The CCAAT/enhancer binding proteins (C/EBPs) are differentially expressed throughout mammary gland development and interact with binding sites within the promoter of a milk protein gene, beta-casein. The specific roles of C/EBPbeta and C/EBPalpha in mouse mammary gland development and differentiation have been investigated in mice that carry targeted deletions of these genes. C/EBPbeta-/- virgi...

AIM AND METHODS The recent discovery of a new isoform of estrogen receptor (ER), ER beta, has promoted the investigation of its expression on mammary gland. This study was carried out to examine the expression of ER alpha, ER beta and proliferating cell nuclear antigen (PCNA) in the carcinogen-induced mammary tumors induced by N-methyl-N-nitrosourea (MNU) or 7,12-dimethylbenz[a]anthracene (DMBA...

The acquisition of immortalization is an early and carefully documented event in mouse mammary tumorigenesis. Activation of telomerase activity is one hypothesis to explain the acquisition of immortalization. We examined the activity of telomerase in well-defined immortalized, non-tumor cell populations of mouse mammary tissue in vivo. The results indicated that normal virgin and mid-pregnant m...

The Hedgehog pathway is vital for the development of many epidermal appendages, but its role in mammary development has been unclear. Here, we show that although Gli2 and Gli3 are expressed during embryonic mammary development, transcriptional reporters of positive Hedgehog signaling are absent. Nevertheless, Gli3(xt/xt) embryos show aberrant early mammary marker expression and lack two pairs o...

Zinc is essential for cell proliferation. Several human studies have shown that in breast cancer tissues, zinc concentration expressed on a per tissue weight basis is higher than that in normal breast tissues. However, the mechanisms involved are unknown. N-methyl-N-nitrosourea (MNU)-induced rat mammary tumorigenesis is one of the most widely used rodent mammary tumorigenesis models for studyin...

Four cows received thyroxine injections (T4; 20 mg/d) and three cows received growth hormone injections (GH, 44 mg/d) for 4 d during successive 16-d experimental periods. Milk fat, lactose output, mammary uptake of glucose, oxygen and milk fat precursors were determined with each treatment. Injection of T4 increased lactose yield by 25% and fat yield 42%. The injection of GH increased fat and l...

Insertional mutation of the Int3 gene, a member of the Notch gene family, is frequently associated with primary mouse mammary tumors induced by the mouse mammary tumor virus (MMTV). A major consequence of these mutations is the production of a shortened 2.4-kb tumor specific Int3 RNA transcript that encodes the entire intracellular domain of the Int3 protein. Previous studies have demonstrated ...

background: hyperprolactinemia is a common side effect of antipsychotic drugs that requires further investigation. the current study was designed to evaluate dose-dependent effect of chlorpromazine (cpz) on hormonal changes and uterine horn histological structure in rats. moreover, the mammary glands were analyzed to show hyperprolactinemia-induced histological changes. methods: albino wistar r...

Parathyroid hormone-related protein (PTHrP) regulates cell fate and specifies the mammary mesenchyme during embryonic development. Loss of PTHrP or its receptor (Pthr1) abolishes the expression of mammary mesenchyme markers and allows mammary bud cells to revert to an epidermal fate. By contrast, overexpression of PTHrP in basal keratinocytes induces inappropriate differentiation of the ventral...

OBJECTIVE Previous work has suggested that white adipocytes may also show a mammary luminal secretory cell phenotype during lactation. The capacity of brown and beige/brite adipocytes to display a mammary cell phenotype and the levels at which they demonstrate such phenotypes in vivo is currently unknown. METHODS To investigate the putative adipocyte origin of mammary gland cells, we performe...