PT - JOURNAL ARTICLE AU - NATASHA EMMANUEL AU - KRISTOPHER A. LOFGREN AU - ESTHER A. PETERSON AU - DAVID R. MEIER AU - ERIC H. JUNG AU - PARAIC A. KENNY TI - Mutant GATA3 Actively Promotes the Growth of Normal and Malignant Mammary Cells AID - 10.21873/anticanres.12745 DP - 2018 Aug 01 TA - Anticancer Research PG - 4435--4441 VI - 38 IP - 8 4099 - http://ar.iiarjournals.org/content/38/8/4435.short 4100 - http://ar.iiarjournals.org/content/38/8/4435.full SO - Anticancer Res2018 Aug 01; 38 AB - Background/Aim: GATA3, a transcription factor expressed in luminal breast epithelial cells, is required for mammary gland development. Heterozygous GATA3 mutations occur in up to 15% of estrogen receptor (ER)-positive breast tumors and have been proposed to be null alleles resulting in haploinsufficiency; however, the mutation spectrum of GATA3 in breast cancer is in sharp contrast to that found in HDR syndrome, a true GATA3 haploinsufficiency disease. Materials and Methods: Transgenic mice, 3D cultures and xenografts were used to examine the effect of mutant GATA3 expression on mammary cell proliferation. Results: Mutant GATA3 accelerated tumor growth of ZR751 cell xenografts and promoted precocious lobuloalveolar development in transgenic mouse mammary glands. Conclusion: GATA3 mutations, recently observed in breast cancer, encode active transcription factors, which elicit proliferative phenotypes in normal mammary epithelium and promote the growth of ER-positive breast cancer cell lines.