Mammary gland involution represents one of the most dramatic examples of programmed cell death/apoptosis and tissue regression during development, yet large gaps still exist in the understanding of the mechanisms involved, and the key factors that trigger involution, are not yet identified. With the focus on identifying "novel" genes associated with mammary gland regression, we used microarray ...

The cyclooxygenase (COX)-2 gene encodes an inducible prostaglandin synthase enzyme that is overexpressed in adenocarcinomas and other tumors. Deletion of the murine Cox-2 gene in Min mice reduced the incidence of intestinal tumors, suggesting that it is required for tumorigenesis. However, it is not known if overexpression of Cox-2 is sufficient to induce tumorigenic transformation. We have der...

Breast cancer cell lines that express the nuclear peroxisome proliferator-activated receptor (PPAR ) can be prompted to undergo growth arrest and differentiation when treated with synthetic PPAR ligands. To evaluate the therapeutic potential of increased PPAR signaling in vivo, we generated transgenic mice that express a constitutively active form of PPAR in mammary gland. These mice are indist...

Cultured BALB/c mouse mammary gland epithelial cells of varying oncogenic potential in vivo have been examined for their ability to multinucleate in the presence of cytochalasin B (CB). Highly tumorigenic cell lines derived from mammary tumors with hormonal, viral, or chemical carcinogen etiologies were extensively multinucleated when cultured in CB-supplemented medium. Normal mammary gland cel...

To investigate the role of membrane-type matrix metalloproteinase-1 (MT1-MMP) in mammary gland development and tumorigenesis, transgenic mice overexpressing MT1-MMP in mammary gland under the control of the mouse mammary tumor virus long terminal repeat-promoter were generated. The mouse mammary tumor virus/MT1-MMP transgenic mice displayed abnormalities in 82% of female mammary glands. The abn...

Sialomucin complex (SMC, Rat Muc4) is a heterodimeric glycoprotein complex consisting of a mucin subunit ASGP-1 (ascites sialoglycoprotein-1) and a transmembrane subunit ASGP-2, which can act as a ligand for the receptor tyrosine kinase ErbB2. SMC is highly expressed on the surface of ascites 13762 rat mammary adenocarcinoma cells, approximately 100 times the level in lactating mammary gland an...

A comparisonof the transferRNA(tRNA)methyltransferases from rat mammary gland and mammary tumors was carried out to explore possible tumor-specific differences in enzyme activ ity, substrate specificity, and capacity to methylatebacterial tRNA substrates. Enzymes from 9,10-dimethyl-1,2-benzan thracene-induced mammary tumors had specific activities 2to 3-fold higher than those from normal mammar...

Wnt ligand-driven tumor growth is inhibited by the soluble Wnt inhibitor Fzd8CRD, but the mechanism through which this effect is mediated is unknown. In the MMTV-Wnt1 mouse model, regression of mammary tumors by Fzd8CRD treatment coincides with an acute and strong induction of insulin-like growth factor (IGF)-binding protein IGFBP5, an antagonist of IGF signaling that mediates involution of mam...

The Wnt-1 proto-oncogene is transcriptionally activated by mouse mammary tumor virus in mouse mammary tumor virus-induced tumors. Previous studies using transgenic mice showed that Wnt-1 expression in mammary gland causes alveolar hyperplasias which resemble mammary glands of pregnant mice. To understand the role of mammogenic hormones in the genesis of these hyperplasias, we examined the devel...

Correction to: Journal of Mammary Gland Biology and Neoplasia