Cancer risk in men exposed in utero to diethylstilbestrol

Evidence of binding between diethylstilbestrol (DES) and the goldfish (Carassius auratus) membrane progesterone receptor α

BACKGROUND

In a previous study, diethylstilbestrol (DES) was shown to induce oocyte maturation in fish. In the present study, the interaction of DES on goldfish membrane progesterone receptor α (GmPRα) was investigated using a competitive binding assay with radiolabeled steroids. The results indicate that DES exerts its effects on membrane progesterone receptor alpha (mPRα) and induces oocyte maturation through nongenomic steroid mechanisms. This study provides empirical data that demonstrate the binding between DES and GmPRα.

METHODS

Binding of DES to GmPRα was achieved by using radiolabeled DES and recombinant GmPRα expressed in culture cells or purified GmPRα proteins that coupled to graphene quantum dots (GQDs). Additionally, the competitive binding of fluorescently labeled progesterone to GmPRα-expressing cells was evaluated.

RESULTS

Although significant nonspecific binding of radiolabeled DES to the cell membrane that expresses GmPRα has been observed, specific binding of DES to GmPRα has been successfully identified in the presence of digitonin. Furthermore, the specific binding of DES to GmPRα was confirmed by a binding assay using GQD-GmPRα. The radiolabeled DES was shown to bind to GQD-GmPRα. Additionally, the competition for the binding of fluorescently labeled progesterone to GmPRα-expressing cells was achieved with the DES.

CONCLUSIONS

The results of the experiments revealed that DES binds to GmPRα. Thus, it can be concluded that DES induces goldfish oocyte maturation by binding to GmPRα.

The Male Reproductive System and Endocrine Disruptors

The male reproductive system is exposed to a great number of chemical substances which can interfere with the normal hormonal milieu and reproductive function; these are called endocrine disruptors (EDs). Despite a growing number of studies evaluating the negative effects of EDs, their production is continuously growing although some of which have been prohibited. The prevalence of poor semen quality, hypospadias, cryptorchidism, and testicular cancer have increased in the last decades, and recently, it has been postulated that these could all be part of a unique syndrome called testicular dysgenesis syndrome. This syndrome could be related to exposure to a number of EDs which cause imbalances in the hormonal milieu and oestrogenic over-exposure during the foetal stage. The same EDs can also impair spermatogenesis in offspring and have epigenetic effects. Although studies on animal and in vitro models have raised concerns, data are conflicting. However, these studies must be considered as the basis for future research to promote male reproductive health.

Prenatal Diethylstilbestrol Exposure and Cancer Risk in Males

BACKGROUND

The influence of prenatal diethylstilbestrol (DES) exposure on cancer incidence among middle-aged men has not been well-characterized. We investigated whether exposure to DES before birth impacts overall cancer risk, and risk of site-specific cancers.

METHODS

Men (mean age in 2016 = 62.0 years) who were or were not prenatally DES exposed were identified between 1953 and 1994 and followed for cancer primarily via questionnaire approximately every 5 years between 1994 and 2016. The overall and site-specific cancer rates of the two groups were compared using Poisson regression and proportional hazards modeling with adjustment for age.

RESULTS

DES exposure was not associated with either overall cancer [hazard ratio (HR), 0.94; 95% confidence interval (CI), 0.77-1.15] or total prostate cancer rates (HR, 0.95; 95% CI, 0.68-1.33), but was inversely associated with urinary tract cancer incidence (HR, 0.48; 95% CI, 0.23-1.00).

CONCLUSIONS

There was no increase in either overall or prostate cancer rates among men prenatally DES exposed relative to those unexposed. An unexpected risk reduction was observed for urinary system cancers among the exposed relative to those unexposed. These findings suggest that prenatal DES exposure is unlikely to be an important contributor to cancer development in middle-aged men.

IMPACT

The results of this study could lend reassurance to middle-aged men who were prenatally DES exposed that their exposure does not adversely influence their overall cancer risk.

Are the Effects of DES Over? A Tragic Lesson from the Past

Diethylstilbestrol (DES), a transplacental endocrine-disrupting chemical, was prescribed to pregnant women for several decades. The number of women who took DES is hard to know precisely, but it has been estimated that over 10 million people have been exposed around the world. DES was classified in the year 2000 as carcinogenic to humans. The deleterious effects induced by DES are very extensive, such as abnormalities or cancers of the genital tract and breast, neurodevelopmental alterations, problems associated with socio-sexual behavior, and immune, pancreatic and cardiovascular disorders. Not only pregnant women but also their children and grandchildren have been affected. Epigenetic alterations have been detected, and intergenerational effects have been observed. More cohort follow-up studies are needed to establish if DES effects are transgenerational. Even though DES is not currently in use, its effects are still present, and families previously exposed and their later generations deserve the continuity of the research studies.

Evidence of intergenerational transmission of Diethylstilbestrol (DES) health effects: Hindsight and insight

This review summarizes key findings from the US National Cancer Institute (NCI) DES Combined Cohort Study with a focus on the results of the NCI Third Generation Study, a cohort of DES-exposed and unexposed granddaughters. Findings to date from the Third Generation Study are discussed in the context of other research efforts and case reports suggesting an intergenerational heritability of DES-related effects. The DES story serves as a model for the influence of endocrine disrupting chemicals on human health. It also serves as a warning of the special hazards of pregnancy exposures, and more broadly, of the potential for invisible health consequences arising from new or changing exposures.

Testicular Stem Cell Dysfunction Due to Environmental Insults Could Be Responsible for Deteriorating Reproductive Health of Men

Reproductive health of men has declined over time including reduced semen quality specifically sperm count, increased incidence of infertility, and testicular cancers. Our recent findings suggest that these disease states possibly arise as a result of disruption of testicular stem cells biology by perinatal insults including exposure to endocrine disrupting chemicals. Testicular stem cells include relatively quiescent, very small embryonic-like stem cells (VSELs), and actively dividing spermatogonial stem cells (SSCs). Both VSELs and SSCs express estrogen receptors and are directly vulnerable to endocrine disruption. Exposing mice pups to estradiol (20 μg/pup/day on days 5-7) or diethylstilbestrol (2 μg/pup/day on days 1-5) affected spermatogenesis during adult life with reduced numbers of tubules in stage VIII, tetraploid cells and sperm. These mice were infertile and majority of diethylstilbestrol treated mice revealed testicular cancer-like changes. An increase in VSEL numbers, observed by both flow cytometry and qRT-PCR, was associated with marked reduction of c-KIT positive spermatogonial cells. VSELs undergo epigenetic changes due to endocrine disruption that results in blocked differentiation (impaired spermatogenesis) leading to reduced sperm count and infertility, and their excessive self-renewal initiates cancer-like changes in adult life. Thus, testicular dysgenesis syndrome (TDS) has a stem cell rather than a genetic basis.

Prenatal diethylstilbestrol exposure and risk of diabetes, gallbladder disease, and pancreatic disorders and malignancies

Prenatal diethylstilbestrol (DES) exposure is associated with increased risk of hormonally mediated cancers and other medical conditions. We evaluated the association between DES and risk of pancreatic cancer and pancreatic disorders, type 2 diabetes, and gallbladder disease, which may be involved with this malignancy. Our analyses used follow-up data from the US National Cancer Institute DES Combined Cohort Study. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for age, sex, cohort, body mass index, smoking, and alcohol for the association between prenatal DES exposure and type 2 diabetes, gallbladder disease (mainly cholelithiasis), pancreatic disorders (mainly pancreatitis), and pancreatic cancer among 5667 exposed and 3315 unexposed individuals followed from 1990 to 2017. Standardized incidence rate (SIR) ratios for pancreatic cancer were based on age-, race-, and calendar year-specific general population cancer incidence rates. In women and men combined, the hazards for total pancreatic disorders and pancreatitis were greater in the prenatally DES exposed than the unexposed (HR = 11, 95% CI 2.6–51 and HR = 7.0, 95% CI 1.5–33, respectively). DES was not associated overall with gallbladder disease (HR = 1.2, 95% CI 0.88–1.5) or diabetes (HR = 1.1, 95% CI 0.9–1.2). In women, but not in men, DES exposure was associated with increased risk of pancreatic cancer compared with the unexposed (HR: 4.1, 95% CI 0.84–20) or general population (SIR: 1.9, 95% CI 1.0–3.2). Prenatal DES exposure may increase the risk of pancreatic disorders, including pancreatitis in women and men. The data suggested elevated pancreatic cancer risk in DES-exposed women, but not in exposed men.

GPER and Testicular Germ Cell Cancer

The G protein-coupled estrogen receptor (GPER), also known as GPR30, is a widely conserved 7-transmembrane-domain protein which has been identified as a novel 17β-estradiol-binding protein that is structurally distinct from the classic oestrogen receptors (ERα and ERβ). There are still conflicting data regarding the exact role and the natural ligand of GPER/GPR30 in reproductive tracts as both male and female knock-out mice are fertile and have no abnormalities of reproductive organs. Testicular germ cell cancers (TGCCs) are the most common malignancy in young males and the most frequent cause of death from solid tumors in this age group. Clinical and experimental studies suggested that estrogens participate in the physiological and pathological control of male germ cell proliferation. In human seminoma cell line, while 17β-estradiol (E2) inhibits in vitro cell proliferation through an ERβ-dependent mechanism, an impermeable E2 conjugate (E2 coupled to BSA), in vitro cell proliferation is stimulated by activating ERK1/2 and protein kinase A through a membrane GPCR that we further identified as GPER/GPR30. The same effect was observed with low but environmentally relevant doses of BPA, an estrogenic endocrine disrupting compound. Furthermore, GPER/GPR30 is specifically overexpressed in seminomas but not in non-seminomas and this overexpression is correlated with an ERβ-downregulation. This GPER/GPR30 overexpression could be linked to some genetic variations, as single nucleotide polymorphisms, which was also reported in other hormone-dependent cancers. We will review here the implication of GPER/GPR30 in TGCCs pathophysiology and the arguments to consider GPER/GPR30 as a potential therapeutic target in humans.

Genital tract and reproductive characteristics in daughters of women and men prenatally exposed to diethylstilbestrol (DES)

OBJECTIVE

Prenatal exposure of women to diethylstilbestrol (DES) has been associated with reproductive tract anomalies, menstrual irregularity, infertility and pregnancy complications. In prenatally exposed men, adverse effects included genital anomalies and possible risk of infertility. In children of prenatally exposed women, i.e the third generation, an increased incidence of genital defects was observed in sons (hypospadias), but not in daughters. In daughters of prenatally exposed men, the incidence of genital anomalies was in the normal range. Experimental studies in mice evidenced an increased incidence of reproductive tract anomalies in the female descendants of females and males prenatally exposed to DES, indicative of transgenerational transmission of DES defects. The aim of this study is to assess genital tract defects, fertility and pregnancy outcome, in daughters of women and men prenatally exposed to DES.

METHODS

In a retrospective observational analysis, 759 daughters of prenatally exposed women and men reported their genital and reproductive characteristics that were compared with those of: 1) general population in France; 2) two cohorts of daughters of exposed women reported in previous publications; 3) women prenatally exposed to DES.

RESULTS

An increased incidence of uterine defects was observed, with both doubling of uterus and bicornuate and aplastic uterus which constitutes the Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS). No specific anomalies described in prenatally exposed women such as T-shape or hypoplastic uterus were reported. Infertility appeared to be in the normal range. Pregnancy outcomes of our 121 pregnancies of women born to DES exposed mothers and two other published cohorts presented inconsistent results for ectopic pregnancy, miscarriage and preterm delivery. Early and late miscarriages were higher than expected in general population in our cohort but not in the two others.

CONCLUSION

These results must be considered as preliminary, due to the small numbers of patients, limited follow-up duration after birth due to young age of the studied population, and observational methods. An important point is that the high risk of reproductive dysfunction of women prenatally exposed to DES was not observed in their daughters. There is a signal on the high incidence of uterine defects, especially aplastic uterus, and its possible link with DES exposure through epigenetic effects is discussed in our findings. Inconsistent findings regarding pregnancy outcomes in the third generation are worthy of further examination.

Untangling the association between environmental endocrine disruptive chemicals and the etiology of male genitourinary cancers

Endocrine disrupting chemicals disrupt normal physiological function of endogenous hormones, their receptors, and signaling pathways of the endocrine system. Most endocrine disrupting chemicals exhibit estrogen/androgen agonistic and antagonistic activities that impinge upon hormone receptors and related pathways. Humans are exposed to endocrine disrupting chemicals through food, water and air, affecting the synthesis, release, transport, metabolism, binding, function and elimination of naturally occurring hormones. The urogenital organs function as sources of steroid hormones, are targeted end organs, and participate within systemic feedback loops within the endocrine system. The effects of endocrine disruptors can ultimately alter cellular homeostasis leading to a broad range of health effects, including malignancy. Human cancer is characterized by uncontrolled cell proliferation, mechanisms opposing cell-death, development of immortality, induction of angiogenesis, and promotion of invasion/metastasis. While hormonal malignancies of the male genitourinary organs are the second most common types of cancer, the molecular effects of endocrine disrupting chemicals in hormone-driven cancers has yet to be fully explored. In this commentary, we examine the molecular evidence for the involvement of endocrine disrupting chemicals in the genesis and progression of hormone-driven cancers in the prostate, testes, and bladder. We also report on challenges that have to be overcome to drive our understanding of these chemicals and explore the potential avenues of discovery that could ultimately allow the development of tools to prevent cancer in populations where exposure is inevitable.

Is Testicular Germ Cell Cancer Estrogen Dependent? The Role of Endocrine Disrupting Chemicals

Testicular germ cell cancer (TGCC) is the most frequent cancer of the young male, with an increasing incidence worldwide. The pathogenesis and reasons for this increase remain unknown. However, epidemiological and experimental data have suggested that, similar to genital malformations and sperm impairment, it could result from the interaction of genetic and environmental factors including fetal exposure to endocrine-disrupting chemicals (EDCs) with estrogenic effects. In this review, we analyze the expression of classic and nonclassic estrogen receptors by TGCC cells, the way they may influence germ cell proliferation induced by EDCs, and discuss how this estrogen dependency supports the developmental and environmental hypothesis.

Prenatal Diethylstilbestrol Exposure and Risk of Depression in Women and Men

BACKGROUND

Prenatal exposure to diethylstilbestrol (DES), an endocrine-disrupting chemical, may be associated with depression in adulthood, but previous findings are inconsistent.

METHODS

Women (3,888 DES exposed and 1,729 unexposed) and men (1,021 DES exposed and 1,042 unexposed) participating in the National Cancer Institute (NCI) DES Combined Cohort Follow-up Study were queried in 2011 for any history of depression diagnosis or treatment. Hazard ratios (HRs; 95% confidence intervals [CIs]) estimated the associations between prenatal DES exposure and depression risk.

RESULTS

Depression was reported by 993 (26%) exposed and 405 (23%) unexposed women, and 177 (17%) exposed and 181 (17%) unexposed men. Compared with the unexposed, HRs for DES and depression were 1.1 (95% CI = 0.9, 1.2) in women and 1.0 (95% CI = 0.8, 1.2) in men. For medication-treated depression, the HRs (CIs) were 1.1 (0.9, 1.2) in women and 0.9 (0.7, 1.2) in men. In women, the HR (CI) for exposure to a low cumulative DES dose was 1.2 (1.0, 1.4), and for DES exposure before 8 weeks' gestation was 1.2 (1.0, 1.4). In men, the HR for low dose was 1.2 (95% CI = 0.9, 1.6) and there was no association with timing. In women, associations were uninfluenced by the presence of DES-related vaginal epithelial changes or a prior diagnosis of DES-related adverse outcomes.

CONCLUSIONS

Prenatal DES exposure was not associated overall with risk of depression in women or men. In women, exposure in early gestation or to a low cumulative dose may be weakly associated with an increased depression risk.

Systematic Review and Meta-analysis of Testicular Germ Cell Tumors Following In Utero Exposure to Diethylstilbestrol

Background

Early exposure to estrogen-like compounds has been implicated in the etiology of testicular cancer, but individual level epidemiologic data addressing this hypothesis are scarce. The synthetic estrogen diethylstilbestrol (DES) was administered during pregnancy from 1948 to 1971, but sequelae of in utero exposure have been more extensively characterized in females than in males.

Methods

By systematic review, we sought to identify all epidemiologic research relating testicular cancer to a history of in utero exposure to diethylstilbestrol. Identified studies were critically appraised to assemble a set of nonredundant data in which any in utero exposure to DES was compared between men with incident testicular cancer and cancer-free men. These data were synthesized using random effects meta-analysis to estimate the summary association between in utero DES exposure and testicular cancer.

Results

By meta-analysis of data from the six qualifying studies, the summary odds ratio estimate of the in utero DES-testicular cancer association was 2.98 (95% confidence interval = 1.15 to 7.67).

Conclusions

Results of this comprehensive meta-analysis accord with a threefold increase in testicular cancer risk among men who were exposed in utero to DES, implicating early hormonal exposures in etiology of testicular cancer. Because use of DES ceased in 1971, this work may provide the most comprehensive estimate of this association that will be made.

Testicular Cancer: Genes, Environment, Hormones

Testicular cancer (TC) represents one of the most peculiar clinical challenges at present. In fact, currently treatments are so effective ensuring a 5 years disease-free survival rate in nearly 95% of patients. On the other hand however, TC represents the most frequent newly diagnosed form of cancer in men between the ages of 14 and 44 years, with an incidence ranging from <1 to 9.9 affected individuals per 100,000 males across countries, while the overall incidence is also increasing worldwide. Furthermore, cancer survivors show a 2% risk of developing cancer in the contralateral testis within 15 years of initial diagnosis. This complex and multifaceted scenario requires a great deal of effort to understand the clinical base of available evidence. It is now clear that genetic, environmental and hormonal risk factors concur and mutually influence both the development of the disease and its prognosis, in terms of response to treatment and the risk of recurrence. In this paper, the most recent issues describing the relative contribution of the aforementioned risk factors in TC development are discussed. In addition, particular attention is paid to the exposure to environmental chemical substances and thermal stress, whose role in cancer development and progression has recently been investigated at the molecular level.

The Impact of Nutrition and Environmental Epigenetics on Human Health and Disease

Environmental epigenetics describes how environmental factors affect cellular epigenetics and, hence, human health. Epigenetic marks alter the spatial conformation of chromatin to regulate gene expression. Environmental factors with epigenetic effects include behaviors, nutrition, and chemicals and industrial pollutants. Epigenetic mechanisms are also implicated during development in utero and at the cellular level, so environmental exposures may harm the fetus by impairing the epigenome of the developing organism to modify disease risk later in life. By contrast, bioactive food components may trigger protective epigenetic modifications throughout life, with early life nutrition being particularly important. Beyond their genetics, the overall health status of an individual may be regarded as an integration of many environmental signals starting at gestation and acting through epigenetic modifications. This review explores how the environment affects the epigenome in health and disease, with a particular focus on cancer. Understanding the molecular effects of behavior, nutrients, and pollutants might be relevant for developing preventative strategies and personalized heath programs. Furthermore, by restoring cellular differentiation, epigenetic drugs could represent a potential strategy for the treatment of many diseases including cancer.

Higher intake of medications for digestive disorders in children prenatally exposed to drugs with atropinic properties

Childhood digestive disorders are a common occurrence and are sometimes unexplained. Maternal medication during the development of the foetus' digestive system may contribute to the increase in childhood digestive disorders, especially with drugs acting on the cholinergic system. This study investigated the association between prenatal exposure to drugs with atropinic properties and the use of digestive disorder medications in childhood (0-3 years). Children from POMME (PrescriptiOn Médicaments Mères Enfants), a French database of reimbursed drugs for pregnant women and their children, were included (N = 8 372). Each drug prescribed during antenatal life was assigned an atropinic score (0 = null, 1 = low, 3 = strong). The prenatal atropinic burden was calculated as the sum of atropinic scores of drugs prescribed. More than 30% (N = 2 652) of the children were prenatally exposed to atropinic drugs. They used significantly more digestive disorder medications than unexposed children (RRa = 1.11 [1.06; 1.16]). The strength of the association increased with the prenatal atropinic burden. Our results suggest long-term digestive effects after prenatal exposure to atropinic drugs.

Birth defects in children of men exposed in utero to diethylstilbestrol (DES)

OBJECTIVE

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse effects, including genital anomalies and cancers in men and women. Animal studies showed birth defects and tumors in the offspring of mice prenatally exposed to DES. In humans, birth defects, such as hypospadias were observed in children of prenatally exposed women. The aim of this research was to assess the birth defects in children of prenatally exposed men.

METHODS

In a retrospective study conceived by a patients' association (Réseau DES France), the reports of men prenatally exposed to DES on adverse health effects in their children were compared with those of unexposed controls and general population.

RESULTS

An increased incidence of two genital anomalies, cryptorchidism (OR=5.72; 95% CI 1.51-21.71), and hypoplasia of the penis (OR=22.92; 95% CI 3.81-137.90), was observed in the 209 sons of prenatally exposed men compared with controls, but hypospadias incidence was not increased in comparison with either the controls or the general population. No increase of genital anomalies was observed in daughters.

CONCLUSION

With caution due to the methods and to the small numbers of defects observed, this work suggests an increased incidence of two male genital tract defects in sons of men prenatally exposed to DES. This transgenerational effect, already observed in animals and in the offspring of women prenatally exposed to DES, could be the result of epigenetic changes transmitted to the subsequent generation through men.

Germline and reproductive tract effects intensify in male mice with successive generations of estrogenic exposure

The hypothesis that developmental estrogenic exposure induces a constellation of male reproductive tract abnormalities is supported by experimental and human evidence. Experimental data also suggest that some induced effects persist in descendants of exposed males. These multi- and transgenerational effects are assumed to result from epigenetic changes to the germline, but few studies have directly analyzed germ cells. Typically, studies of transgenerational effects have involved exposing one generation and monitoring effects in subsequent unexposed generations. This approach, however, has limited human relevance, since both the number and volume of estrogenic contaminants has increased steadily over time, intensifying rather than reducing or eliminating exposure. Using an outbred CD-1 mouse model, and a sensitive and quantitative marker of germline development, meiotic recombination, we tested the effect of successive generations of exposure on the testis. We targeted the germline during a narrow, perinatal window using oral exposure to the synthetic estrogen, ethinyl estradiol. A complex three generation exposure protocol allowed us to compare the effects of individual, paternal, and grandpaternal (ancestral) exposure. Our data indicate that multiple generations of exposure not only exacerbate germ cell exposure effects, but also increase the incidence and severity of reproductive tract abnormalities. Taken together, our data suggest that male sensitivity to environmental estrogens is increased by successive generations of exposure.

Etiology and early pathogenesis of malignant testicular germ cell tumors: towards possibilities for preinvasive diagnosis

Malignant testicular germ cell tumors (TGCT) are the most frequent cancers in Caucasian males (20-40 years) with an 70% increasing incidence the last 20 years, probably due to combined action of (epi)genetic and (micro)environmental factors. It is expected that TGCT have carcinoma in situ(CIS) as their common precursor, originating from an embryonic germ cell blocked in its maturation process. The overall cure rate of TGCT is more than 90%, however, men surviving TGCT can present long-term side effects of systemic cancer treatment. In contrast, men diagnosed and treated for CIS only continue to live without these long-term side effects. Therefore, early detection of CIS has great health benefits, which will require an informative screening method. This review described the etiology and early pathogenesis of TGCT, as well as the possibilities of early detection and future potential of screening men at risk for TGCT. For screening, a well-defined risk profile based on both genetic and environmental risk factors is needed. Since 2009, several genome wide association studies (GWAS) have been published, reporting on single-nucleotide polymorphisms (SNPs) with significant associations in or near the genes KITLG, SPRY4, BAK1, DMRT1, TERT, ATF7IP, HPGDS, MAD1L1, RFWD3, TEX14, and PPM1E, likely to be related to TGCT development. Prenatal, perinatal, and postnatal environmental factors also influence the onset of CIS. A noninvasive early detection method for CIS would be highly beneficial in a clinical setting, for which specific miRNA detection in semen seems to be very promising. Further research is needed to develop a well-defined TGCT risk profile, based on gene-environment interactions, combined with noninvasive detection method for CIS.

Adverse health effects in children of women exposed in utero to diethylstilbestrol (DES)

OBJECTIVE

Exposure to diethylstilbestrol (DES) in utero is associated with adverse health effects, including genital anomalies in women and men, and cancers in women. Animal studies showed birth defects and tumors in the offspring of DES exposed mice, revealing transgenerational transmission of DES effects. In humans, birth defects, such as hypospadias were observed in children of prenatally exposed women. The aim of this research was to further assess the health effects in children of prenatally exposed women.

METHODS

In a retrospective cohort study, the reports of women exposed to DES in utero on their 4409 children were compared with those of unexposed women on their 6203 children. Comparisons used odd ratios (OR) between children of exposed and unexposed women and standardized incidence rate (SIR) with the general population. These cohorts were recruited on a voluntary basis to answer questionnaires.

RESULTS

There was a global increase of defects in children born to exposed women when compared with those born to unexposed (OR 2.29, 95% CI: 1.80-2.79, P<0.001) and with the general population (SIR 2.39, 95% CI: 2.11-2.68). Increased defects were observed in male genital tract, esophagus, lip or palate, musculoskeletal and circulatory systems. For female genital tract anomalies, there was no significant increase. However, this cohort being relatively young, further follow-up is needed. An increase of cerebral palsy was revealed. The incidence of cancers was not increased, in particular for breast, uterus and ovary.

CONCLUSION

Our results confirmed a transgenerational transmission of defects in male genital tract. With caution due to possible bias associated with this method, our data suggest an increase of defects for esophagus, lip or palate, musculoskeletal and circulatory system in children of exposed women.

Environmental endocrine disruptors: Effects on the human male reproductive system

Incidences of altered development and neoplasia of male reproductive organs have increased during the last 50 years, as shown by epidemiological data. These data are associated with the increased presence of environmental chemicals, specifically "endocrine disruptors," that interfere with normal hormonal action. Much research has gone into testing the effects of specific endocrine disrupting chemicals (EDCs) on the development of male reproductive organs and endocrine-related cancers in both in vitro and in vivo models. Efforts have been made to bridge the accruing laboratory findings with the epidemiological data to draw conclusions regarding the relationship between EDCs, altered development and carcinogenesis. The ability of EDCs to predispose target fetal and adult tissues to neoplastic transformation is best explained under the framework of the tissue organization field theory of carcinogenesis (TOFT), which posits that carcinogenesis is development gone awry. Here, we focus on the available evidence, from both empirical and epidemiological studies, regarding the effects of EDCs on male reproductive development and carcinogenesis of endocrine target tissues. We also critique current research methodology utilized in the investigation of EDCs effects and outline what could possibly be done to address these obstacles moving forward.

Reproductive health risks associated with occupational exposures to antineoplastic drugs in health care settings: a review of the evidence

OBJECTIVES

Antineoplastic drugs are known reproductive and developmental toxicants. Our objective was to review the existing literature of reproductive health risks to workers who handle antineoplastic drugs.

METHODS

A structured literature review of 18 peer-reviewed, English language publications of occupational exposure and reproductive outcomes was performed.

RESULTS

Although effect sizes varied with study size and population, occupational exposure to antineoplastic drugs seems to raise the risk of both congenital malformations and miscarriage. Studies of infertility and time to pregnancy also suggested an increased risk for subfertility.

CONCLUSIONS

Antineoplastic drugs are highly toxic in patients receiving treatment, and adverse reproductive effects have been well documented in these patients. Health care workers with long-term, low-level occupational exposure to these drugs also seem to have an increased risk of adverse reproductive outcomes. Additional precautions to prevent exposure should be considered.

The history of Distilbène® (Diethylstilbestrol) told to grandchildren--the transgenerational effect

The Distilbène® story is a dramatic episode which belongs to the history of medicine. It provided several useful lessons such as the importance of evidence-based medicine and the hazard to develop treatments during pregnancy without careful animal verifications. However, this experience has also provided unexpected progress by suggesting new pathophysiological concepts: fetal programming of adult diseases and/or transgenerational transmission of environmental effects through epigenetic modifications.

Nontesticular cancers in relatives of testicular germ cell tumor (TGCT) patients from multiple-case TGCT families

Testicular germ cell tumors (TGCT) exhibit striking familial aggregation that remains incompletely explained. To improve the phenotypic definition of familial TGCT (FTGCT), we studied an international cohort of multiple-case TGCT families to determine whether first-degree relatives of FTGCT cases are at increased risk of other types of cancer. We identified 1041 first-degree relatives of TGCT cases in 66 multiple-case TGCT families from Norway and 64 from the United States (combined follow-up of 31,556 person-years). We collected data on all cancers (except nonmelanoma skin cancers) reported by the family informant in these relatives, and we attempted to verify all reported cancer diagnoses through medical or cancer registry records. We calculated observed-to-expected (O/E) standardized incidence ratios, together with 95% confidence intervals (CI), for invasive cancers other than TGCT. We found no increase in risk of cancer overall (Norway O/E = 0.8; 95% CI: 0.6–1.1 and United States O/E = 0.9; 95% CI: 0.7–1.3). Site-specific analyses pooled across the two countries revealed a leukemia excess (O/E = 6.5; 95% CI: 3.0–12.3), deficit of female breast cancer (O/E = 0.0; 95% CI: 0.0–0.6) and increased risk of soft tissue sarcoma (O/E = 7.2; 95% CI: 2.0–18.4); in all instances, these results were based on small case numbers and statistically significant only in Norway. While limited by sample size and potential issues relating to completeness of cancer reporting, this study in multiple-case TGCT families does not support the hypothesis that cancers other than testis cancer contribute to the FTGCT phenotype.

Risk of cancer in children, adolescents, and young adults with autistic disorder

OBJECTIVES

To investigate whether individuals with autism have an increased risk for cancer relative to the general population.

STUDY DESIGN

We enrolled patients with autistic disorder from the Taiwan National Health Insurance database in years 1997-2011. A total of 8438 patients diagnosed with autism were retrieved from the Registry for Catastrophic Illness Patients database. The diagnosis of cancers was also based on the certificate of catastrophic illness, which requires histological confirmation. The risk of cancer among the autism cohort was determined with a standardized incidence ratio (SIR).

RESULTS

During the observation period, cancer occurred in 20 individuals with autism, which was significantly higher than a total number of expected cancers with a SIR estimate of 1.94 (95% CI 1.18-2.99). The number of cancer in males was greater than the expected number with a SIR of 1.95 (1.11-3.16), but no excess risk was found for females with a SIR of 1.91 (0.52-4.88). Cancer developed more than expected in individuals age 15-19 years with the SIR of 3.58 (1.44-7.38), but did not differ in other age range groups. The number of cancers of genitourinary system was significantly in excess of the expected number (SIR 4.15; 95% CI 1.13-10.65), and increased risk was found in ovarian cancer with SIR of 9.21 (1.12-33.29).

CONCLUSIONS

Our study demonstrated that patients with autistic disorder have an increased risk of cancer.

Nuclear receptors and endocrine disruptors in fetal and neonatal testes: a gapped landscape

During the last decades, many studies reported that male reproductive disorders are increasing among humans. It is currently acknowledged that these abnormalities can result from fetal exposure to environmental chemicals that are progressively becoming more concentrated and widespread in our environment. Among the chemicals present in the environment (air, water, food, and many consumer products), several can act as endocrine disrupting compounds (EDCs), thus interfering with the endocrine system. Phthalates, bisphenol A (BPA), and diethylstilbestrol (DES) have been largely incriminated, particularly during the fetal and neonatal period, due to their estrogenic and/or anti-androgenic properties. Indeed, many epidemiological and experimental studies have highlighted their deleterious impact on fetal and neonatal testis development. As EDCs can affect many different genomic and non-genomic pathways, the mechanisms underlying the adverse effects of EDC exposure are difficult to elucidate. Using literature data and results from our laboratory, in the present review, we discuss the role of classical nuclear receptors (genomic pathway) in the fetal and neonatal testis response to EDC exposure, particularly to phthalates, BPA, and DES. Among the nuclear receptors, we focused on some of the most likely candidates, such as peroxisome-proliferator activated receptor (PPAR), androgen receptor (AR), estrogen receptors (ERα and β), liver X receptors (LXR), and small heterodimer partner (SHP). First, we describe the expression and potential functions (based on data from studies using receptor agonists and mouse knockout models) of these nuclear receptors in the developing testis. Then, for each EDC studied, we summarize the main evidences indicating that the reprotoxic effect of each EDC under study is mediated through a specific nuclear receptor(s). We also point-out the involvement of other receptors and nuclear receptor-independent pathways.

Estrogenic exposure alters the spermatogonial stem cells in the developing testis, permanently reducing crossover levels in the adult

Bisphenol A (BPA) and other endocrine disrupting chemicals have been reported to induce negative effects on a wide range of physiological processes, including reproduction. In the female, BPA exposure increases meiotic errors, resulting in the production of chromosomally abnormal eggs. Although numerous studies have reported that estrogenic exposures negatively impact spermatogenesis, a direct link between exposures and meiotic errors in males has not been evaluated. To test the effect of estrogenic chemicals on meiotic chromosome dynamics, we exposed male mice to either BPA or to the strong synthetic estrogen, ethinyl estradiol during neonatal development when the first cells initiate meiosis. Although chromosome pairing and synapsis were unperturbed, exposed outbred CD-1 and inbred C3H/HeJ males had significantly reduced levels of crossovers, or meiotic recombination (as defined by the number of MLH1 foci in pachytene cells) by comparison with placebo. Unexpectedly, the effect was not limited to cells exposed at the time of meiotic entry but was evident in all subsequent waves of meiosis. To determine if the meiotic effects induced by estrogen result from changes to the soma or germline of the testis, we transplanted spermatogonial stem cells from exposed males into the testes of unexposed males. Reduced recombination was evident in meiocytes derived from colonies of transplanted cells. Taken together, our results suggest that brief exogenous estrogenic exposure causes subtle changes to the stem cell pool that result in permanent alterations in spermatogenesis (i.e., reduced recombination in descendent meiocytes) in the adult male.

Implications of prenatal steroid perturbations for neurodevelopment, behavior, and autism

The prenatal brain develops under the influence of an ever-changing hormonal milieu that includes endogenous fetal gonadal and adrenal hormones, placental and maternal hormones, and exogenous substances with hormonal activity that can cross the placental barrier. This review discusses the influences of endogenous fetal and maternal hormones on normal brain development and potential consequences of pathophysiological hormonal perturbations to the developing brain, with particular reference to autism. We also consider the effects of hormonal pharmaceuticals used for assisted reproduction, the maintenance of pregnancy, the prevention of congenital adrenal hypertrophy, and hormonal contraceptives continued into an unanticipated pregnancy, among others. These treatments, although in some instances life-saving, may have unintended consequences on the developing fetuses. Additional concern is raised by fetal exposures to endocrine-disrupting chemicals encountered universally by pregnant women from food/water containers, contaminated food, household chemicals, and other sources. What are the potential outcomes of prenatal steroid perturbations on neurodevelopmental and behavioral disorders, including autism-spectrum disorders? Our purposes here are 1) to summarize some consequences of steroid exposures during pregnancy for the development of brain and behavior in the offspring; 2) to summarize what is known about the relationships between exposures and behavior, including autism spectrum disorders; 3) to discuss the molecular underpinnings of such effects, especially molecular epigenetic mechanisms of prenatal steroid manipulations, a field that may explain effects of direct exposures, and even transgenerational effects; and 4) for all of these, to add cautionary notes about their interpretation in the name of scientific rigor.

Familial testicular germ cell tumors (FTGCT) - overview of a multidisciplinary etiologic study

This Review summarizes the cumulative results of the National Cancer Institute Clinical Genetics Branch Multidisciplinary Etiologic Study of Familial Testicular Germ Cell Tumors (FTGCT). Initiated 12 years ago, this protocol enrolled 724 subjects from 147 unrelated families with either ≥2 affected men (n = 90) with TGCT or a proband with bilateral TGCT and a negative family history for this cancer (n = 57). Data were collected directly from 162 subjects evaluated at the NIH Clinical Center, and 562 subjects provided information from their home communities (Field Cohort). The primary study aims included (i) ascertaining, enrolling eligible FTGCT kindred, (ii) characterizing the clinical phenotype of multiple-case families, (iii) identifying the underlying genetic mechanism for TGCT susceptibility in families, (iv) evaluating counseling, psychosocial, and behavioral issues resulting from membership in an FTGCT family, and (v) creating an annotated biospecimen repository to permit subsequent translational research studies. Noteworthy findings include (i) documenting the epidemiologic similarities between familial and sporadic TGCT, (ii) demonstrating significantly younger age-at-diagnosis for familial vs. sporadic TGCT, (iii) absence of a dysmorphic phenotype in affected family members, (iv) shifting the focus of gene discovery from a search for rare, highly penetrant susceptibility variants to the hypothesis that multiple, more common, lower penetrance genes underlie TGCT genetic risk, (v) implicating testicular microlithiasis in FTGCT risk, and (vi) observing that aberrant methylation may contribute to FTGCT risk. A clinically based, biospecimen-intensive, multidisciplinary research strategy has provided novel, valuable insights into the etiology of FTGCT, and created a research resource which will support FTGCT clinical and laboratory studies for years to come.

Effects of n-butylparaben on steroidogenesis and spermatogenesis through changed E₂ levels in male rat offspring

Parabens are widely used as antibacterial agents, which are concerned recently in the relationship between the use of parabens and reproductive toxicity. So that reassessment of the risk of parabens is needed. In this study, one of parabens, n-butylparaben (n-BP) was orally administered to pregnant Wistar rats (0, 64, 160, 400 and 1000 mg/kg/day) from gestation day (GD) 7 through postnatal day (PND) 21. Reduced anogenital distance (AGD) and delayed preputial separation (PPS) were observed in the male offspring. The weights of the testes were significantly reduced at PND 21-90. The weights of the epididymides were significantly reduced at all monitoring points, except PND 35. Seminal vesicle weights were significantly reduced on PND 21. Serum testosterone (T) was significantly decreased, especially on PND 49. The levels of 17β-estradiol (E2) showed an increase at each of the tested points except on PND 180. Serum luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels in the n-BP treated groups were lower on PND 21, 35 and 49 but elevated on PND 90 compared to control levels. n-BP reduced epididymal cauda sperm counts and daily sperm production in a dose-dependent manner; this difference was statistically significant at exposure groups of 400 and 1000 mg/kg/day. The present study strongly suggests that exposure to n-BP in utero and during lactation has adverse effects on the reproductive system in male offspring, with a no observed adverse effect level (NOAEL) of 160 mg/kg/day. To our knowledge, this is the first study that reports increased E2 levels of male rats following n-BP exposure; we suggest that E2 levels may be considered as biomarkers for some endocrine disrupting chemicals (EDCs).

Recent advances in molecular and cell biology of testicular germ-cell tumors

Testicular germ-cell tumors (TGCTs) are the most frequent solid malignant tumors in men 20-40 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs comprise two major histologic groups: seminomas and nonseminomas germ-cell tumors (NSGCTs). NSGCTs can be further divided into embryonal, carcinoma, Teratoma, yolk sac tumor, and choriocarcinoma. Seminomas and NSGCTs present significant differences in clinical features, therapy, and prognosis, and both show characteristics of the primordial germ cells. Many discovered biomarkers including OCT3/4, SOX2, SOX17, HMGA1, Nek2, GPR30, Aurora-B, estrogen receptor β, and others have given further advantages to discriminate between histological subgroups and could represent useful novel molecular targets for antineoplastic strategies. More insight into the pathogenesis of TGCTs is likely to improve disease management not only to better treatment of these tumors but also to a better understanding of stem cells and oncogenesis.

Exposure to diethylstilbestrol during sensitive life stages: a legacy of heritable health effects

Diethylstilbestrol (DES) is a potent estrogen mimic that was predominantly used from the 1940s to the 1970s by pregnant women in hopes of preventing miscarriage. Decades later, DES is known to enhance breast cancer risk in exposed women and cause a variety of birth-related adverse outcomes in their daughters such as spontaneous abortion, second trimester pregnancy loss, preterm delivery, stillbirth, and neonatal death. Additionally, children exposed to DES in utero suffer from sub/infertility and cancer of reproductive tissues. DES is a pinnacle compound that demonstrates the fetal basis of adult disease. The mechanisms of cancer and endocrine disruption induced by DES are not fully understood. Future studies should focus on common target tissue pathways affected and the health of the DES grandchildren.

Diethylstilboestrol exposure does not reduce testosterone production in human fetal testis xenografts

In rodents, in utero exposure to exogenous estrogens including diethylstilboestrol (DES) results in major suppression of steroidogenesis in fetal testes. Whether similar effects occur in the human fetal testis is equivocal. Based on the results of the rodent studies, we hypothesised that exposure of human fetal testes to DES would result in a reduction in testosterone production. We show, using a xenograft approach, that testosterone production is not reduced in human fetal testis following DES exposure. Human fetal testes (15–19 weeks’ gestation, n = 6) were xenografted into castrate male nude mice which were then treated for 35 days with vehicle or 100 µg/kg DES three times a week. For comparison, similar treatment was applied to pregnant rats from e13.5–e20.5 and effects on fetal testes evaluated at e21.5. Xenograft testosterone production was assessed by measuring host seminal vesicle (SV) weights as an indirect measure over the entire grafting period, and single measurement of serum testosterone at termination. Human fetal testis xenografts showed similar survival in DES and vehicle-exposed hosts. SV weight (44.3 v 26.6 mg, p = 0.01) was significantly increased in DES compared to vehicle-exposed hosts, respectively, indicating an overall increase in xenograft testosterone production over the grafting period, whilst serum testosterone at termination was unchanged. In contrast intra-testicular testosterone levels were reduced by 89%, in fetal rats exposed to DES. In rats, DES effects are mediated via Estrogen Receptor α (ESR1). We determined ESR1 protein and mRNA expression in human and rat fetal testis. ESR1 was expressed in rat, but not in human, fetal Leydig cells. We conclude that human fetal testis exposure to DES does not impair testosterone production as it does in rats, probably because ESR1 is not expressed in human fetal Leydig cells. This indicates that DES exposure is likely to pose minimal risk to masculinization of the human fetus.

Circulating maternal perfluoroalkyl substances during pregnancy in the C8 Health Study

Perfluoroalkyl substances are manmade chemicals used in many consumer products and have become ubiquitous in the environment. Animal studies and a limited number of human studies have demonstrated developmental effects in offspring exposed to perfluoroalkyl substances in utero, but the implications of timing of in utero exposure have not been systematically investigated. The present study investigated variation in perfluorocarbon levels of 9952 women of childbearing age who had been exposed to perfluorooctanoic acid (PFOA) in drinking water contaminated by industrial waste. An analysis of variance with contrast was performed to compare the levels of PFOA and perfluorooctanesulfonic acid (PFOS) in pregnant and nonpregnant women overall and during each trimester of pregnancy. We found that pregnant women had lower circulating PFOA and PFOS concentrations in peripheral blood than nonpregnant women and that PFOA levels were consistently lower throughout all trimesters for pregnancy, suggesting transfer to the fetus at an early stage of gestation. These results are discussed in the context of the endocrine-disrupting properties of perfluoroalkyl substances that have been characterized in animal and human studies. Our conclusion is that further, systematic study of the potential implications of intrauterine perfluorocarbon exposure during critical periods of fetal development is urgently needed.

Speciation, phenotypic variation and plasticity: what can endocrine disruptors tell us?

Phenotype variability, phenotypic plasticity, and the inheritance of phenotypic traits constitute the fundamental ground of processes such as individuation, individual and species adaptation and ultimately speciation. Even though traditional evolutionary thinking relies on genetic mutations as the main source of intra- and interspecies phenotypic variability, recent studies suggest that the epigenetic modulation of gene transcription and translation, epigenetic memory, and epigenetic inheritance are by far the most frequent reliable sources of transgenerational variability among viable individuals within and across organismal species. Therefore, individuation and speciation should be considered as nonmutational epigenetic phenomena.

Implication of the Strand-Specific Imprinting and Segregation Model: Integrating in utero Hormone Exposure, Stem Cell and Lateral Asymmetry Hypotheses in Breast Cancer Aetiology

Known genetic mutations and familial hereditary factors account for less than 20–25% of breast cancer cases in women, therefore, most instances have been classified as sporadic cases of unknown aetiologies. Single nucleotide polymorphisms (SNPs) were considered as breast cancer risk factors, but numerous studies have failed to support this assertion. Recent evidence correlates aberrant epigenetic mechanisms in the development and metastatic progression of breast cancer, yet there has been limited progress made to identify the primary aetiology underlying sporadic cases of breast cancer. This has led some researchers to consider alternative hypotheses including in utero exposure to deleterious chemical agents during early development, the immortal strand and the strand-specific imprinting and selective chromatid segregation hypotheses. Here, we integrate prominent alternate models to help guide future research on this very important topic concerning human health.

TRA-1-60+, SSEA-4+, POU5F1+, SOX2+, NANOG+ Clones of Pluripotent Stem Cells in the Embryonal Carcinomas of the Testes

INTRODUCTION

Cancer of the testes is currently the most frequent neoplasm and a leading cause of morbidity in men 15-35 years of age. Its incidence is increasing. Embryonal carcinoma is its most malignant form, which either may be resistant or may develop resistance to therapies, which results in relapses. Cancer stem cells are hypothesized to be drivers of these phenomena.

SPECIFIC AIM

The specific aim of this work was identification and isolation of spectra of single, living cancer stem cells, which were acquired directly from the patients' biopsies, followed by testing of their pluripotency.

PATIENTS METHODS

Biopsies were obtained from the patients with the clinical and histological diagnoses of the primary, pure embryonal carcinomas of the testes. The magnetic and fluorescent antibodies were genetically engineered. The SSEA-4 and TRA-1-60 cell surface display was analyzed by multiphoton fluorescence spectroscopy (MPFS), flow cytometry (FCM), immunoblotting (IB), nuclear magnetic resonance spectroscopy (NMRS), energy dispersive x-ray spectroscopy (EDXS), and total reflection x-ray spectroscopy (TRXFS). The single, living cells were isolated by magnetic or fluorescent sorting followed by their clonal expansion. The OCT4A, SOX2, and NANOG genes' transcripts were analyzed by qRTPCR and the products by IB and MPFS.

RESULTS

The clones of cells, with the strong surface display of TRA-1-60 and SSEA-4, were identified and isolated directly from the biopsies acquired from the patients diagnosed with the pure embryonal carcinomas of the testes. These cells demonstrated high levels of transcription and translation of the pluripotency genes: OCT4A, SOX2, and NANOG. They formed embryoid bodies, which differentiated into ectoderm, mesoderm, and endoderm.

CONCLUSION

In the pure embryonal carcinomas of the testes, acquired directly from the patients, we identified, isolated with high viability and selectivity, and profiled the clones of the pluripotent stem cells. These results may help in explaining therapy-resistance and relapses of these neoplasms, as well as, in designing targeted, personalized therapy.

Environmental Toxicology: Children at Risk

Children today live in a world that is vastly different from a few generations ago. While industrialization has maximized (for many) children’s opportunities to survive, develop and enjoy high levels of health, education, recreation, and fulfillment, it has also added significant challenges to their development.

[Carcinoma in situ of the testis: predisposition, evolution and early detection]

Carcinoma in situ (CIS), also known as intratubular germ cell neoplasia unclassified, is the common obligate precursor lesion of malignant testicular seminomatous and non-seminomatous germ cell tumors (GCT), which show a steadily increasing incidence in Europe. Although GCT is a potentially curable cancer with excellent prognosis even in patients with organ metastasis, many patients suffer from chemotherapy-associated effects and some develop a secondary (non-germ cell) malignancy. Recently, genome-wide association studies revealed genetic predispositions linked to six genes (KITL, SPRY4, BAK1, TERT, ATF7IP, DMRT1). Exposure to environmental factors was also linked to increased prevalence of testicular dysgenesis and CIS/GCT by the action of hormone disruptors on embryonal gonadal tissue during pregnancy. By unknown mechanisms these genetic and environmental factors might create a disturbed microenvironment in the fetal testis leading to survival of embryonic germ cells and subsequent malignant transformation might result in CIS. Molecular pathways involved in this process include activated cKIT pathway and LIN28 associated deregulation of miRNA targets. The challenge for the future is to identify high risk patients prior to invasive GCT, to develop non-invasive tests for detection of CIS on seminal material and elucidate the precise role of the microenvironment in CIS initiation.

Testicular germ cell tumours: predisposition genes and the male germ cell niche

Testicular germ cell tumours (TGCTs) of adults and adolescents are putatively derived from primordial germ cells or gonocytes. Recently reported genome-wide association studies implicate six gene loci that predispose to TGCT development. Remarkably, the functions of proteins encoded by genes within these regions bridge our understanding between the pathways involved in primordial germ cell physiology, male germ cell development and the molecular pathology of TGCTs. Furthermore, this improved understanding of the mechanisms underlying TGCT development and dissemination has clinical relevance for the management of patients with these tumours.

Effect of high intratesticular estrogen on global gene expression and testicular cell number in rats

BACKGROUND

The identification of estrogen receptors alpha and beta and aromatase in the testis has highlighted the important role of estrogens in regulating spermatogenesis. There is a wealth of information on the deleterious effects of fetal and neonatal exposure of estrogens and xenoestrogens in the testis, including spermiation failure and germ cell apoptosis. However, very little is known about gene transcripts affected by exogenous estradiol exposure in the testis. The objective of the present study was to unveil global gene expression profiles and testicular cell number changes in rats after estradiol treatment.

METHODS

17beta-estradiol was administered to adult male rats at a dose of 100 micrograms/kg body weight in saline daily for 10 days; male rats receiving only saline were used as controls. Microarray analysis was performed to examine global gene expression profiles with or without estradiol treatment. Real time RT-PCR was conducted to verify the microarray data. In silico promoter and estrogen responsive elements (EREs) analysis was carried out for the differentially expressed genes in response to estradiol. Quantitation of testicular cell number based on ploidy was also performed using flow cytometry in rats with or without estradiol treatment.

RESULTS

We found that 221 genes and expressed sequence tags (ESTs) were differentially expressed in rat testes treated with estradiol compared to the control; the microarray data were confirmed by real time RT-PCR. Gene Ontology analysis revealed that a number of the differentially expressed genes are involved in androgen and xenobiotic metabolism, maintenance of cell cytoskeleton, endocytosis, and germ cell apoptosis. A total of 33 up-regulated genes and 67 down-regulated genes showed the presence of EREs. Flow cytometry showed that estradiol induced a significant decrease in 2n cells (somatic and germ cells) and 4n cells (pachytene spermatocytes) and a marked increase in the number of elongated and elongating spermatids.

CONCLUSIONS

This study provides a novel insight into the molecular basis for spermiation failure and apoptosis caused by 17beta-estradiol and it also offers new mechanisms by which adult exposure to environmental estrogens can affect spermatogenesis and fertility.

Birth defects in the sons and daughters of women who were exposed in utero to diethylstilbestrol (DES)

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse health outcomes, including anatomic anomalies of the reproductive tract in women and of the genitourinary tract in men. The mouse model, which replicates many DES-related effects seen in humans, suggests that prenatal DES exposure causes alterations that may affect the next generation of offspring. We asked women participating in a large, multi-centre study of prenatal DES exposure to report birth defects occurring among 4029 sons and 3808 daughters (i.e., the third generation). A subcohort of 793 third generation daughters was also queried for birth defects. We used logistic regression models to generate odds ratio and 95% confidence intervals for the association between prenatal DES exposure in the mother and birth defects in the offspring. Based on the mothers' reports, overall birth defects were elevated in the sons (OR = 1.53; 95% CI = 1.04, 2.23) and in the daughters (OR = 2.35; 95% CI = 1.44, 3.82). Most estimates of association were imprecise, but daughters appeared to have an excess of heart conditions (OR = 4.56; 95% CI = 1.27, 16.34). Our data suggest a possible association between the mother's prenatal DES exposure and birth defects in their offspring, particularly in daughters. We cannot, however, rule-out the possible influence of reporting bias. In particular, the exposed daughters' elevated risk of cardiac defects may be as a result of the underreporting of these conditions by unexposed mothers.