Dysregulation of gap junction intercellular communication (GJIC) is recognized as one of the key hallmarks for identifying non-genotoxic carcinogens (NGTxC). Currently, there is a demand for in vitro assays addressing the gap junction hallmark, which would have the potential to eventually become an integral part of an integrated approach to the testing and assessment (IATA) of NGTxC. The scrape loading-dye transfer (SL-DT) technique is a simple assay for the functional evaluation of GJIC in various in vitro cultured mammalian cells and represents an interesting candidate assay. Out of the various techniques for evaluating GJIC, the SL-DT assay has been used frequently to assess the effects of various chemicals on GJIC in toxicological and tumor promotion research. In this review, we systematically searched the existing literature to gather papers assessing GJIC using the SL-DT assay in a rat liver epithelial cell line, WB-F344, after treating with chemicals, especially environmental and food toxicants, drugs, reproductive-, cardio- and neuro-toxicants and chemical tumor promoters. We discuss findings derived from the SL-DT assay with the known knowledge about the tumor-promoting activity and carcinogenicity of the assessed chemicals to evaluate the predictive capacity of the SL-DT assay in terms of its sensitivity, specificity and accuracy for identifying carcinogens. These data represent important information with respect to the applicability of the SL-DT assay for the testing of NGTxC within the IATA framework.

• Klíčová slova
• carcinogenesis, carcinogens, gap junction intercellular communication, scrape loading-dye transfer,
• MeSH
• barvicí látky metabolismus   MeSH
• biotest metody   MeSH
• buněčné linie MeSH
• fluorescenční mikroskopie metody   MeSH
• játra patologie   MeSH
• karcinogeny MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• mezerový spoj metabolismus   MeSH
• mezibuněčná komunikace účinky léků   fyziologie   MeSH
• testy karcinogenity metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• barvicí látky MeSH
• karcinogeny MeSH

The relative potencies of non-ortho-substituted coplanar polychlorinated biphenyl (PCB) congeners to activate the aryl hydrocarbon receptor (AhR) and to cause the AhR-dependent toxic events are essential for their risk assessment. Since some studies suggested that abundant non-dioxin-like PCB congeners (NDL-PCBs) may alter the AhR activation by PCB mixtures and possibly cause non-additive effects, we evaluated potential suppressive effects of NDL-PCBs on AhR activation, using a series of 24 highly purified NDL-PCBs. We investigated their impact on the model AhR agonist-induced luciferase reporter gene expression in rat hepatoma cells and on induction of CYP1A1/1B1 mRNAs and deregulation of AhR-dependent cell proliferation in rat liver epithelial cells. PCBs 128, 138, and 170 significantly suppressed AhR activation (with IC50 values from 1.4 to 5.6 μM), followed by PCBs 28, 47, 52, and 180; additionally, PCBs 122, 153, and 168 showed low but still significant potency to reduce luciferase activity. Detection of CYP1A1 mRNA levels in liver epithelial cells largely confirmed these results for the most abundant NDL-PCBs, whereas the other AhR-dependent events (CYP1B1 mRNA expression, induction of cell proliferation in confluent cells) were less sensitive to NDL-PCBs, thus indicating a more complex regulation of these endpoints. The present data suggest that some NDL-PCBs could modulate overall dioxin-like effects in complex mixtures.

• Klíčová slova
• Aryl hydrocarbon receptor, Cytochrome P450, DR-CALUX® assay, Disruption of contact inhibition, NDL-PCBs, Relative effect potency,
• MeSH
• buněčné linie MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• epitelové buňky cytologie   účinky léků   metabolismus   MeSH
• exprese genu účinky léků   MeSH
• hepatocyty cytologie   účinky léků   metabolismus   MeSH
• játra účinky léků   metabolismus   MeSH
• krysa rodu Rattus MeSH
• polychlorované bifenyly chemie   toxicita   MeSH
• proliferace buněk účinky léků   MeSH
• receptory aromatických uhlovodíků genetika   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytochrom P-450 CYP1A1 MeSH
• polychlorované bifenyly MeSH
• receptory aromatických uhlovodíků MeSH