Interlaboratory prevalidation of a new in vitro transcriptional activation assay for the screening of (anti-)androgenic activity of chemicals using the UALH-hAR cell line.

We report an interlaboratory evaluation of a recently developed androgen receptor (AR) transactivation assay using the UALH-hAR reporter cell line that stably expresses the luciferase gene under the transcriptional control of androgen receptor elements (AREs) with no glucocorticoid receptor (GR) crosstalk. Herein, a two-step prevalidation study involving three laboratories was conducted to assess performance criteria of the method such as transferability as well as robustness, sensitivity, and specificity. The first step consisted in the validation of the transfer of the cell line to participant laboratories through the testing of three reference chemicals: the AR agonist dihydrotestosterone, the AR antagonist hydroxyflutamide and the glucocorticoid dexamethasone. Secondly, a blinded study was conducted by screening a selection of ten chemicals, including four AR agonists, five AR antagonists, and one non-active chemical. All test compounds yielded the same activity profiles in all laboratories. The logEC50 (agonist assay) or logIC50 (antagonist assay) were in the same range, with intra-laboratory coefficients of variation (CVs) of 0.1-3.4% and interlaboratory CVs of 1-4%, indicating very good within- and between-laboratory reproducibility. Our results were consistent with literature and regulatory data (OECD TG458). Overall, this interlaboratory study demonstrated that the UALH-hAR assay is transferable, produces reliable, accurate and specific (anti)androgenic activity of chemicals, and can be considered for further regulatory validation.

Cosmet'eau-Changes in the personal care product consumption practices: from whistle-blowers to impacts on aquatic environments.

The Cosmet'eau project (2015-2018) investigates the "changes in the personal care product (PCP) consumption practices: from whistle-blowers to impacts on aquatic environments." In this project, the example of PCPs will be used to understand how public health concerns related to micropollutants can be addressed by public authorities-including local authorities, industries, and consumers. The project aims to characterize the possible changes in PCP consumption practices and to evaluate the impact of their implementation on aquatic contamination. Our goals are to study the whistle-blowers, the risk perception of consumers linked with their practices, and the contamination in parabens and their substitutes, triclosan, and triclocarban from wastewater to surface water. The project investigates the following potential solutions: modifications of industrial formulation or changes in consumption practices. The final purpose is to provide policy instruments for local authorities aiming at building effective strategies to fight against micropollutants in receiving waters.

Generation and modulation of hepatocellular carcinoma circulating cells: a new experimental model.

BACKGROUND: To establish a new experimental model of human hepatocellular carcinoma by orthotopic implantation of tumoral cells with its subsequent removal, to generate and modulate circulating tumoral cells. MATERIALS AND METHODS: Three human hepatoma cell lines (HepG2, PLC/PRF, and Mahlavu) were orthotopically implanted under the Glisson's capsule of the left lateral lobe of the liver in a total of 56 non-obese diabetic/severe combined immunodeficiency mice. Tumor removal was performed 30 d after injection, and a laparotomy without tumor removal was done in control mice. Generation of circulating cells was monitored by flow cytometry using fluorescein isothiocyanate-conjugated anti-HLA antibody. RESULTS: In 26 mice implanted with Mahlavu cells, 20 developed a unique tumor allowing a resection (77%), which was technically feasible in 80% of cases. The overall perioperative mortality was 30% (3/10) after resection; no mortality was observed in the control group. The circulating tumoral cells decreased dramatically after resection of the tumor as compared with control mice. CONCLUSION: This new model is feasible and may be an interesting useful tool to study the hepatocellular carcinoma metastatic process and is consistent with the human clinical practice.

Tripterine inhibits the expression of adhesion molecules in activated endothelial cells.

Cell adhesion molecules (CAM) expressed by vascular endothelium in response to cytokine stimulation play a key role in leukocyte adhesion to endothelium during the inflammatory response. Tripterine, a chemical compound of the Chinese plant Tripterygium wilfordii Hook f, displays anti-inflammatory properties in several animal models. However, mechanisms of its action are poorly understood. In the present study, we show that in inflammatory conditions, mimicked by tumor necrosis factor alpha (TNF-alpha) stimulation, pretreatment for 6 h with tripterine at nontoxic concentrations of 20-200 nM inhibits the expression of E-selectin, vascular cell adhesion molecule (CAM)-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells (HUVEC) in a dose-dependent manner. Tripterine (200 nM) almost completely inhibits expression of VCAM-1 [50% inhibitory concentration (IC50) = 52 nM] and ICAM-1 (IC50 = 51 nM) and 73% of E-selectin (IC50 = 94 nM). This inhibition effect is prominent, compared with that of dexamethasone, ibuprofen, methotrexate, or probucol, which revealed a much weaker inhibition at doses as high as 1 mM. Effects on endothelial CAM of other proinflammatory cytokines, such as interleukin-1beta and interferon-gamma, were also inhibited significantly by tripterine. Moreover, significant inhibition was equally observable in postincubation experiments. In addition, tripterine inhibited adhesion of human monocytes and T lymphocytes to TNF-alpha-stimulated HUVEC. Finally, tripterine inhibited TNF-alpha-driven CAM mRNA transcription and nuclear factor-kappaB nuclear (NF-kappaB) translocation. Hence, we describe a new mechanism of tripterine's anti-inflammatory action obtained at nanomolar concentrations, owing to the negative regulation of cytokine-induced adhesion molecule expression and adhesiveness in human endothelium.