BioProject

To investigate the impact of combined Rb and p53 loss in mammary tumorigenesis, we used transgenic and viral approaches to delete Rb and p53 floxed alleles specifically in the mouse mammary epithelium. More...

To investigate the impact of combined Rb and p53 loss in mammary tumorigenesis, we used transgenic and viral approaches to delete Rb and p53 floxed alleles specifically in the mouse mammary epithelium. Although MMTV-Cre (NLST) targets stem/bi-potent progenitors in the mammary gland, a subset of MMTV-Cre:Rbf/f;p53f/f mice developed non-mammary tumors. Thus, freshly isolated primary mammary epithelial cells from these animals were transplanted into the mammary fat pads of immunodeficient mice and monitored for tumor formation. In addition, primary MECs were isolated from Cre-negative Rbf/f;p53f/f mice, infected with Ad-Cre followed by orthotopic transplantation. In all these cases, resulting tumors shared similar spindle-shape histology, expressed high levels of vimentin, a mesenchymal marker, but not E-cadherin, a luminal marker, and were classified as adeno-sacrcomatoid/spindle-cell/mesenchymal-like breast cancer. We used microarrays to detect differentially expressed genes in the Rb/p53 double-knock-out vs p53 single deletion or normal mammary tissue. Overall design: Total RNA was extracted from tumors developed by double Trizol method and hybridized on Affymetrix microarrays Less...