Expression profiling of MMTV-PyMT tumors retrovirally over-expressing GATA-3

ABSTRACT: The primary cause of mortality in breast cancer is metastasis, a process which is still poorly understood. To study the process of breast cancer metastasis, we isolated focal hyperplasias from the MMTV-PyMT transgenic breast cancer model and transplanted to syngeneic hosts. The transplants underwent stereotyped progression to adenoma, early carcinoma, and late carcinoma at 5, 8 and 18 weeks post-transplant, respectively. We compared the gene expression profiles of adenomas and late carcinomas by microarray. Analysis of the data revealed that the most differentially expressed gene family between adenomas and late carcinomas were luminal differentiation genes, among them GATA-3. Adenomas were uniformly immunopositive for GATA-3, whereas early carcinomas displayed partial loss of GATA-3. Disseminated tumour cells and 18-week late carcinomas were invariably GATA-3 negative. We found that re-introduction of GATA-3 in late carcinomas induced markers of luminal differentiation and inhibited tumour dissemination to distant sites. Keywords: spotted oligonucleotide Full length GATA-3 was cloned into the PMIG retroviral vector, which contains an IRES-GFP cassette. Primary cultures of non-fluorescent MMTV-PyMT carcinomas were infected with the GATA-3 and control retroviruses and transplanted back into the cleared mammary fat pads of wild-type mice. After six weeks of growths, tumors were isolated and total RNA harvested by the Trizol method. Total RNA from GATA-3 infected tumor outgrowths were compared to empty vector infected tumor outgrowths.

ORGANISM(S): Mus musculus

SUBMITTER: Hosein Kouros-Mehr 

PROVIDER: E-GEOD-5223 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress