy groups, while FOXO3a was upregulated. Ovarian injuries may lead to oxidative damages and inflammatory injuries, downregulate the expression of P13k and Akt, upregulate the expression of FOXO3a, and lead to follicular atresia in the ovary.

Effects of low-dose X-ray medical diagnostics on female gonads: Insights from large animal oocytes and human ovaries as complementary models

Diagnostic imaging has significantly grown over the last thirty years as indispensable support for diagnostic, prognostic, therapeutic and monitoring procedures of human diseases. This study explored the effects of low-dose X-ray medical diagnostics exposure on female fertility. To aim this, cumulus-oocyte complexes (COCs) recovered from the ovaries of juvenile sheep and human ovaries were used as complementary models for in vitro studies. In the sheep model, the effects of low-dose X-rays on oocyte viability and developmental competence were evaluated. In human ovaries originated from two age group (21–25 and 33–36 years old) subjects with gender dysphoria, X-rays effects on tissue morphology, follicular density and expression of apoptosis-related (NOXA, PUMA, Bcl2, Bak, γH2AX) and cell cycle-related genes (p21 and ki67) were investigated. It was noted that in sheep, the minimum dose of 10 mGy did not influence most of examined parameters at oocyte and embryo levels, whereas 50 and 100 mGy X-ray exposure reduced oocyte bioenergetic/oxidative activity but without any visible effects on oocyte and embryo development. In addition, blastocyst bioenergetic/oxidative status was reduced with all used doses. Overall data on human ovaries showed that low-dose X-rays, similarly as in sheep, did not alter any of examined parameters. However, in women belonging to the 33–36 year group, significantly reduced follicular density was observed after exposure to 50 and 100 mGy, and increased NOXA and Bax expression after exposure at 50 mGy. In conclusion, used low-doses of X-ray exposure, which resemble doses used in medical diagnostics, produce weak damaging effects on female fertility with increased susceptibility in advanced age.

Sphingosine-1-phosphate and its mimetic FTY720 do not protect against radiation-induced ovarian fibrosis in the nonhuman primate†

Oocytes are highly radiosensitive, so agents that prevent radiation-induced ovarian follicle destruction are important fertility preservation strategies. A previous study in rhesus macaques demonstrated that ovarian treatment with antiapoptotic agents, sphingosine-1-phosphate (S1P) and FTY720, its long-acting mimetic, preserved follicles following a single dose of 15 Gy X-ray radiation, and live offspring were obtained from FTY720-treated animals. However, it is unknown whether these antiapoptotic agents also protected the ovarian stroma from late effects of radiation, including vascular damage and fibrosis. Using ovarian histological sections from this study, we evaluated the vasculature and extracellular matrix in the following cohorts: vehicle + sham irradiation, vehicle + irradiation (OXI), S1P + irradiation (S1P), and FTY720 + irradiation (FTY720). One ovary from each animal was harvested prior to radiation whereas the contralateral ovary was harvested 10 months post-treatment. We assessed vasculature by immunohistochemistry with a PECAM1 antibody, hyaluronan by a hyaluronan binding protein assay, and collagen by picrosirius red and Masson's trichrome staining. Disorganized vessels were observed in the medulla in the OXI and S1P cohorts relative to the sham, but the vasculature in the FTY720 cohort appeared intact, which may partially explain fertoprotection. There were no differences in the hyaluronan matrix among the cohorts, but there was thickening of the tunica albuginea and fibrosis in the OXI cohort relative to the sham, which was not mitigated by either S1P or FTY720 treatment. Thus, the fertoprotective properties of S1P and FTY720 may be limited given their inability to protect the ovarian stroma against the late effects of radiation-induced fibrosis.

The different doses of radiation therapy-induced damage to the ovarian environment in rats

PURPOSE

The sequelae of premature loss of ovarian function can undoubtedly have undesirable effects for a woman although radiotherapy is one of the most relevant treatment modalities for various types of malignancies. The aim of this study was to determine the effect of different doses of radiation on ovarian folliculogenesis, inflammation, and apoptotic markers.

MATERIALS AND METHODS

For this purpose, 40 healthy Wistar albino female rats divided into four groups: 1) Control group; 2) those that were exposed to total body 1 Gy of gamma rays; 3) those that were exposed to the total body 5 Gy of gamma rays, and 4) those that were exposed to total body 10 Gy of gamma rays. External irradiation to the total body was given with gamma irradiation delivered by the Co60 teletherapy machine. The day after radiation application the rats were sacrificed and the ovaries were removed in all groups. Histopathologic examination, follicle counting, and classification were performed in the ovarian tissues. The expression of AMH, TNF-α, IL1-β, Bax, and Bcl-2 was detected. The stained sections were examined for caspase 3 positive apoptotic cell numbers.

RESULTS

The recorded results revealed that increased radiation dose induced obvious ovarian injuries that were indicated by histopathological, and immunohistochemical alterations, including elevation of ovarian injury markers. A significantly lower number of total and primordial follicles was detected with increasing radiation dose compared with the control group. According to our immunohistochemical results, 10 Gy of gamma rays group had the lowest AMH expression levels, while had the highest TNF-α, IL1-β expression level compared to the control group. When the groups were evaluated in terms of apoptosis, it was seen that the number of caspase 3 positive cells and Bax immunoreactivity intensity increased with radiation dose. In contrast, Bcl-2 immunoreactivity intensity decreased with increasing radiation dose compared with the control group.

CONCLUSIONS

We demonstrate here that dose rate plays an important role when estimating the relation between exposure to an increased dose of ionizing radiation and the risk of ovarian disease. According to these results, certain factors have to be optimized before introducing them into clinics.

Novel molecular mechanisms underlying the ameliorative effect of N-acetyl-L-cysteine against ϒ-radiation-induced premature ovarian failure in rats

Radiotherapy represents a critical component in cancer treatment. However, premature ovarian failure (POF) is a major hurdle of deleterious off-target effects in young females, which, therefore, call for an effective radioprotective agent. The present study aimed to explore the molecular mechanism underlying the protective effects of N-acetyl-L-cysteine (NAC) against γ-radiation-provoked POF. Immature female Sprague-Dawley rats were orally-administered NAC (50 mg/kg) and were exposed to a single whole-body dose of 3.2 Gy ϒ-radiation. NAC administration remarkably reversed abnormal serum estradiol and anti-Müllerian hormone levels by 73% and 40%, respectively while ameliorating the histopathological and ultrastructural alterations-triggered by γ-radiation. Mechanistically, NAC alleviated radiation-induced oxidative damage through significantly increased glutathione peroxidase activity by 102% alongside with decreasing NADPH oxidase subunits (p22 and NOX4) gene expressions by 48% and 38%, respectively compared to the irradiated untreated group. Moreover, NAC administration achieved its therapeutic effect by inhibiting ovarian apoptosis-induced by radiation through downregulating p53 and Bax levels by 33% and 16%, respectively while increasing the Bcl-2 mRNA expression by 135%. Hence, the Bax/Bcl2 ratio and cytochrome c expression were subsequently reduced leading to decreased caspase 3 activity by 43%. Importantly, the anti-apoptotic property of NAC could be attributed to inactivation of MAPK signaling molecules; p38 and JNK, and enhancement of the ovarian vascular endothelial growth factor (VEGF) expression. Taken together, our results suggest that NAC can inhibit radiotherapy-induced POF while preserving ovarian function and structure through upregulating VEGF expression and suppressing NOX4/MAPK/p53 apoptotic signaling.

Pharmacological management of ionizing radiation injuries: current and prospective agents and targeted organ systems

Introduction: There is a limited array of currently available medicinals that are useful for either the prevention, mitigation or treatment of bodily injuries arising from ionizing radiation exposure.Area covered: In this brief article, the authors review those pharmacologic agents that either are currently being used to counter the injurious effects of radiation exposure, or those that show promise and are currently under development.Expert opinion: Although significant, but limited progress has been made in the development and fielding of safe and effective pharmacotherapeutics for select types of acute radiation-associated injuries, additional effort is needed to broaden the scope of drug development so that overall health risks associated with both short- and long-term injuries in various organ systems can be reduced and effectively managed. There are several promising radiation countermeasures that may gain regulatory approval from the government in the near future for use in clinical settings and in the aftermath of nuclear/radiological exposure contingencies.

Carvacrol and Thymol Modulate the Cross-Talk between TNF-α and IGF-1 Signaling in Radiotherapy-Induced Ovarian Failure

Premature ovarian failure (POF) is a common cause of infertility in premenopausal women who are unavoidably exposed to cytotoxic therapy. Radiotherapy is one of the most effective cytotoxic treatments. However, the radiosensitivity of ovarian tissues limits its therapeutic outcome and results in the depletion of the primordial follicle and loss of fertility. Therefore, the need for an effective radioprotective therapy is evident especially when none of the current clinically used modalities for radioprotection succeeds efficiently. The present study investigated the potential radioprotective effect of carvacrol (CAR) (80 mg) or thymol (80 mg) on gamma- (γ-) irradiation-induced ovarian damage as well as their role in the cross-talk between IGF-1 and TNF-α signaling and antioxidative activity. In immature female Wister rats, a single dose of whole-body irradiation (3.2 Gy, LD₂₀) produced considerable ovarian damage, which was evident by histopathological findings and hormonal changes. Interestingly, pretreatment with CAR or thymol significantly enhanced the follicular development and restored the anti-Mullerian hormone (AMH), E2, and FSH levels. Both essential oils improved the irradiation-mediated oxidative stress and reduction in proliferating cell nuclear antigen (PCNA) expression. Moreover, irradiated rats exhibited an inverse relationship between IGF-1 and TNF-α levels two days post irradiation, which was further inverted by the pretreatment with CAR and thymol and ought to contribute in their radioprotective mechanisms. In conclusion, CAR and thymol showed a radioprotective effect and rescued the ovarian reserve mainly through counteracting oxidative stress and the dysregulated cross-talk between IGF-1 and TNF-α.

Recommendations for assessing ovarian health and fertility potential in survivors of childhood cancer

Most children diagnosed with cancer survive for many years after treatment. However, the fertility potential of these patients may suffer due to their oncologic therapies. Certain chemotherapies and radiation are more likely to be detrimental to gonadal function, and put patients at risk of acute or premature ovarian failure. Prepubertal cancer patients will need different follow-up and testing from their post-pubertal counterparts. This review will present evidence to help patients, family members and physicians determine who is most at risk of ovarian insufficiency and how to monitor childhood cancer survivors. It will discuss the impact of age at diagnosis and cancer therapies on reproductive outcomes, and guide caregivers and patients on monitoring gonadal function after therapy.

Use of a Small Animal Radiation Research Platform (SARRP) facilitates analysis of systemic versus targeted radiation effects in the mouse ovary

BACKGROUND

Radiation exposure is known to cause accelerated aging and damage to the ovary, but the contribution of indirect versus direct effects is not well understood. We used the Small Animal Radiation Research Platform (SARRP) (Xstrahl) to deliver radiation to precise fields equivalent to clinical practice, allowing us to investigate systemic versus targeted damage in a structure as small as the mouse ovary. The X-ray dose was kept constant at 1 Gy, but the field varied. Mice either received total body irradiation (TBI), radiation targeted to both ovaries (T2), or radiation targeted to one ovary (left) while the contralateral ovary (right) was spared (T1). Sham mice, handled similarly to the other cohorts but not exposed to radiation, served as controls. Two weeks post-exposure, ovaries were harvested and analyzed histologically to identify and count follicles within each ovary.

RESULTS

Radiation significantly reduced primordial follicles in the TBI and T2 cohorts compared to the Sham cohort. There were no significant differences between these two irradiated groups. These findings suggest that at 1 Gy, the extent of damage to the ovary caused by radiation is similar despite the different delivery methods. When investigating the T1 cohort, targeted ovaries showed a significant decrease in primordial and growing follicles compared to non-targeted contralateral ovaries.

CONCLUSIONS

These findings demonstrate that the SARRP is an effective strategy for delivering precise ionizing radiation to small organs such as mouse ovaries. Such tools will facilitate identifying the relative risks to ovarian function associated with different radiation fields as well as screening the efficacy of emerging fertoprotective agents.

Oocytes from stem cells

Folliculogenesis describes the process of activating an oocyte-containing primordial follicle from the ovarian reserve and its development to the mature ovulatory stage. This process is highly complex and is controlled by extra- and intra-ovarian signaling events. Oocyte competence and capacity for fertilization to support a viable pregnancy are acquired during folliculogenesis. Cancer and cancer-based therapies can negatively affect this process, compromising fertility. Currently, preservation of fertility in these patients remains limited to surrogacy, oocyte freezing, oocyte donation, or in vitro maturation (IVM). Recent reports of stem cells being used to produce fully competent oocytes and subsequently healthy offspring in mice have opened up a novel avenue for fertility preservation. However, translating these findings into human health first relies on enhancing our understanding of follicle growth and mimicking its intricacies in vitro. Indeed, the future of oocytes from stem cells in humans comes with many possibilities but currently faces several technical and ethical obstacles.