Environmental effects on hormonal regulation of testicular descent

Maternal use of personal care products during pregnancy and risk of testicular germ cell tumors in sons

BACKGROUND

The etiology of testicular germ cell tumors (TGCT) is poorly understood, however, exposure to endocrine disrupting chemicals (EDCs) may be related to increased risk. Personal care products, some of which contain EDCs, are widely used on a daily basis and are known to cross the placenta, be present in breastmilk, and are capable of inducing reproductive tract abnormalities. To determine the association between personal care product use during pregnancy and breastfeeding and TGCT risk, an analysis among mothers of TGCT cases and controls was conducted.

METHODS

The US Servicemen's Testicular Tumor Environmental and Endocrine Determinants (STEED) study enrolled TGCT cases and controls and their mothers between 2002 and 2005. The current analysis examined personal care product use during pregnancy among 527 mothers of TGCT cases and 562 mothers of controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression adjusting for identified covariates.

RESULTS

Maternal use of face lotion more than one time per week was associated with a significantly increased risk of TGCT (OR: 1.42, 95% CI: 1.08-1.86, p-trend: 0.01). None of the other products examined (perfume, hairspray, nail polish, hair dye, permanent wave, body lotion, deodorant, sunscreen) were associated with TGCT risk.

CONCLUSIONS

Frequent exposure to face lotion during pregnancy and while breastfeeding may be associated with increased TGCT risk. Further investigation into the endocrine disrupting effects of personal care products is warranted.

Effects of exposure to polychlorinated biphenyls during different periods of development on ethanol consumption by male and female rats

In two experiments, male and female Sprague-Dawley rats were exposed to Polychlorinated Biphenyls (PCBs) to assess the effect PCBs, an estrogenic endocrine disrupting chemical (EEDC), would have on the voluntary consumption of alcohol. There are several EEDCs in our food that are known to increase estrogen in adolescent females. Our objective was to assess the effect that increasing estrogen, by adding the EEDC PCBs would have on volitional intake of alcohol. In Experiment 1, pregnant dams were exposed from gestational days 5-19 to a 1:1 mixture of Aroclor 1254/1260. In Experiment 2, lactating females were exposed to the same dose of 1254:1260 from postnatal days 1-21. In both experiments, a fade-in procedure was used to gradually introduce the rats to the taste of alcohol. At the end of the fade-in series all animals were given limited access (1 h/day) to a water/alcohol solution. We found that females exposed to PCBs, at two developmental periods, consumed significantly more alcohol than unexposed females and exposed and unexposed males. Results of the experiments are discussed in terms of how PCB exposure can disrupt endocrine processes (e.g., estrogenic endocrine disrupting chemicals, EEDC) that increase estrogen in females, thereby leading to increased alcohol consumption. Thus, the present findings suggest that EEDCs, such as PCBs, could contribute to the increase abuse of alcohol in adolescent females.

Hershberger Assays for Di-2-ethylhexyl Phthalate and Its Substitute Candidates

In the present study, we employed Hershberger assay to determine possible androgenic or antiandrogenic activities of three di-2-ethylhexyl phthalate (DEHP) substitute candidates. The assay was carried out using immature castrated Sprague-Dawley male rats. After 7 days of the surgery, testosterone propionate (TP, 0.4 mg/kg/day) and test materials (low dose, 40 mg/kg/day; high dose, 400 mg/kg/day) were administered for 10 consecutive days by subcutaneous (s.c.) injection and oral gavage, respectively. Test materials were DEHP, 2-ethylhexyl oleate (IOO), 2-ethylhexyl stearate (IOS) and triethyl 2-acetylcitrate (ATEC). The rats were necropsied, and then the weights of five androgen-dependent tissues [ventral prostate, seminal vesicle, coagulating glands, levator ani-bulbocavernosus (LABC) muscle, paired Cowper's glands, and glans penis] and four androgen-insensitive tissues (kidney, adrenal glands, spleen and liver) were measured. All test materials including DEHP did not exhibit any androgenic activity in the assay. On the contrary, antiandrogen-like activities were found in all test groups, and the order of the intensity was ATEC < DEHP < ISO < IOO in the five androgen-sensitive tissues. There was no statistical difference between low dose treatment and high dose treatment of all replacement candidate groups. In DEHP groups, high dose treatment exhibited significant weight gains in LABC and Glan Penis. There was no statistical difference in androgen-insensitive tissue measurements. Since the effects of ATEC treatment on the accessory sex organs were much less or not present at all when compared to those of DEHP, ATEC could be a strong candidate to replace DEHP. IOO treatment brought most severe weight reduction in all of androgen-sensitive tissues, so this material should be excluded for further screening of DEHP substitute selection.

Time trends and occupational variation in the incidence of testicular cancer in the Nordic countries

OBJECTIVE

To describe the trends and occupational variation in the incidence of testicular cancer in the Nordic countries utilising national cancer registries, NORDCAN (NORDCAN project/database presents the incidence, mortality, prevalence and survival from >50 cancers in the Nordic countries) and NOCCA (Nordic Occupational Cancer) databases.

PATIENTS AND METHODS

We obtained the incidence data of testicular cancer for 5-year periods from 1960-1964 to 2000-2014 and for 5-year age-groups from the NORDCAN database. Morphological data on incident cases of seminoma and non-seminoma were obtained from national cancer registries. Age-standardised incidence rates (ASR) were calculated per 100 000 person-years (World Standard). Regression analysis was used to evaluate the annual change in the incidence of testicular cancer in each of the Nordic countries. The risk of testicular cancer in different professions was described based on NOCCA information and expressed as standardised incidence ratios (SIRs).

RESULTS

During 2010-2014 the ASR for testicular cancer varied from 11.3 in Norway to 5.8 in Finland. Until 1998, the incidence was highest in Denmark. There has not been an increase in Denmark and Iceland since the 1990s, whilst the incidence is still strongly increasing in Norway, Sweden, and Finland. There were no remarkable changes in the ratio of seminoma and non-seminoma incidences during the past 50 years. There was no increase in the incidences in children and those of pension age. The highest significant excess risks of testicular seminoma were found in physicians (SIR 1.48, 95% confidence interval [CI] 1.07-1.99), artistic workers (SIR 1.47, 95% CI 1.06-1.99) and religious workers etc. (SIR 1.33, 95% CI 1.14-1.56). The lowest SIRs of testicular seminoma were seen amongst cooks and stewards (SIR 0.56, 95% CI 0.29-0.98), and forestry workers (SIR 0.64, 95% CI 0.47-0.86). The occupational category of administrators was the only one with a significantly elevated SIR for testicular non-seminoma (SIR 1.21, 95% CI 1.04-1.42). The only SIRs significantly <1.0 were seen amongst engine operators (SIR 0.60, 95% CI 0.41-0.84) and public safety workers (SIR 0.67, 95% CI 0.43-0.99).

CONCLUSIONS

There have always been differences in the incidence of testicular cancer between the Nordic countries. There is also some divergence in the incidences in different age groups and in the trends of the incidence. The effect of occupation-related factors on incidence of testicular cancer is only moderate. Our study describes the differences, but provides no explanation for this variation.

Endocrine Disrupting Chemicals Interfere With Leydig Cell Hormone Pathways During Testicular Descent in Idiopathic Cryptorchidism

Cryptorchidism, a frequent genital malformation in male newborn, remains in most cases idiopathic. On the basis of experimental, epidemiological, and clinical data, it has been included in the testicular dysgenesis syndrome and believed to be influenced, together with genetic and anatomic factors, by maternal exposure to endocrine disrupting chemicals (EDCs). Here, we analyze how EDCs may interfere with the control of testicular descent, which is regulated by two Leydig cell hormones, testosterone, and insulin like peptide 3 (INSL3).

Endocrine Disruptors Leading to Obesity and Related Diseases

The review aims to comprehensively present the impact of exposure to endocrine disruptors (EDs) in relation to the clinical manifestation of obesity and related diseases, including diabetes mellitus, metabolic syndrome, cardiovascular diseases, carcinogenesis and infertility. EDs are strong participants in the obesity epidemic scenery by interfering with cellular morphological and biochemical processes; by inducing inflammatory responses; and by presenting transcriptional and oncogenic activity. Obesity and lipotoxicity enhancement occur through reprogramming and/or remodeling of germline epigenome by exposure to EDs. Specific population groups are vulnerable to ED exposure due to current dietary and environmental conditions. Obesity, morbidity and carcinogenicity induced by ED exposure are an evolving reality. Therefore, a new collective strategic approach is deemed essential, for the reappraisal of current global conditions pertaining to energy management.

Phytochemicals Targeting Estrogen Receptors: Beneficial Rather Than Adverse Effects?

In mammals, the effects of estrogen are mainly mediated by two different estrogen receptors, ERα and ERβ. These proteins are members of the nuclear receptor family, characterized by distinct structural and functional domains, and participate in the regulation of different biological processes, including cell growth, survival and differentiation. The two estrogen receptor (ER) subtypes are generated from two distinct genes and have partially distinct expression patterns. Their activities are modulated differently by a range of natural and synthetic ligands. Some of these ligands show agonistic or antagonistic effects depending on ER subtype and are described as selective ER modulators (SERMs). Accordingly, a few phytochemicals, called phytoestrogens, which are synthesized from plants and vegetables, show low estrogenic activity or anti-estrogenic activity with potentially anti-proliferative effects that offer nutraceutical or pharmacological advantages. These compounds may be used as hormonal substitutes or as complements in breast cancer treatments. In this review, we discuss and summarize the in vitro and in vivo effects of certain phytoestrogens and their potential roles in the interaction with estrogen receptors.

Concepts and Updates in the Evaluation and Diagnosis of Common Disorders of Sexual Development

Our understanding of disorders of sexual differentiation (DSD) has evolved from aberrations of human genital development to a broad group of complex disorders of etiological and functional significance. The unique challenge of DSD conditions is that they create a cause for significant angst and concern for both parents and physician, as they frequently lead to questions with regards to gender assignment, surgically corrective options, long-term outlook regarding gender identity, and reproductive potential. To further add to the burden, many patients who present with genital abnormalities do not have a clear explanation as to the underlying basis of their disorder. This review looks at DSD from a pediatric urology point of view with emphasis on evaluation, diagnosis, and algorithm for work-up. We also discuss novel genetic analysis techniques and their value in diagnosis. Overall, this is an all-encompassing review on a diagnostic approach to DSD, with inclusion of recent developments and controversies, which will benefit urologists and other physicians alike.

Cord blood insulin-like peptide 3 (INSL3) but not testosterone is reduced in idiopathic cryptorchidism

BACKGROUND

Cryptorchidism, the most frequent congenital malformation in full-term male newborns, increases the risk of hypofertility and testicular cancer. Most cases remain idiopathic but epidemiological and experimental studies have suggested a role of both genetic and environmental factors. Physiological testicular descent is regulated by two major Leydig hormones: insulin-like peptide 3 (INSL3) and testosterone.

OBJECTIVES

To study the endocrine context at birth as a reflection of late pregnancy in isolated idiopathic cryptorchidism and to analyse the possible disruptions of INSL3 and/or testosterone.

METHODS

From a prospective case-control study at Nice University Hospital, we assessed 180 boys born after 34 weeks gestation: 52 cryptorchid (48 unilateral, 4 bilateral; 26 transient, 26 persistent), and 128 controls matched for term, weight and time of birth. INSL3 and testosterone were measured in cord blood and compared in both groups as were other components of the pituitary-gonadic axis: LH, HCG, FSH, AMH and SHBG.

RESULTS

INSL3 was decreased in cryptorchid boys (P = 0·031), especially transient cryptorchid (P = 0·029), while testosterone was unchanged as were the other hormones measured. INSL3 was significantly decreased (P = 0·018) in the group of 20 with nonpalpable testes compared with the group of 21 with palpable testes (15 suprascrotal, five inguinal, one high scrotal) according to Scorer classification. In the whole population, INSL3 correlated positively with LH and negatively with AMH, but with no other measured hormones.

CONCLUSIONS

INSL3 but not testosterone is decreased at birth in idiopathic cryptorchidism, especially in transient forms. This hormonal decrease may contribute to the impaired testicular descent along with genetic and anatomical factors. Whether foetal environment (nutritional and/or toxicological) interferes with INSL3 secretion in humans remains to be confirmed.

Diethylstilbestrol affects the expression of GPER in the gubernaculum testis

Recent evidence suggested a positive correlation between environmental estrogens (EEs) and high incidence of abnormalities in male urogenital system. EEs are known to cause the abnormalities of testes development and testicular descent. Diethylstilbestrol (DES) is a nonsteroidal synthetic estrogen that disrupts the morphology and proliferation of gubernacular cells, and its nongenomic effects on gubernaculum testis cells may be mediated by G protein-coupled estrogen receptor (GPER). In this study, we detected the expression of GPER in mouse gubernacular testis and investigated the effects of DES on the expression of GPER in gubernaculum testis cells. RT-PCR analysis revealed that GPER mRNA was expressed in the gubernaculum. GPER protein was detected in the parenchymal cells of the gubernaculum early in development. Furthermore, we demonstrate that GPER inhibitor G15 relieved DES-induced inhibition of GPER expression in gubernaculum testis cell, but ER inhibitor ICI 182780 had the converse effects on DES-induced inhibition of GPER expression in these cells. These data suggest that the effects of DES on mouse gubernaculum testis cells are mediated at least partially by the regulation of GPER expression.

Man is not a big rat: concerns with traditional human risk assessment of phthalates based on their anti-androgenic effects observed in the rat foetus

Phthalates provide one of the most documented example evidencing how much we must be cautious when using the traditional paradigm based on extrapolation of experimental data from rodent studies for human health risk assessment of endocrine disruptors (EDs). Since foetal testis is known as one of the most sensitive targets of EDs, phthalate risk assessment is routinely based on the capacity of such compounds to decrease testosterone production by the testis or to impair masculinization in the rat during foetal life. In this paper, the well-established inhibiting effects of phthalates of the foetal Leydig cells function in the rat are briefly reviewed. Then, data obtained in humans and other species are carefully analysed. Already in January 2009, using the organotypic culture system named Fetal Testis Assay (FeTA) that we developed, we reported that phthalates might not affect testosterone production in human foetal testes. Several recent experimental studies using xenografts confirm the absence of detectable anti-androgenic effect of phthalates in the human foetal testes. Epidemiological studies led to contradictory results. Altogether, these findings suggest that phthalates effects on foetal Leydig cells are largely species-specific. Consequently, the phthalate threshold doses that disturb foetal steroidogenesis in rat testes and that are presently used to define the acceptable daily intake levels for human health protection must be questioned. This does not mean that phthalates are safe because these compounds have many deleterious effects upon germ cell development that may be common to the different studied species including human. More generally, the identification of common molecular, cellular or/and phenotypic targets in rat and human testes should precede the choice of the toxicological endpoint in rat to accurately assess the safety threshold of any ED in humans.

In vitro effects of estradiol-17β, monobutyl phthalate and mono-(2-ethylhexyl) phthalate on the secretion of testosterone and insulin-like peptide 3 by interstitial cells of scrotal and retained testes in dogs

The objective was to determine the effects of estradiol-17β, monobutyl phthalate (MBP) and mono-(2-ethylhexyl) phthalate (MEHP) on testosterone and insulin-like peptide 3 (INSL3) secretions in cultured testicular interstitial cells isolated (enzymatic dispersion) from scrotal and retained testes of small-breed dogs. Suspension cultures were treated with estradiol-17β (0, 10, and 100 ng/mL), MBP (0, 0.8, and 8 mmol/L) or MEHP (0, 0.2, and 0.8 mmol/L) for 18 h, in the presence or absence of 0.1 IU/mL hCG. Testosterone (both basal and hCG-induced) and INSL3 (basal) concentrations were measured in spent medium. Effects of estradiol-17β, MBP, and MEHP on testosterone and INSL3 secretions were not affected (P > 0.15) by cell source (scrotal versus retained testis); therefore, data were combined and analyzed, and outcomes reported as percentage relative to the control. In testicular interstitial cells, basal testosterone secretion was increased (P < 0.01) by 100 ng/mL estradiol-17β (130.2 ± 10.6% of control). Among phthalates, 0.2 and 0.8 mmol/L MEHP stimulated (P < 0.01) basal testosterone secretion (135.5 ± 8.3% and 154.6 ± 12.9%, respectively). However, hCG-induced testosterone secretion was inhibited (P < 0.01) by 8 mmol/L MBP (67.7 ± 6.0%), and tended to be inhibited (P = 0.056) by 0.8 mmol/L MEHP (84.5 ± 5.6%). Basal INSL3 secretion was inhibited (P < 0.01) by 8 mmol/L MBP (73.6 ± 6.8%) and 0.8 mmol/L MEHP (76.9 ± 11.3%). In conclusion, we inferred that estradiol-17β and certain phthalate monoesters had direct effects on secretions of testosterone and INSL3 in canine testicular interstitial cells, with no significant difference between scrotal and retained testes.

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.

Visualization of Reinke's crystals in normal and cryptorchid testis

Within the human testis, Reinke's crystals are found in Leydig cells but their nature and function are poorly understood. The aim of our study was to investigate the properties of Reinke's crystals in man with the normal morphology of the testis (control group) and infertile patients diagnosed with cryptorchidism. 20 biopsies from infertile patients and six biopsies from men with regular spermatogenesis (20-30 years.) were used. Sections of the testis tissue were stained with haematoxylin and eosin and a modified Masson's method. Specimens were observed by bright field, confocal and transmission electron microscopy (TEM). The number of Reinke's crystals in investigated groups was determined applying stereological methods. In both groups, Reinke's crystals were noted within the cytoplasm and nuclei of Leydig cells. Some "free" crystals were found within the interstitial space, outside Leydig cells. Confocal microscopy proved to be very useful in the assessment of the shape and 3D reconstruction of the crystal. TEM analysis confirmed a hexagonal form of the crystal, while crystallographic data on sections of 70-300 nm thickness provided a better insight into the organization of the crystal lattice. Stereological analysis revealed a significant increase in the number of crystals in cryptorchid testes when compared with controls. Increased number of crystals in cryptorchid specimens leads to the assumption that the prolonged exposure to higher (abdominal) temperature might stimulate enzymes involved in the synthesis of the proteins of the crystal. However, the exact molecular nature of the crystal lattice remains in both normal and cryptorchid testis obscure.

ESR1 promoter polymorphism is not associated with nonsyndromic cryptorchidism

The ESR1 promoter microsatellite (TA)n was reported as a potential functional polymorphism. In a case-control study, we were unable to demonstrate any association between (TA)n and nonsyndromic cryptorchidism in Italian and Spanish study populations.

Prenatal environmental exposures, epigenetics, and disease

This review summarizes recent evidence that prenatal exposure to diverse environmental chemicals dysregulates the fetal epigenome, with potential consequences for subsequent developmental disorders and disease manifesting in childhood, over the lifecourse, or even transgenerationally. The primordial germ cells, embryo, and fetus are highly susceptible to epigenetic dysregulation by environmental chemicals, which can thereby exert multiple adverse effects. The data reviewed here on environmental contaminants have potential implications for risk assessment although more data are needed on individual susceptibility to epigenetic alterations and their persistence before this information can be used in formal risk assessments. The findings discussed indicate that identification of environmental chemicals that dysregulate the prenatal epigenome should be a priority in health research and disease prevention.

Altered expression and localization of estrogen receptors alpha and beta in the testes of a cryptorchid rat model

OBJECTIVES

To assess the involvement of estrogen in spermatogenesis, we evaluated the expression of estrogen receptors (ERs) alpha (ERalpha) and beta (ERbeta) in the cryptorchid testes in model rats exposed to flutamide during the fetal stage.

METHODS

Cryptorchid model rats were produced by administering flutamide to pregnant Sprague-Dawley rats. To evaluate the sequential change in the expression of ERalpha and ERbeta genes, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using specific primers. Immunohistochemistry with ERalpha and ERbeta antibodies was performed, and the results were evaluated to determine the influences of orchiopexy.

RESULTS

Real-time RT-PCR revealed that ERalpha expression in control testes increases with growth and peaks value at 7 weeks and significantly decreases in cryptorchid testes. ERbeta expression was low, and there were no significant differences between both the cryptorchid and control testes groups. Immunohistochemistry revealed that ERalpha protein was present in the spermatids and Sertoli cells of descended testes, and that this protein was strongly expressed in the Leydig cells of cryptorchid testes. ERbeta was detected in multiple cells in both groups. After orchiopexy, ERalpha expression was detected in the spermatids of cryptorchid testes.

CONCLUSIONS

Spermatogenesis in cryptorchid rats is disrupted. Because the expression of ERbeta was unchanged in both control and cryptorchid testes, we supposed that alteration in ERalpha levels is more closely related to spermatogenic failure than ERbeta levels in the cryptorchid testes. We considered that increased expression of ERalpha in Leydig cells of cryptorchid testes is associated with estradiol level in the testicular tissue, and androgen-estrogen imbalance deteriorates spermatogenesis in cryptorchidism.

[Cryptorchidism: from physiopathology to infertility]

Cryptorchidism is a defect of testicular descent. Hormonal, genetic and environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years in industrialised countries. Cryptorchidism itself might be considered a complex disease. This testicular pathology represents the best-characterized risk factor for reduced fertility and testicular cancer. The purpose of this review is to better understand physiopathology and mechanisms of infertility in men with history of cryptorchidism.

Further insights into the role of T222P variant of RXFP2 in non-syndromic cryptorchidism in two Mediterranean populations

The aetiopathogenesis of isolated cryptorchidism remains largely unknown. Mutation screenings in the most relevant candidate genes for testicular maldescent lead to controversial data in the literature. In particular, the role of the T222P genetic variant of the RXFP2 gene is still debated. Given the controversies, the aim of this study was to provide further data on this genetic variant in two Mediterranean populations. A total of 577 subjects from Spain and 550 from Italy (with and without a history of cryptorchidism) were analysed. The T222P substitution was found in both unilateral and bilateral cases and in a total of 12 controls. These data exclude a clear-cut cause-effect relationship between T222P variant and testicular maldescent. The T222P variant was found at a similar frequency in both cases and controls in the Spanish population, whereas in Italy, the frequency of T222P resulted significantly higher in the cryptorchid group (p = 0.031). The observed difference between the two countries and the highly variable phenotypic expression of the T222P variant may depend on the genetic background or on environmental conditions. The haplotype analysis of the RXFP2 gene in T222P carriers and their parents showed that this variant is linked to the previously inferred C-C-G-A-13 haplotype and consequently provides further support to the 'founder effect' hypothesis. In conclusion, our data indicate that T222P is a frequent variant in the Spanish population with no pathogenic effect. Although in Italy it seems to confer a mild risk (odds ratio = 3.17, 95% confidence interval: 1.07-9.34) to cryptorchidism, the screening for this variant for diagnostic purposes is not advised because of the relatively high frequency of control carriers (1.4% of Italian men without a history of cryptorchidism).

Prenatal DDT exposure and testicular cancer: a nested case-control study

The authors examined maternal serum levels of DDT-related compounds in relation to son's risk of testicular cancer 30 years later. Fifteen of 9,744 live-born sons were diagnosed with germ cell testicular cancer and had maternal serum samples. Cases were matched to three controls on race and birth year. Maternal serum DDT-related compounds, measured in the early postpartum, were associated with her son's risk of testicular cancer. Despite low statistical power, we observed that mothers of cases had a significantly higher ratio of p,p'-DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) to p,p'-DDE (1,1'-dichloro-2,2'-bis(p-chlorophenyl)ethylene) and lower o,p'-DDT (1,1,1-tricholoro-2-(p-chlororphenyl)-2-(o-chlorophenyl)ethane). These findings are consistent with earlier exposure to DDT and with slower p,p'-DDT elimination among mothers of cases. Whether these associations could be direct, or operate via other pathways is unknown. Further research on interindividual differences in DDT metabolism could provide clues to testicular cancer etiology.

Polychlorinated biphenyls and risk of testicular germ cell tumors

Exposure to endocrine-disrupting chemicals, such as polychlorinated biphenyls (PCB), may alter hormonal balance and thereby increase risk of testicular germ cell tumors (TGCT). To study the relationship of PCBs to TGCT, prediagnostic serum samples from 736 cases and 913 controls in the Servicemen's Testicular Tumor Environmental and Endocrine Determinants study were analyzed. Adjusted odds ratios and 95% confidence intervals were estimated using logistic regression. PCB levels were examined in association with all TGCT and, separately, with each histologic type (seminoma and nonseminoma). Risks associated with seven functional groupings of PCBs, as well as sum of PCBs, were also examined. There were significantly decreased risks of TGCT in association with eight PCBs (PCB-118, PCB-138, PCB-153, PCB-156, PCB-163, PCB-170, PCB-180, and PCB-187) and no association with the remaining three (PCB-99, PCB-101, and PCB-183). The same eight congeners were significantly associated with decreased risk of nonseminoma, whereas five (PCB-138, PCB-153, PCB-156, PCB-163, and PCB-170) were associated with decreased risk of seminoma. All functional groupings of PCBs were also associated with decreased risk of TGCT and of nonseminoma, whereas six of the seven functional groups were associated with decreased risk of seminoma. Sum of PCBs was significantly associated with decreased risk of TGCT (P(trend) = 0.006), nonseminoma (P(trend) = 0.007), and seminoma (P(trend) = 0.05). Overall, these data do not support the hypothesis that PCB exposure increases the risk of TGCT.

Role of hormones, genes, and environment in human cryptorchidism

Cryptorchidism is the most frequent congenital birth defect in male children (2-4% in full-term male births), and it has the potential to impact the health of the human male. In fact, although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. Furthermore, some reports have highlighted a significant increase in the prevalence of cryptorchidism over the last few decades. Etiology of cryptorchidism remains for the most part unknown, and cryptorchidism itself might be considered a complex disease. Major regulators of testicular descent from intraabdominal location into the bottom of the scrotum are the Leydig-cell-derived hormones testosterone and insulin-like factor 3. Research on possible genetic causes of cryptorchidism has increased recently. Abundant animal evidence supports a genetic cause, whereas the genetic contribution to human cryptorchidism is being elucidated only recently. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene have been recognized as causes of cryptorchidism in some cases, but some chromosomal alterations, above all the Klinefelter syndrome, are also frequently involved. Environmental factors acting as endocrine disruptors of testicular descent might also contribute to the etiology of cryptorchidism and its increased incidence in recent years. Furthermore, polymorphisms in different genes have recently been investigated as contributing risk factors for cryptorchidism, alone or by influencing susceptibility to endocrine disruptors. Obviously, the interaction of environmental and genetic factors is fundamental, and many aspects have been clarified only recently.

Xenohormone transactivities are inversely associated to serum POPs in Inuit

BACKGROUND

The persistent organic pollutants (POPs) are highly lipophilic and resistant to biodegradation and found in e.g. seafood and marine mammals. Greenlandic Inuit have high intake of marine food and thus high POP burden that varies according to local conditions and dietary preference. We do for the very first time report the serum POP related non-steroidal xenohormone activity of Inuit across Greenland. The aims were 1) to determine the integrated xenohormone bioactivities as an exposure biomarker of the actual lipophilic serum POP mixture measuring the effect on estrogen (ER) and androgen receptor (AR) transactivity in citizens from different Greenlandic districts and 2) to evaluate associations to serum POP markers (14 PCBs and 10 pesticides) and lifestyle characteristics.

METHODS

Serum samples from 121 men and 119 women from Nuuk, Sisimiut and Qaanaaq were extracted using SPE-HPLC fractionation to obtain the serum POP fraction free of endogenous hormones. The serum POP fraction was used for determination of xenohormone transactivity using ER and AR reporter gene assays.

RESULTS

In overall, the xenohormone transactivities differed between districts as well as between the genders. Associations between the transactivities and age, n-3/n-6 and smoker years were observed. The xenoestrogenic and xenoandrogenic transactivities correlated negatively to the POPs for the combined female and male data, respectively.

CONCLUSION

The non-steroidal xenohormone transactivities can be used as an integrated biomarker of POP exposure and lifestyle characteristics. The actual serum POP mixtures antagonized the age adjusted sex hormone receptor functions. Comparison of different study populations requires in addition to age inclusion of diet and lifestyle factors.

Cryptorchidism at birth in Nice area (France) is associated with higher prenatal exposure to PCBs and DDE, as assessed by colostrum concentrations

BACKGROUND

Since fetal exposure to anti-androgenic and/or estrogenic compounds has adverse effect on animal reproduction, such exposure could be harmful to human fetus. Data are scarce on cryptorchidism and human exposure to endocrine disruptors.

METHODS

We performed a prospective case-control study to assess the incidence of cryptorchidism and fetal exposure to selected chemicals in the Nice area. One hundred and fifty-one cord bloods (67 cryptorchid, 84 tightly matched controls) and 125 colostrums (56 for cryptorchid and 69 for controls) were screened for xenobiotics, including anti-androgenic dichloro-diphenyl-trichloro-ethylene (DDE), polychlorinated biphenyls (PCBs), and dibutylphthalate (and metabolite monobutylphthalate, mBP).

RESULTS

Median concentrations in colostrum were higher, although not statistically significantly, in cryptorchid versus controls. Cryptorchid boys were more likely to be classified in the most contaminated groups in colostrum for DDE, Sigma PCBs and the composite score PCB + DDE. The same trend, but again not statistically significantly was observed for mBP. Odds ratio for cryptorchidism was increased for the highest score of Sigma PCB, with a trend only for DDE and Sigma PCB + DDE versus the lowest score of those components.

CONCLUSIONS

Our results support an association between congenital cryptorchidism and fetal exposure to PCBs and possibly DDE. Higher concentrations in milk could be a marker of higher exposure or for an impaired detoxification pattern in genetically predisposed individuals.

Polymorphisms of the luteinizing hormone/chorionic gonadotropin receptor gene: association with maldescended testes and male infertility

OBJECTIVE

Maldescended testes are the most common genital anomaly in newborns and are associated with testicular malignancy and infertility. As the inguinoscrotal phase of testis descent is androgen-dependent and requires integrity of the luteinizing hormone/chorionic gonadotropin receptor (LHCGR), we investigated whether nonsynonymous polymorphisms of the LHCGR gene are associated with maldescended testes.

METHODS

This was a retrospective case-control study including 278 patients with maldescended testes, 277 infertile men without maldescensus and 271 controls with normal sperm concentrations. Clinical and endocrinological workup of the patients was performed. Single nucleotide polymorphism (SNP) analysis was performed by GeneScan and TaqMan technology.

RESULTS

Men with maldescended testes had significantly lower testis volumes, higher serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) but similar testosterone levels compared with both the control groups. The insLQ polymorphism in exon 1 (rs4539842) and the N291S SNP in exon 10 (rs12470652), showing increased receptor sensitivity in vitro, were not differently distributed between patients and controls. The S312N SNP in exon 10 (rs2293275) was significantly less frequent in men with maldescended testes than in controls. This difference was confirmed when infertile men with and without maldescensus were considered together.

CONCLUSIONS

In men with maldescensus, a high LH drive maintains normal testosterone levels but this LH resistance is not associated with any particular LHCGR genotype. A significant association with the S312N polymorphism in exon 10 of the LHCGR is correlated to the spermatogenetic damage rather than to the maldescensus itself. Either the LHCGR itself or another genomic region linked to this SNP, possibly the germ cell-specific TFIIA-alpha/beta-like factor gene transcribed from the same genomic region in the opposite direction, is a risk factor for male infertility.

Hormonal and genetic control of testicular descent

Cryptorchidism has the potential to affect the health of the human male. Although it is often considered a mild malformation, it represents the best-characterized risk factor for reduced fertility and testicular cancer. The aetiology of cryptorchidism remains, for the most part, unknown and cryptorchidism itself might be considered a complex disease. This reflects the intricate mechanisms regulating testicular development and descent from intra-abdominal location into the bottom of the scrotum, involving different anatomical and hormonal factors. Major actors of testicular descent are the Leydig cell-derived hormones testosterone and insulin-like factor 3, even if other factors may play a role. Although considerable evidence exists in animals to support a genetic cause, the genetic contribution to human cryptorchidism is only recently being elucidated. Environmental factors might also contribute to the aetiology of cryptorchidism and its increased incidence in recent years. Mutations in the gene for insulin-like factor 3 and its receptor and in the androgen receptor gene explain a minority of cases of cryptorchidism, but research on genetic polymorphisms that may also influence susceptibility to endocrine disruptors is shedding light on this field.

Endocrine-Disrupting Activities In Vivo of the Fungicides Tebuconazole and Epoxiconazole

The triazole fungicides tebuconazole and epoxiconazole were investigated for reproductive toxic effects after exposure during gestation and lactation. Rats were dosed with epoxiconazole (15 or 50 mg/kg bw/day) or tebuconazole (50 or 100 mg/kg bw/day) during pregnancy from gestational day (GD) 7 and continued during lactation until postnatal day (PND) 16. Some dams were randomly chosen for cesarean section at GD 21 to evaluate effects on sexual differentiation in the fetuses. Other dams delivered normally, and the pups were examined (e.g., anogenital distance [AGD] and hormone levels) at birth, at PND 13 or PND 16, and semen quality was assessed in adults. Both tebuconazole and epoxiconazole affected reproductive development in the offspring after exposure in utero. Both compounds virilized the female offspring as shown by an increased AGD PND 0. Furthermore, tebuconazole had a feminizing effect on male offspring as shown by increased nipple retention. This effect was likely caused by the reduced testosterone levels seen in male fetuses. Tebuconazole increased the testicular concentrations of progesterone and 17alpha-hydroxyprogesterone in male fetuses, indicating a direct impact on the steroid synthesis pathway in the Leydig cells. The high dose of epoxiconazole had marked fetotoxic effects, while the lower dose caused increased birth weights. The increased birth weights may be explained by a marked increase in testosterone levels in dams during gestation. Common features for azole fungicides are that they increase gestational length, virilize female pups, and affect steroid hormone levels in fetuses and/or dams. These effects strongly indicate that one major underlying mechanism for the endocrine-disrupting effects of azole fungicides is disturbance of key enzymes like CYP17 involved in the synthesis of steroid hormones.