GATA3 in Breast Cancer: Tumor Suppressor or Oncogene?

GATA3 is a highly conserved, essential transcription factor expressed in a number of tissues, including the mammary gland. GATA3 expression is required for normal development of the mammary gland where it is estimated to be the most abundant transcription factor in luminal epithelial cells. In breast cancer, GATA3 expression is highly correlated with the luminal transcriptional program. Recent genomic analysis of human breast cancers has revealed high-frequency mutation in GATA3 in luminal tumors, suggesting "driver" function(s). Here we discuss mutation of GATA3 in breast cancer and the potential mechanism(s) by which mutation may lead to a growth advantage in cancer.