GATA-3
(GATA binding protein 3) is a member of the GATA family of transcription
factors. This 50 kDa nuclear protein regulates the development and subsequent
maintenance of multiple tissues. GATA-3 orchestrates gene expression profiles
during embryogenesis of a variety of human tissues, including hematopoietic
cells, skin, kidney, mammary gland, and the central nervous system. Among
several other roles, GATA-3 has recently been identified as a key player of
luminal cell differentiation in the mammary gland. GATA-3 appears to control a
set of genes involved in the differentiation and proliferation of breast cancer.
The expression of GATA-3 has a strong association with the expression of
estrogen receptor-alpha (ER) in breast cancer, and there is mounting evidence
that GATA-3 can be used as a clinical marker to determine response to hormonal
therapy and to refine the prognosis of breast cancer patients. GATA-3 has also
been shown to be a novel marker for bladder cancer. In one study, GATA-3 stained
67% (grade 3) of 308 urothelial carcinomas, but was negative for all prostate or
renal carcinomas.