To study the mechanism of 1-integrin function in vivo, we have generated transgenic mouse expressing a dominant negative mutant of 1-integrin under the control of mouse mammary tumor virus (MMTV) promoter (MMTV1-cyto). Mammary glands from MMTV1-cyto transgenic females present significant growth defects during pregnancy and lactation and impaired differentiation of secretory epithelial cells at ...

The whey acidic protein (WAP) is a milk protein that contains a cysteine-rich motif. This characteristic WAP signature has also been found in some protease inhibitors and certain proteins involved in tissue modeling. WAP is specifically synthesized in mammary tissue from late pregnant and lactating animals, and precocious synthesis results in impaired lobuloalveolar development of the gland in ...

In search of the degree of responsiveness of mammary adenocarcinomas to signals of differentiation, mouse mammary tumors were induced to undergo a course of development leading to multiple foci of squamous metaplasia, and subsequently a differentiation manifested by marked keratinization. The mammary tumors had spontaneously arisen in the preneoplastic mammary outgrowths of the transplantable l...

We report a female Crlj:CD1(ICR) mouse with a spontaneous mammary gland tumor composed of biphasic tumor cells, i.e., epithelioid and spindle-shaped myoepithelial cells. Macroscopically, a subcutaneous mass, approximately 3 cm in diameter was found in the lumbodorsal region. Histopathologically, the epithelioid cells proliferated in an alveolar or nest-like growth pattern, occasionally forming ...

Myoepithelial cells are smooth muscle like cells having epithelial origin. They are present in salivary glands, mammary gland, sweat gland and lacrimal gland. Myoepithelial cells are stellate or spindle shaped with 4 to 8 cytoplasmic processes. They play vital role during expulsion of saliva and regulates the electrolytic exchange. They also act as tumor suppressor and are considered very impor...

Fibroblast growth factor-3 (FGF-3) is a crucial developmental regulator. Aberrant activation of this gene by mouse mammary tumor virus insertion results in pregnancy-responsive mammary tumorigenesis. To characterize better FGF-3 function in postnatal mammary gland development and cancer initiation/progression, we used a mifepristone (RU486)-inducible regulatory system to express conditionally F...

Basosquamous carcinoma (BSCC) is a rare malignancy, primarily composed of basal cells with foci of squamous differentiation. It is considered to be histologically an intermediate type between basal cell carcinoma and squamous cell carcinoma, and is known to have aggressive behaviors. BSCC occurred in a 17-year-old female minipin with a history of surgical excision for a mammary tumor. The right...

Breast cancer is the second leading cause of cancer deaths in the United States. At present, the etiology of breast cancer is unknown; however the possibility of a distinct cell of origin, i.e. a cancer stem cell, is a heavily investigated area of research. Influencing signals from the tissue niche are known to affect stem cells. Literature has shown that cancer cells lose their tumorigenic pot...

Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor (MGT), we clarified its distribution and expression level in normal mammary gland, benign MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was observed in the cytoplasm of luminal epith...

Somatostatin receptor 2 (SSTR2) is a negative regulator of cell proliferation in human breast cancer. Since there is little information about SSTR2 in canine mammary gland tumor (MGT), we clarified its distribution and expression level in normal mammary gland, benign MGT and malignant MGT. SSTR2 expression determined by immunohistochemical staining was observed in the cytoplasm of luminal epith...