Development of risk assessment system for human by environmental disruptants using nuclear hormone receptor

点击翻译按钮获取中文摘要

Endocrine disruptants are thought to have various effects on various organs. Estrogenic responses by endocrine disruptants were analyzed using eukaryotic cells and yeast, which are overexpressing human estrogen receptors. In wildlife, some species such as seagulls contaminated with large amount of environmental pollutants showed thyroid hyperplasia and thyroid tumors. To address the effects on thyroid hormone system by endocrine disruptants, the HeLaTR cells that constitutively overexpressed thyroid hormone receptor were constructed and analyzed. Luciferase activity was induced by the addition of T3 in HeLaTR cells transfected with the plasmid containing thyroid hormone response element as an enhancer. Bisphenol A and 2-diethylhexyl phtalate, both could bind to estrogen receptor, had no effect on the luciferase activity, but hydroxylated PCB repressed the luciferase activity caused by the addition of T3. In contrast, dioxin enhanced the luciferase activity, however dioxin alone caused no effect on the activity. These results suggested that HeLaTR cells could be used as the tool for thyroid hormone action by endocrine disruptants.