Expression array of mammary epithelial cells isolated from epithelial Mmp14-targeted mammary glands

Mammary gland branching morphogenesis is thought to relie on the mobilization of the membrane-anchored matrix metalloproteinase, Mmp14/MT1-MMP, to drive mammary epithelial invasion by remodeling the extracellular matrix and triggering associated signaling cascades. However, the roles that this proteinase plays during postnatal mammary gland development in vivo remain undefined. A mammary gland branching program that occurs during the first 4 weeks of postnatal mouse development, in tandem with recently developed Mmp14-floxed mice and MMTV-Cre transgenics that express Cre recombinase throughout the mammary epithelial cell compartment, were used to characterize the impact of deleting epithelial cell Mmp14 on mammary gland morphogenesis. Transcriptome profiling of mammary epithelial cells was used to investigate the functional roles of MT1-MMP in the postnatal mammary epithelial cell compartment in an unbiased fashion Mammary epithelial cells were harvested from the mammary glands of conditional knockout [MMTV-Cre+/Mmp14(f/f)] mice and wild-type [Mmp14(f/f)] littermates on a congenic FVB/NJ background at 4 weeks after birth for RNA extraction and hybridization on Affymetrix microarrays.