Molnar L A, Dhirani N, Tran K, McBlain W A
Department of Medicine, University of Alberta, Edmonton, Canada.
Clin Chem. 1989 May;35(5):824-8.
Accurate quantification of estrogen receptor (ER) is essential for optimal clinical characterization of individual cases of breast cancer. If breast tumors are mishandled, the relatively labile ER protein may lose its steroid-binding capacity (become inactivated) and not be measurable by the routine steroid-binding assay. We tested whether the commercial enzyme immunoassay of Abbott Laboratories could quantify inactivated ER. Samples of powdered breast tumors from humans were exposed to various temperature and homogenization conditions known to inactivate ER, and any remaining ER was quantified by both the immunoassay and the steroid-binding assay. For all inactivation conditions tested, the two assay methods detected the same proportions of remaining ER. We conclude that the inactivation reaction for ER also alters one or both of the antigenic site(s) necessary for the immunoassay. Hence, for breast tumors mishandled to the extent of inactivating ER, the immunoassay offers no advantage over the more conventional steroid-binding assay for quantifying any remaining ER.
准确量化雌激素受体（ER）对于乳腺癌个体病例的最佳临床特征描述至关重要。如果乳腺肿瘤处理不当，相对不稳定的ER蛋白可能会失去其类固醇结合能力（失活），并且无法通过常规类固醇结合测定法进行测量。我们测试了雅培实验室的商业酶免疫测定法是否能够量化失活的ER。将来自人类的乳腺肿瘤粉末样本暴露于已知会使ER失活的各种温度和匀浆条件下，并用免疫测定法和类固醇结合测定法对任何剩余的ER进行量化。对于所有测试的失活条件，两种测定方法检测到的剩余ER比例相同。我们得出结论，ER的失活反应也会改变免疫测定所需的一个或两个抗原位点。因此，对于因处理不当而导致ER失活的乳腺肿瘤，在量化任何剩余的ER方面，免疫测定法相对于更传统的类固醇结合测定法没有优势。
