Laboratory of Microbiology and Host Defenses, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
Environ Toxicol Pharmacol. 2002 Aug;12(1):27-35. doi: 10.1016/s1382-6689(02)00011-x.
A green fluorescent protein (GFP)-reporter vector regulated by an estrogen response element (ERE) was constructed and transfected into human breast carcinoma MCF7 cells. Stable transfectants were selected and their GFP fluorescence intensity was measured using a quantitative fluorescent imaging system. 17β-estradiol (E(2)) and bisphenol A (BPA) induced a dose-dependent increase in GFP intensity in the cells, reaching maximum response at 5×10(-10) and 10(-5) M, respectively. Using this GFP expression system, we examined the estrogenicity of mono-, di-, tri-, and tetra-chlorinated BPAs, which were detected in wastewater from waste-paper recycling plants using sodium hypochlorite as a bleaching agent. 3-ClBPA and 3,3'-diClBPA showed similar estrogenicities, effective at lower concentrations than parent BPA. On the other hand, the maximum activities of BPA and 3,3',5-triClBPA, whose EC(50) were similar, were higher than other chlorinated BPAs. This is the first demonstration of the estrogenicity of chlorinated BPAs. Since polychlorinated BPAs were not easily biodegraded, chlorinated BPAs might be more severe endocrine disruptors than BPA.
构建了受雌激素反应元件（ERE）调控的绿色荧光蛋白（GFP）报告基因载体，并将其转染入人乳腺癌 MCF7 细胞中。选择稳定转染子，并使用定量荧光成像系统测量其 GFP 荧光强度。17β-雌二醇（E（2））和双酚 A（BPA）以剂量依赖的方式诱导细胞中 GFP 强度增加，分别在 5×10（-10）和 10（-5）M 时达到最大反应。使用该 GFP 表达系统，我们检测了单氯、二氯、三氯和四氯 BPA 的雌激素活性，这些物质在使用次氯酸钠作为漂白剂的废纸回收厂废水中被检测到。3-ClBPA 和 3,3'-二氯 BPA 表现出相似的雌激素活性，在较低浓度下比母体 BPA 更有效。另一方面，BPA 和 3,3',5-三氯 BPA 的最大活性与其 EC（50）相似，高于其他氯代 BPA。这是氯代 BPA 具有雌激素活性的首次证明。由于多氯代 BPA 不易生物降解，氯代 BPA 可能比 BPA 更严重的内分泌干扰物。
