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Third-generation aromatase inhibitors such as anastrozole (ATZ) and letrozole (LTZ) are widely used to treat estrogen receptor-positive (ER+) breast cancers in postmenopausal women. Investigating their ability to coordinate metals could lead to the emergence of a new category of anticancer drug candidates with a broader spectrum of pharmacological activities. In this study, a series of ruthenium(II) arene complexes bearing the aromatase inhibitor anastrozole was synthesized and characterized. Among these complexes, [Ru(η6-C6H6)(PPh3)(η1-ATZ)Cl]BPh4 (3) was found to be the most stable in cell culture media, to lead to the highest cellular uptake and in vitro cytotoxicity in two ER+ human breast cancer cell lines (MCF7 and T47D), and to induce a decrease in aromatase activity in H295R cells. Exposure of zebrafish embryos to complex 3 (12.5 μM) did not lead to noticeable signs of toxicity over 96 h, making it a suitable candidate for further in vivo investigations.

International audience; Estrogen biosynthesis during pregnancy is dependent on the collaboration between the fetus producing the androgen precursors, and the placenta expressing the enzyme aromatase (CYP19). Disruption of estrogen production by contaminants may result in serious pregnancy outcomes. We used our recently developed in vitro co-culture model of fetoplacental steroidogenesis to screen the effects of three neonicotinoid insecticides on the catalytic activity of aromatase and the production of steroid hormones. A co-culture of H295R human adrenocortical carcinoma cells with fetal characteristics and BeWo human choriocarcinoma cells which display characteristics of the villous cytotrophoblast was exposed for 24h to various concentrations of three neonicotinoids: thiacloprid, thiamethoxam and imidacloprid. Aromatase catalytic activity was determined in both cell lines using the tritiated water-release assay. Hormone production was measured by ELISA. The three neonicotinoids induced aromatase activity in our fetoplacental co-culture and concordingly, estradiol and estrone production were increased. In contrast, estriol production was strongly inhibited by the neonicotinoids. All three pesticides induced the expression of CYP3A7 in H295R cells, and this induction was reversed by co-treatment of H295R cells with exogenous estriol. CYP3A7 is normally expressed in fetal liver and is a key enzyme involved in estriol synthesis. We suggest that neonicotinoids are metabolized by CYP3A7, thus impeding the 16α-hydroxylation of fetal DHEA(-sulfate), which is normally converted to estriol by placental aromatase. We successfully used the fetoplacental co-culture as a physiologically relevant tool to highlight the potential effects of neonicotinoids on estrogen production, aromatase activity and CYP3A7 expression during pregnancy.

International audience; The role of placental serotonin has been an active topic of research notably because of its crucial role in brain development. However, which cell types synthesize serotonin in human placenta remains unknown. Moreover, it is not known if the two tryptophan hydroxylase isoforms (TPH1 and TPH2), the rate-limiting enzymes in serotonin biosynthesis, are expressed in placenta. Human placentas were obtained in first trimester or at term, and trophoblast cells were isolated and purified using a magnetic cell sorter and placed in primary culture. The tissue sublocalization of each TPH was determined by immunohistochemistry. TPH expression in primary villous trophoblasts was determined by PCR and immunoblotting, and serotonin secretion by LC-MS/MS. Villous cytotrophoblasts, syncytiotrophoblast, fetal capillaries, extravillous cytotrophoblasts, and decidual cells co-expressed TPH1 and TPH2. Moreover, mRNA and protein levels of both TPHs were detected in human primary trophoblast as well as in mouse placental tissues. Finally, human trophoblast cells were shown to produce serotonin de novo. This study demonstrates that both TPH1 and TPH2 are expressed in human and mouse placenta throughout pregnancy and helps to better understand the placental serotonin system, which is crucial for healthy pregnancy and fetal development. It is therefore important to further understand regulation of the placental serotonin system and how its disruption during pregnancy may impact the developing fetus and subsequent child programming.

Third-generation aromatase inhibitors such as anastrozole (ATZ) and letrozole (LTZ) are widely used to treat estrogen receptor-positive ER+ breast cancers in postmenopausal women. Investigating their ability to coordinate metals could lead to the emergence of a new category of anticancer drug candidates with a broader spectrum of pharmacological activities. In this study, a series of ruthenium (II) arene complexes bearing the aromatase inhibitor anastrozole was synthesized and characterized. Among these complexes, [Ru(η(6)-C(6)H(6))(PPh(3))(η(1)-ATZ)Cl]BPh(4) (3) was found to be the most stable in cell culture media, to lead to the highest cellular uptake and in vitro cytotoxicity in two ER+ human breast cancer cell lines (MCF7 and T47D), and to induce a decrease in aromatase activity in H295R cells. Exposure of zebrafish embryos to complex 3 (12.5 μM) did not lead to noticeable signs of toxicity over 96 h, making it a suitable candidate for further in vivo investigations.

International audience; We have reviewed the scientific literature related to four diseases in which to serotonin (5-HT) is involved in the etiology, herein named 5-HT-linked diseases, and whose prevalence is influenced by estrogenic status: depression, migraine, irritable bowel syndrome and eating disorders. These diseases all have in common a sex-dimorphic prevalence, with women more frequently affected than men. The co-occurrence between these 5-HT-linked diseases suggests that they have common physiopathological mechanisms. In most 5-HT-linked diseases (except for anorexia nervosa and irritable bowel syndrome), a decrease in the serotonergic tone is observed and estrogens are thought to contribute to the improvement of symptoms by stimulating the serotonergic system. Human pregnancy is characterized by a unique 5-HT and estrogen synthesis by the placenta. Pregnancy-specific disorders, such as hyperemesis gravidarum, gestational diabetes mellitus and pre-eclampsia, are associated with a hyperserotonergic state and decreased estrogen levels. Fetal programming of 5-HT-linked diseases is a complex phenomenon that involves notably fetal-sex differences, which suggest the implication of sex steroids. From a mechanistic point of view, we hypothesize that estrogens regulate the serotonergic system, resulting in a protective effect against 5-HT-linked diseases, but that, in turn, 5-HT affects estrogen synthesis in an attempt to retrieve homeostasis. These two processes (5-HT and estrogen biosynthesis) are crucial for successful pregnancy outcomes, and thus, a disruption of this 5-HT-estrogen relationship may explain pregnancy-specific pathologies or pregnancy complications associated with 5-HT-linked diseases.

Ruthenium-based complexes currently attract great attention as they hold promise to replace platinum-based drugs as a first line cancer treatment. Whereas ruthenium arene complexes are some of the most studied species for their potential anticancer properties, other types of ruthenium complexes have been overlooked for this purpose. Here, we report the synthesis and characterization of Ru(II) cyclopentadienyl (Cp), Ru(II) cyclooctadienyl (COD) and Ru(III) complexes bearing anastrozole or letrozole ligands, third-generation aromatase inhibitors currently used to treat estrogen receptor-positive (ER+) breast cancer. Among these complexes, Ru(II)Cp 2 was the only species found to be stable in DMSO and in cell culture media and as a result, the only complex for which the in vitro and in vivo biological activities were investigated. Unlike anastrozole alone, complex 2 was considerably cytotoxic in vitro (IC50 values < 1μM) in human ER+ breast cancer (T47D and MCF7), triple negative breast cancer (TNBC) (MBA-MB-231), as well as in aggressive (H295R) adrenocortical cells. Theoretical (docking simulation) and experimental (aromatase catalytic activity) studies suggested that an interaction between 2 and the aromatase enzyme was not likely to occur and that the bulkiness of the PPh(3) ligands could be an important factor preventing the complex to reach the active site of the enzyme. Exposure of zebrafish embryos to complex 2 at concentrations around its IC(50) in vitro cytotoxicity value (0.1–1 μM) did not lead to noticeable signs of toxicity over 96h, making it a suitable candidate for further in vivo investigations. This study confirms the potential of Ru(II)Cp complexes for breasts cancer therapy, more specifically against TNBCs that are usually not responsive to currently used chemotherapeutic agents.

International audience; Prostate cancer is the second leading cause of cancer-related deaths in men in North America and there is an urgent need for development of more effective therapeutic treatments against this disease. We have recently shown that diindolylmethane (DIM) and several of its halogenated derivatives (ring-DIMs) induce death and protective autophagy in human prostate cancer cells. However, the in vivo efficacy of ring-DIMs and the use of autophagy inhibitors as adjuvant therapy have not yet been studied in vivo. The objective of this study was to determine these effects on tumor growth in nude CD-1 mice bearing bioluminescent androgen-independent PC-3 human prostate cancer cells. We found that chloroquine (CQ) significantly sensitized PC-3 cells to death in the presence of sub-toxic concentrations of DIM or 4,4'-Br2DIM in vitro. Moreover, a combination of DIM (10 mg/kg) and CQ (60 mg/kg), 3× per week, significantly decreased PC-3 tumor growth in vivo after 3 and 4 weeks of treatment. Furthermore, 4,4'-Br2DIM at 10 mg/kg (3× per week) significantly inhibited tumour growth after 4 weeks of treatment. Tissues microarray analysis showed that DIM alone or combined with CQ induced apoptosis marker TUNEL; the combination also significantly inhibited the cell proliferation marker Ki67. In conclusion, we have confirmed that DIM and 4,4'-Br2DIM are effective agents against prostate cancer in vivo and shown that inhibition of autophagy with CQ enhances the anticancer efficacy of DIM. Our results suggest that including selective autophagy inhibitors as adjuvants may improve the efficacy of existing and novel drug therapies against prostate cancer.

International audience; Estrogen production by the human villous trophoblast is dependent on the biosynthetic enzyme aromatase (CYP19; CYP19A1) and is crucial for successful placental development and pregnancy outcome. Using villous cytotrophoblast cells (vCTs) freshly isolated from normal term placenta, we characterized the promoter-specific expression of CYP19A1 mRNA (derived from promoters I.1, I.4, I.8 or total transcript) and aromatase activity during villous trophoblast syncytialization. CYP19A1 mRNA levels and aromatase activity in vCTs reached a maximum after about 48 h of culture. The cAMP inducer forskolin (10 μM) and protein kinase C stimulant phorbol myristate acetate (1 μM) increased CYP19A1 mRNA levels by 1.8- and 1.6-fold, respectively, as well as inducing aromatase catalytic activity. Dexamethasone (100 nM) and vascular endothelial growth factor (5 ng/mL) decreased CYP19A1 mRNA levels, while having no effect on aromatase activity. Our results emphasize the importance of not solely studying CYP19A1 regulation and function at the mRNA level but also considering posttranslational mechanisms that alter the final catalytic activity of aromatase.

International audience; BACKGROUND: Aromatase (CYP19) is a key enzyme in estrogens biosynthesis. In the mammary gland, CYP19 gene is expressed at low levels under the regulation of its I.4 promoter. In hormone-dependent breast cancer, fibroblast cells surrounding the tumor express increased levels of CYP19 mRNA due to a decrease of I.4 promoter activity and an increase of PII, I.3, and I.7 promoter activity. Little is known about the effects of environmental chemicals on the promoter-specific CYP19 expression.OBJECTIVE: We aimed to determine the effects of two neonicotinoids (thiacloprid and imidacloprid) on promoter-specific CYP19 expression in Hs578t breast cancer cells and understand the signaling pathways involved.METHODS: Hs578t cells were exposed to various signaling pathway stimulants or neonicotinoids for 24 h. Promoter-specific expression of CYP19 was determined by real-time quantitative polymerase chain reaction and catalytic activity of aromatase by tritiated water release assay.RESULTS: To our knowledge, we are the first to demonstrate that the normal I.4 promoter and the breast cancer-relevant PII, I.3, and I.7 promoters of CYP19 are active in these cells. We found that the expression of CYP19 via promoters PII, I.3, and I.7 in Hs578t cells was, in part, dependent on the activation of two VEGF signaling pathways: mitogen-activated protein kinase (MAPK) 1/3 and phospholipase C (PLC). Exposure of Hs578t cells to environmental concentrations of imidacloprid and thiacloprid resulted in a switch in CYP19 promoter usage, involving inhibition of I.4 promoter activity and an increase of PII, I.3, and I.7 promoter-mediated CYP19 expression and aromatase catalytic activity. Greater effects were seen at lower concentrations. Our results suggest that thiacloprid and imidacloprid exert their effects at least partially by inducing the MAPK 1/3 and/or PLC pathways.CONCLUSIONS: We demonstrated in vitro that neonicotinoids may stimulate a change in CYP19 promoter usage similar to that observed in patients with hormone-dependent breast cancer.

International audience; INTRODUCTION: Between 2 and 10% of pregnant women are treated with selective serotonin-reuptake inhibitors (SSRIs) for depression. The extravillous trophoblasts (evTBs), which migrate and invade maternal tissues, are crucial for embryo implantation and remodeling of maternal spiral arteries. Poor migration/invasion of evTBs can cause serious pregnancy complications, yet the effects of SSRIs on these processes has never been studied. To determine the effects of five SSRIs (fluoxetine, norfluoxetine, citalopram, sertraline and venlafaxine) on migration/invasion, we used JEG-3 and HIPEC cells as evTB models.METHODS: Cells were treated with increasing concentrations (0.03-10 μM) of SSRIs. Cell proliferation was monitored using an impedance-based system and cell cycle by flow cytometry. Migration was determined using a scratch test, and metalloproteinase (MMP) activities, by zymography. Invasion markers were determined by RT-qPCR.RESULTS: Fluoxetine and sertraline (10 μM) significantly decreased cell proliferation by 94% and by 100%, respectively, in JEG-3 cells, and by 58.6% and 100%, respectively, in HIPEC cells. Norfluoxetine increased MMP-9 activity in JEG-3 cells by 2.0% at 0.03 μM and by 43.9% at 3 μM, but decreased MMP-9 activity in HIPEC cells by 63.7% at 3 μM. Sertraline at 0.03 μM increased mRNA level of TIMP-1 in JEG-3 cells by 36% and that of ADAM-10 by 85% and 115% at 0.3 and 3 μM, respectively. In HIPEC cells, venlafaxine at 0.03 and 0.3 μM, increased ADAM-10 mRNA levels by 156% and 167%, respectively.DISCUSSION: This study shows that SSRIs may affect evTBs homeostasis at therapeutic levels and provides guidance for future research.

The placenta is a key element during pregnancy for the health of the fetus and the mother, which justifies why placental studies are so important. One of the best models for placental studies is the primary cell culture of cytotrophoblast cells from human term placentas. In this chapter, we will detail firstly the isolation of cytotrophoblast cells, with tissue preparation, digestion, Percoll gradient, and cell freezing, and secondly the cell immunopurification and seeding.

In vitro functional analyses of cells are widely used to investigate the molecular mechanisms involved in preeclampsia. Common cellular functions studied include adhesion, apoptosis, proliferation, migration, and invasion. At present, most researchers will use endpoint experimental assays that only allow the determination of cell function at a single time point, with the need to repeat the experiment for an alternate time point. Here, we describe an electrical impedance-based tool that allows real-time monitoring of cells, which enables the efficient assessment of multiple time points over the duration of a single experiment.

Estrogens are produced in large amounts during pregnancy, as a result of a tightly regulated cooperation between the maternal and fetal adrenal cortex, which produce androgen precursors, and the placental villous trophoblast, which transforms these precursors into estrogens. These estrogens play an important role in proper placental function, in adaptation of the mother to pregnancy, as well as in adequate fetal development. Disruption of estrogen production is associated with poor pregnancy outcomes and fetal malformation or altered fetal programming. Pregnant women may be exposed to endocrine disruptors from environmental sources or medications, and it is crucial to study the effects of such compounds on feto-placental steroidogenesis. The H295R/BeWo co-culture model offers the opportunity to study these interactions, by making it possible to evaluate the effects of chemical exposures on androgen and estrogen biosynthesis, as well as on various other aspects of feto-placental communication.

Estrogens are produced in large amounts during pregnancy, as a result of a tightly regulated cooperation between the maternal and fetal adrenal cortex, which produce androgen precursors, and the placental villous trophoblast, which transforms these precursors into estrogens. These estrogens play an important role in proper placental function, in adaptation of the mother to pregnancy, as well as in adequate fetal development. Disruption of estrogen production is associated with poor pregnancy outcomes and fetal malformation or altered fetal programming. Pregnant women may be exposed to endocrine disruptors from environmental sources or medications, and it is crucial to study the effects of such compounds on feto-placental steroidogenesis. The H295R/BeWo co-culture model offers the opportunity to study these interactions, by making it possible to evaluate the effects of chemical exposures on androgen and estrogen biosynthesis, as well as on various other aspects of feto-placental communication.

The placenta is a key element during pregnancy for the health of the fetus and the mother, which justifies why placental studies are so important. One of the best models for placental studies is the primary cell culture of cytotrophoblast cells from human term placentas. In this chapter, we will detail firstly the isolation of cytotrophoblast cells, with tissue preparation, digestion, Percoll gradient, and cell freezing, and secondly the cell immunopurification and seeding.

International audience; 3,3'-Diindolylmethane (DIM) and its synthetic halogenated derivatives 4,4'-Br2- and 7,7'-Cl2DIM (ring-DIMs) have recently been shown to induce protective autophagy in human prostate cancer cells. The mechanisms by which DIM and ring-DIMs induce autophagy have not been elucidated. As DIM is a mitochondrial ATP-synthase inhibitor, we hypothesized that DIM and ring-DIMs induce autophagy via alteration of intracellular AMP/ATP ratios and activation of AMP-activated protein kinase (AMPK) signaling in prostate cancer cells. We found that DIM and ring-DIMs induced autophagy was accompanied by increased autophagic vacuole formation and conversion of LC3BI to LC3BII in LNCaP and C42B human prostate cancer cells. DIM and ring-DIMs also induced AMPK, ULK-1 (unc-51-like autophagy activating kinase 1; Atg1) and acetyl-CoA carboxylase (ACC) phosphorylation in a time-dependent manner. DIM and the ring-DIMs time-dependently induced the oncogenic protein astrocyte-elevated gene 1 (AEG-1) in LNCaP and C42B cells. Downregulation of AEG-1 or AMPK inhibited DIM- and ring-DIM-induced autophagy. Pretreatment with ULK1 inhibitor MRT 67307 or siRNAs targeting either AEG-1 or AMPK potentiated the cytotoxicity of DIM and ring-DIMs. Interestingly, downregulation of AEG-1 induced senescence in cells treated with overtly cytotoxic concentrations of DIM or ring-DIMs and inhibited the onset of apoptosis in response to these compounds. In summary, we have identified a novel mechanism for DIM- and ring-DIM-induced protective autophagy, via induction of AEG-1 and subsequent activation of AMPK. Our findings could facilitate the development of novel drug therapies for prostate cancer that include selective autophagy inhibitors as adjuvants.

In vitro functional analyses of cells are widely used to investigate the molecular mechanisms involved in preeclampsia. Common cellular functions studied include adhesion, apoptosis, proliferation, migration, and invasion. At present, most researchers will use endpoint experimental assays that only allow the determination of cell function at a single time point, with the need to repeat the experiment for an alternate time point. Here, we describe an electrical impedance-based tool that allows real-time monitoring of cells, which enables the efficient assessment of multiple time points over the duration of a single experiment.

Several pesticides suspected or known to have endocrine disrupting effects were screened for pro- or antiandrogenic properties by determining their effects on proliferation, prostatic-specific antigen (PSA) secretion and androgen receptor (AR) expression, and AR phosphorylation in androgen-dependent LNCaP human prostate cancer cells, as well as on the expression and catalytic activity of the enzyme CYP17 in H295R human adrenocortical carcinoma cells, an in vitro model of steroidogenesis. Effects on SRD5A gene expression were determined in both cell lines. Benomyl, vinclozolin, and prochloraz, but not atrazine, concentration dependently (1-30 muM) decreased dihydrotestosterone (DHT)-stimulated proliferation of LNCaP cells. All pesticides except atrazine decreased DHT-stimulated PSA secretion, AR nuclear accumulation, and AR phosphorylation on serines 81 and 213 in LNCaP cells. Benomyl and prochloraz, but not vinclozolin or atrazine, decreased levels of CYP17 gene and protein expression, as well as catalytic activity in H295R cells. In the case of prochloraz, some of these effects corresponded with cytotoxicity. H295R cells expressed AR protein and SRD5A1, but not SRD5A2 transcripts. SRD5A1 gene expression in H295R cells was increased by 10 nM DHT, whereas in LNCaP cells significant induction was observed by 0.1 nM DHT. AR protein expression in H295R cells was not increased by DHT. Vinclozolin decreased DHT-induced SRD5A1 gene expression in LNCaP, but not H295R cells, indicating a functional difference of AR between the cell lines. In conclusion, pesticides may exert antiandrogenic effects through several mechanisms that are cell type-specific, including AR antagonism and down-regulation or catalytic inhibition of androgen biosynthetic enzymes, such as CYP17 and SRD5A1.

Serotonin reuptake inhibitors (SRIs) are currently the main molecules prescribed to pregnant women that suffer from depression. Placental cells are exposed to SRIs via maternal blood, and we have previously shown that SRIs alter feto-placental steroidogenesis in an in vitro co-culture model. More specifically, serotonin (5-HT) regulates the estrogen biosynthetic enzyme aromatase (cytochrome P450 19; CYP19), which is disrupted by fluoxetine and its active metabolite norfluoxetine in BeWo choriocarcinoma cells. Based on molecular simulations, the present study illustrates that the SRIs fluoxetine, norfluoxetine, paroxetine, sertraline, citalopram and venlafaxine exhibit binding affinity for the active-site pocket of CYP19, suggesting potential competitive inhibition. Using BeWo cells and primary villous trophoblast cells isolated from normal term placentas, we compared the effects of the SRIs on CYP19 activity. We observed that paroxetine and sertraline induce aromatase activity in BeWo cells, while venlafaxine, fluoxetine, paroxetine and sertraline decrease aromatase activity in primary villous trophoblast. The effects of the paroxetine and sertraline in primary villous trophoblasts were observed at the lower doses tested. We also showed that 5-HT and the 5-HT(2A) receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) induced CYP19 activity. An increase in phosphorylation of serine and tyrosine and a decrease in threonine phosphorylation of CYP19 was also associated with DOI treatment. Our results contribute to better understanding how 5-HT and SRIs interact with CYP19 and may affect estrogen production. Moreover, this study suggests that alteration of placental 5-HT levels due to depression and/or SRI treatment during pregnancy may be associated with disruption of placental estrogen production.

In this study, we determined whether estragole and its isomer trans-anethole interfered with feto-placental steroidogenesis in a human co-culture model composed of fetal-like adrenocortical (H295R) and placental trophoblast-like (BeWo) cells. Estragole and trans-anethole are considered the biologically active compounds within basil and fennel seed essential oils, respectively. After a 24 h exposure of the co-culture to 2.5, 5.2 and 25 μM estragole or trans-anethole, hormone concentrations of estradiol, estrone, dehydroepiandrosterone, androstenedione, progesterone and estriol were significantly increased. Using RT-qPCR, estragole and trans-anethole were shown to significantly alter the expression of several key steroidogenic enzymes, such as those involved in cholesterol transport and steroid hormone biosynthesis, including StAR, CYP11A1, HSD3B1/2, SULT2A1, and HSD17B1, -4, and -5. Furthermore, we provided mechanistic insight into the ability of estragole and trans-anethole to stimulate promoter-specific expression of CYP19 through activation of the PKA pathway in H295R cells and the PKC pathway in BeWo cells, in both cases associated with increased cAMP levels. Moreover, we show new evidence suggesting a role for progesterone in regulating steroid hormone biosynthesis through regulation of the StAR gene.

International audience; The effects of fluoxetine, one of the most prescribed selective serotonin-reuptake inhibitors (SSRIs) during pregnancy, and its active metabolite norfluoxetine were studied on placental aromatase (CYP19) and feto-placental steroidogenesis. Fluoxetine did not alter estrogen secretion in co-culture of fetal-like adrenocortical (H295R) and trophoblast-like (BeWo) cells used as a model of the feto-placental unit, although it induced CYP19 activity, apparently mediated by the serotonin (5-HT)2A receptor/PKC signaling pathway. Norfluoxetine decreased estrogen secretion in the feto-placental co-culture and competitively inhibited catalytic CYP19 activity in BeWo cells. Decreased serotonin transporter (SERT) activity in the co-culture was comparable to 17β-estradiol treatment of BeWo cells. This work shows that the complex interaction of fluoxetine and norfluoxetine with placental estrogen production, involves 5-HT-dependent and -independent mechanisms. Considering the crucial role of estrogens during pregnancy, our results raise concern about the impact of SSRI treatment on placental function and fetal health.

Aromatase (CYP19) is the key enzyme in the biosynthesis of estrogens. In humans, it is expressed in a tissue- and promoter-specific manner. In hormone-dependent breast cancer, CYP19 is overexpressed through the activation of several additional promoters (PII, I.3 and I.7) that are normally inactive in the healthy mammary gland. In the normal mammary gland, low basal CYP19 expression is regulated by the I.4 promoter, which is also active in adipose tissue. Here, we highlight our recent study of the effects of neonicotinoid pesticides on the promoter-specific expression of CYP19 in various human in vitro models. We also discuss the implications of endocrine disruption by environmental chemicals for the development of hormone-dependent diseases, such as breast cancer.

Abdelbaqi K, Lack N, Guns ET, Kotha L, Safe S, Sanderson JT. BACKGROUND : Cruciferous vegetables protect against prostate cancer. Indole-3-carbinol (I3C) and its major metabolite 3,3'-diindolylmethane (DIM), exhibit antitumor activities in vitro and in vivo. Several synthetic ring-substituted dihaloDIMs (ring-DIMs) appear to have increased anticancer activity. METHODS : Inhibition of LNCaP prostate cancer cell growth was measured by a WST-1 cell viability assay. Cytoplasmic and nuclear (...)

Lithocholic acid (LCA) is a secondary bile acid that is selectively toxic to human neuroblastoma, breast and prostate cancer cells, whilst sparing normal cells. We previously reported that LCA inhibited cell viability and proliferation and induced apoptosis and necrosis of androgen-dependent LNCaP and androgen-independent PC-3 human prostate cancer cells. In the present study, we investigated the roles of endoplasmic reticulum (ER) stress, autophagy and mitochondrial dysfunction in the toxicity of LCA in PC-3 and autophagy deficient, androgen-independent DU-145 cells. LCA induced ER stress-related proteins, such as CCAAT-enhancer-binding protein homologous protein (CHOP), and the phosphorylation of eukaryotic initiation factor 2-alpha (p-eIF2α) and c-Jun N-terminal kinases (p-JNK) in both cancer cell-types. The p53 upregulated modulator of apoptosis (PUMA) and B cell lymphoma-like protein 11 (BIM) levels were decreased at overtly toxic LCA concentrations, although PUMA levels increased at lower LCA concentrations in both cell lines. LCA induced autophagy-related conversion of microtubule-associated proteins 1A/1B light chain 3B (LC3BI–LC3BII), and autophagy-related protein ATG5 in PC-3 cells, but not in autophagy-deficient DU-145 cells. LCA (>10 µM) increased levels of reactive oxygen species (ROS) concentration-dependently in PC-3 cells, whereas ROS levels were not affected in DU-145 cells. Salubrinal, an inhibitor of eIF2αdephosphorylation and ER stress, reduced LCA-induced CHOP levels slightly in PC-3, but not DU-145 cells. Salubrinal pre-treatment increased the cytotoxicity of LCA in PC-3 and DU-145 cells and resulted in a statistically significant loss of cell viability at normally non-toxic concentrations of LCA. The late-stage autophagy inhibitor bafilomycin A1 exacerbated LCA toxicity at subtoxic LCA concentrations in PC-3 cells. The antioxidantα-tocotrienol strongly inhibited the toxicity of LCA in PC-3 cells, but not in DU-145 cells. Collectively, although LCA induces autophagy and ER stress in PC-3 cells, these processes appear to be initially of protective nature and subsequently consequential to, but not critical for the ROS-mediated mitochondrial dysfunction and cytotoxicity of LCA. The full mechanism of LCA-induced mitochondrial dysfunction and cytotoxicity in the similarly sensitive DU-145 cells remains to be elucidated.

Aromatase activity was determined in brain and gonads of wild bream collected along the river Elbe, Germany, and correlated with other endocrine and reproductive endpoints such as plasma sex steroid concentrations, secondary sex characteristics (STI), plasma vitellogenin, gonad size (GSI), and maturation stages of germ cells (MS) that were reported for the same fish in a previous study. Furthermore, regional patterns of aromatase activity were correlated to a number of environmental factors such as exposure to environmental contaminants and parasitism. While aromatase activity was not detectable in the gonads of male and female fish with the assay used, fish of both genders revealed relatively great brain enzyme activities. As for most of the endocrine and reproductive parameters, with the exception of plasma testosterone (T), aromatase activities were significantly less in fish from a river stretch characterized by elevated exposures to organic contaminants and metals. Brain aromatase activity was positively and significantly correlated with plasma estradiol (E2) and MS in females, and showed a similar trend with plasma 11-ketotestosterone (11KT) and STI in males. No comparable trend occurred for T. This decrease of the reproductively relevant hormones 11KT and E2 may be indicative of a disruption of the last step in sex hormone synthesis, a hypothesis that was supported for E2 by the strong (R2=0.78, p0.05) linear regression between aromatase activity and E2 in female bream. It is also hypothesized that the effects on brain aromatase activity were likely to be related to the disruption of other reproductive parameters including sexual maturity and expression of secondary sex characteristics. Although a number of factors such as exposure to pollutants and prevalence of the tapeworm Ligula intestinalis correlated with the suppression of aromatase activity, the exact causes for the regional decrease in brain aromatase activity remain unclear due to inconsistencies of these correlations between sampling events or gender.

The present study investigated the effects of the known xenoestrogen bisphenol A (BPA) relative to eight BPA-related diphenylalkanes on estrogen receptor (ER)-mediated vitellogenin (vtg) production in hepatocytes from male carp (Cyprinus carpio), and on aromatase (CYP19) activity in the human adrenocortical H295R carcinoma cell line. Of the eight diphenylalkanes, only 4,4'-(hexafluoropropylidene)diphenol (BHF) and 2,2'-bis(4-hydroxy-3-methylphenyl)propane (BPRO) induced vtg, i.e., to a maximum of 3% to 4% (at 100 microM) compared with 8% for BPA relative to the maximum induction by 17beta-estradiol (E2, 1 microM). Bisphenol A diglycidyl ether (BADGE) was a potent antagonist of vtg production with an IC50 of 5.5 microM, virtually 100% inhibition of vtg at 20 microM, and an inhibitive (IC50) potency about one-tenth that of the known ER antagonist tamoxifen (IC50, 0.6 microM). 2,2'-Diallyl bisphenol A, 4,4'-(1,4-phenylene-diisopropylidene)bisphenol, BPRO, and BHF were much less inhibitory with IC50 concentrations of 20-70 microM, and relative potencies of 0.03 and 0.009 with tamoxifen. Bisphenol ethoxylate showed no anti-estrogenicity (up to 100 microM), and 4,4'-isopropylidene-diphenol diacetate was only antagonistic at 100 microM. When comparing the (anti)estrogenic potencies of these bisphenol A analogues/diphenylalkanes, anti-estrogenicity occurred at lower concentrations than estrogenicity. 4,4'-Isopropylidenebis(2,6-dimethylphenol) (IC50, 2.0 microM) reduced E2-induced (EC50, 100 nM) vtg production due to concentration-dependent cytotoxicity as indicated by a parallel decrease in MTT activity and vtg, whereas the remaining diphenylalkanes did not cause any cytotoxicity relative to controls. None of the diphenylalkanes (up to 100 microM) induced EROD activity indicating that concentration-dependent, CYP1A enzyme-mediated metabolism of E2, or any Ah-receptor-mediated interaction with the ER, was not a likely explanation for the observed anti-estrogenic effects. At concentrations as great as 100 microM, none of the diphenylalkanes directly inhibited aromatase (CYP19) activity in H295R cells. Environmental exposure of fish to BPA and related diphenylalkanes, depending on the structure, may pose anti-estrogenic, and to a lesser extent estrogenic, risks to development and reproduction.

Gene expression profiles show considerable promise for the evaluation of the toxic potential of environmental contaminants. For example, any alterations in the pathways of steroid synthesis or breakdown have the potential to Cause endocrine disruption. Therefore monitoring these pathways can provide information relative to a chemical's ability to impact endocrine function. One approach to monitoring these pathways has been to use a human adrenocortical carcinoma cell line (H295R) that expresses all the key enzymes necessary for steroidogenesis. In this study we have further developed these methods using accurate and specific quantification methods utilizing molecular beacon-based quantitative RT-PCR (Q-RT-PCR). The assay system was used to analyze the expression patterns of 11 steroidogenic genes in H295R cells. The expression of gene transcripts was measured using a real-time PCR system and quantified based on both a standard curve method using a dilution series of RNA standards and a comparative Ct method. To validate the optimized method, cells were exposed to specific and nonspecific model compounds (inducers and inhibitors of various steroidogenic enzymes) for gene expression profiling. Similar gene expression profiles were exhibited by cells treated with chemicals acting through common mechanisms of action. Overall, our findings demonstrated that the present assay can facilitate the development of compound-specific response profiles, and will provide a sensitive and integrative screen for the effects of chemicals on steroidogenesis.

In this study we evaluated the rat Leydig cell carcinoma cell line R2C and the human adrenocorticocarcinoma cell line H295R for their suitability as in vitro screening tools for potential interference of xenobiotics with aromatase activity. A 24h exposure to prochloraz (PRO), fadrozole (FAD) and epoxyconazole (EPO) resulted in complete catalytic inhibition in H295R and R2C cells. In H295R cells, PRO and FAD were mixed-type inhibitors with apparent K(i) values of 0.04 and 0.03 microM, and apparent K(i)' values of 0.33 and 0.06 microM, respectively. EPO was a competitive inhibitor with an apparent K(i) value of 0.51microM. In R2C, all three compounds showed mixed type inhibition kinetics, with apparent K(i) values (microM) of 0.004, 0.003 and 0.07, and apparent K(i)' values (microM) of 0.41, 0.01 and 2.42, respectively. Exposure for 24h of H295R cells to 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP), prostaglandin E2 (PGE2), phorbol 12-myristate 13-acetate (PMA), or dexamethasone (DEX) resulted in 4.0, 2.8, 3.6 or 3.6-fold induction of aromatase activity, respectively, as well as in an increase of several human aromatase transcripts with promoter-specific 5'-ends (pII and I.3). In R2C cells, only PMA slightly induced aromatase activity. A 24h exposure of H295R cells to atrazine (ATR), resulted in a three-fold induction of aromatase activity and a slight increase in pII and I.3 aromatase transcripts. However, ATR did not induce aromatase activity in R2C cells. We conclude that the H295R cell line contains aromatase promoter regions, which are responsive to the respective stimulants. They play a role in aromatase regulation in various tissues such as brain, placenta, healthy and diseased gonadal and breast tissue and therefore, they may play an important role in tumor genesis, development, behavior and reproduction. The H295R cell line may therefore be a relevant and useful tool in risk assessment of xenobiotics. The R2C cell line, although not suitable for studying induction, appears to be a more sensitive cell line for studying inhibitory effects of xenobiotics on aromatase activity.

Various environmental chemicals have been found to exert antiandrogenic effects in exposed animals and there is a concern that such compounds may also result in adverse effects in humans. Attempts to elucidate potential mechanisms of antiandrogenic action require knowledge of the functions of androgens in the body and the various ways in which environmental chemicals may disrupt these functions. Environmental antiandrogens may compete with the endogenous androgens testosterone and dihydrotestosterone (DHT) for the androgen receptor (AR), thus blocking its intracellular signaling pathway, which is responsible for the majority of androgenic functions. Other disruptions of androgen function may be caused by inhibition of androgen biosynthesis via catalytic inhibition of key steroidogenic enzymes. Two important enzymes that can be targets for environmental chemicals are cytochrome P450 17-mediated steroid 17α-hydroxylase/17,20-lyase and steroid 5α-reductase activity, which are responsible for the production of the precursor C19-steroids dehydroepiandrosterone (DHEA) and androstenedione, and the conversion of testosterone to its more potent androgenic metabolite DHT, respectively. Various environmental chemicals, most notably pesticides, such as the DDT metabolite p,p-DDE, and fungicides, such as vinclozolin, procymidone, and prochloraz, have been identified to act via several of these antiandrogenic mechanisms to cause reproductive malformations in male rats exposed either in utero or in adult life. In addition to in vivo models to screen for proandrogenic or antiandrogenic compounds (rodent Hershberger assay), several in vitro cell bioassays have been developed for the rapid, mechanism-based screening of disruptors of androgen action either at the level of AR signaling (LNCaP human prostate cancer cells or various reporter-gene systems) or at the level of steroidogenesis (H295R human adrenocortical carcinoma cells). Interestingly, very few if any environmental chemicals have been found to act as androgen mimics, in contrast to the many compounds found to act as estrogens in the environment. The consequences of human exposure to environmental levels of antiandrogens remains unclear.

Various pesticides known or suspected to interfere with steroid hormone function were screened in H295R cells for effects on catalytic activity and mRNA expression of aromatase. Dibutyl-, tributyl-, and triphenyltin chloride decreased aromatase and ethoxyresorufin O-deethylase activities concentration dependently (1-300 nM; 24-h exposure). However, these decreases occurred only at cytotoxic concentrations, indicated by decreases in mitochondrial MTT reduction and intracellular neutral red uptake. The organotins did not cause direct inhibition during the catalytic assay (1-1000 nM; 1.5-h exposure). The same was true for p,p'-DDT, and o,p-DDT, and o,p-DDE, which decreased aromatase activity only at cytotoxic concentrations (> or =10 microM; 24-h exposure). p,p'-DDE had no effect on aromatase activity or cell viability at 1 and 10 microM. Various imidazole-like fungicides were aromatase inhibitors. Imazalil and prochloraz were potent mixed inhibitors (K(i)/K(i)(') = 0.04/0.3 and 0.02/0.3 microM, respectively), whereas propiconazole, difenoconazole, and penconazole were less potent competitive inhibitors (K(i) = 1.9, 4.5, and 4.7 microM, respectively). Fenarimol, tebuconazole, and hexaconazole decreased aromatase activity close to cytotoxic concentrations. Vinclozolin, as was shown previously for atrazine, induced aromatase activity and CYP19 mRNA levels about 2.5- and 1.5-fold, respectively. To investigate the mechanism of aromatase induction in H295R cells, the ability of the pesticides to increase intracellular cAMP levels was examined. Vinclozolin (100 microM) and atrazine (30 microM) increased cAMP levels about 1.5-fold above control. Forskolin and isobutyl methylxanthine (IBMX) increased cAMP levels 3 and 1.8-fold, respectively. Time-response curves for cAMP induction and concentration-response curves for aromatase induction by vinclozolin, atrazine, and IBMX were similar, suggesting that the mechanism of aromatase induction by these pesticides is mediated through inhibition of phosphodiesterase activity.

Background: Experimental tools for studying the complex steroidogenic interactions that occur between placenta and fetus during human pregnancy are extremely limited. Objectives: We aimed to develop a co-culture model to study steroidogenesis by the human fetoplacental unit and its disruption by exposure to environmental contaminants. Methods: We cultured BeWo human choriocarcinoma cells, representing the villous cytotrophoblast, and H295R human adrenocortical carcinoma cells, representing the fetal unit, in a carefully adapted co-culture medium. We placed H295R cells in 24-well plates and BeWo cells on transwell inserts with or without pesticide treatment (atrazine or prochloraz) and assessed CYP19 activity and hormonal production after 24 hr of co-culture. Results: The co-culture exhibited the steroidogenic profile of the fetoplacental unit, allowing a synergistic production of estradiol and estriol (but not of estrone) of 133.3 ± 11.3 pg/mL and 440.8 ± 44.0 pg/mL, respectively. Atrazine and prochloraz had cell-type specific effects on CYP19 activity and estrogen production in co-culture. Atrazine induced CYP19 activity and estrogen production in H295R cells only, but did not affect overall estrogen production in co-culture, whereas prochloraz inhibited CYP19 activity exclusively in BeWo cells and reduced estrogen production in co-culture by almost 90%. In contrast, prochloraz did not affect estradiol or estrone production in BeWo cells in monoculture. These differential effects underline the relevance of our co-culture approach to model fetoplacental steroidogenesis. Conclusions: The co-culture of H295R and BeWo cells creates a unique in vitro model to reproduce the steroidogenic cooperation between fetus and placenta during pregnancy and can be used to study the endocrine-disrupting effects of environmental chemicals. Citation: Hudon Thibeault AA, Deroy K, Vaillancourt C, Sanderson JT. 2014. A unique co-culture model for fundamental and applied studies of human fetoplacental steroidogenesis and interference by environmental chemicals. Environ Health Perspect 122:371–377; http://dx.doi.org/10.1289/ehp.1307518

We investigated a potential mechanism for the estrogenic properties of three chloro-s-triazine herbicides and six metabolites in vitro in several cell systems. We determined effects on human aromatase (CYP19), the enzyme that converts androgens to estrogens, in H295R (adrenocortical carcinoma), JEG-3 (placental choriocarcinoma), and MCF-7 (breast cancer) cells; we determined effects on estrogen receptor-mediated induction of vitellogenin in primary hepatocyte cultures of adult male carp (Cyprinus carpio). In addition to atrazine, simazine, and propazine, two metabolites--atrazine-desethyl and atrazine-desisopropyl--induced aromatase activity in H295R cells concentration-dependently (0.3-30 microM) and with potencies similar to those of the parent triazines. After a 24-hr exposure to 30 microM of the triazines, an apparent maximum induction of about 2- to 2.5-fold was achieved. The induction responses were confirmed by similar increases in CYP19 mRNA levels, determined by reverse-transcriptase polymerase chain reaction. In JEG-3 cells, where basal aromatase expression is about 15-fold greater than in H295R cells, the induction responses were similar but less pronounced; aromatase expression in MCF-7 cells was neither detectable nor inducible under our culture conditions. The fully dealkylated metabolite atrazine-desethyl-desisopropyl and the three hydroxylated metabolites (2-OH-atrazine-desethyl, -desisopropyl, and -desethyl-desisopropyl) did not induce aromatase activity. None of the triazine herbicides nor their metabolites induced vitellogenin production in male carp hepatocytes; nor did they antagonize the induction of vitellogenin by 100 nM (EC(50) 17beta-estradiol. These findings together with other reports indicate that the estrogenic effects associated with the triazine herbicides in vivo are not estrogen receptor-mediated, but may be explained partly by their ability to induce aromatase in vitro.

In vitro bioassays were developed for the detection of chemicals that can be bioactivated to reactive free radical species in microsomal fractions. Two methods were deployed, a down-scaled spectrophotometric method for the detection of chemicals that can cause lipid peroxidation using the measurement of thiobarbituric acid-reactive substances (TBARS) and a fluorometric method for the detection of chemicals that can undergo redox cycling to generate superoxide radicals based on the detection of hydrogen peroxide. The response of these systems to prototypical and environmentally relevant chemicals, including tetrachloromethane and paraquat, was examined. The detection limit of the lipid peroxidation bioassay, based on the formation of TBARS, was about 1 μM for tetrachloromethane; that of the bioassay for redox cylers, based on the production of hydrogen peroxide, was about 2 μM for paraquat and about 100-fold lower for the potent redox cycler 2,3,5,6-tetramethylbenzoquinone (TMBQ). Several binary mixtures of chemicals were tested for potential nonadditive effects in both in vitro systems. Some antagonistic effects among halogenated methanes were observed in the lipid peroxidation assay. In the hydrogen peroxide production assay, greater than additive effects were seen between small concentrations of paraquat and TMBQ. A number of surface water concentrates from several locations in The Netherlands, with various levels of chemical contamination, exhibited a weak response in the hydrogen peroxide production assay. Acetone was found to interfere with the response of the bioassay to redox cyclers and, therefore, the water concentrates (originally in acetone) were transferred to ethanol prior to testing. A good correlation was observed between the response of the water concentrates in the hydrogen peroxide production assay and their acute toxicity in Daphnia magna. No correlation was observed between this bioassay response and toxicity in the MicrotoxTM assay using Photobacterium phosphoreum.

(1999). Toxic Equivalency Factors (TEFs) and Their Use in Ecological Risk Assessment: A Successful Method When Used Appropriately. Human and Ecological Risk Assessment: An International Journal: Vol. 5, No. 1, pp. 43-52.

Ethoxyresorufin-O-deethylase (EROD) and porphyrin induction responses of primary hepatocytes to halogenated aromatic hydrocarbons (HAHs) were examined in newly hatched domestic chickens, herring gulls, ring-billed gulls, double-crested cormorants, and Forster's terns. Concentration–response relationships were determined for both biochemical responses in hepatocyte preparations derived from individual avian livers (except for the tern). The choice of vehicle used to dose chicken hepatocytes greatly affected the potencies and efficacies of HAHs. Dimethyl sulfoxide resulted in median effective concentration (EC50) values for EROD induction that were between 10 and 15 times less than isooctane (isooctane was used throughout the study). Neither vehicle induced EROD activity by itself. Concentration-dependent increases in EROD activity were observed with several HAHs, and their potencies (EC50 values) were compared to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) within each hepatocyte preparation to determine relative potency factors (RPFs). Differences in sensitivity to these responses were observed among individuals within each of the species and among species. Median EC50 values (nM) for EROD induction by TCDD were 0.72, 13, 20, 25, and 150 for the chicken, cormorant, ring-billed gull, herring gull, and tern hatchling, respectively. Relative potency factors for several HAHs were different, in both ranking and potency, from those generally derived in mammalian hepatocytes. Porphyrin accumulation was observed occasionally with the most potent aryl hydrocarbon receptor agonists, but most HAHs were not tested at concentrations sufficiently high to observe a consistent response. This study provides information on interindividual and interspecies differences in responsiveness to TCDD-like compounds and provides species-specific RPFs that may prove useful for the purpose of hazard and risk assessment for fish-eating birds.

Aroclors 1242 and 1254 were anaerobically dechlorinated by microorganisms eluted from polychlorinated biphenyl (PCB)-contaminated River Raisin (RR) and Silver Lake (SL) sediments. Dechlorination occurred primarily from the meta positions. H4IIE rat hepatoma cell bioassays for ethoxyresorufin-O-deethylase (EROD) induction potency, a measure of aryl hydrocarbon receptor-mediated toxic potential, revealed that the potencies of the Aroclors were considerably reduced after dechlorination. The decreases in EROD induction potencies were dependent on the extent of dechlorination of the non-ortho-substituted and mono-ortho-substituted PCBs. Calculated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TEqscalc) for the PCB mixtures were 5.7, 0.08, and 0.05 pM TEqcalc/μmole of PCBs for non-, RR-, and SL-dechlorinated Aroclor 1242, and 7.8, 1.6, and 1.0 pM TEqcalc/μmole of PCBs for non-, RR-, and SL-dechlorinated Aroclor 1254, respectively. Correspondence between TEqsassay determined using the H4IIE bioassay and TEqscalc indicated that no unexpected synergistic interactions occurred among components of the dechlorinated mixtures. These results indicate that the dioxinlike toxicities of PCB mixtures are substantially reduced by microbial reductive dechlorination, and that a constant ratio of TEq to total PCBs cannot be assumed in risk assessments.

In a continuing effort to evaluate biomarkers of exposure of great blue herons (Ardea herodias) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons, we examined the effect of TCDD on hepatic microsomal testosterone hydroxylase activities. Heron embryos were exposed in ovo to 2 μg TCDD/kg egg (or corn oil vehicle) and sacrificed at hatch or 7 d posthatch. Adult herons were exposed intraperitoneally to 20 μg TCDD/kg and sacrificed 2 weeks later. The sex of the birds was known for the adults only. Hepatic microsomes of herons of each age group were able to hydroxylate testosterone at the 2β, 6β, 15α, 16α, or 16β positions. In 7-d-old chicks, an additional unidentified compound was formed. The age of the untreated herons had a strong influence on the activities of the five hydroxylases, with changes of up to 17-fold. The TCDD significantly (p < 0.05) induced 2β-, 6β-, and 15α-testosterone hydroxylase activities in the adult females, 15α- in the adult males, and 6β-testosterone hydroxylase activity in the hatchlings. In the 7-d-old chicks, induction was no longer apparent. A significant correlation existed between hepatic microsomal ethoxyresorufin O-deethylase (EROD) and 6β-testosterone hydroxylase activity in hatchlings (r = 0.91; n = 12) and adult female herons (r = 1.0; n = 4). The TCDD-induced changes in testosterone hydroxylase activities occurred at doses that resulted in tissue concentrations and levels of EROD induction that were environmentally relevant, but did not result in overt toxicities.

Caffeic acid and its naturally occurring derivative caffeic acid phenethyl ester (CAPE) have antiproliferative and cytotoxic properties in a variety of cancer cell lines without displaying significant toxicity toward healthy cells, and are considered to be potential anticancer agents. However, little is known about their effects on prostate cancer cells. We synthesized and evaluated the effects of caffeic acid, CAPE (2) and 18 synthetic derivatives on cell viability and androgen-dependent cell proliferation, subcellular localisation and expression of androgen receptor (AR) and secretion of prostate-specific antigen (PSA) in LNCaP human hormone-dependent prostate cancer cells. Several synthetic derivatives of CAPE were strong, concentration-dependent cytotoxic agents in LNCaP cells with IC50 values in the 6.8-26.6 μM range, potencies that were up to five-fold greater than that of CAPE (33.7±4.0 μM). A number of caffeic acid derivatives were inhibitors of androgen-stimulated LNCaP cell proliferation with concomitant inhibition of DHT-stimulated PSA secretion. Compound 24 was the most cytotoxic and antiproliferative caffeic acid derivative (IC50 values of 6.8±0.3 and 2.4±0.8 μM, respectively) inhibiting DHT-stimulated cell proliferation and PSA secretion statistically significantly at concentrations as low as 0.3 μM. Exposure to DHT increased cytoplasmic and nuclear AR levels and co-treatment with increasing concentrations of compound 24 or CAPE (2), notably, further increased these levels. In conclusion, a number of synthetic derivatives of caffeic acid are potent inhibitors of androgen-dependent prostate cancer cell proliferation and viability, acting, at least in part, via an antiandrogenic mechanism that involves increased nuclear accumulation of (presumably inactive) AR.

Polychlorinated diphenyl ethers (PCDEs) are structurally similar to polychlorinated biphenyls (PCBs), and some PCDE congeners have been reported to cause toxic responses similar to those caused by some of the non-ortho-substituted PCBs, which are mediated by the aryl hydrocarbon receptor (AhR). Twenty-nine PCDEs were tested for their potency as AhR agonists relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) by measuring their ability to induce the cytochrome P-450 1A1-associated enzyme activity, ethoxyresorufin-O-deethylase (EROD), in the H4IIE rat hepatoma cell bioassay. All PCDE congeners tested were found to be inactive as EROD inducers except for PCDE 156, which was a weak EROD inducer with a 2,3,7,8-TCDD equivalency factor of about 1.2 {times} 10{sup {minus}5}. During this study the authors determined that small amounts of polychlorinated dibenzofurans (PCDFs) that occurred as impurities in the PCDE preparations were the cause of the apparent EROD induction initially measured in their experiments. Once the PCDF impurities were removed by purification on florisil, little or no activity could be attributed to the PCDEs.

Anthropogenic organic contaminants have been found in even the most remote locations. To assess the global distribution and possible effects of such contaminants, we examined the tissues of two species of albatross collected from Midway Atoll in the central North Pacific Ocean. These birds have an extensive feeding range covering much of the subtropical and northern Pacific Ocean. Anthropogenic contaminants were found at relatively great concentrations in these birds. The sum of 19 polychlorinated biphenyl (PCB) congeners ranged from 177 ng/g wet weight in eggs to 2,750 ng/g wet weight in adult fat. Total toxic equivalents (TEQs) derived from polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) ranged from 17.2 to 297 pg/g wet weight in the same tissues, while the inclusion of TEQs from PCBs increased these values to 48.4 and 769 pg/g wet weight, respectively. While contaminant concentrations varied between species and tissues, the contaminant profile was relatively uniform. The profile of contaminants detected was unusual in that much of the TEQs was contributed by two pentachlorinated congeners (2,3,4,7,8-pentachlorinated dibenzofuran and 1,2,3,7,8-pentachlorinated dibenzo-p-dioxin), and the profiles of PCB congeners did not match known sources. When compared to other studies the concentrations detected in the Midway Atoll samples were near or above the thresholds known to cause adverse effects in other fish-eating bird species.

Plant-derived non-essential fatty acids are important dietary nutrients, and some are purported to have chemopreventive properties against various cancers, including that of the prostate. In this study, we determined the ability of seven dietary C-18 fatty acids to cause cytotoxicity and induce apoptosis in various types of human prostate cancer cells. These fatty acids included jacaric and punicic acid found in jacaranda and pomegranate seed oil, respectively, three octadecatrienoic geometric isomers (alpha- and beta-calendic and catalpic acid) and two mono-unsaturated C-18 fatty acids (trans- and cis-vaccenic acid). Jacaric acid and four of its octadecatrienoic geoisomers selectively induced apoptosis in hormone-dependent (LNCaP) and -independent (PC-3) human prostate cancer cells, whilst not affecting the viability of normal human prostate epithelial cells (RWPE-1). Jacaric acid induced concentration- and time-depedent LNCaP cell death through activation of intrinsic and extrinsic apoptotic pathways resulting in cleavage of PARP-1, modulation of pro- and antiapoptotic Bcl-2 family of proteins and increased cleavage of caspase-3, -8 and -9. Moreover, activation of a cell death-inducing signalling cascade involving death receptor 5 was observed. Jacaric acid induced apoptosis in PC-3 cells by activation of the intrinsic pathway only. The spatial conformation cis, trans, cis of jacaric and punicic acid was shown to play a key role in the increased potency and efficacy of these two fatty acids in comparison to the five other C-18 fatty acids tested. Three-dimensional conformational analysis using the PubChem Database (http://pubchem.ncbi.nlm.nih.gov) showed that the cytotoxic potency of the C-18 fatty acids was related to their degree of conformational similarity to our cytotoxic reference compound, punicic acid, based on optimized shape (ST) and feature (CT) similarity scores, with jacaric acid being most 'biosimilar' (ST(ST-opt)=0.81; CT(CT-opt)=0.45). This 3-D analysis of structural similarity enabled us to rank geoisomeric fatty acids according to cytotoxic potency, whereas a 2-D positional assessment of cis/trans structure did not. Our findings provide mechanistic evidence that nutrition-derived non-essential fatty acids have chemopreventive biological activities and Exhibit 3-D structure-activity relationships that could be exploited to develop new strategies for the prevention or treatment of prostate cancer regardless of hormone dependency.

International audience; BACKGROUND: Cruciferous vegetables protect against prostate cancer. Indole-3-carbinol (I3C) and its major metabolite 3,3'-diindolylmethane (DIM), exhibit antitumor activities in vitro and in vivo. Several synthetic ring-substituted dihaloDIMs (ring-DIMs) appear to have increased anticancer activity. METHODS: Inhibition of LNCaP prostate cancer cell growth was measured by a WST-1 cell viability assay. Cytoplasmic and nuclear proteins were analyzed by immunoblotting and immunofluorescence. Androgen receptor (AR) activation was assessed by measuring prostate-specific antigen (PSA) expression and using LNCaP cells containing human AR and an AR-dependent probasin promoter-green fluorescent protein (GFP) construct. RESULTS: Like DIM, several ring-substituted dihaloDIM analogs, namely 4,4'-dibromo-, 4,4'-dichloro-, 7,7'-dibromo-, and 7,7'-dichloroDIM, significantly inhibited DHT-stimulated growth of LNCaP cells at concentrations ≥1 µM. We observed structure-dependent differences for the effects of the ring-DIMs on AR expression, nuclear AR accumulation and PSA levels in LNCaP cells after 24 hr. Both 4,4'- and 7,7'-dibromoDIM decreased AR protein and mRNA levels, whereas 4,4'- and 7,7'-dichloroDIM had minimal effect. All four dihaloDIMs (10 and 30 µM) significantly decreased PSA protein and mRNA levels. Immuofluorescence studies showed that only the dibromoDIMs increased nuclear localization of AR. All ring-DIMs caused a concentration-dependent decrease in fluorescence induced by the synthetic androgen R1881 in LNCaP cells transfected with wild-type human AR and an androgen-responsive probasin promoter-GFP gene construct, with potencies up to 10-fold greater than that of DIM. CONCLUSION: The antiandrogenic effects of ring-DIMs suggest they may form the basis for the development of novel agents against hormone-sensitive prostate cancer, alone or in combination with other drugs.

International audience; Prostate cancer is a commonly diagnosed cancer in men, and dietary chemoprevention by pomegranate (Punica granatum) extracts has shown noticeable benefits. In this study, we investigated the growth inhibitory, antiandrogenic, and pro-apoptotic effects of 13 pure compounds found in the pomegranate in androgen-dependent LNCaP human prostate cancer cells. Cells deprived of steroid hormones were exposed to increasing concentrations (1-100 μM) of pomegranate compounds in the presence of 0.1 nM dihydrotestosterone (DHT), and the inhibition of cell growth was measured by WST-1 colorimetric assay after a 4 day exposure. Four compounds, epigallocatechin gallate (EGCG), delphinidin chloride, kaempferol, and punicic acid, were found to inhibit DHT-stimulated cell growth at concentrations of 10 μM and above. These four pomegranate compounds inhibited DHT-stimulated androgen receptor nuclear accumulation and the expression of the androgen receptor-dependent genes prostate specific antigen and steroid 5α-reductase type 1 at concentrations ≥10 μM. We determined the possible contribution of apoptosis to the observed decrease in cell growth and found that three compounds, EGCG, kaempferol, and, in particular, punicic acid, induced DNA fragmentation after a 24 h treatment, at concentrations in the 10-100 μM range. Punicic acid, an important fatty acid in pomegranate seeds, was further found to induce intrinsic apoptosis via a caspase-dependent pathway. In conclusion, punicic acid, the main constituent of pomegranate seed (70-80%), exhibited potent growth inhibitory activities in androgen-dependent LNCaP cells, which appear to be mediated by both antiandrogenic and pro-apoptotic mechanisms.

Certain indirubin derivatives are potent cyclin-dependent kinase (CDK) and glycogen synthase kinase (GSK-3β) inhibitors and may be effective against various cancers. We evaluated the effects of aloisine A, alsterpaullone, aminopurvalanol, indirubin-3'-oxime, 6-Br-indirubin-3'-oxime, kenpaullone, olomoucine and roscovitine on cell proliferation, prostate-specific antigen (PSA) expression, androgen receptor (AR) activation, and GSK-3β and β-catenin expression in androgen-dependent LNCaP human prostate cancer cells. Effects were also evaluated in MDA-kb2 human breast cancer cells containing an AR-responsive luciferase construct. Steroid-deprived LNCaP cells were exposed to indirubins±dihydrotestosterone (DHT, 0.1 nM) and cell proliferation was assessed by MTT assay after 120 h. PSA expression was determined by real-time quantitative RT-PCR after 24h. Cytoplasmic and nuclear GSK-3β/β-catenin expression and phosphorylation status was determined by Western blotting. Effects on MDA-kb2 luciferase expression were determined after 24h using Steady-Glo (Promega). Indirubin-3'-oxime, 6-Br-indirubin-3'-oxime, alsterpaullone and kenpaullone increased LNCaP cell proliferation and PSA expression (0.03-1 μM; apoptosis occurred >1 μM), whereas aminopurvalanol significantly (p