Breast cancer proliferation and deterioration-associated metabolic heterogeneity changes induced by exposure of bisphenol S, a widespread replacement of bisphenol A

Development and validation of an analytical methodology based on solvent microextraction and UHPLC-MS/MS for determining bisphenols in honeys from different botanical origins

A new analytical methodology was proposed to determine fourteen bisphenols in honeys from different botanical origins using ultra-high performance liquid chromatography-tandem mass spectrometry. A fast, efficient, environmentally-friendly and simple sample treatment (recoveries between 81% and 116%; matrix effect <20% for all studied compounds except for bisphenol E, F and S) was proposed, which involved a solvent microextraction with acetone and a small volume/amount of 1-hexanol. Chromatographic analysis (< 15 min) was performed in a Kinetex EVO C18 column under gradient elution mode. The method was validated in terms of selectivity, limits of detection (0.2-1.5 μg/kg) and quantification (0.5-4.7 μg/kg), linearity, matrix effect, trueness, and precision (relative standard deviation <17%). Finally, thirty honey samples were analyzed, revealing the presence of residues of nine bisphenols in some of them. However, quantification was possible only in two cases for bisphenol A, with a concentration of approximately 13 μg/kg.

Mass spectrometry imaging for spatially resolved multi-omics molecular mapping

The recent upswing in the integration of spatial multi-omics for conducting multidimensional information measurements is opening a new chapter in biological research. Mapping the landscape of various biomolecules including metabolites, proteins, nucleic acids, etc., and even deciphering their functional interactions and pathways is believed to provide a more holistic and nuanced exploration of the molecular intricacies within living systems. Mass spectrometry imaging (MSI) stands as a forefront technique for spatially mapping the metabolome, lipidome, and proteome within diverse tissue and cell samples. In this review, we offer a systematic survey delineating different MSI techniques for spatially resolved multi-omics analysis, elucidating their principles, capabilities, and limitations. Particularly, we focus on the advancements in methodologies aimed at augmenting the molecular sensitivity and specificity of MSI; and depict the burgeoning integration of MSI-based spatial metabolomics, lipidomics, and proteomics, encompassing the synergy with other imaging modalities. Furthermore, we offer speculative insights into the potential trajectory of MSI technology in the future.

Fetal Origin of Abnormal Glucose Tolerance in Adult Offspring Induced by Maternal Bisphenol A Analogs Exposure

With the widespread use of bisphenol A (BPA) analogs, their health risks have attracted attention. The effects of maternal BPA analogs exposure on glucose homeostasis in adult offspring and the underlying fetal origins require further exploration. Herein, we exposed pregnant mice to two types of BPA analogs─BPB and BPAF; we evaluated glucose homeostasis in adult offspring and maternal-fetal glucose transport by testing intraperitoneal glucose tolerance, determining glucose and glycogen contents, conducting positron emission tomography (PET)/computed tomography (CT), detecting expression of placental nutrient transport factors, and assessing placental barrier status. We observed that adult female offspring maternally exposed to BPB and BPAF exhibited low fasting blood glucose in adulthood, with even abnormal glucose tolerance in the BPAF group. This phenomenon can be traced back to the elevated fetal glucose induced by the increased efficiency of placenta glucose transport in late pregnancy. On the other hand, the expression of genes associated with vascular development and glucose transport was significantly altered in the placenta in the BPAF group, potentially contributing to enhanced fetal glucose. These findings provide preliminary insights into potential mechanisms underlying the disturbance of glucose metabolism in adult female offspring mice induced by maternal exposure to BPA analogs.

Unveiling the intricacies of BPA and BPS: comprehensive insights into its toxic effects using a cutting-edge microphysiological system

Concerns over Bisphenol A (BPA) and its substitute, Bisphenol S (BPS), have led to innovative exploration due to potential adverse health effects. BPS, replacing BPA in some regions to avoid toxic impacts, remains insufficiently studied. Besides this, the organ-on-a-chip technology emerges as a transformative solution in drug discovery and chemiclas toxicity testing, minimizing costs and aligning with ethical standards by reducing reliance on animal models, by integrating diverse tissues and dynamic cell environments enhances precision in predicting organ function. Here, we employ a 3-organ-on-a-chip microfluidic device with skin, intestine, and liver cultures to assess the effects of BPA and BPS via topical and oral administration. Our evaluation focused on gene markers associated with carcinogenicity, systemic toxicity, and endocrine disruption. BPA exhibited expected absorption profiles, causing liver injury and genetic modulation in related pathways. BPS, a safer alternative, induced adverse effects on gene expression, particularly in topical absorption, with distinct absorption patterns. Our findings underscore the urgency of addressing BPA and BPS toxicity concerns, highlighting the crucial role of organ-on-a-chip technology in understanding associated health risks. The study promotes the organ-on-a-chip methodology as a valuable tool for safe drug development and disease treatments, offering a novel liver toxicity screening alternative to traditional animal tests. This contributes to advancing comprehension of the biological effects of these compounds, fostering improved safety assessments in human health.

Mass spectrometry imaging methods for visualizing tumor heterogeneity

Profiling spatial distributions of lipids, metabolites, and proteins in tumors can reveal unique cellular microenvironments and provide molecular evidence for cancer cell dysfunction and proliferation. Mass spectrometry imaging (MSI) is a label-free technique that can be used to map biomolecules in tumors in situ. Here, we discuss current progress in applying MSI to uncover molecular heterogeneity in tumors. First, the analytical strategies to profile small molecules and proteins are outlined, and current methods for multimodal imaging to maximize biological information are highlighted. Second, we present and summarize biological insights obtained by MSI of tumor tissue. Finally, we discuss important considerations for designing MSI experiments and several current analytical challenges.

Mapping Spatiotemporal Heterogeneity in Multifocal Breast Tumor Progression by Noninvasive Ultrasound Elastography-Guided Mass Spectrometry Imaging Strategy

Spatiotemporal heterogeneity of tumors provides an escape mechanism for breast cancer cells, which can obstruct the investigation of tumor progression. While molecular profiling obtained from mass spectrometry imaging (MSI) is rich in biochemical information, it lacks the capacity for in vivo analysis. Ultrasound diagnosis has a high diagnostic accuracy but low chemical specificity. Here, we describe a noninvasive ultrasound elastography (UE)-guided MSI strategy (UEg-MSI) that integrates physical and biochemical characteristics of tumors acquired from both in vivo and in vitro imaging. Using UEg-MSI, both elasticity histopathology metabolism "fingerprints" and reciprocal crosstalk are revealed, indicating the intact, multifocal spatiotemporal heterogeneity of spontaneous tumorigenesis of the breast from early, middle, and late stages. Our results demonstrate a gradual increase in malignant degree of primary focus in cervical and thoracic mammary glands. This progression is characterized by increased stiffness according to elasticity scores, histopathological changes from hyperplasia to increased nests of neoplastic cells and necrotic areas, and regional metabolic heterogeneity and reprogramming at the spatiotemporal level. De novo fatty acid (FA) synthesis focused on independent (such as ω-9 FAs) and dependent (such as ω-6 FAs) dietary FA intake in the core cancerous nest areas in the middle and late stages of tumor or in the peripheral microareas in the early stage of the tumor. SM-Cer signaling pathway and GPs biosynthesis and degradation, as well as glycerophosphoinositol intensity, changed in multiple characteristic microareas. The UEg-MSI strategy holds the potential to expand MSI applications and enhance ultrasound-mediated cancer diagnosis. It offers new insight into early cancer discovery and the occurrence of metastasis.

Novel molecularly imprinted nanogel modified microfluidic paper-based SERS substrate for simultaneous detection of bisphenol A and bisphenol S traces in plastics

Paper-based surface-enhanced Raman scattering (SERS) optical nanoprobes provide ultrasensitive analyte detection; however, they lack selectivity, making them difficult to use in real-world sample analysis without a pretreatment process. This work describes the design of a microfluidic paper-based SERS substrate based on molecularly imprinted nanogels decorated with silver nanoparticles to simultaneously detect bisphenol A (BPA) and bisphenol S (BPS) traces in plastic toys and receipts. The synthesized nanogels have two characteristics that boost SERS performance: molecularly imprinted cavities that allow for selective adsorption and a wrinkled surface that creates uniformly distributed hot spots. Simple paper-based sensor devices were built as 'drop and read' SERS substrates with a separate reservoir to detect a single target, while advanced SERS platforms were designed as a microfluidic chip with two reservoirs connected by a channel for simultaneous detection of BPA and BPS. The SERS platform with a single reservoir showed outstanding analytical performance for the detection of BPA and BPS, with low detection limits of 0.38 pM and 0.37 pM, respectively. The microfluidic paper-based sensor allowed simultaneous and selective detection of BPA and BPS with detection limits estimated at 0.68 nM and 0.47 nM, respectively. The developed sensors are successfully applied to detect BPA and BPS in plastic products and receipts. Finally, the results obtained with our method showed greater sensitivity than those of commercially available ELISA kits, and the acquired values within the ELISA detection range were in excellent agreement.

Boron nitride quantum dots-enhanced laser desorption/ionization mass spectrometry analysis and imaging of bisphenol A

Bisphenol A (BPA) displays harmful effects on the human health, including potent endocrine activity and potential impact on the development of cancer. Analysis BPA residues in water and plastic products attracted considerable attention in the past decades. However, dominantly used conventional analysis techniques are unable to directly and non-destructively identify the correct species of BPA in plastic products. Hence, this study demonstrates the effective utilisation of boron nitride quantum dots (BNQDs) as an inorganic matrix in matrix-assisted laser desorption/ionization mass spectrometry analysis and imaging (MALDI-MS & MSI) for BPA. The presence of abundant hydroxyl and amino groups on the BNQDs' surface is favourable for the formation of hydrogen bonds with BPA, and increases their ionization and chemoselectivity. Intriguingly, the BNQDs matrix offers a distinct signal for phenolic hazardous molecules featuring different hydroxyl groups. The method was applied to detect BPA at nanomolar level in environmental water, and also allowed non-destructive and in situ mapping of BPA in plastics and pacifiers. This research provides a novel strategy for adapting nanomaterials as inorganic matrices for analysis of small molecular pollutants in environmentally relevant samples using MALDI-MS & MSI.

Prenatal bisphenol S exposure induces hepatic lipid deposition in male mice offspring through downregulation of adipose-derived exosomal miR-29a-3p

The increased usage of bisphenol S (BPS) results in wide distribution in pregnant women. In this study, pregnant mice were given multiple-dose BPS during gestation. Results showed that prenatal BPS exposure (50 μg/kg/day) induced increased weight gain, dyslipidemia, higher liver triglyceride (TG), adipocyte hypertrophy, and hepatic lipid deposition in male offspring. Exosomes play important roles in regulating lipid metabolism. Here, serum exosomes and adipose miRNA sequencing of male offspring indicated a remarkable decrease in miR-29a-3p expression. To clarify whether adipocyte-derived exosomes mediate hepatic lipid deposition, exosomes were extracted from BPS-treated adipocytes and co-cultured with hepatocytes. These exosomes could be taken up by hepatocytes and promoted lipid deposition, and notably, exosomal miR-29a-3p was downregulated. Furthermore, miR-29a-3p knockdown in adipocyte-derived exosomes promoted hepatocyte lipid deposition, whereas overexpression led to the opposite effect. Also, the role of miR-29a-3p was demonstrated in hepatocytes by overexpressing or knocking it down. Subsequent studies have shown that miR-29a-3p can promote lipid deposition by directly targeting Col4a1. Taken together, prenatal BPS exposure could lead to lower miR-29a-3p yield in adipocyte-derived exosomes and decrease miR-29a-3p content transported to hepatocytes, which further negatively regulate Col4a1 and promote hepatic lipid deposition. Our findings provided clues to maternal environmental exposure-induced liver metabolic diseases.

Sensitive determination of bisphenols in environmental samples by magnetic porous carbon solid-phase extraction combined with capillary electrophoresis

Bisphenol compounds exist widely in the environment and pose potential hazards to the environment and human health, which has aroused widespread concern. Therefore, there is an urgent need for an efficient and sensitive analytical method to enrich and determine trace bisphenols in environmental samples. In this work, magnetic porous carbon (MPC) was synthesized by one-step pyrolysis combined with a solvothermal method for magnetic solid-phase extraction of bisphenols. The structural properties of MPC were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and saturation magnetization analysis. Its adsorption properties were evaluated by adsorption kinetics and adsorption isotherm studies. By optimizing the magnetic solid-phase extraction and capillary electrophoresis separation conditions, a capillary electrophoresis separation and detection method for four bisphenols was successfully constructed. The results showed that the detection limits of the proposed method for the four bisphenols were 0.71-1.65 ng/mL, the intra-day and inter-day precisions were 2.27-4.03% and 2.93-4.42%, respectively, and the recoveries were 87.68%-108.0%. In addition, the MPC could be easily recycled and utilized, and even if the magnetic solid-phase extraction was repeated 5 times, the extraction efficiency could still be kept above 75%.

Exploration of the damage and mechanisms of BPS exposure on the uterus and ovary of adult female mice

Bisphenol S (BPS) has been followed with interest for its endocrine disrupting effects, but exploration on the reproductive system of adult females is lack of deep investigation. In the present study, adult female CD-1 mice were treated with BPS for 28 days at 300 μg/kg/day. After that, uteruses and ovaries were harvested for histopathological examination, RNA-seq analysis, and diseases risk prediction. Hematoxylin-eosin (H&E) staining results showed significant histological alterations in the uterus and ovary of the BPS-exposed mice. Bioinformatics analysis of the RNA-seq screened a certain number of differentially expressed genes (DEGs) in both uterus and ovary between BPS group and their corresponding vehicle control groups (Veh), respectively. Functional enrichment analysis of DEGs found that hormone metabolism and immunoinflammatory related pathways were enriched. Disease risk evaluation of the hub genes was performed and the results indicated that diseases associated with uterus and ovary were mainly related to tumors and cancers. Further pan cancer and ovarian cancer survival analysis based on human diseases database pointed out, Foxa1, Gata3, S100a8 and Shh for uterus, Itgam, Dhcr7, Fdps, Hmgcr, Hsd11b1, Hsd3b1, Ptges, F3, Fn1, Ptger4 and Srd5a1 for ovary were significant correlation with cancer. The findings suggest that BPS causes some histopathological changes, alters the expressions of hub genes, enhances uterine and ovarian tumors or even cancer risks.

Bisphenols S and F drive ovarian granulosa cell tumor invasion via a metabolic switch

Alterations in the metabolism of cancer cells are crucial for tumor growth and progression. However, the mechanism whereby environmental pollutants such as bisphenols F (BPF) and S (BPS) affect glucose metabolism through the glycolytic pathway, and therefore influence tumor progression, are unclear. Both bisphenols are endocrine-disrupting molecules that are used in plastics. As a consequence of their widespread use, these compounds have been detected in various human body fluids. Thus, hormone-sensitive cancers, such as ovarian cancers, are exposed to these compounds. In the present study, we aimed to determine the effects of the concentrations of BPS and BPF found in body fluids on the cell viability, glucose uptake, glycolysis, oxygen consumption, and invasion by the adult ovarian granulosa cell tumor (AGCT) cell line. We found that BPS and BPF increased the glucose uptake, hexokinase activity, proliferation, and invasion of the cells at environmentally relevant concentrations. Furthermore, we identified an inhibition of glycolysis in parallel with an increase in oxygen consumption, suggesting a BPS/BPF-induced switch from aerobic glycolysis to mitochondrial respiration. In summary, these findings demonstrate a new mechanism through which BPS and BPF promote ovarian granulosa cell tumor progression by increasing energy production through mitochondrial respiration. Thus, both bisphenols induced a metabolic switch that appears to be a stimulus for AGCT progression.

Decreasing the hazardous effect of waste quartz powder and the toxicity of epoxy resin by its synergistic application in industrial coatings

Quartz powder sourced from industrial wastes is very hazardous. It is because it contains large amounts of fine particles. Thus, it has the potential to cause cancer and nervous system impact on humans and animals. Furthermore, its disposal leads to water pollution and plant pollination (negative for the environment). It will not be dangerous if incorporated into a hardened epoxy resin coating. In turn, epoxy resin is very harmful to the environment, in particular to aquatic organisms; therefore, it is necessary to reduce its mass in coatings by using additives. The article describes the systematic investigation of the adhesion of an epoxy resin coating and an economic and toxicity analysis showing the cost and toxicity reduction of the epoxy resin coating by replacing a part of the epoxy resin mass with waste quartz powder. The key novelty of the following article is to highlight a new way to decrease the hazardous effect of waste quartz powder, thanks to its utilization in epoxy resin coatings. Furthermore, the novelty is to decrease the toxicity of epoxy resin by reducing its mass necessary to make the industrial coating.

Aptamer-functionalised metal-organic frameworks as an 'on-off-on' fluorescent sensor for bisphenol S detection

Bisphenol S (BPS) is an industrial chemical that is widely used to manufacture daily items, such as plastic water bottles, milk bottles, water cups, and paper products. BPS is a biologically toxic environmental endocrine disruptor. Long-term exposure to BPS can disrupt the reproductive system, endanger health, and increase the risk of cancer. The metal-organic framework UiO-66 is characterised with high thermal and chemical stability, a simple synthetic route, and low preparation cost. In this study, we modified UiO-66 with nucleic acid aptamers to prepare an 'on-off-on' fluorescent sensor for the simple and rapid detection of BPS. The FAM-labelled aptamer was selected as the fluorescent probe (i.e. 'on'). In the presence of UiO-66, the FAM-labelled aptamer adsorbed onto the surface of the UiO-66 material, and the fluorescence of FAM was quenched by photoinduced electron transfer (i.e. 'off'). When BPS was introduced into the system, the configuration of the FAM-labelled aptamer changed after binding to BPS, and the adsorption of FAM on UiO-66 weakened, resulting in fluorescence recovery (i.e. 'on'). Based on this principle, the reaction system was optimised, and the BPS content was analysed according to the change in the fluorescence signal. The signals changed linearly in the BPS concentration range of 2.0 × 10^-4-4.0 × 10^-2 mmol L^-1, and the system had a detection limit of 1.84 × 10^-4 mmol L^-1. The sensor was successfully used to detect the BPS content in commercial plastic bottled water.

Evaluation of toxicological effects of bisphenol S with an in vitro human bone marrow mesenchymal stem cell: Implications for bone health

As the use of bisphenol A (BPA) has been restricted in consumer products, bisphenol S (BPS) is one major alternative to BPA for various materials, leading to growing concerns about its health risks in human beings. However, little is known about the toxic effects of BPS on bone health. We employed human bone marrow mesenchymal stem cells (hBMSCs) for the in vitro assessment of BPS on cell proliferation, differentiation, and self-renewal. Our study revealed that BPS at concentrations of 10^-10-10^-7 M increased cell viability but induced the morphological changes of hBMSCs. Moreover, BPS decreased ROS generation and increased Nrf2 expression. Furthermore, BPS not only activated ERα/β expression but also increased β-catenin expression and induced the replicative senescence of hBMSCs. Furthermore, we found that the upregulation of β-catenin induced by BPS was mediated, in part, by ER signaling. Overall, our results suggested BPS exposure caused the homeostatic imbalance of hBMSCs.

Effects of the long-term influence of bisphenol A and bisphenol S on the population of nitrergic neurons in the enteric nervous system of the mouse stomach

Bisphenol A (BPA) is an endocrine disruptor commonly used in the production of plastics. Due to its relatively well-known harmful effects on living organisms, BPA is often replaced by its various analogues. One of them is bisphenol S (BPS), widely used in the plastics industry. Until recently, BPS was considered completely safe, but currently, it is known that it is not safe for various internal organs. However, knowledge about the influence of BPS on the nervous system is scarce. Therefore, the aim of this study was to investigate the influence of two doses of BPA and BPS on the enteric nitrergic neurons in the CD1 strain mouse stomach using the double-immunofluorescence technique. The study found that both substances studied increased the number of nitrergic neurons, although changes under the impact of BPS were less visible than those induced by BPA. Therefore, the obtained results, for the first time, clearly indicate that BPS is not safe for the innervation of the gastrointestinal tract.

New insights into the effect of bisphenol AF exposure on maternal mammary glands at various stages of gestation in mice

Bisphenol AF (BPAF) is the most estrogenic compound among BPA analogs. Mammary glands (MDs) are special organs that undergo repeated cycles of structural development, metabolism, and functional differentiation. Gestation is a sensitive window for MDs. In the present study, plug-positive CD-1 mice were exposed to vehicle (Veh) or 300 μg/kg BPAF through oral gavage every second day during gestation, and maternal MDs were collected from different developmental windows at 9.5, 13.5, and 18.5 d of gestation (gestation day [GD]9.5, GD13.5 and GD18.5). The results showed that gestational BPAF exposure induced a significantly elevated MD density at GD18.5. Non-target metabolomics analysis was used to screen for tyrosine, valine, ornithine, proline, threonine, phenylalanine and asymmetrical dimethylarginine (ADMA) amino acids, which changed significantly at all time points. Furthermore, the mRNA expression levels of genes related to these amino acids also changed significantly. Additionally, amino acid levels in BPAF-treated MGs at GD18.5 were related to the serum ammonia concentration of the corresponding offspring. These results provide a comprehensive view of the adverse effects of BPAF exposure during gestation on the maternal MG structure and function, which may affect milk components during lactation. Moreover, higher amino acids content may lead to amino acid imbalance or hyperammonemia in newborns.

iMS2Net: A multiscale networking methodology to decipher metabolic synergy of organism

The metabolic responses of organism to external stimuli are characterized by the multicellular- and multiorgan-based synergistic regulation. Network analysis is a powerful tool to investigate this multiscale interaction. The imaging mass spectrometry (iMS)-based spatial omics provides multidimensional and multiscale information, thus offering the possibility of network analysis to investigate metabolic response of organism to environmental stimuli. We present iMS dataset-sourced multiscale network (iMS2Net) strategy to uncover prenatal environmental pollutant (PM2.5)-induced metabolic responses in the scales of cell and organ from metabolite abundances and metabolite-metabolite interaction using mouse fetal model, including metabotypic similarity, metabolic vulnerability, metabolic co-variability and metabolic diversity within and between organs. Furthermore, network-based analysis results confirm close associations between lipid metabolites and inflammatory cytokine release. This networking methodology elicits particular advantages for modeling the dynamic and adaptive processes of organism under environmental stresses or pathophysiology and provides molecular mechanism to guide the occurrence and development of systemic diseases.

Molecular network strategy in multi-omics and mass spectrometry imaging

Human physiological activities and pathological changes arise from the coordinated interactions of multiple molecules. Mass spectrometry (MS)-based multi-omics and MS imaging (MSI)-based spatial omics are powerful methods used to investigate molecular information related to the phenotype of interest from homogenated or sliced samples, including the qualitative, relative quantitative and spatial distributions. Molecular network strategy provides efficient methods to help us understand and mine the biological patterns behind the phenotypic data. It illustrates and combines various relationships between molecules, and further performs the molecule identification and biological interpretation. Here, we describe the recent advances of network-based analysis and its applications for different biological processes, such as, obesity, central nervous system diseases, and environmental toxicology.

Bisphenol A exposure induces metastatic aggression in low metastatic MCF-7 cells via PGC-1α mediated mitochondrial biogenesis and epithelial-mesenchymal plasticity

AIMS

The frequency of estrogen receptor alpha (ERα)-positive breast cancers and their metastatic progression is prevalent in females globally. Aberrant interaction of estrogen-like endocrine-disrupting chemicals (EDCs) is highly implicated in breast carcinogenesis. Studies have shown that single or acute exposures of weak EDCs such as bisphenol A (BPA) may not have a substantial pro-carcinogenic/metastatic effect. However, repeated exposure to EDCs is expected to strongly induce carcinogenic/metastatic progression, which remains to be studied.

MAIN METHODS

Low metastatic ERα-positive human breast cancer cells (MCF-7) were exposed to nanomolar doses of BPA every 24 h (up to 200 days) to study the effect of repeated exposure on metastatic potential. Following the designated treatment of BPA, markers of epithelial-mesenchymal transition (EMT), migration and invasion, mitochondrial biogenesis, ATP levels, and peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) knockdown assays were performed.

KEY FINDINGS

A repeated exposure of low dose BPA induced stable epithelial-mesenchymal plasticity in MCF-7 cells to augment migration and invasion in the ERα-dependent pathway. Repeated exposures of BPA increased the levels of several mesenchymal markers such as N-cadherin, vimentin, cluster of differentiation 44 (CD44), slug, and alpha-smooth muscle actin (α-SMA), whereas reduced the level of E-cadherin drastically. BPA-induced mitochondrial biogenesis favored metastatic aggression by fulfilling bioenergetics demand via PGC-1α/NRF1/ERRα signaling. Knockdown of PGC-1α resulted in suppressing both mitochondrial biogenesis and EMT in BPA exposed MCF-7 cells.

SIGNIFICANCE

Repeated exposures of low dose BPA may induce metastatic aggression in ERα-positive breast cancer cells via PGC-1α-mediated mitochondrial biogenesis and epithelial-mesenchymal plasticity.

A high-throughput screening assay for identification of chemicals with liver tumor promoting potential using a transgenic zebrafish line

Traditional high-throughput methods for identification of chemicals with liver tumor promotion potentials are based on established cancer cell lines, and rapid and cost-effective high-throughput screening assays in whole organisms are presently lacking. In this study, a transgenic zebrafish liver cancer model was employed to develop a method that could be used to identify chemicals with liver tumor promotion effect quickly and accurately. The method consisted of three parts, including exposure preparation, exposure process and image acquisition. In brief, after chemical exposure for 7 days, 96-well plate exposure system for zebrafish larvae was assessed by microplate reader. Then, the liver cancer promoting potential chemicals were evaluated by field area and field average intensity of fluorescence. The results were further validated by conducting histopathological examination. Our data demonstrated that the high-throughput screening assay developed in this study was reproducible and could be used to rapidly screen chemicals with liver tumor promoting potentials by using tris-(2-chloropropyl)-phosphate (TDCIPP) as a positive control. Furthermore, some other positive chemicals found in previous studies and environmental compounds were assessed using the established method. Results indicated that 86.7% of the positive chemicals and five environmental compounds out of seventeen compounds could enhance liver tumor progression.

Bisphenol A drives di(2-ethylhexyl) phthalate promoting thyroid tumorigenesis via regulating HDAC6/PTEN and c-MYC signaling

Bisphenol A (BPA) and di-(2-ethylhcxyl) phthalate (DEHP) are exist widespread in the environment and produce adverse effect to human as environmental disruptors (EDCs). Epidemiological studies have found that the exposure of DEHP and BPA could increase the susceptibility to thyroid diseases including thyroid cancer and benign thyroid nodules. Due to the existence of multiple pollutants in our daily life, the mixed toxic effects of exposure and their interrelationships may distinguish from the exposure to a single chemical, so it is of great significance to explore the mixed toxic effect of DEHP and BPA co-exposure. Thyroid, as one of the target organs of EDCs, is prone to tumor occurrence, however, whether the mixture of BPA and DEHP will affect the occurrence of thyroid cancer is still obscure. We aim to investigate the effect of single or combined exposure to BPA and DEHP on the occurrence of thyroid cancer. An animal model of exposure to BPA and DEHP was firstly established to evaluate their effect on DMD-induced thyroid cancer. Additionally, human thyroid cancer cells BCPAP and thyroid cells Nthy-ori3-1 were used to further clarify some possible mechanisms of BPA and MEHP, the main metabolite of DEHP. Consequently, we found that BPA alone could increase the incidence of thyroid tumors in female rats compared with DEHP, and DEHP enhanced the effect of BPA on cancer promotion. BPA alone and in combination with DEHP mainly induced the expression of HDAC6, inhibited tumor suppressor gene PTEN upregulated the expression of oncogene c-MYC, and eventually elevate the susceptibility to thyroid tumors. Mechanistically, BPA alone and in combination with MEHP could significantly induce the proliferation of BCPAP cells depending on HDAC6, which could modulate H3K9ac to inhibit PTEN, activate AKT signaling pathway, and simultaneously upregulate the expression of c-MYC. Interestingly, we found that BPA alone and in combination with MEHP could significantly induce the proliferation of Nthy-ori3-1 cells independent on HDAC6 via activating ERK signaling pathway. Taken together, these findings not only provide new evidence of the promoting effect of BPA and DEHP on thyroid cancer but also discusses some possible mechanisms underlying these effects.