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(-)CD29(H)CD24(H) subpopulation of tumor-initiating cells. Upon subsequent transplantation, this subpopulation generated heterogeneous tumors that displayed properties similar to the primary tumor. Analy...

The branching of complex N-glycans attached to growth factor receptors promotes tumor progression by prolonging growth factor signaling. The addition of the bisecting GlcNAc to complex N-glycans by Mgat3 has varying effects on cell adhesion, cell migration, and hepatoma formation. Here, we show that Chinese hamster ovary cells expressing Mgat3 and the polyoma middle T (PyMT) antigen have reduce...

Although the presence of macrophages in tumors has been correlated with poor prognosis, until now there was no direct observation of how macrophages are involved in hematogenous metastasis. In this study, we use multiphoton microscopy to show, for the first time, that tumor cell intravasation occurs in association with perivascular macrophages in mammary tumors. Furthermore, we show that periva...

High molecular weight DNAs of five tumors induced by mouse mammary tumor virus (MMTV), two mouse mammary tumors induced by a chemical carcinogen, and one human mammary tumor cell line (MCF-7) were assayed for the presence of transmissible activated transforming genes by transfection of NIH 3T3 mouse cells. DNAs of all five MMTV-induced tumors, one chemical carcinogen-induced tumor, and the huma...

Background: Radiotherapy is an effective and important therapeutic method for breast cancer, but at the same time it has a radiation-induced bystander effect on normal tissue around the tumor. Repair of double-strand breaks (DSBs) by normal cells can reduce the extent of damage caused by this effect. Caveolin-1 (Cav-1) is an important regulatory molecule in cell signal transduction. However, th...

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...

Previous studies have demonstrated that normal and malignant mouse mammary cells are indistinguishable in many surface-related properties that often denote transformation of other cell types such as fibroblasts. In the present investigation, the interactions of normal, dysplastic, and malignant mammary epithelial cells with fibronectin in tissues and cultures were examined by indirect immunoflu...

The anticancer activities of beta-carotene, astaxanthin and canthaxanthin against the growth of mammary tumors were studied in female eight-wk-old BALB/c mice. The mice were fed a synthetic diet containing 0, 0.1 or 0.4% beta-carotene, astaxanthin or canthaxanthin. After 3 weeks, all mice were inoculated with 1 x 10(6) WAZ-2T tumor cells into the mammary fat pad. All animals were killed on 45 d...

An 18-year-old female black leopard (Panthera pardus) showed renal failure, leukocytosis and presence of subcutaneous masses in the lower abdominal region and right shoulder; she eventually died. Histopathological observations included a mammary gland carcinoma with comedo, solid and tubulopapillary patterns in subcutaneous tissue, and highly proliferated tumor cells in systemic organs. The tum...

BACKGROUND Conjugated linoleic acid (CLA), a naturally occurring linoleic acid isomer found in ruminant-produced foods, has the potential to serve as an effective chemopreventive nutriceutical factor for breast cancer prevention based upon previous published studies. There are several CLA isomers in ruminant-produced food products, among which t10,c12-CLA and c9,t11-CLA are more potent. Express...