RNA complexity analyses of total cellular polyadenylate-containing RNA isolated from lactating human breast tissue, human breast tumor tissue, and a mixture of established cell lines of mammary origin demonstrate extensive homology between the tissue RNA populations but suggest a decrease in the complexity of cell line nuclear RNA populations, with the exception of an early-passage MCF-7 cell l...

AbstractEpidermal inclusion cysts are uncommon in the breast, but the consequences can besevere when these cysts occur in the breast parenchyma. Here, we report two suchcases. The patient in case 1 was an 37-year-old woman with a 3-cm palpable mass inthe right breast. Mammography revealed a round and smoothly outlined mass, whichindicated a benign tumor, and sonography showed an irregularly sha...

Mammary stem and progenitor cells are essential for mammary gland homeostasis and are also candidates for cells of origin of mammary tumors. Here, we have investigated the function of the protein kinase p38α in the mammary gland using mice that delete this protein in the luminal epithelial cells. We show that p38α regulates the fate of luminal progenitor cells through modulation of the transcri...

AIMS AND BACKGROUND The microenvironment has a well recognized role in breast cancer progression. Despite different theories, the mechanism of early pregnancy protection in mammary carcinogenesis is unknown. Since pregnancy is responsible for mammary gland differentiation, we tested the hypothesis that differentiated mammary epithelial cells may inhibit breast cancer progression. In other words...

Tumorigenesis is often described as a result of accumulated mutations that lead to growth advantage and clonal expansion of mutated cells. There is evidence in the literature that cancer cells are influenced by the microenvironment. Our previous studies demonstrated that the mouse mammary gland is capable of redirecting mouse cells of non-mammary origins as well as Mouse Mammary Tumor Virus (MM...

The submandibular gland is a rich source of epidermal growth factor (EGF) in mice. The concentration of EGF in the gland of virgin female mice of C3H/HeN strain increased as much as 9-fold from the age of 30 to 52 weeks. During this period, the incidence of mammary tumor in virgin females increased markedly to a maximal level of 62.5% (n = 48) at 52 weeks of age. Removal of the submandibular gl...

A mammary-derived growth inhibitor-related gene (MRG) was previously identified and characterized. MRG induces differentiation of mammary epithelial cells in vitro and its expression is associated with mammary differentiation. To further define the role of MRG on mammary gland differentiation, a MRG transgenic mice model under the control of mouse mammary tumor virus promoter was established an...

Because morphopathological diagnosis of tumors plays a key role in prognosis and therapeutic decisions, the reproducibility and coherence among pathologists is important. To determine the level of inter-observer variation among veterinary pathologists for the diagnosis of canine mammary gland tumors, 15 canine mammary gland tumor slides were coded and evaluated independently by 10 veterinary pa...

Using a syngeneic p53-null mouse mammary gland tumor model that closely mimics human breast cancer, we have identified, by limiting dilution transplantation and in vitro mammosphere assay, a Lin CD29CD24 subpopulation of tumor-initiating cells. Upon subsequent transplantation, this subpopulation generated heterogeneous tumors that displayed properties similar to the primary tumor. Analysis of b...