Developmental estrogen exposures predispose to prostate carcinogenesis with aging

Elevated parkinsonism pathological markers in dopaminergic neurons with developmental exposure to atrazine

Atrazine (ATZ) is one of the most used herbicides in the US and a known endocrine disruptor. ATZ is frequently detected in drinking water, especially in Midwestern regions of the United States, exceeding the EPA regulation of maximum contamination level (MCL) of 3 ppb. Epidemiology studies have suggested an association between ATZ exposure and neurodegeneration. Less, however, is known about the neurotoxic mechanism of ATZ, particularly for exposures at a developmental stage. Here, we exposed floor plate progenitors (FPPs) derived from human induced pluripotent stem cells (hiPSCs) to low concentrations of ATZ at 0.3 and 3 ppb for two days followed by differentiation into dopaminergic (DA) neurons in ATZ-free medium. We then examined the morphology, activity, pathological protein aggregation, and transcriptomic changes of differentiated DA neurons. We observed significant decrease in the complexity of neurite network, increase of neuronal activity, and elevated tau- and α-synuclein (aSyn) pathologies after ATZ exposure. The ATZ-induced neuronal changes observed here align with pathological characteristics in Parkinson's disease (PD). Transcriptomic analysis further corroborates our findings; and collectively provides a strong evidence base that low-concentration ATZ exposure during development can elicit increased risk of neurodegeneration.

Prostate histological investigation in rats exposed to bisphenol a and phytochemicals during the perinatal period and subjected to hormonal stimulus in adulthood

Bisphenol A (BPA) is an environmentally dispersed chemical associated with tumor development. Phytochemicals such as indole-3-carbinol (I3C) and genistein (GEN) have chemoprotective effects on tumor cells. Thus, this study aimed to evaluate the prostatic morphological aspects of rats exposed to BPA, GEN, and I3C during the perinatal period and submitted to hormonal stimulus in adulthood. Blood was collected to obtain hormone concentrations. Slides stained with hematoxylin & eosin, and picrosirius were subjected to fractal, stereological, morphometric, and collagen quantification analysis. I3C decreased the plasma dihydrotestosterone levels, and both phytochemicals increased the plasma estrogen levels. Unlike phytochemicals, BPA did not alter any of the parameters evaluated. GEN reduced the epithelial height, while I3C increased the fractal dimension and stromal collagen. Although BPA did not alter the prostate morphology, the phytochemicals provided beneficial effects for the prostate histological organization in adult animals subjected to hormonal stimulus.

Early-life origin of prostate cancer through deregulation of miR-206 networks in maternally malnourished offspring rats

The Developmental Origins of Health and Disease (DOHaD) concept has provided the framework to assess how early life experiences can shape health and disease throughout the life course. While maternal malnutrition has been proposed as a risk factor for the developmental programming of prostate cancer (PCa), the molecular mechanisms remain poorly understood. Using RNA-seq data, we demonstrated deregulation of miR-206-Plasminogen (PLG) network in the ventral prostate (VP) of young maternally malnourished offspring. RT-qPCR confirmed the deregulation of the miR-206-PLG network in the VP of young and old offspring rats. Considering the key role of estrogenic signaling pathways in prostate carcinogenesis, in vitro miRNA mimic studies also revealed a negative correlation between miR-206 and estrogen receptor α (ESR1) expression in PNT2 cells. Together, we demonstrate that early life estrogenization associated with the deregulation of miR-206 networks can contribute to the developmental origins of PCa in maternally malnourished offspring. Understanding the molecular mechanisms by which early life malnutrition affects offspring health can encourage the adoption of a governmental policy for the prevention of non-communicable chronic diseases related to the DOHaD concept.

Long exposure to a mixture of endocrine disruptors prediposes the ventral prostate of rats to preneoplastic lesions

Endocrine disruptors (ED) are compounds dispersed in the environment that modify hormone biosynthesis, affecting hormone-dependent organs such as the prostate. Studies have only focused on evaluating the effects of ED alone or in small groups and short intervals and have not adequately portrayed human exposure. Therefore, we characterized the prostate histoarchitecture of rats exposed to an ED mixture (ED Mix) mimicking human exposure. Pregnant females of the Sprague-Dawley strain were randomly distributed into two experimental groups: Control group (vehicle: corn oil, by gavage) and ED Mix group: received 32.11 mg/kg/day of the ED mixture diluted in corn oil (2 ml/kg), by gavage, from gestational day 7 (DG7) to post-natal day 21 (DPN21). After weaning at DPN22, the male pups continued to receive the complete DE mixture until they were 220 days old when they were euthanized. The ED Mix decreased the epithelial compartment, increased the fractal dimension, and decreased glandular dilation. In addition, low-grade prostatic intraepithelial neoplasia was observed in addition to regions of epithelial atrophy in the group exposed to the ED Mix. Exposure to the mixture decreased both types I and III collagen area in the stroma. We concluded that the ED Mix was able to cause alterations in the prostatic histoarchitecture and induce the appearance of preneoplastic lesions.

Impacts of heavy metal exposure on the prostate of murine models: Mechanisms of toxicity

Heavy metals are elements found into the environment mainly due to anthropogenic activities. Naturally occurring and higher released doses cause disorders in the prostate, which depends on appropriate hormonal regulation, and exposure to heavy metals may impair prostate homeostasis. The current work highlighted the main mechanisms of toxicity of different environmental heavy metal contaminants, such as aluminum, arsenic, cadmium, chromium, lead, mercury, and nickel, and their impacts found in the prostate morphophysiology of murine models. The repercussions triggered by heavy metals on the prostate include hormonal imbalance and oxidative damage, leading to morphological alterations, which can vary according to the chemical properties of each element, exposure time and concentration, and age. The information of altered biological pathways and its impacts on the prostate of exposed murines are related to human outcomes being useful in the real context of human exposure.

Prevention of cleft lip and/or palate in A/J mice by licorice solution

Cleft lip and/or palate anomalies (CL ± P) are the most frequent birth defects affecting the orofacial region in humans. Although their etiology remains unclear, the involvement of environmental and genetic risk factors is known. This observational study aimed to investigate how the use of  crude drugs with estrogen activity influenced an animal model's ability to prevent CL ± P. A/J mice were randomly divided into six experimental groups. Five of these groups consumed a drink containing crude drug licorice root extract, with the following weights attributed to each group: 3 g in group I, 6 g in group II, 7.5 g in group III, 9 g in group IV, and 12 g in group V, whereas a control group consumed tap water. The effect of licorice extract was examined for fetal mortality and fetal orofacial cleft development compared to the control group. The rates for fetal mortality were 11.28%, 7.41%, 9.18%, 4.94%, and 7.90% in groups I, II, III, IV, and V, respectively, compared to 13.51% in the control group. There were no significant differences in the mean weight of alive fetuses in all five groups compared to the control group (0.63 ± 0.12). Group IV showed the lowest orafacial cleft occurrence of 3.20% (8 fetuses) with statistical significance (p = 0.0048) out of 268 live fetuses, whereas the control group had the occurrence of 8.75% (42 fetuses) among 480 live fetuses. Our study showed that the dried licorice root extract may reduce orofacial birth defects in experimental animal studies.

Androgenic induction of penile features in postnatal female mouse external genitalia from birth to adulthood: Is the female sexual phenotype ever irreversibly determined?

Female mice were treated for 35 days from birth to 60 days postnatal (P0, [birth], P5, P10, P20 and adult [∼P60]) with dihydrotestosterone (DHT). Such treatment elicited profound masculinization the female external genitalia and development of penile features (penile spines, male urogenital mating protuberance (MUMP) cartilage, corpus cavernosum glandis, corporal body, MUMP-corpora cavernosa, a large preputial space, internal preputial space, os penis). Time course studies demonstrated that DHT elicited canalization of the U-shaped clitoral lamina to create a U-shaped preputial space, preputial lining epithelium and penile epithelium adorned with spines. The effect of DHT was likely due to signaling through androgen receptors normally present postnatally in the clitoral lamina and associated mesenchyme. This study highlights a remarkable male/female difference in specification and determination of urogenital organ identity. Urogenital organ identity in male mice is irreversibly specified and determined prenatally (prostate, penis, and seminal vesicle), whereas many aspects of the female urogenital organogenesis are not irreversibly determined at birth and in the case of external genitalia are not irreversibly determined even into adulthood, the exception being positioning of the female urethra, which is determined prenatally.

miR-18a-5p Is Involved in the Developmental Origin of Prostate Cancer in Maternally Malnourished Offspring Rats: A DOHaD Approach

The Developmental Origins of Health and Disease (DOHaD) concept correlates early life exposure to stressor conditions with the increased incidence of non-communicable chronic diseases, including prostate cancer (PCa), throughout the life span. However, the molecular mechanisms involved in this process remain poorly understood. In this study, the deregulation of two miRNAs (rno-miR-18a-5p and rno-miR-345-3p) was described in the ventral prostate VP of old rats born to dams fed with a low protein diet (LPD) (6% protein in the diet) during gestational and lactational periods. Integrative analysis of the (VP) transcriptomic and proteomic data revealed changes in the expression profile of 14 identified predicted targets of these two DE miRNAs, which enriched terms related to post-translational protein modification, metabolism of proteins, protein processing in endoplasmic reticulum, phosphonate and phosphinate metabolism, the calnexin/calreticulin cycle, metabolic pathways, N-glycan trimming in the ER and the calnexin/calreticulin cycle, hedgehog ligand biogenesis, the ER-phagosome pathway, detoxification of reactive oxygen species, antigenprocessing-cross presentation, RAB geranylgeranylation, collagen formation, glutathione metabolism, the metabolism of xenobiotics by cytochrome P450, and platinum drug resistance. RT-qPCR validated the deregulation of the miR-18a-5p/P4HB (prolyl 4-hydroxylase subunit beta) network in the VP of older offspring as well as in the PNT-2 cells transfected with mimic miR-18a-5p. Functional in vitro studies revealed a potential modulation of estrogen receptor α (ESR1) by miR-18a-5p in PNT-2 cells, which was also confirmed in the VP of older offspring. An imbalance of the testosterone/estrogen ratio was also observed in the offspring rats born to dams fed with an LPD. In conclusion, deregulation of the miR-18a-5p/P4HB network can contribute to the developmental origins of prostate cancer in maternally malnourished offspring, highlighting the need for improving maternal healthcare during critical windows of vulnerability early in life.

Chronic coexposure to arsenic and estrogen potentiates genotoxic estrogen metabolic pathway and hypermethylation of DNA glycosylase MBD4 in human prostate epithelial cells

BACKGROUND

Previously we reported that arsenic and estrogen cause synergistic effects in the neoplastic transformation of human prostate epithelial cells. In addition to receptor-mediated pathways, DNA-reactive estrogen metabolites have also been shown to play a critical role in mutagenicity and carcinogenicity. Both estrogen and arsenic are known prostate carcinogens, however, the effect of coexposure to these two chemicals on genes involved in estrogen metabolism is not known. Therefore, the objective of this study was to evaluate the role of arsenic and estrogen coexposure on the expression of estrogen receptors and estrogen metabolism-associated genes. Earlier, we also reported the synergistic effect of arsenic and estrogen on decreased expression of MBD4 genes that play an important role in DNA repair through its DNA glycosylase activity. To further understand the mechanism, the promoter methylation of this gene was also analyzed.

METHODS

Total RNA and protein were isolated from RWPE-1 human prostate epithelial cells that were coexposed to arsenic and estrogen for a chronic duration (6 months). The expression of estrogen receptors, estrogen metabolism associated phase I genes (CYP 1A1, 1A2, 3A4, and 1B1) and phase II gene catechol-O-methyltransferase (COMT), as well as antioxidant MnSOD, were analyzed either at the RNA level by quantitative reverse transcriptase-polymerase chain reaction or at the protein level by western blot. Promoter methylation of MBD4 was analyzed by pyrosequencing.

RESULTS

Expression of MnSOD and phase I genes that convert E₂ into genotoxic metabolites 2-OH-E₂ and 4-OH-E₂ were significantly increased, whereas the expression of phase II gene COMT that detoxifies estrogen metabolites was significantly decreased in arsenic and estrogen coexposed cells. MBD4 promoter was hypermethylated in arsenic and estrogen coexposed cells. Coexposure to arsenic and estrogen has synergistic effects on the expression of these genes as well as in MBD4 promoter hypermethylation.

CONCLUSIONS

These novel findings suggest that coexposure to arsenic and estrogen acts synergistically in the activation of not only the estrogen receptors but also the genes associated with genotoxic estrogen metabolism and epigenetic inactivation of DNA glycosylase MBD4. Together, these genetic and epigenetic aberrations provide the molecular basis for the potentiation of carcinogenicity of arsenic and estrogen coexposure in prostate epithelial cells.

Impact of chronic exposure of rats to bisphenol A from perinatal period to adulthood on intraprostatic levels of 5α-reductase isozymes, aromatase, and genes implicated in prostate cancer development

The synergetic effect of estrogens and androgens is known to play a crucial role in the physiopathology of the prostate gland. Bisphenol A (BPA) is an endocrine disrupting compound that can interfere with endocrine hormone functioning and thereby influence prostate development. The objective of this study was to examine the impact on prostate expression of aromatase, 5α-R isozymes, and prostate cancer-related genes of exposure to low doses of BPA from perinatal period to adulthood. Vehicle or BPA (2.5 μg/kg b.w./day) was administered to gestating Wistar rats from gestational day 12 (GD12) to parturition and then to their male pups from postnatal day 1 (PND1) until euthanization on PND90. Their prostate glands were examined by qRT-PCR, Western blot, PCR array, and morphological study. mRNA and protein levels of 5α-R2 were significantly reduced and mRNA and protein levels of aromatase were significantly increased in BPA-treated animals, which also showed modifications of 8 out of the 84 key genes implicated in the development of prostate cancer. Because BPA interferes with genes involved in intraprostatic androgen and estrogen production and others implicated in prostate cancer, research is warranted into the prostate disease risk associated with chronic low-dose BPA exposure throughout life.

Mucinous metaplasia in Pten conditional knockout mice and mucin family genes as prognostic markers for prostate cancer

AIMS

This study evaluated the association of mucinous metaplasia (MM) with tumor cell proliferation, androgen receptor (AR) expression and invasiveness in Pten conditional knockout mice and the prognostic value of MM markers for patients with PCa.

MAIN METHODS

Prostatic lobes samples from genetic engineered mouse model Pten^f/f and Pb-Cre4/Pten^f/f were submitted for histopathological analysis and tissue expression of AR, the proliferation marker Ki67, alpha-smooth muscle actin, and laminin. RNAseq data of prostatic lobes samples were analyzed searching for MM gene expression patterns. We also investigated gene and protein expression related to MM in human PCa public databases.

KEY FINDINGS

All knockout animals analyzed showed at least one area of stroma-invading MM, which was absent in the control animals. The tumoral regions of MM showed a proliferative index 5 times higher than other tumoral areas and low expression of the AR (less than 20% of the cells were AR-positive). Disrupted basement membrane areas were observed in MM. The mouse and human PCa transcriptomes exhibited increased expression of the MM markers such as MUC1, MUC19, MUC4, MUC5AC, MUC5B, and TFF3. Gene expression profile was associated with castration-resistant prostate cancer (CRPC) and with a lower probability of freedom from biochemical recurrence.

SIGNIFICANCE

The expression of goblet cell genes, such as MUC1, MUC5AC, MUC5B, and TFF3 have significant prognostic value for PCa patients and represent another class of potential therapeutic targets.

Combined Effects of Different Endocrine-Disrupting Chemicals (EDCs) on Prostate Gland

Endocrine-disrupting chemicals (EDCs) belong to a heterogeneous class of environmental pollutants widely diffused in different aquatic and terrestrial habitats. This implies that humans and animals are continuously exposed to EDCs from different matrices and sources. Moreover, pollution derived from anthropic and industrial activities leads to combined exposure to substances with multiple mechanisms of action on the endocrine system and correlated cell and tissue targets. For this reason, specific organs, such as the prostate gland, which physiologically are under the control of hormones like androgens and estrogens, are particularly sensitive to EDC stimulation. It is now well known that an imbalance in hormonal regulation can cause the onset of various prostate diseases, from benign prostate hyperplasia to prostate cancer. In this review, starting with the description of normal prostate gland anatomy and embryology, we summarize recent studies reporting on how the multiple and simultaneous exposure to estrogenic and anti-androgenic compounds belonging to EDCs are responsible for an increase in prostate disease incidence in the human population.

Stromal cell interplay in prostate development, physiology, and pathological conditions

Advances in prostatic stroma studies over the past few decades have demonstrated that the stroma not only supports and nourishes the gland's secretory epithelium but also participates in key aspects of morphogenesis, in the prostate's hormonal metabolism, and in the functionality of the secretory epithelium. Furthermore, the stroma is implicated in the onset and progression of prostate cancer through the formation of the so-called reactive stroma, which corresponds to a tumorigenesis-permissive microenvironment. Prostatic stromal cells are interconnected and exchange paracrine signals among themselves in a gland that is highly sensitive to endocrine hormones. There is a growing body of evidence that telocytes, recently detected interstitial cells that are also present in the prostate, are involved in stromal organization, so that their processes form a network of interconnections with both the epithelium and the other stromal cells. The present review provides an update on the different types of prostate stromal cells, their interrelationships and implications for prostate development, physiology and pathological conditions.

Exploring the Biological Activity and Mechanism of Xenoestrogens and Phytoestrogens in Cancers: Emerging Methods and Concepts

Xenoestrogens and phytoestrogens are referred to as "foreign estrogens" that are produced outside of the human body and have been shown to exert estrogen-like activity. Xenoestrogens are synthetic industrial chemicals, whereas phytoestrogens are chemicals present in the plant. Considering that these environmental estrogen mimics potentially promote hormone-related cancers, an understanding of how they interact with estrogenic pathways in human cells is crucial to resolve their possible impacts in cancer. Here, we conducted an extensive literature evaluation on the origins of these chemicals, emerging research techniques, updated molecular mechanisms, and ongoing clinical studies of estrogen mimics in human cancers. In this review, we describe new applications of patient-derived xenograft (PDX) models and single-cell RNA sequencing (scRNA-seq) techniques in shaping the current knowledge. At the molecular and cellular levels, we provide comprehensive and up-to-date insights into the mechanism of xenoestrogens and phytoestrogens in modulating the hallmarks of cancer. At the systemic level, we bring the emerging concept of window of susceptibility (WOS) into focus. WOS is the critical timing during the female lifespan that includes the prenatal, pubertal, pregnancy, and menopausal transition periods, during which the mammary glands are more sensitive to environmental exposures. Lastly, we reviewed 18 clinical trials on the application of phytoestrogens in the prevention or treatment of different cancers, conducted from 2002 to the present, and provide evidence-based perspectives on the clinical applications of phytoestrogens in cancers. Further research with carefully thought-through concepts and advanced methods on environmental estrogens will help to improve understanding for the identification of environmental influences, as well as provide novel mechanisms to guide the development of prevention and therapeutic approaches for human cancers.

EDCs and male urogenital cancers

Male sex determination and sexual differentiation occur between 6-12 weeks of gestation. During the "male programming window" the fetal testes start to produce testosterone that initiates the development of the male reproductive tract. Exposure to endocrine disrupting chemicals (EDCs) able to mimic or disrupt steroid hormone actions may disrupt testicular development and adversely impact reproductive health at birth, during puberty and adulthood. The testicular dysgenesis syndrome (TDS) occurs as a result inhibition of androgen action on fetal development preceding Sertoli and Leydig cell dysfunction and may result from direct or epigenetic effects. Hypospadias, cryptorchidism and poor semen quality are elements of TDS, which may be considered a risk factor for testicular germ cell cancer (TGCC). Exposure to estrogen or estrogenic EDCs results in developmental estrogenization/estrogen imprinting in the rodent for prostate cancer (PCa). This can disrupt prostate histology by disorganization of the epithelium, prostatic intraepithelial neoplasia (PIN) lesions, in particular high-grade PIN (HGPIN) lesions which are precursors of prostatic adenocarcinoma. These defects persist throughout the lifespan of the animal and later in life estrogen exposure predispose development of cancer. Exposure of pregnant dams to vinclozolin, a competitive anti-androgen, and results in prominent, focal regions of inflammation in all exposed animals. The inflammation closely resembles human nonbacterial prostatitis that occurs in young men and evidence indicates that inflammation plays a central role in the development of PCa. In conclusion, in utero exposure to endocrine disrupters may predispose to the development of TDS, testicular cancer (TCa) and PCa and are illustrations of Developmental Origins of Health and Disease (DOHaD).

Endocrine disrupting chemicals (EDCs) and sex steroid receptors

Sex-steroid receptors (SSRs) are essential mediators of estrogen, progestin, and androgen signaling that are critical in vast aspects of human development and multi-organ homeostasis. Dysregulation of SSR function has been implicated in numerous pathologies including cancers, obesity, Type II diabetes mellitus, neuroendocrine disorders, cardiovascular disease, hyperlipidemia, male and female infertility, and other reproductive disorders. Endocrine disrupting chemicals (EDCs) modulate SSR function in a wide variety of cell and tissues. There exists strong experimental, clinical, and epidemiological evidence that engagement of EDCs with SSRs may disrupt endogenous hormone signaling leading to physiological abnormalities that may manifest in disease. In this chapter, we discuss the molecular mechanisms by which EDCs interact with estrogen, progestin, and androgen receptors and alter SSR functions in target cells. In addition, the pathological consequences of disruption of SSR action in reproductive and other organs by EDCs is described with an emphasis on underlying mechanisms of receptors dysfunction.

Targeted inhibition of ERα signaling and PIP5K1α/Akt pathways in castration-resistant prostate cancer

Selective ERα modulator, tamoxifen, is well tolerated in a heavily pretreated castration-resistant prostate cancer (PCa) patient cohort. However, its targeted gene network and whether expression of intratumor ERα due to androgen deprivation therapy (ADT) may play a role in PCa progression is unknown. In this study, we examined the inhibitory effect of tamoxifen on castration-resistant PCa in vitro and in vivo. We found that tamoxifen is a potent compound that induced a high degree of apoptosis and significantly suppressed growth of xenograft tumors in mice, at a degree comparable to ISA-2011B, an inhibitor of PIP5K1α that acts upstream of PI3K/AKT survival signaling pathway. Moreover, depletion of tumor-associated macrophages using clodronate in combination with tamoxifen increased inhibitory effect of tamoxifen on aggressive prostate tumors. We showed that both tamoxifen and ISA-2011B exert their on-target effects on prostate cancer cells by targeting cyclin D1 and PIP5K1α/AKT network and the interlinked estrogen signaling. Combination treatment using tamoxifen together with ISA-2011B resulted in tumor regression and had superior inhibitory effect compared with that of tamoxifen or ISA-2011B alone. We have identified sets of genes that are specifically targeted by tamoxifen, ISA-2011B or combination of both agents by RNA-seq. We discovered that alterations in unique gene signatures, in particular estrogen-related marker genes are associated with poor patient disease-free survival. We further showed that ERα interacted with PIP5K1α through formation of protein complexes in the nucleus, suggesting a functional link. Our finding is the first to suggest a new therapeutic potential to inhibit or utilize the mechanisms related to ERα, PIP5K1α/AKT network, and MMP9/VEGF signaling axis, providing a strategy to treat castration-resistant ER-positive subtype of prostate cancer tumors with metastatic potential.

Asociación entre el cociente del segundo y cuarto dedo y el riesgo de cáncer de próstata: Un estudio de casos y controles en población mediterránea

Objetivo Evaluar la asociación entre el cociente de los dedos segundo y cuarto (2D:4D), como un biomarcador de la exposición prenatal a andrógenos, y la presencia de cáncer de próstata (CaP).

Métodos Estudio de casos y controles con 260 hombres que consultaron en el Servicio de Urología del Hospital General Universitario Reina Sofía (Murcia, España). Los casos (n = 125) fueron pacientes diagnosticados de CaP por anatomía patológica a los que se les realizó una prostatectomía radical. Los controles (n = 135) fueron pacientes que consultaron en Urología por otro motivo y que no mostraron signos ni síntomas de patología prostática. La longitud del 2D y 4D de la mano derecha fue medida mediante un pie de rey digital y se calculó el cociente entre ambos (2D:4D). Para los análisis estadísticos se utilizaron modelos de regresión logística obteniendo Odds ratios (OR) crudas y ajustadas e intervalos de confianza al 95%.

Resultados Los casos presentaron un cociente 2D:4D significativamente menor que los controles. El cociente 2D:4D se relacionó significativamente con la presencia de CaP. Tras el ajuste multivariante, se observó que los varones que se encontraban en el primer tercil de distribución del cociente 2D:4D, presentaban casi el doble de riesgo de padecer CaP (OR 1,9: IC 95% 1,1–4,0; P-valor = 0,040) en comparación con los varones que se encontraban en el segundo y tercer tercil.

Conclusiones Una mayor exposición prenatal a andrógenos, reflejada por un cociente 2D:4D menor, podría estar asociado con riesgo aumentado de padecer CaP, pero más estudios son necesarios para corroborar esos hallazgos.

Gestational bisphenol A exposure induces fatty liver development in male offspring mice through the inhibition of HNF1b and upregulation of PPARγ

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) associated with non-alcoholic fatty liver disease (NAFLD). The effects of gestational BPA exposure on hepatic lipid accumulation in offspring are not fully understood. Here, we investigate the sex-dependent effects of gestational BPA exposure on hepatic lipid and glucose metabolism in the offspring of mice to reveal the mechanisms underlying gestational BPA exposure-associated NAFLD. Pregnant mice were administered gavage with or without 1 μg kg-1 day-1 BPA at embryonic day 7.5 (E7.5)-E16.5. Hepatic glucose and lipid metabolism were evaluated in these models. Both male and female offspring mice exhibited hepatic fatty liver after BPA treatment. Lipid accumulation and dysfunction of glucose metabolism were observed in male offspring. We revealed abnormal expression of lipid regulators in the liver and that inhibition of peroxisome proliferator-activated receptor γ (PPARγ) repressed hepatic lipid accumulation induced by gestational BPA exposure. We also found a sex-dependent decrease of hepatocyte nuclear factor 1b (HNF1b) expression in male offspring. The transcriptional repression of PPARγ by HNF1b was confirmed in L02 cells. Downregulation of HNF1b, upregulation of PPARγ, and subsequent upregulation of hepatic lipid accumulation were essential for NAFLD development in male offspring gestationally exposed to BPA as well as BPA-exposed adult male mice. Dysregulation of the HNF1b/PPARγ pathway may be involved in gestational BPA exposure-induced NAFLD in male offspring. These data provide new insights into the mechanism of gestational BPA exposure-associated sex-dependent glucose and lipid metabolic dysfunction. Graphical abstract Schematic of the mechanism of gestational BPA exposure-induced glucose and lipid metabolic dysfunction.

The Chemical Exposome of Human Aging

Aging is an inevitable biological phenomenon displayed by single cells and organs to entire organismal systems. Aging as a biological process is characterized as a progressive decline in intrinsic biological function. Understanding the causative mechanisms of aging has always captured the imagination of researchers since time immemorial. Although both biological and chronological aging are well defined and studied in terms of genetic, epigenetic, and lifestyle predispositions, the hallmarks of aging in terms of small molecules (i.e., endogenous metabolites to chemical exposures) are limited to obscure. On top of the endogenous metabolites leading to the onset and progression of healthy aging, human beings are constantly exposed to a natural and anthropogenic "chemical" environment round the clock, from conception till death, affecting one's physiology, health and well-being, and disease predisposition. The research community has started gaining sizeable insights into deciphering the aging factors such as immunosenescence, nutrition, frailty, inflamm-aging, and diseases till date, without much input from their interaction with exogenous chemical exposures. The "exposome" around us, mostly, accelerates the process of aging by affecting the internal biological pathways and signaling mechanisms that result in the deterioration of human health. However, the entirety of exposome on human aging is far from established. This review intends to catalog the known and established associations of the exposome from past studies focusing on aging in humans and other model organisms. Further discussed are the current technologies and informatics tools that enable the study of aging exposotypes, and thus, provide a window of opportunities and challenges to study the "aging exposome" in granular details.

Ontogeny of estrogen receptors in human male and female fetal reproductive tracts

This paper reviews and provides new observations on the ontogeny of estrogen receptor alpha (ESR1) and estrogen receptor beta (ESR2) in developing human male and female internal and external genitalia. Included in this study are observations on the human fetal uterine tube, the uterotubal junction, uterus, cervix, vagina, penis and clitoris. We also summarize and report on the ontogeny of estrogen receptors in the human fetal prostate, prostatic urethra and epididymis. The ontogeny of ESR1 and ESR2, which spans from 8 to 21 weeks correlates well with the known "window of susceptibility" (7-15 weeks) for diethylstilbestrol (DES)-induced malformations of the human female reproductive tract as determined through examination of DES daughters exposed in utero to this potent estrogen. Our fairly complete mapping of the ontogeny of ESR1 and ESR2 in developing human male and female internal and external genitalia provides a mechanistic framework for further investigation of the role of estrogen in normal development and of abnormalities elicited by exogenous estrogens.

Grouping of endocrine disrupting chemicals for mixture risk assessment - Evidence from a rat study

Exposure to mixtures of endocrine disrupting chemicals may contribute to the rising incidence of hormone-related diseases in humans. Real-life mixtures are complex, comprised of chemicals with mixed modes of action, and essential knowledge is often lacking on how to group such chemicals into cumulative assessment groups, which is an essential prerequisite to conduct a chemical mixture risk assessment. We investigated if mixtures of chemicals with diverse endocrine modes of action can cause mixture effects on hormone sensitive endpoints in developing and adult rat offspring after perinatal exposure. Wistar rats were exposed during pregnancy and lactation simultaneously to either bisphenol A and butylparaben (Emix), diethylhexyl phthalate and procymidone (Amix), or a mixture of all four substances (Totalmix). In male offspring, the anogenital distance was significantly reduced and nipple retention increased in animals exposed to Amix and Totalmix, and the mixture effects were well approximated by the dose addition model. The combination of Amix and Emix responded with more marked changes on these and other endocrine-sensitive endpoints than each binary mixture on its own. Sperm counts were reduced by all exposures. These experimental outcomes suggest that the grouping of chemicals for mixture risk assessment should be based on common health outcomes rather than only similar modes or mechanisms of action. Mechanistic-based approaches such as the concept of Adverse Outcome Pathway (AOP) can provide important guidance if both the information on shared target tissues and the information on shared mode/mechanism of action are taken into account.

Postnatal exposure to finasteride causes different effects on the prostate of male and female gerbils

The development and maintenance of prostate function depend on a fine balance between oestrogen and androgen levels. Finasteride inhibits 5α-reductase, which is responsible for the conversion of testosterone into its most active form, dihydrotestosterone. Enzymes that metabolize these hormones have a highly relevant role in both the normal prostate metabolism and in the occurrence of pathological conditions. There are few studies on the impact of finasteride on male prostate development and fewer studies on the female prostate and possible intersexual differences. Therefore, we treated male and female gerbils from 7 to 14 days in postnatal life with a high dose of finasteride (500 μg/kg/day); the prostate complexes were then removed and submitted to immunohistochemistry, immunofluorescence and three-dimensional reconstruction. In addition, hormonal serum dosages were administered. Treatment with finasteride resulted in an increased thickness of the periductal smooth musculature in the prostate of both male and female gerbils, such as well as a reduction in the thickness of developing prostate alveoli in both sexes. In addition, intersexual differences were observed as increased epithelial proliferation and decreases in the number of developing alveoli in females. Together, the data indicate that postnatal exposure to finasteride causes greater changes in the female gerbil prostate than in the male.

Impact of perinatal bisphenol A and 17β estradiol exposure: Comparing hormone receptor response

Hormonal regulation controls mammary gland (MG) development. Therefore some hormone-related factors can disrupt the early phases of MGs development, making the gland more susceptible to long term modifications in its response to circulating hormones. Endocrine disruptors, such as bisphenol A (BPA), are able to cause alterations in hormone receptor expression, leading to changes in the cell proliferation index, which may expose the tissue to neoplastic alterations. Thus, we evaluated the variations in hormone receptor expression in the MG of 6-month old Mongolian gerbils exposed to BPA and 17β estradiol during the perinatal period. Receptors for estrogen alpha (ERα), beta (ERβ), progesterone (PGR), prolactin (PRL-R), and co-localization of connexin 43 (Cx43) and ERα in gerbils were analyzed, and serum concentrations of estradiol and progesterone were assessed. No alterations in body, liver, and ovary-uterus complex weights were observed. However, there was an increase in epithelial ERα expression in the 17β estradiol (E2) group and in PGR in the BPA group. Although immunohistochemistry did not show alterations in ERβ expression, western blotting revealed a decrease in this protein in the BPA group. PRL-R was more present in epithelial cells in the vehicle control (VC), E2, and BPA groups in comparison to the intact control group. Cx43 was more frequent in E2 and BPA groups, suggesting a protective response from the gland against possible malignancy. Serum concentration of estradiol reduced in VC, E2, and BPA groups, confirming that alterations also impacts steroid levels. Consequently, perinatal exposure to BPA and the reference endogenous estrogen, 17β estradiol, are able to increase the tendency of endocrine disruption in MG in a long term manner, since repercussions are observed even 6 months after exposure.

Low-dose in utero exposure to finasteride promotes developmental changes in both male and female gerbil prostates

The prostate is an accessory reproductive gland that is sensitive to the action of exogenous compounds known as endocrine disrupters that alter normal hormonal function. Finasteride is a widely used chemical that acts to inhibit the conversion of testosterone in its most active form, dihydrotestosterone. It is known that intrauterine exposure to finasteride causes changes in the male prostate even at low dosages; however, it is not known whether these dosages are capable of causing changes in the female prostate, which is present in a large number of mammalian species, including humans. In the present study, histochemistry, immunohistochemistry, immunofluorescence, serological dosages, and three-dimensional reconstruction techniques were employed to evaluate the effects of intrauterine exposure to a low dose of finasteride (100 μg.BW/d) on postnatal prostate development in male and female Mongolian gerbils. The results indicate that the gerbil female prostate also undergoes alterations following intrauterine exposure to finasteride, exhibiting a thickening of periductal smooth muscle and increased stromal proliferation. There are also intersex differences in the impact of exposure on the expression of the androgen receptor, which was increased in males, and of the estrogen-α receptor, which was decreased in the male prostate but unchanged in females. Altogether, this study indicates there are sex differences in the effects of finasteride exposure even at low dosages.

Bisphenol A-Induced Epigenetic Changes and Its Effects on the Male Reproductive System

Bisphenol A (BPA) is a widespread chemical agent which can exert detrimental effects on the male reproductive system. Exposure to BPA has been shown to induce several epigenetic modifications in both animal and human cells. Specifically, BPA could not only modify the methylation pattern of multiple genes encoding proteins related to reproductive physiology but also directly influence the genes responsible for DNA methylation. BPA effects include hormonal alterations, microscopic and macroscopic alteration of male reproductive organs, and inheritable epigenetic changes involving human reproduction. BPA exposure was also linked to prostate cancer. This review aims to show the current scenario of BPA-induced epigenetic changes and its effects on the male reproductive system. Possible strategies to counter the toxic effect of BPA were also addressed.

Genome-Wide Analysis of Low Dose Bisphenol-A (BPA) Exposure in Human Prostate Cells

Endocrine disrupting compounds (EDCs) have the potential to cause adverse effects on wild-life and human health. Two important EDCs are the synthetic estrogen 17α-ethynylestradiol (EE2) and bisphenol-A (BPA) both of which are xenoestrogens (XEs) as they bind the estrogen receptor and dis-rupt estrogen physiology in mammals and other vertebrates. In the recent years the influence of XEs on oncogenes, specifically in relation to breast and prostate cancer has been the subject of considerable study.

Bisphenol S alters development of the male mouse mammary gland and sensitizes it to a peripubertal estrogen challenge

Humans are exposed to estrogenic chemicals in food and food packaging, personal care products, and other industrial and consumer goods. Bisphenol A (BPA), a well-studied xenoestrogen, is known to alter development of estrogen-sensitive organs including the brain, reproductive tract, and mammary gland. Bisphenol S (BPS; 4,4'-sulfonyldiphenol), which has a similar chemical structure to BPA, is also used in many consumer products, but its effects on estrogen-sensitive organs in mammals has not been thoroughly examined. Here, we quantified the effects of perinatal exposures to BPS on the male mouse mammary gland. In our first study, pregnant CD-1 mice were orally exposed to BPS (2 or 200 μg/kg/day) starting on pregnancy day 9 through lactation day 20, and male mammary glands were evaluated on embryonic day 16, prior to puberty, and in early adulthood. We observed modest changes in tissue organization in the fetal gland, and significant increases in growth of the gland induced by developmental BPS exposure in adulthood. In our second study, pregnant CD-1 mice were orally exposed to BPS (2, 200 or 2000 μg/kg/day) starting on pregnancy day 9 through lactational day 2. After weaning, the male pups were administered either oil (vehicle) or an estrogen challenge (1 μg ethinyl estradiol/kg/day) for ten days starting prior to puberty. After the 10-day estrogen challenge, we examined hormone-sensitive outcomes including anogenital index (AGI), weight of the seminal vesicles, and morphological parameters of the mammary gland. Although AGI and seminal vesicle weight were not affected by BPS, we observed dose-specific effects on the response of male mammary glands to the peripubertal estrogen challenge. Because male mammary glands are structurally less developed compared to females, they may provide a simple model tissue to evaluate the effects of putative xenoestrogens.

Oxidative damage in patients with benign prostatic hyperplasia and prostate cancer co-exposed to phthalates and to trace elements

Evidence indicates that prostates exposed to environmental endocrine disruptors and trace metals will cause adverse health outcomes. We assessed the association between urinary phthalate metabolites and serum trace metal levels, and oxidative damage in benign prostatic hyperplasia (BPH) patients, prostate cancer (PCa) patients, and healthy controls. Levels of cadmium (Cd), nickel (Ni), and copper (Cu) were significantly higher in BPH patients than in controls, and mercury (Hg) was highest in PCa patients. An Hg level >1 μg/L posed a significant risk (OR: 42.86, 95% CI: 1.092-1684) for PCa, but a zinc (Zn) level >1 μg/L was marginally negative (OR: 0.979, 95% CI: 0.957-1.002). We also found strong associations between PCa and mono-isononyl phthalate (MiNP), and between BPH and mono-isodecyl phthalate (MiDP), malonyldialdehyde (MDA) were significantly higher in PCa and BPH patients than in controls; 8‑hydroxydeoxyguanosine (8‑OH‑dG) and DNA strand breakage were highest in BPH patients and lowest in controls. When the prostate was simultaneously co-exposed to phthalates and trace metals, phthalates had a less significant effect on PCa and BPH. Thus, we hypothesize that, for patients with prostate disease, exposure to trace metals is more significant than is exposure to phthalates.

Prenatal Steroids and Metabolic Dysfunction: Lessons from Sheep

Prenatal exposure to excess steroids or steroid mimics can disrupt the normal developmental trajectory of organ systems, culminating in adult disease. The metabolic system is particularly susceptible to the deleterious effects of prenatal steroid excess. Studies in sheep demonstrate that prenatal exposure to excess native steroids or endocrine-disrupting chemicals with steroidogenic activity, such as bisphenol A, results in postnatal development of numerous cardiometabolic perturbations, including insulin resistance, increased adiposity, altered adipocyte size and distribution, and hypertension. The similarities in the phenotypic outcomes programmed by these different prenatal insults suggest that common mechanisms may be involved, and these may include hormonal imbalances (e.g., hyperandrogenism and hyperinsulinemia), oxidative stress, inflammation, lipotoxicity, and epigenetic alterations. Animal models, including the sheep, provide mechanistic insight into the metabolic repercussions associated with prenatal steroid exposure and represent valuable research tools in understanding human health and disease. Focusing on the sheep model, this review summarizes the cardiometabolic perturbations programmed by prenatal exposure to different native steroids and steroid mimics and discusses the potential mechanisms underlying the development of adverse outcomes.

Estrogens and prostate cancer

BACKGROUND

Hormonal influences such as androgens and estrogens are known contributors in the development and progression of prostate cancer (CaP). While much of the research to the hormonal nature of CaP has focused on androgens, estrogens also have critical roles in CaP development, physiology as well as a potential therapeutic intervention.

METHODS

In this review, we provide a critical literature review of the current basic science and clinical evidence for the interaction between estrogens and CaP.

RESULTS

Estrogenic influences in CaP include synthetic, endogenous, fungi and plant-derived compounds, and represent a family of sex hormones, which cross hydrophobic cell membranes and bind to membrane-associated receptors and estrogen receptors that localize to the nucleus triggering changes in gene expression in various organ systems.

CONCLUSIONS

Estrogens represent a under-recognized contributor in CaP development and progression. Further research in this topic may provide opportunities for identification of environmental influencers as well as providing novel therapeutic targets in the treatment of CaP.

In utero and lactational exposure of DEHP increases the susceptibility of prostate carcinogenesis in male offspring through PSCA hypomethylation

As an ubiquitous environmental endocrine disruptor, di(2-ethylhexyl) phthalate (DEHP) has been shown to interfere with the development of reproductive organs and induce pathological changes in prostate. Our previous finding showed that in utero and lactational (IUL) DEHP exposure could disrupt the balance of testosterone and estrogen and increase the susceptibility of prostate carcinogenesis. The purpose of this study is to investigate whether the early-life specific epigenetic modifications could mediate the effect of DEHP exposure on prostate carcinogenesis in rodents, for epigenetic modifications play important roles in regulating prostate carcinogenesis. The pregnant rats were treated with corn oil (negative control) or DEHP at 0.01, 0.1 and 1 mg/kg BW/day from GD7 to PND21. On PND21, the expression and DNA methylation change of six prostate carcinogenesis-related genes (ESR2/GSTP1/NKX3.1/PSCA/PTGS2/Rassf1a) were assessed through SYBR-Green real-time PCR combined with pyrosequencing assay in F1 male offspring. On PND196, the relationship b(STP1, PSCA and PTGS2 in a dose-dependent manner, which were positively correlated with PIN scores, Gleason scores, serum PSA concentrations and negatively correlated with prostate/body weight ratio on PND196. Meanwhile, 1 mg/kg BW/day DEHP markedly reduced DNA methylation level of PSCA in all studied CpG sites. Significant inverse correlations between methylation levels of the promoter CpG site and PSCA mRNA expression were observed. These results indicated that transcriptional changes of GSTP1, PSCA and PTGS2 induced by DEHP exposure might be contribute to the increasing susceptibility of prostate carcinogenesis in late life. Moreover, hypomethylation of PSCA could mediate the effect of DEHP on prostate carcinogenesis in rats.

Basal Cells Show Increased Expression of Aromatase and Estrogen Receptor α in Prostate Epithelial Lesions of Male Aging Rats

Besides androgens, estrogen signaling plays a key role in normal development and pathologies of the prostate. Irreversible synthesis of estrogens from androgens is catalyzed by aromatase. Interestingly, animals lacking aromatase do not develop cancer or prostatitis, whereas those with overexpression of aromatase and, consequently, high estrogen levels develop prostatitis and squamous metaplasia via estrogen receptor 1 (ERα). Even with this evidence, the aromatase expression in the prostate is controversial. Moreover, little is known about the occurrence of age-dependent variation of aromatase and its association with histopathological changes commonly found in advanced age, a knowledge gap that is addressed herein. For this purpose, the immunoexpression of aromatase was evaluated in the prostatic complex of young adult to senile Wistar rats. ERα was also investigated, to extend our understanding of estrogen responsiveness in the prostate. Moderate cytoplasmic immunoreactivity for aromatase was detected in the glandular epithelium. Eventually, some basal cells showed intense staining for aromatase. The expression pattern for aromatase appeared similar in the normal epithelium when young and senile rats were compared; this result was corroborated by Western blotting. Conversely, in senile rats, there was an increase in the frequency of basal cells intensely stained for aromatase, which appeared concentrated in areas of intraepithelial proliferation and prostatitis. These punctual areas also presented increased ERα positivity. Together, these findings suggest a plausible source for hormonal imbalance favoring estrogen production, which, by acting through ERα, may favor the development of prostatic lesions commonly found in advanced age.

Recent advances on bisphenol-A and endocrine disruptor effects on human prostate cancer

Endocrine disrupting chemicals (EDCs) are man-made substances widespread in the environment that include, among many others, bisphenol A (BPA), organochlorinated pesticides and hormone derivatives detectable in meat from animals raised in concentrated animal feeding operations. Increasing evidence indicates that EDCs have a negative impact on human health as well as on male and female fertility. They may also be associated with some endocrine diseases and increased incidence of breast and prostate cancer. This review aims to summarize available data on the (potential) impact of some common EDCs, focusing particularly on BPA, prostate cancer and their mechanisms of action. These compounds interfere with normal hormone signal pathway transduction, resulting in prolonged exposure of receptors to stimuli or interference with cellular hormone signaling in target cells. Understanding the effects of BPA and other EDCs as well as their molecular mechanism(s) may be useful in sensitizing the scientific community and the manufacturing industry to the importance of finding alternatives to their indiscriminate use.

'Omics' and endocrine-disrupting chemicals - new paths forward

The emerging field of omics - large-scale data-rich biological measurements of the genome - provides new opportunities to advance and strengthen research into endocrine-disrupting chemicals (EDCs). Although some EDCs have been associated with adverse health effects in humans, our understanding of their impact remains incomplete. Progress in the field has been primarily limited by our inability to adequately estimate and characterize exposure and identify sensitive and measurable outcomes during windows of vulnerability. Evolving omics technologies in genomics, epigenomics and mitochondriomics have the potential to generate data that enhance exposure assessment to include the exposome - the totality of the lifetime exposure burden - and provide biology-based estimates of individual risks. Applying omics technologies to expand our knowledge of individual risk and susceptibility will augment biological data in the prediction of variability and response to disease, thereby further advancing EDC research. Together, refined exposure characterization and enhanced disease-risk prediction will help to bridge crucial gaps in EDC research and create opportunities to move the field towards a new vision - precision public health.

The Plasticizer Bisphenol A Perturbs the Hepatic Epigenome: A Systems Level Analysis of the miRNome

Ubiquitous exposure to bisphenol A (BPA), an endocrine disruptor (ED), has raised concerns for both human and ecosystem health. Epigenetic factors, including microRNAs (miRNAs), are key regulators of gene expression during cancer. The effect of BPA exposure on the zebrafish epigenome remains poorly characterized. Zebrafish represents an excellent model to study cancer as the organism develops a disease that resembles human cancer. Using zebrafish as a systems toxicology model, we hypothesized that chronic BPA-exposure impacts the miRNome in adult zebrafish and establishes an epigenome more susceptible to cancer development. After a 3 week exposure to 100 nM BPA, RNA from the liver was extracted to perform high throughput mRNA and miRNA sequencing. Differential expression (DE) analyses comparing BPA-exposed to control specimens were performed using established bioinformatics pipelines. In the BPA-exposed liver, 6188 mRNAs and 15 miRNAs were differently expressed (q ≤ 0.1). By analyzing human orthologs of the DE zebrafish genes, signatures associated with non-alcoholic fatty liver disease (NAFLD), oxidative phosphorylation, mitochondrial dysfunction and cell cycle were uncovered. Chronic exposure to BPA has a significant impact on the liver miRNome and transcriptome in adult zebrafish with the potential to cause adverse health outcomes including cancer.

Atrazine exposure decreases the activity of DNMTs, global DNA methylation levels, and dnmt expression

Atrazine, a herbicide used on agricultural crops is widely applied in the Midwestern United States as well as other areas of the globe. Atrazine frequently contaminates potable water supplies and is a suspected endocrine disrupting chemical. Previous studies have reported morphological, hormonal, and molecular alterations due to developmental and adulthood atrazine exposure; however, studies examining epigenetic alterations are limited. In this study, the effects of atrazine exposure on DNA methyltransferase (DNMT) activity and kinetics were evaluated. Global DNA methylation levels and dnmt expression in zebrafish larvae exposed to 0, 3, or 30 parts per billion (ppb) atrazine throughout embryogenesis was then assessed. Results indicate that atrazine significantly decreased the activity of maintenance DNMTs and that the inhibition mechanism can be described using non-competitive Michaelis-Menten kinetics. Furthermore, results show that an embryonic atrazine exposure decreases global methylation levels and the expression of dnmt4 and dnmt5. These findings indicate that atrazine exposure can decrease the expression and activity of DNMTs, leading to decreased DNA methylation levels.

Benzene and 2-ethyl-phthalate induce proliferation in normal rat pituitary cells

PURPOSE

Endocrine disruptors are known to modulate a variety of endocrine functions and increase the risk for neoplasia. Epidemiological data reported increased prevalence of pituitary tumors in high industrial areas while genotyping studies showed that mutations in the aryl hydrocarbon receptor (AhR) interacting protein (AIP)-chaperone to the dioxin ligand AhR-gene are linked to predisposition to pituitary tumor development. Aim of the present study was to establish whether endocrine pollutants can induce cell proliferation in normal rat pituitary cells.

METHODS

Pituitary primary cultures were incubated with 250, 650 and 1250 pM benzene or 2-ethyl-phthalate for up to 96 h and viability, energy content and cell proliferation assessed. Expression of pituitary tumor transforming gene (PTTG), cyclin D1 (Ccnd1), AhR and AIP was quantified by RT-qPCR.

RESULTS

Incubation with benzene or 2-ethyl-phthalate increased viability and energy content in pituitary cells. The endocrine disruptors also increased cell proliferation as well as Ccnd1 and PTTG expression. Increased AhR and AIP expression was observed after incubation with the two pollutants.

CONCLUSIONS

Our findings indicate that benzene and 2-ethyl-phthalate activate AhR/AIP expression and stimulate proliferation in normal rat pituitary cells. This study is the first demonstration that pollutants can induce normal pituitary cells to proliferate and provides a link between epidemiological and genomic findings in pituitary tumors.

DNA Methylation Targets Influenced by Bisphenol A and/or Genistein Are Associated with Survival Outcomes in Breast Cancer Patients

Early postnatal exposures to Bisphenol A (BPA) and genistein (GEN) have been reported to predispose for and against mammary cancer, respectively, in adult rats. Since the changes in cancer susceptibility occurs in the absence of the original chemical exposure, we have investigated the potential of epigenetics to account for these changes. DNA methylation studies reveal that prepubertal BPA exposure alters signaling pathways that contribute to carcinogenesis. Prepubertal exposure to GEN and BPA + GEN revealed pathways involved in maintenance of cellular function, indicating that the presence of GEN either reduces or counters some of the alterations caused by the carcinogenic properties of BPA. We subsequently evaluated the potential of epigenetic changes in the rat mammary tissues to predict survival in breast cancer patients via the Cancer Genomic Atlas (TCGA). We identified 12 genes that showed strong predictive values for long-term survival in estrogen receptor positive patients. Importantly, two genes associated with improved long term survival, HPSE and RPS9, were identified to be hypomethylated in mammary glands of rats exposed prepuberally to GEN or to GEN + BPA respectively, reinforcing the suggested cancer suppressive properties of GEN.

Developmental exposures to bisphenol S, a BPA replacement, alter estrogen-responsiveness of the female reproductive tract: a pilot study

Developmental exposures to bisphenol A (BPA), an estrogen receptor agonist, can disrupt development of the female reproductive tract in rodents and non-human primates. Due to an increased public knowledge of negative health effects associated with BPA exposure, BPA has begun to be phased out of many consumer products and in some cases it has been replaced with structurally similar compounds including bisphenol S (BPS). This study examined CD-1 mice exposed to a low dose of BPS during early development (200 µg/kg/day from gestational day 8 until postnatal day 19). BPS altered expression of estrogen-responsive genes in both the uterus and ovary, and induced increases in ovarian follicular development in pre-pubertal females evaluated at postnatal day 22. Prior studies have revealed that developmental exposures to environmental chemicals including BPA alter the response of animals to hormonal or carcinogen challenges experienced later in life. To evaluate whether early life exposures to BPS alter responses of females to an estrogen challenge, additional females were exposed to ethinyl estradiol from postnatal day 19 through postnatal day 21. BPS-treated females responded abnormally to this estrogen challenge, displaying heightened responses in the uterus and diminished responses in the ovary. Although additional studies are needed to characterize the mechanisms by which BPS alters the female reproductive tract, this pilot study provides evidence that a common BPA replacement chemical may have endocrine disrupting properties.

Atrazine exposure elicits copy number alterations in the zebrafish genome

Atrazine is an agricultural herbicide used throughout the Midwestern United States that frequently contaminates potable water supplies resulting in human exposure. Using the zebrafish model system, an embryonic atrazine exposure was previously reported to decrease spawning rates with an increase in progesterone and ovarian follicular atresia in adult females. In addition, alterations in genes associated with distinct molecular pathways of the endocrine system were observed in brain and gonad tissue of the adult females and males. Current hypotheses for mechanistic changes in the developmental origins of health and disease include genetic (e.g., copy number alterations) or epigenetic (e.g., DNA methylation) mechanisms. As such, in the current study we investigated whether an atrazine exposure would generate copy number alterations (CNAs) in the zebrafish genome. A zebrafish fibroblast cell line was used to limit detection to CNAs caused by the chemical exposure. First, cells were exposed to a range of atrazine concentrations and a crystal violet assay was completed, showing confluency decreased by ~60% at 46.3μM. Cells were then exposed to 0, 0.463, 4.63, or 46.3μM atrazine and array comparative genomic hybridization completed. Results showed 34, 21, and 44 CNAs in the 0.463, 4.63, and 46.3μM treatments, respectively. Furthermore, CNAs were associated with previously reported gene expression alterations in adult male and female zebrafish. This study demonstrates that atrazine exposure can generate CNAs that are linked to gene expression alterations observed in adult zebrafish exposed to atrazine during embryogenesis providing a mechanism of the developmental origins of atrazine endocrine disruption.

Exploring the epigenetic drug discovery landscape

INTRODUCTION

Epigenetic modification has been implicated in a wide range of diseases and the ability to modulate such systems is a lucrative therapeutic strategy in drug discovery. Areas covered: This article focuses on the concepts and drug discovery aspects of epigenomics. This is achieved by providing a survey of the following concepts: (i) factors influencing epigenetics, (ii) diseases arising from epigenetics, (iii) epigenetic enzymes as druggable targets along with coverage of existing FDA-approved drugs and pharmacological agents, and (iv) drug repurposing/repositioning as a means for rapid discovery of pharmacological agents targeting epigenetics. Expert opinion: Despite significant interests in targeting epigenetic modifiers as a therapeutic route, certain classes of target proteins are heavily studied while some are less characterized. Thus, such orphan target proteins are not yet druggable with limited report of active modulators. Current research points towards a great future with novel drugs directed to the many complex multifactorial diseases of humans, which are still often poorly understood and difficult to treat.

A comprehensive review of regulatory test methods for endocrine adverse health effects

Development of new endocrine disruption-relevant test methods has been the subject of intensive research efforts for the past several decades, prompted in part by mandates in the 1996 Food Quality Protection Act (FQPA). While scientific understanding and test methods have advanced, questions remain on whether current scientific methods are capable of adequately addressing the complexities of the endocrine system for regulatory health and ecological risk assessments. The specific objective of this article is to perform a comprehensive, detailed evaluation of the adequacy of current test methods to inform regulatory risk assessments of whether a substance has the potential to perturb endocrine-related pathways resulting in human adverse effects. To that end,  approximately 42 existing test guidelines (TGs) were considered in the evaluation of coverage for endocrine-related adverse effects. In addition to evaluations of whether test methods are adequate to capture endocrine-related effects, considerations of further enhancements to current test methods, along with the need to develop novel test methods to address existing test method gaps are described. From this specific evaluation, up to 35 test methods are capable of informing whether a chemical substance perturbs known endocrine related biological pathways. Based on these findings, it can be concluded that current validated test methods are adequate to discern substances that may perturb the endocrine system, resulting in an adverse health effect. Together, these test methods predominantly form the core data requirements of a typical food-use pesticide registration submission. It is recognized, however, that the current state of science is rapidly advancing and there is a need to update current test methods to include added enhancements to ensure continued coverage and public health and environmental protection.

Pubertal exposure to ethinylestradiol promotes different effects on the morphology of the prostate of the male and female gerbil during aging

In rodents, the final growth and maturation of the prostate occur at puberty, a crucial period for prostate development. The present study is a serological, morphological, morphometric, and immunohistochemical analysis of the effects of exposure to ethinylestradiol (EE) (15 µg/kg/day) during puberty (EE/PUB group) on the male ventral and female prostate in senile gerbils. In the study, male and female gerbils (Meriones unguiculatus) (42 days) received by gavage 15 μg/kg/day of EE (a component of the contraceptive pill), diluted in 100 µL of Nujol® for 1 week (EE/PUB group). In the control group, males and females were not treated. Animals were killed (n = 5) after 12 months in the experimental groups. In the senile male in the EE/PUB group, we observed a reduction in testosterone levels and a decrease in the prostatic epithelial thickness, as well as in the thickness of the muscle layer. In addition, an increase in PIN multiplicity and prostatic inflammation was observed. In the senile female in the EE/PUB group, we observed increased testosterone and estradiol levels, an enhanced prostatic epithelial thickness and an increase in the thickness of the muscle layer. Immunohistochemical analysis revealed an increase in positive cells (%) for AR and PCNA in the male prostate and an increase in positive basal cells for p63 in the female prostate of the EE/PUB group. Exposure to EE during puberty resulted in an inhibitory action on the male ventral prostate and an anabolic effect on the female prostate in senile gerbils. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 477-489, 2017.

Acute exposure to bisphenol A and cadmium causes changes in the morphology of gerbil ventral prostates and promotes alterations in androgen-dependent proliferation and cell death

Bisphenol A (BPA) and cadmium (Cd) are environmental pollutants that are implicated in potential reproductive effects, including damage to the prostate gland. Their action during puberty requires analysis to determine the relationship of these compounds with the testosterone peak that occurs during this phase. This study evaluated whether exposure to BPA and Cd during puberty can cause changes in the morphology, proliferation and cell death and androgen receptor (AR) immunostaining of the ventral prostates of normal and castrated male gerbils (Meriones unguiculatus), considering an acute exposure to the chemicals and evaluation after short (52d) and long (120d) periods. Generally, morphometric-stereological results demonstrated that administration of BPA and Cd (individually or in combination) increased epithelial height, smooth muscle layer (SML) thickness and nuclear area and perimeter, and that these parameters were reduced in castrated animals. In addition, these groups showed important inflammatory processes but not prostate lesions. The proliferation/death rates of prostatic cells obtained by PCNA and TUNEL immunostaining demonstrated increased cell death in the 52d groups; in contrast, the gland acquired a more proliferative nature in the 120d groups. AR immunostaining showed that BPA and Cd compounds interact with ARs in different ways depending on the evaluated period and the hormonal profile of the animal. We conclude that BPA and cadmium are important agents in changing the morphology, proliferation and death of prostatic cells, in addition to interacting with ARs in different patterns. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 48-61, 2017.