乳腺癌中雌激素受体DNA结合功能区的检测及意义

目的：发展检测雌激素受体（ＥＲ）ＤＮＡ结合功能区（ＤＢＤ）的方法，探讨其在内分泌治疗乳腺癌方面的临床意义。方法：根据ＥＲ特异地与雌激素应答元件（ＥＲＥ）汀结合的原理，合成含有ＥＲＥ核心序列的ＤＮＡ片段，经＾３２Ｐ标记后作为探讨。选取经激素结合法测定ＥＲ，ＰＲ（孕激素受体）同时阳性的１９例乳腺癌组织标本，制备乳腺癌组织和细胞株ＭＣＦ－７的蛋白抽提液。应用凝胶滞留法检测ＥＲＥ探针与抽提液中ＥＲ的结合能

Study of estrogen receptor DNA binding domain and its significance in patients with breast cancer

AIM: To develop a method of detecting the effect of estrogen receptor (ER) DNA binding domain (DBD) and to investigate its clinic significance in endocrine therapy for breast cancer. METHODS: In the light of the mechanism that ER can specifically bind to its estrogen response element (ERE), we synthesized the DNA segment containing core sequence of ERE, which was then labeled with 32P]ATP to be used as a probe. Protein extracts were prepared from ERcontaining human breast cancer cell line MCF7 and 19 patients' frozen tissues of tumors which were confirmed both ER (+) and PR (+) by hormonebinding assay. Using gel retardation assay, ERERE complexes were detected, which were used to represent the function of ER DBD. RESULTS: The results of autoradiograph showed that there was a band intensity of ERERE complexes (ERERE+) in the human breast cancer cell line MCF7 while in the colon cancer cells no band intensity of ERERE complexes (ERERE-) was observed. It was also found that when unlabeled ERE into the binding reaction, the band intensity decreased. Our research revealed that in 12 of the 13 cancer cases with ERERE (+) there was no recurrence or metastasis within 3 years and 4 of the 6 cases with ERERE (-) had lung metastasis within 2 years. CONCLUSION: Application of ERE probe can directly evaluate the function of ER DBD the results of which can be used as reliable indexes in clinic endocrine therapy and prognosis estimation.