Wong Patrick S Y, Matsumura Fumio
Center for Health and the Environment, Department of Environmental Toxicology, The University of California, 129 Old Davis Road, Davis, CA 95616, USA.
Toxicol In Vitro. 2006 Apr;20(3):382-94. doi: 10.1016/j.tiv.2005.08.016. Epub 2005 Oct 19.
Most xenobiotic estrogeniety assay methods rely on direct agonist action on the estrogen receptor (ER) to approximate activation potential. Such methods do have drawbacks since some ER activating pesticides are weak or non-agonistic in ligand-binding assays. This study discusses a method that detects pesticide estrogenic actions regardless of ER ligand binding ability. Using a serum-free BG-1 ovarian cell culture model, we investigated the ability of several organochlorine (OC) pesticides to stimulate known estrogenic actions. We observed concentration dependent ER mediated cell proliferation in BG-1 cells using heptachlor epoxide (HE), beta-hexachlorohexane (beta-HCH), and endosulfan (Endo). In addition, we observed upregulation of the ERE-dependent proteins progesterone receptor and PS2. Gel-shift/EMSA studies for ERE binding further supported these OC's ERE activating abilities. All of these effects were abolished using ICI 164,384(ICI). Using the same culture conditions, we tested the blocking action of growth factor antibodies for erbB2(9G6) and insulin-like growth factor (IGF-Ab) receptors and discovered they inhibited BG-1 proliferation (9G6: HE and beta-HCH/ IGF-Ab: Endo.) This experiment confirms the existence of a possible cross-talk between ER and growth factor receptors in OC ligand-dependent activation and also validates this sensitive method for determining both ligand-dependent and independent estrogenic activity of selected pesticides.
大多数外源性雌激素活性检测方法依靠对雌激素受体（ER）的直接激动剂作用来估算激活潜力。由于一些能激活ER的农药在配体结合试验中表现较弱或无激动作用，这类方法确实存在缺陷。本研究探讨了一种能检测农药雌激素作用的方法，而无需考虑ER配体结合能力。我们使用无血清BG-1卵巢细胞培养模型，研究了几种有机氯（OC）农药刺激已知雌激素作用的能力。我们观察到，使用环氧七氯（HE）、β-六氯环己烷（β-HCH）和硫丹（Endo）时，BG-1细胞中ER介导的细胞增殖呈浓度依赖性。此外，我们观察到雌激素反应元件（ERE）依赖性蛋白孕激素受体和PS2的上调。针对ERE结合的凝胶迁移/电泳迁移率变动分析（EMSA）研究进一步支持了这些OC农药的ERE激活能力。使用ICI 164,384（ICI）可消除所有这些效应。在相同培养条件下，我们测试了生长因子抗体对erbB2（9G6）和胰岛素样生长因子（IGF-Ab）受体的阻断作用，发现它们抑制了BG-1细胞增殖（9G6：针对HE和β-HCH；IGF-Ab：针对Endo）。该实验证实了在OC配体依赖性激活过程中，ER与生长因子受体之间可能存在相互作用，同时也验证了这种灵敏的方法可用于确定所选农药的配体依赖性和非依赖性雌激素活性。
