Relationship between the results of in vitro receptor binding assay to human estrogen receptor α and in vivo uterotrophic assay: Comparative study with 65 selected chemicals

Evaluation of the in vitro estrogenicity of emerging bisphenol analogs and their respective estrogenic contributions in municipal sewage sludge in China

“…These characteristics of BPA have been attributed to the effects on steroid hormone receptors such as ER (Matsushima et al, 2010). Okada et al (2008) reported that BPAF bound more strongly to ERa than BPA, and that it could cause adverse reproductive and developmental effects in several different in vivo and in vitro models (Akahori et al, 2008;Bermudez et al, 2010). TBBPA showed a weak estrogenic response in cultured MCF-7 breast cancer cells (Olsen et al, 2003), and inhibited in vitro estradiol sulfonation (Hamers et al, 2004), indicating the potential for both direct and indirect estrogenic activity in vivo.…”

Courage for simplification and imperfection in the 21st century assessment of “Endocrine disruption”

“…However, this high concordance was achieved only when a cut-off RBA limit for the detection of estrogenic/anti-estrogenic and androgenic/anti-androgenic responses was introduced. A recently published part of the latter study (Akahori et al, 2008) comparing the estrogenic/anti-estrogenic response of 65 chemicals in the recombinant hERα binding and the in vivo rat uterotrophic assay, also demonstrated 82% concordance, 14% false negatives and 23% false-positives. However, using all data for the hERα binding and the uterotrophic response without employing the cut-off RBA = 0.00233%, i.e., the lowest eR binding potency that elicits estrogenic/anti-estrogenic activity in the uterotrophic assay, resulted in a much reduced concordance of 66%, as well as false-negative and false-positive rates of 14% and 57%, respectively.…”

“…A subsequent, more critical analysis of the available data via meta analysis (as exemplified via the CAMARADeS (Collaborative Approach to Meta-analysis and Review of Animal Data in experimental Studies)) would allow determination of whether or not the reported findings were interpreted correctly (Sena et al, 2010). For some, but certainly not a sufficient number, of the endpoints, in silico (Bovee et al, 2008;Breen et al, 2010;Rusyn and Daston, 2010) and in vitro methods have been developed (Akahori et al, 2008;Freyberger et al, 2010a;Witters et al, 2010) and, in some cases, already validated under the auspices of the OeCD, eCVAM or the USePA/ICCVAM. However, as often cited, the validation of these assays, e.g., within the OeCD, is taking too long (up to 10 years) (Judson et al, 2009).…”

NTP Research Report on Biological Activity of Bisphenol A (BPA) Structural Analogues and Functional Alternatives

“…In brief, analogues were prioritized for inclusion in the systematic review based on (1) detection in the environment (e.g., dust, water, sewage), foodstuff, or human biological samples; (2) identification by the US EPA Design for the Environment (DfE) program as being a potential alternative to BPA in thermal paper (henceforth referred to as the "US EPA DfE report") 140 ; (3) use as a halogenated flame retardant; and (4) considered of emerging interest, i.e. relatively datapoor and not the focus of many previous or on-going hazard or risk evaluations.…”