GATA-3 is expressed in association with estrogen receptor in breast cancer

✍ Scribed by Renee V. Hoch; Devon A. Thompson; Robin J. Baker; Ronald J. Weigel

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: French
• Weight: 128 KB
• Volume: 84
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/(sici)1097-0215(19990420)84:2<122::aid-ijc5>3.0.co;2-s

✦ Synopsis

To better understand the molecular basis for the hormoneresponsive phenotype in breast cancer, we have used a human cDNA array to compare patterns of gene expression between breast carcinoma cell lines discordant for estrogen receptor (ER) expression. These experiments indicated abundant expression of the transcription factor GATA-3 in the ER-positive cell lines MCF7 and T-47D, with minimal or no expression in the ER-negative cells lines MDA-MB-231 and HBL-100. Northern blot analysis of a panel of human breast carcinoma cell lines demonstrated a correlation between ER and GATA-3 expression. Studies of MCF7 cells grown in the absence or presence ␤-estradiol indicated that GATA-3 expression was not responsive to estradiol. Protein immunoprecipitation and gel shift analysis confirmed the presence of functional GATA-3 protein in MCF7 but not in HBL-100 nuclear extracts. A panel of 47 primary breast cancers was characterized for expression of ER and GATA-3 using immunoperoxidase assay. In primary tumors, a statistically significant correlation between ER and GATA-3 expression was established (p F 0.0001, 2 ). Our results indicate that GATA-3, in association with ER, is likely to regulate genes critical to the hormone-responsive breast cancer phenotype.