Identification of nonmonotonic concentration-responses in Tox21 high-throughput screening estrogen receptor assays

Short-Term Exposure to Foodborne Xenoestrogens Affects Breast Cancer Cell Morphology and Motility Relevant for Metastatic Behavior In Vitro

Breast cancer is highly susceptible to metastasis formation. During the time of disease progression, tumor pathophysiology can be impacted by endogenous factors, like hormonal status, as well as by environmental exposures, such as those related to diet and lifestyle. New lines of evidence point toward a potential role for foodborne endocrine disruptive chemicals in this respect; however, mechanistic understanding remains limited. At the molecular level, crucial steps toward metastasis formation include cell structural changes, alteration of adhesion, and reorganization of cytoskeletal proteins involved in motility. Hence, this study investigates the potential of dietary xenoestrogens to impact selected aspects of breast cancer cell mechanotransduction. Taking the onset of the metastatic cascade as a model, experiments focused on cell-matrix adhesion, single-cell migration, and adaptation of cell morphology. Dietary mycoestrogens alternariol (AOH, 1 μM) and α-zearalenol (α-ZEL, 10 nM), soy isoflavone genistein (GEN, 1 μM), and food packaging plasticizer bisphenol A (BPA, 10 nM) were applied as single compounds or in mixtures. Pursuing the hypothesis that endocrine active molecules could affect cell functions beyond the estrogen receptor-dependent cascade, experiments were performed comparing the MCF-7 cell line to the triple negative breast cancer cells MDA MB-231. Indeed, the four compounds functionally affected the motility and the adhesion of both cell types. These responses were coherent with rearrangements of the actin cytoskeleton and with the modulation of the expression of integrin β1 and cathepsin D. Mechanistically, molecular dynamics simulations confirmed a potential interaction with fragments of the α1 and β1 integrin subunits. In sum, dietary xenoestrogens proved effective in modifying the motility and adhesion of breast cancer cells, as predictive end points for metastatic behavior in vitro. These effects were measurable after short incubation times (1 or 8 h) and contribute to shed novel light on the activity of compounds with hormonal mimicry potential in breast cancer progression.

Association of serum bisphenols, parabens, and triclosan concentrations with Sjögren Syndrome in the Hangzhou, China population

Exposure to endocrine-disrupting chemicals (EDCs) has been linked to various immune deficiency disorders, including autoimmune diseases like Sjögren Syndrome (SjS). However, the detrimental effects of exposure to EDCs, including bisphenols, parabens, and triclosan (TCS), on SjS have been inadequately documented. Thus, we conducted a cross-sectional study that included both healthy individuals (controls) and patients with SjS (cases). We assessed serum concentrations of bisphenol A (BPA), bisphenol S (BPS), methyl parabens (MeP), ethyl parabens (EtP), and TCS. The relationship between the five EDCs levels and the risk of SjS was also explored. Additionally, we conducted an in-depth analysis of the collective influence of these EDCs mixtures on SjS, employing a weighted quantile sum regression model. Out of the five EDCs analyzed, EtP displayed the highest mean concentration (2.80 ng/mL), followed by BPA (2.66 ng/mL) and MeP (1.99 ng/mL), with TCS registering the lowest level (0.36 ng/mL). Notably, BPS exposure was significantly positively associated with the risk of being diagnosed with SjS (with an odds ratio [OR] of 1.17, p = 0.042). No statistically significant associations with SjS were observed for BPA, MeP, EtP, and TCS (p > 0.05). And we did not observe any significant effects of the EDCs mixture on SjS. To the best of our knowledge, this study is the first to suggest that BPS may potentially increase the risk of SjS. Although no significant effects were observed between other EDCs and SjS risk, we cannot disregard the potential harm of EDCs due to their non-monotonic dose response.

Effects of prenatal single and mixed bisphenol exposure on bone mineral density in preschool children: A population-based prospective cohort study

Exposure to bisphenols can affect bone mineral density (BMD) in animals and humans. However, the effects of maternal exposure to bisphenols during pregnancy on bone health in preschool children remain unknown. We aimed to assess the effects of prenatal exposure to single and multiple bisphenols on bone health in preschool children. A total of 230 mother-child pairs were included in this study. Generalized linear regression, restricted cubic spline (RCS), principal component analysis (PCA), and Bayesian kernel machine regression (BKMR) were utilized to assess the relationship between bisphenol levels and bone health in preschool children. Each natural log (Ln) unit increase in tetrabromobisphenol A was related to a 0.007 m/s (95 % CI: -0.015, 0.000) decrease in Ln-transformed speed of sound (SOS) among girls. Decreased BMD Z scores in preschool children were found only in the high bisphenol S exposure group (β = -0.568; 95 % CI: -1.087, -0.050) in boys. The risk of low BMD (BMDL) was significantly higher in the middle-exposure group (OR = 4.695; 95 % CI: 1.143, 24.381) and high-exposure group of BPS (OR = 6.165, 95 % CI: 1.445, 33.789) compared with the low-exposure group in boys. In girls, the risk of BMDL decreased with increasing bisphenol A concentration (OR = 0.413, 95 % CI: 0.215, 0.721). RCS analysis revealed a U-shaped nonlinear correlation between BPB concentration and BMDL in girls (P-overall = 0.011, P-nonlinear = 0.009). In PCA, a U-shaped dose-response relationship was found between PC2 and the risk of BMDL (P-overall = 0.048, P-nonlinear = 0.032), and a significant association was only noted in girls when stratified by sex. The BKMR model revealed a horizontal S-shaped curve relationship between bisphenol mixtures and BMDL in girls. The results indicated that prenatal exposure to single and mixed bisphenols can affect BMD in preschool children, exerting nonmonotonic and child sex-specific effects.