mRNA Expression Comparison Between Igfbp7-null and wild type mice at Lactation Day 3
Insulin like growth factor binding protein 7, Igfbp7, is a secreted protein that in addition to modulating insulin and insulin-like growth factor signaling, it acts as a tumor suppressor gene in breast and other cancers. To elucidate the role of Igfbp7 in regulating the proliferation and differentiation of mammary epithelial cells, we examined the growth and differentiation of mammary gland through different stages of its development in Igfbp7-null mice. Using transcriptome profiling in addition to functional assays we demonstrate that loss of Igfbp7 leads to diminished luminal cell differentiation and  expansion of the luminal progenitors. These studies identify the endocrine factor Igfbp7, as a key regulator of luminal progenitor functions in the mammary gland. Overall design: Mammary gland mRNA profiles of lactation day 3  wild type (WT) and Igfbp7-/- (KO) mice were generated by deep sequencing using SOLiD5500xl