Cardiovascular disrupting effects of bisphenols, phthalates, and parabens related to endothelial dysfunction: Review of toxicological and pharmacological mechanisms

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. CVDs are promoted by the accumulation of lipids and immune cells in the endothelial space resulting in endothelial dysfunction. Endothelial cells are important components of the vascular endothelium, that regulate the vascular flow. The imbalance in the production of vasoactive substances results in the loss of vascular homeostasis, leading the endothelial dysfunction. Thus, endothelial dysfunction plays an essential role in the development of atherosclerosis and can be triggered by different cardiovascular risk factors. On the other hand, the 17β-estradiol (E2) hormone has been related to the regulation of vascular tone through different mechanisms. Several compounds can elicit estrogenic actions similar to those of E2. For these reasons, they have been called endocrine-disrupting compounds (EDCs). This review aims to provide up-to-date information about how different EDCs affect endothelial function and their mechanistic roles in the context of CVDs.

Effects of calcitriol upon TGF-βs and their receptors in trophoblast cells

Calcitriol levels increase during pregnancy, contributing to the hormonal and immunological balance, but its deficiency has been associated with problems during this period. Meanwhile, transforming growth factors-β (TGF-βs) play an important role in the maintenance of fetal-maternal immune tolerance; however, exacerbated concentrations of this growth factor are associated with complicated pregnancies. Therefore, we studied the effects of calcitriol on TGF-βs and their receptors in trophoblast cells. Term placentas from uncomplicated pregnancies after cesarean sections were used for cell cultures. Basal gene expression and the effect of calcitriol upon TGF-β1, TGF-β2, TGF-β3, and their receptors TGF-βR1 and TGF-βR2 were assessed using real-time PCR from trophoblast cells. The presence of TGF-β1, 2, 3, and TGF-βR1 were evaluated by immunofluorescence, and the protein abundance and secretion of TGF-β1 were assessed by Western blot and ELISA, respectively. Basal gene expression of TGF-β1 in trophoblast from term placentas was higher than TGF-β2 and TGF-β3, while TGF-βR2 was higher than TGF-βR1. The presence and cellular localization of TGF-β1, 2, 3, and TGF-βR1 were detected in the cytoplasm of syncytiotrophoblast, with TGF-β1 showing the highest intensity. Calcitriol significantly inhibited gene expression of TGF-β1, TGF-β2, and TGF-βR1. Likewise, calcitriol decreased the secretion and abundance of TGF-β1. In conclusion, results indicate that calcitriol is a regulator of TGF-βs in cultured trophoblast cells from term placentas and therefore may be an important player in the development of healthy pregnancies.

The Phytochemical α-Mangostin Inhibits Cervical Cancer Cell Proliferation and Tumor Growth by Downregulating E6/E7-HPV Oncogenes and KCNH1 Gene Expression

Cervical cancer is the fourth most common cancer among women worldwide. The main factor associated with the onset and progression of this neoplasia is the human papillomavirus (HPV) infection. The HPV-oncogenes E6 and E7 are critical drivers of cellular transformation, promoting the expression of oncogenes such as KCNH1. The phytochemical α-mangostin (AM) is a potent antineoplastic and antiviral compound. However, its effects on HPV oncogenes and KCNH1 gene expression remain unknown. This study evaluated the effects of AM on cell proliferation, cell cycle distribution and gene expression, including its effects on tumor growth in xenografted mice. AM inhibited cell proliferation in a concentration-dependent manner, being the most sensitive cell lines those with the highest number of HPV16 copies. In addition, AM promoted G1-cell cycle arrest in CaSki cells, while led to cell death in SiHa and HeLa cells. Of interest was the finding of an AM-dependent decreased gene expression of E6, E7 and KCNH1 both in vitro and in vivo, as well as the modulation of cytokine expression, Ki-67, and tumor growth inhibition. On these bases, we suggest that AM represents a good option as an adjuvant for the treatment and prevention of cervical cancer.

A Rollover Ir(III) Complex of 2-(6-bromopyridin-2-yl)imidazo[1,2-a]pyridine

Here in, we report a rollover iridacycle complex cis-[Ir(κ2-C^N-L1)(κ2-N^N-L1)Cl2], which can be easily obtained as yellow solid, through the reaction of two equivalents of new 2-(6-bromopyridin-2-yl)imidazo[1,2-a]pyridine (L1) type ligand and...

Intratumoral Treatment with 5-Androstene-3β, 17α-Diol Reduces Tumor Size and Lung Metastasis in a Triple-Negative Experimental Model of Breast Cancer

Breast cancer treatment failure is related to low response rates, high costs, and long-term toxicities. Thus, it is necessary to find less toxic, cheaper, and more effective treatments. In situ administration ensures drug delivery to tumor cells and decreases systemic toxic effects. The androstene-3β, 17α-diol (α-AED) reduces breast tumor cell proliferation and is an ideal candidate to treat mammary tumors. This study aims to identify the in vitro and in vivo effects of α-AED on a triple-negative mammary tumor model. An in vitro biphasic steroid effect was observed in mouse and human mammary tumor cells treated with α-AED. In this sense, cells treated with higher doses (100 and 200 μM) showed an antiproliferative effect. The α-AED administrated intratumorally reduced average tumor weight and increased the percentage of natural killer cells (NK), plasmatic, and plasmablast cells in mice tumors. Of note, VEGF levels in all α-AED-treated tumors was lower than in the control and vehicle groups. The tumor in situ increased response was reflected systemically by higher anti-4T1 IgG concentration in serum from α-AED-treated mice, but no other associated systemic changes were detected. The reduction in tumor size for the local injection of α-AED is associated with the anti-proliferative effect of this steroid, and the lower local levels of VEGF may be related to the imperceptible macroscopic metastasis in α-AED-treated mice. The above suggests that α-AED may be used in clinical studies to prove its efficacy as an alternative breast tumor treatment or in conjunction with already established therapies.

The Interplay of GPER1 with 17β-Aminoestrogens in the Regulation of the Proliferation of Cervical and Breast Cancer Cells: A Pharmacological Approach

The G-protein-coupled receptor for estrogen (GPER1) is a transmembrane receptor involved in the progression and development of various neoplasms whose ligand is estradiol (E2). 17β-aminoestrogens (17β-AEs) compounds, analogs to E2, are possible candidates for use in hormone replacement therapy (HRT), but our knowledge of their pharmacological profile is limited. Thus, we explored the molecular recognition of GPER1 with different synthetic 17β-AEs: prolame, butolame, and pentolame. We compared the structure and ligand recognition sites previously reported for a specific agonist (G1), antagonists (G15 and G36), and the natural ligand (E2). Then, the biological effects of 17β-AEs were analyzed through cell viability and cell-cycle assays in two types of female cancer. In addition, the effect of 17β-AEs on the phosphorylation of the oncoprotein c-fos was evaluated, because this molecule is modulated by GPER1. Molecular docking analysis showed that 17β-AEs interacted with GPER1, suggesting that prolame joins GPER1 in a hydrophobic cavity, similarly to G1, G15, and E2. Prolame induced cell proliferation in breast (MCF-7) and cervical cancer (SIHA) cells; meanwhile, butolame and pentolame did not affect cell proliferation. Neither 17β-AEs nor E2 changed the activation of c-fos in MCF-7 cells. Meanwhile, in SIHA cells, E2 and 17β-AEs reduced c-fos phosphorylation. Thus, our data suggest that butolame and pentolame, but not prolame, could be used for HRT without presenting a potential risk of inducing breast- or cervical-cancer-cell proliferation. The novelty of this work lies in its study of compound analogs to E2 that may represent important therapeutic strategies for women in menopause, with non-significant effects on the cell viability of cancer cells. The research focused on the interactions of GPER1, a molecule recently associated with promoting and maintaining various neoplasms.

Association of Serum Levels of Plasticizers Compounds, Phthalates and Bisphenols, in Patients and Survivors of Breast Cancer: A Real Connection?

Phthalates and bisphenols are ubiquitous environmental pollutants with the ability to perturb different systems. Specifically, they can alter the endocrine system, and this is why they are also known as endocrine-disrupting compounds (EDCs). Interestingly, they are related to the development and progression of breast cancer (BC), but the threshold concentrations at which they trigger that are not well established. Objectives: The aim of this study was to compare the concentration measures of parent EDCs in three groups of women (without BC, with BC, and BC survivors) from two urban populations in Mexico, to establish a possible association between EDCs and this disease. We consider the measure of the parent compounds would reflect the individual’s exposure. Methods: The levels of di-ethyl-hexyl-phthalate (DEHP), butyl-benzyl-phthalate (BBP), di-n-butyl phthalate (DBP) and di-ethyl-phthalate (DEP), bisphenol A (BPA) and bisphenol S (BPS) were determined by gas chromatograph-mass spectrometry in 102 subjects, including 37 women without any pathological disease, 46 patients with BC and 19 women survivals of BC of Mexico and Toluca City. Results: All phthalates were detected in 100% of women, two of them were significantly higher in patients with different BC subtypes in Mexico City. Differential increases were observed mainly in the serum concentration of phthalates in women with BC compared to women without disease between Mexico and Toluca City. In addition, when performing an analysis of the concentrations of phthalates by molecular type of BC, DEP and BBP were found mainly in aggressive and poorly differentiated types of BC. It should be noted that female BC survivors treated with anti-hormonal therapy showed lower levels of BBP than patients with BC. BPA and BPS were found in most samples from Mexico City. However, BPS was undetectable in women from Toluca City. Discussion: The results of our study support the hypothesis of a positive association between exposure to phthalates and BC incidence.

Sexual Dimorphism of the Neuroimmunoendocrine Response in the Spleen during a Helminth Infection: A New Role for an Old Player?

The interaction of the nervous, immune, and endocrine systems is crucial in maintaining homeostasis in vertebrates, and vital in mammals. The spleen is a key organ that regulates the neuroimmunoendocrine system. The Taenia crassiceps mouse system is an excellent experimental model to study the complex host–parasite relationship, particularly sex-associated susceptibility to infection. The present study aimed to determine the changes in neurotransmitters, cytokines, sex steroids, and sex-steroid receptors in the spleen of cysticercus-infected male and female mice and whole parasite counts. We found that parasite load was higher in females in comparison to male mice. The levels of the neurotransmitter epinephrine were significantly decreased in infected male animals. The expression of IL-2 and IL-4 in the spleen was markedly increased in infected mice; however, the expression of Interleukin (IL)-10 and interferon (IFN)-γ decreased. We also observed sex-associated differences between non-infected and infected mice. Interestingly, the data show that estradiol levels increased in infected males but decreased in females. Our studies provide evidence that infection leads to changes in neuroimmunoendocrine molecules in the spleen, and these changes are dimorphic and impact the establishment, growth, and reproduction of T. crassiceps. Our findings support the critical role of the neuroimmunoendocrine network in determining sex-associated susceptibility to the helminth parasite.

Combinations of Calcitriol with Anticancer Treatments for Breast Cancer: An Update

Preclinical, clinical, and epidemiological studies indicate that vitamin D3 (VD) deficiency is a risk factor for the development of breast cancer. Underlying mechanisms include the ability of calcitriol to induce cell differentiation, inhibit oncogenes expression, and modify different signaling pathways involved in the control of cell proliferation. In addition, calcitriol combined with different kinds of antineoplastic drugs has been demonstrated to enhance their beneficial effects in an additive or synergistic fashion. However, a recognized adjuvant regimen based on calcitriol for treating patients with breast cancer has not yet been fully established. Accordingly, in the present work, we review and discuss the preclinical and clinical studies about the combination of calcitriol with different oncological drugs, aiming to emphasize its main therapeutic benefits and opportunities for the treatment of this pathology.

Antitumoral effects of dovitinib in triple-negative breast cancer are synergized by calcitriol in vivo and in vitro

Chemotherapy is a standard therapeutic option for triple-negative breast cancer (TNBC); however, its effectiveness is often compromised by drug-related toxicity and resistance development. Herein, we aimed to evaluate whether an improved antineoplastic effect could be achieved in vitro and in vivo in TNBC by combining dovitinib, a multi-kinase inhibitor, with calcitriol, a natural anticancer hormone. In vitro, cell proliferation and cell-cycle distribution were studied by sulforhodamine B-assays and flow cytometry. In vivo, dovitinib/calcitriol effects on tumor growth, angiogenesis, and endothelium activation were evaluated in xenografted mice by caliper measures, Itgb3/VEGFR2-immunohistochemistry and ^99mTc-Ethylenediamine-N,N-diacetic acid/hydrazinonicotinamyl-Glu[cyclo(Arg-Gly-Asp-D-Phe-Lys)]₂ (^99mTc-RGD₂)-tumor uptake. The drug combination elicited a synergistically improved antiproliferative effect in TNBC-derived cells, which allowed a 7-fold and a 3.3-fold dovitinib dose-reduction in MBCDF-Tum and HCC-1806 cells, respectively. Mechanistically, the co-treatment induced a cell cycle profile suggestive of cell death and DNA damage (accumulation of cells in SubG1, S, and G2/M phases), increased the number of multinucleated cells and inhibited tumor growth to a greater extent than each compound alone. Tumor uptake of ^99mTc-RGD₂ was reduced by dovitinib, suggesting angiogenesis inhibition, which was corroborated by decreased endothelial cell growth, tumor-vessel density and VEGFR2 expression. In summary, calcitriol synergized dovitinib anticancer effects in vitro and in vivo, allowing for a significant dose-reduction of dovitinib while maintaining its antiproliferative potency. Our results suggest the beneficial convergence of independent antitumor mechanisms of dovitinib and calcitriol to inhibit TNBC-tumor growth.

Regulation of anti-tumorigenic pathways by the combinatory treatment of calcitriol and TGF-β in PC-3 and DU145 cells

Calcitriol and transforming growth factors beta (TGF-β) are involved in several biological pathways such as cell proliferation, differentiation, migration and invasion. Their cellular effects could be similar or opposite depending on the genetic target, cell type and context. Despite the reported association of calcitriol deficiency and disruption of the TGF-β pathway in prostate cancer and the well-known independent effects of calcitriol and TGF-βs on cancer cells, there is limited information regarding the cellular effects of calcitriol and TGF-β in combination. In this study, we in vitro analyze the combinatory effects of calcitriol and TGF-β on cell growth and apoptosis using PC-3 and DU145 human prostate cancer cell lines. Using high-throughput microarray profiling of PC-3 cells upon independent and combinatory treatments, we identified distinct transcriptional landscapes of each intervention, with a higher effect established by the combinatorial treatment, following by TGF-β1 and later by calcitriol. A set of genes and enriched pathways converge among the treatments, mainly between the combinatory scheme and TGF-β1, but the majority were treatment-specific. Of note, CYP24A1, IGFBP3, CDKN1A, NOX4 and UBE2D3 were significantly up-regulated upon the combinatorial treatment whereas CCNA1, members of the CT45A and APOBEC3 family were down-regulated. By public RNA signatures, we were able to confirm the regulation by the co-treatment over cell proliferation and cell cycle. We finally investigated the possible clinical impact of genes modulated by the combinatorial treatment using benchmark prostate cancer data. This comprehensive analysis reveals that the combinatory treatment impairs cell growth without affecting apoptosis and their combinatory actions might synergize and improved their individual effects to reprogram prostate cancer signaling.

Potential Estrogenic Properties of 17β-Hydroxy-ethylimine Estradiol Derivative Targeted to Menopause Stage

BACKGROUND/AIM

Hormone replacement therapy during menopause increases the risk of thromboembolic diseases and cancer, so safety alternative therapeutic strategies are needed. 17β-Aminoestrogens are a synthetic estrogens group that possess mild anticoagulant activity that contrasts with the pro-coagulant effects showed by estradiol's (E₂) in rodents. Being considered an alternative to conventional hormone replacement therapy during menopause without thrombogenic risks producing. The present study aimed to determine the estrogenic profile and anxiolytic activity of 17β-[hydroxy-ethylimine]-1,3,5(10)-estratrien-3-ol (IE₂), a related compound unknown until now.

METHODS

IE₂ was assessed in immature rats by uterotrophic assay administering IE_2, E_2, or vehicle. In ovariectomized adult Wistar rats (Ovx) to facilitating the lordotic behavior compared with E_2, estradiol benzoate, or vehicle. The effect of IE₂ on anxiety was estimated in Ovx animals treated with IE₂, E₂, or vehicle group and evaluated in the elevated plus-maze model.

RESULTS AND CONCLUSION

IE₂ produced an uterotrophic effect, lordotic behavior, and anxiolytic effect in a dose-dependent manner, similar to E₂. IE₂ depicted estrogenicity, indicating potential clinical use as hormone replacement therapy during menopause.

Environmental parasitology and its impact on the host nueroimmunoendocrine network

The communication between neuroendocrine and immune system maintains a bidirectional complex network. Both systems jointly act during a parasite infection to maintain homeostasis and to eliminate such pathogens. Parasites interfere with the synthesis, secretion, metabolism, action, and elimination of endogenous hormones, as well as with the immune system in the host. Here, we aim to address as how parasite colonization disrupts the normal homeostasis of endocrine organs of the host, likely due to the exacerbated immune response, or by the impact of the parasite directly affecting endocrine tissues.

The chemical environmental pollutants BPA and BPS induce alterations of the proteomic profile of different phenotypes of human breast cancer cells: A proposed interactome

Breast cancer is one of the most common malignancies and the second leading cause of death in women. Despite efforts for its early detection, its worldwide incidence continues to increase. Thus, identification of risk factors for its development and new targets for its therapy are of vital importance. Environmental pollutants derived from human activity have been associated with predisposition to the development of cancer. Bisphenol A (BPA) is an endocrine disruptor compound (EDC) widely used in the manufacture of polycarbonates, and it has affinity for the estrogen receptor (ER). Scientific evidence has proposed an association between increased incidence of breast cancer and BPA exposure at lower doses. Among worldwide concerns with BPA exposure, different industries proceeded to replace BPA with analogs such as bisphenol S (BPS), which is now employed in products labelled as BPA-free. Nevertheless, recent studies exhibit that its exposure results in altered mammary gland development and morphogenesis; and promotes breast cancer cell proliferation. Of note, most of the effects of both BPA and BPS have been performed in estrogen-dependent breast cancer models. However, gaps in knowledge still exist on the roles and mechanisms that both compounds, specifically BPS, may play in cancer initiation and development in hormone-dependent and other types of breast cancer. Thus, the aim of the present study was to deepen the understanding of biological targets modulated by these ubiquitous pollutants in different breast cancer cell lines, representing two scenarios of this pathology: hormone-dependent and hormone-independent breast cancer. Results point out that both compounds induced proliferation in ER positive cells, not showing this effect in the ER-negative breast cancer cells. Different targets modified at the proteomic level in both breast cancer scenarios were also identified. Stem cell markers (eg. CD44) and invasion proteins (eg. MMP-14) were importantly increased by BPA and BPS in ER-positive breast cancer cells. In contrast, growth factors and associated receptors such as EGFR and TGF-β were induced by BPS in the ER-negative breast cancer cells; both pollutants induced an increase of vascular endothelial growth factor (VEGF) protein secretion. This finding suggests that the use of BPS must be considered with more caution than BPA, since it can act independently of the presence of the hormonal receptor. These findings show new evidence that BPA and BPS exposure can contribute to breast cancer development and progression. Our results suggest that both BPA and BPS must be considered equally as outstanding risk factors for this pathology.

An organotin indomethacin derivative inhibits cancer cell proliferation and synergizes the antiproliferative effects of lapatinib in breast cancer cells

It is known that an inflammatory condition in different types of cancer provides a sustained microenvironment that favors tumor growth, invasion, and metastasis. Non-steroidal anti-inflammatory drugs such as indomethacin have demonstrated chemo-preventive, anti-proliferative and cytotoxic effects in a variety of tumors. The aim of this study was to investigate the effects of an organotin indomethacin derivative (OID) on the proliferation of breast and prostate cancer cell lines and the possible mechanisms of action of this compound. Different cancer cell lines were treated in the presence of OID and cell proliferation was measured by quantification of the DNA content, changes in the cell cycle profile and the activation of caspase 3 were evaluated by flow cytometry, interleukin 6 (IL-6) gene expression was evaluated by qPCR and protein expression was analyzed by ELISA and Western blot assays. OID inhibited the cell proliferation of a panel of cancer cell lines in a concentration-dependent manner. Moreover, the addition of OID to lapatinib treatment, targeted therapy for breast cancer, significantly enhanced its antiproliferative response. The effects on cell proliferation of these compounds involved, among others, the induction of apoptosis, the downregulation of IL-6 and a decrease of the MAPK activation pathway. Our results suggest that the use of OID alone or in combination with tyrosine kinase inhibitors could be considered as adjuvants in the treatment of cancer.

How microplastic components influence the immune system and impact on children health: Focus on cancer

BACKGROUND

As a result of human socioeconomic activity, industrial wastes have increased distressingly. Plastic pollution is globally distributed across the world due to its properties of buoyancy and durability. A big health hazard is the sorption of toxicants to plastic while traveling through the environment. Two broad classes of plastic-related chemicals are of critical concern for human health-bisphenols and phthalates. Bisphenol A (BPA) is an endocrine-disruptor compound (EDC) with estrogenic activity. It is used in the production of materials that are used daily. The endocrine modulating activity of BPA and its effects on reproductive health has been widely studied. BPA also has effects on the immune system; however, they are poorly investigated and the available data are inconclusive. Phthalates are also EDCs used as plasticizers in a wide array of daily-use products. Since these compounds are not covalently bound to the plastic matrix, they easily leach out from it, leading to high human exposure. These compounds exert several cell effects through modulating different endocrine pathways, such as estrogen, androgen, peroxisome proliferator-activated receptor gamma, and arylhydrocarbon receptor pathways. The exposure to both classes of plastic derivatives during critical periods has detrimental effects on human health.

METHODS

In this review, we have compiled the most important of their perinatal effects on the function of the immune system and their relationship to the development of different types of cancer.

RESULTS/CONCLUSION

The administration of bisphenols and phthalates during critical stages of development affects important immune system components, and the immune function; which might be related to the development of different diseases including cancer.

Perinatal exposure to bisphenol A increases in the adulthood of the offspring the susceptibility to the human parasite Toxocara canis

Bisphenol A, a very widespread environmental pollutant and endocrine disruptor compound, can interact with several steroid receptors, particularly with estrogen ones. In different studies, it has observed that the endocrine disruption during critical periods of development can trigger alterations in the immune response during the adult life. Male Wistar rats were exposed indirectly to BPA at a dose of 250 μg/kg day during the perinatal period (from day 5 of pregnancy until day 21 postnatal), At the 60 days of age, the adulthood, animals were infected with larvated eggs of the Toxocara canis, and were sacrificed at 7 days post-infection. Parasitic loads in the lung and in the liver were analyzed by artificial digestion. Furthermore, immune cell subpopulations (macrophages, NK cells, Tγδ, total T cells, T helper, T cytotoxic, and B lymphocytes) present in spleen, peripheral and mesenteric lymph nodes were analyzed by flow cytometry. The expression of Th1 and Th2 cytokines at the splenic level was determined by real-time quantitative PCR. Finally, the titers of specific antibodies against to the parasite were analyzed by ELISA. The BPA treatment administrated in the perinatally stage favors a significant increase of the percentage of Toxocara canis larvae in the lungs and liver in the adulthood. Additionally, the exposure to this compound caused a dramatically decrease in the production of specific antibodies against to this parasite, downregulating together Th2 cytokines (IL-4, IL-5 and IL-13), meanwhile upregulated Th1 cytokines (IFN-γ and TNF-α). Perinatal exposure to BPA affects the performance of the immune response during adult life, modifying both cytokines and antibodies production by these cells, which favors the susceptibility to infections, specifically toxocariosis.

Synergistic Antitumorigenic Activity of Calcitriol with Curcumin or Resveratrol is Mediated by Angiogenesis Inhibition in Triple Negative Breast Cancer Xenografts

Calcitriol is a multitarget anticancer hormone; however, its effects on angiogenesis remain contradictory. Herein, we tested whether the antiangiogenic phytochemicals curcumin or resveratrol improved calcitriol antitumorigenic effects in vivo. Triple-negative breast cancer tumoral cells (MBCDF-T) were xenografted in nude mice, maintaining treatments for 3 weeks. Tumor onset, volume and microvessel density were significantly reduced in mice coadministered with calcitriol and curcumin (Cal+Cur). Vessel count was also reduced in mice simultaneously treated with calcitriol and resveratrol (Cal+Rsv). Cal+Cur and Cal+Rsv treatments resulted in less tumor activated endothelium, as demonstrated by decreased tumor uptake of integrin-targeted biosensors in vivo. The renal gene expression of Cyp24a1 and Cyp27b1 suggested increased calcitriol bioactivity in the combined regimens. In vitro, the phytochemicals inhibited both MBCDF-T and endothelial cells proliferation, while potentiated calcitriol’s ability to reduce MBCDF-T cell-growth and endothelial cells migration. Resveratrol induced endothelial cell death, as deduced by increased sub-G1 cells accumulation, explaining the reduced tumor vessel number in resveratrol-treated mice, which further diminished when combined with calcitriol. In conclusion, the concomitant administration of calcitriol with curcumin or resveratrol synergistically promoted anticancer effects in vitro and in vivo in human mammary tumor cells. Whereas the results suggest different mechanisms of action of the phytochemicals when coadministered with calcitriol, the converging biological effect was inhibition of tumor neoangiogenesis.

Sex-associated protective effect of early bisphenol-A exposure during enteric infection with Trichinella spiralis in mice

Bisphenol A (BPA) is an endocrine disruptor compound with estrogenic activity, possessing affinity for both nuclear (ERα and ERβ) and membrane estrogen receptors. The main source of BPA exposure comes from the contamination of food and water by plastic storage containers or disposable bottles, among others, in which case BPA is easily ingested. Exposure to BPA during early pregnancy leads to lifelong effects; however, its effect on the immune system has not been fully studied. Since endocrine and immune systems interact in a bidirectional manner, the disruption of the former may cause permanent alterations of the latter, thus affecting a future anti-parasitic response. In this study, neonate BALB/c mice were exposed to a single dose of BPA (250 μg/kg); once sexual maturity was reached, they were orally infected with Trichinella spiralis (T. spiralis). The analyses performed after 5 days of infection revealed a decreased parasitic load in the duodenum of mice in the BPA-treated group. Flow cytometry analyses also revealed changes in the immune cell subpopulations of the infected animals when compared to the BPA-treated group. RT-PCR analyses of duodenum samples showed an increased expression of TNF-α, IFN-γ, IL-4, IL-5, and IL-9 in the BPA-treated group. These findings show a new aspect whereby early-life exposure to BPA contributes to the protection against T. spiralis by modulating the anti-parasitic immune response.

Immune Tumor Microenvironment in Breast Cancer and the Participation of Estrogen and Its Receptors in Cancer Physiopathology

Breast cancer is characterized by cellular and molecular heterogeneity. Several molecular events are involved in controlling malignant cell process. In this sense, the importance of studying multiple cell alterations in this pathology is overriding. A well-identified fact on immune response is that it can vary depend on sex. Steroid hormones and their receptors may regulate different functions and the responses of several subpopulations of the immune system. Few reports are focused on the function of estrogen receptors (ERs) on immune cells and their roles in different breast cancer subtypes. Thus, the aim of this review is to investigate the immune infiltrating tumor microenvironment and prognosis conferred by it in different breast cancer subtypes, discuss the current knowledge and point out the roles of estrogens and its receptors on the infiltrating immune cells, as well as to identify how different immune subsets are modulated after anti-hormonal treatments in breast cancer patients.

Breast Cancer Metastasis: Are Cytokines Important Players During Its Development and Progression?

In breast cancer, an uncontrolled cell proliferation leads to tumor formation and development of a multifactorial disease. Metastasis is a complex process that involves tumor spread to distant parts of the body from its original site. Metastatic dissemination represents the main physiopathology of cancer. Inter- and intracellular communication in all systems in vertebrates is mediated by cytokines, which are highly inducible, secretory proteins, produced not only by immune system cells, but also by endocrine and nervous system cells. It has become clear in recent years that cytokines, as well as their receptors are produced in the organisms under physiological and pathological conditions; recently, they have been closely related to breast cancer metastasis. The exact initiation process of breast cancer metastasis is unknown, although several hypotheses have emerged. In this study, we thoroughly reviewed the role of several cytokines in breast cancer metastasis. Data reviewed suggest that cytokines and growth factors are key players in the breast cancer metastasis induction. This knowledge must be considered with the aim to development of new therapeutic approaches to counter breast cancer metastasis.

The addition of calcitriol or its synthetic analog EB1089 to lapatinib and neratinib treatment inhibits cell growth and promotes apoptosis in breast cancer cells

In breast cancer the use of small molecule inhibitors of tyrosine kinase activity of the ERBB family members improves survival thus represents a valuable therapeutic strategy. The addition of calcitriol, the most active metabolite of vitamin D, or some of its analogs, to conventional anticancer drugs, including tyrosine kinase inhibitors (TKIs), has shown an increased effect on the inhibition of cancer cell growth. In this work, we have evaluated the effects and the mechanism of action of the combination of calcitriol or its analog EB1089 with lapatinib or neratinib on EGFR and/or HER2 positive breast cancer cell lines. Lapatinib, neratinib, calcitriol and EB1089 inhibited breast cancer cell proliferation in a concentration-dependent manner. Addition of calcitriol or EB1089 to TKIs treatment induced more effective inhibiting effect on cell growth and AKT and MAPK phosphorylation than all compounds alone. The combined treatments incremented also the expression of active caspase 3 and induced cell death in two and three-dimensional cell culture and significantly inhibited anchorage-independent colony formation. Our results suggest that the addition of calcitriol or its analog EB1089 to conventional targeted therapies, including lapatinib or neratinib might be of benefit to patients with breast cancer, particularly those with an EGFR and/or HER2 positive phenotype.

Efficacy and mechanism of action of the tyrosine kinase inhibitors gefitinib, lapatinib and neratinib in the treatment of HER2-positive breast cancer: preclinical and clinical evidence

An increasing number of tumors, including breast cancer, overexpress proteins of the epidermal growth factor receptor (EGFR) family. The interaction between family members activates signaling pathways that promote tumor progression and resistance to treatment. Human epidermal growth factor receptor type II (HER2) positive breast cancer represents a clinical challenge for current therapy. It has motivated the development of novel and more effective therapeutic EGFR family target drugs, such as tyrosine kinase inhibitors (TKIs). This review focuses on the effects of three TKIs mostly studied in HER2- positive breast cancer, lapatinib, gefitinib and neratinib. Herein, we discuss the mechanism of action, therapeutic advantages and clinical applications of these TKIs. To date, TKIs seem to be promising therapeutic agents for the treatment of HER2-overexpressing breast tumors, either as monotherapy or combined with other pharmacological agents.

Calcitriol and its analogues enhance the antiproliferative activity of gefitinib in breast cancer cells

Coexpression of EGFR and HER2 has been associated with poor disease outcome, high rates of metastasis and resistance to conventional treatments in breast cancer. Gefitinib, a tyrosine kinase inhibitor, reduces both cell proliferation and tumor growth of breast cancer cells expressing EGFR and/or HER2. On the other hand, calcitriol and some of its synthetic analogs are important antineoplastic agents in different breast cancer subtypes. Herein, we evaluated the effects of the combined treatment of gefitinib with calcitriol or its analogs on cell proliferation in breast cancer cells. The presence of EGFR, HER2 and vitamin D receptor were evaluated by Western blot in two established breast cancer cell lines: SUM-229PE, SKBR3 and a primary breast cancer-derived cell line. The antiproliferative effects of gefitinib alone or in combination with calcitriol and its analogs, calcipotriol and EB1089, were assessed by growth assay using a DNA content-based method. Inhibitory concentrations on cell proliferation were calculated by non-linear regression analysis using sigmoidal fitting of dose-response curves. Pharmacological effects of the drug combinations were calculated by the Chou-Talalay method. Phosphorylation of ERK1/2 MAPK was evaluated by Western blot. Gene expression of EGFR, HER2 and BIM was assessed by real time PCR. BIM protein levels were analyzed in cells by flow cytometry. The effects of the drugs alone or combinated on cell cycle phases were determined using propidium iodide. Apoptosis was evaluated by detection of subG1 peak and determination of active caspase 3 by flow cytometry. Gefitinib, calcitriol, calcipotriol and EB1089 inhibited cell proliferation in a dose dependent manner. The combinations of gefitinib with calcitriol or its analogs were more effective to inhibit cell growth than each compound alone in all breast cancer cells studied. The gene expression of EGFR and HER2 was downregulated and not affected, respectively, by the combined treatment. Furthermore, phosphorylation of ERK 1/2 was inhibited a greater extent in co-treated cells than in the cells treated with alone compounds. The combination of gefitinib with calcitriol or their synthetic analogs induced apoptosis in SUM-229PE cells, this was shown by the significant upregulation of BIM protein levels, higher percentages of cells in subG1 peak and increase of caspase 3-positive cells. The combination of gefitinib with calcitriol or their synthetic analogs resulted in a greater antiproliferative effect than with either of the agents alone in EGFR and HER2 positive breast cancer cells. The mechanistic explanation for these results includes downregulation of MAPK signaling pathway, decrease of cells in G2/M phase and induction of apoptosis mediated by upregulation of BIM and activation of caspase 3. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.