Establishment of screening system of environmental compounds for estrogenicity via WISP-2-induction

由于许多结构多样的化学物质被报道具有雌激素的功能，因此化合物的雌激素性评价受到广泛关注。我们在MCF-7人乳腺癌细胞系中发现了一个新的雌激素诱导基因WISP-2 （Wnt-1诱导信号通路蛋白2）。黄体酮、地塞米松、三碘甲状腺原氨酸和2,3,7,8-四氯二苯并-对二恶英均未调节WISP-2的表达，表明WISP-2的诱导对与雌激素受体相互作用的激素具有高度特异性。Western blot分析发现，17α-雌二醇（E2）诱导的WISP-2蛋白不仅存在于细胞裂解液中，也存在于暴露细胞的培养上清中，表明WISP-2是一种分泌蛋白。E2在培养上清液中诱导WISP-2蛋白呈剂量依赖性，在10 ~ 100 pM之间估计EC_<50>。这些结果证明了通过WISP-2诱导筛选环境化合物的雌激素性的能力。

As many structurally diverse chemicals have been reported to function as estrogens, evaluations for estrogenicity of compounds are of widespread concern. We identified WISP-2 (Wnt-1 inducible signaling pathway protein 2) as a novel estrogen-inducible gene in the MCF-7 human breast cancer cell lines. Progesterone, dexamethasone, tri-iodothyronine, and 2,3,7,8-tetrachlorodibenzo-p-dioxin did not regulate the expression of WISP-2, indicating that its induction is highly specific for hormones that interact with the estrogen receptor. Western blot analysis detected WISP-2 protein induced by 17α-estradiol(E2), not only in the cell lysates but also in the culture supernatant of exposed cells, indicating that WISP-2 was a secreted protein. The induction of WISP-2 protein by E2 in the culture supernatant was dose-dependent with estimated EC_<50> levels between 10 and 100 pM. These results demonstrated the capacity to screen environmental compounds for estrogenicity via WISP-2 induction.