Multiple observations suggest a cell type-specific role for TP53 in mammary epithelia. We developed an in vitro assay, in which primary mouse mammary epithelial cells (mMECs) progressed from lumenal to basal-like phenotypes based on expression of Krt18 or ΔNp63, respectively. Such transition was markedly delayed in Trp53(-/-) mMECs suggesting that Trp53 is required for specification of the basa...

Stem cells appear to retain labeled DNA for extended periods because of their selective segregation of template DNA strands during mitosis. In this study, proliferating cells in the prepubertal bovine mammary gland were labeled using five daily injections of 5-bromo-2-deoxyuridine (BrdU). Five weeks later, BrdU-labeled mammary epithelial cells were still evident. The percentage of BrdU-labeled ...

Abstract Introduction: Bovine leukemia virus (BLV) causes enzootic bovine leukemia, andis closely related to human T-lymphotropic virus type 1. It expresses microRNAs of unknown function and codes Tax, the protein that mediates malignant transformation. BLV is capable of infecting B- and T-lymphocytes, endothelial cells, and mammary epithelial cells of cattle. Several studies demonstrated the ...

Abstract Introduction: Bovine leukemia virus (BLV) causes enzootic bovine leukemia, andis closely related to human T-lymphotropic virus type 1. It expresses microRNAs of unknown function and codes Tax, the protein that mediates malignant transformation. BLV is capable of infecting B- and T-lymphocytes, endothelial cells, and mammary epithelial cells of cattle. Several studies demonstrated the ...

Mouse mammary tumors grow preferentially upon transplantation into intact mammary glands compared to cleared mammary fat-pads. Both sites provide stroma of the orthotopic site, but the latter lacks epithelial elements. If epithelium from enzymatically dissociated normal mammary glands is added to the tumor cells prior to injection into cleared fat-pads, tumor growth is comparable to that seen i...

Exposure to estrogen has long been associated with an increased risk of developing breast cancer. However, how estrogen signaling promotes breast carcinogenesis remains elusive. Senescence is known as an important protective response to oncogenic events. We aimed to elucidate the role of estrogen receptor alpha (ERα) on senescence in transformed human mammary epithelial cells and breast cancer ...

Spontaneous mammary tumours frequently appear in women, dogs, cats and rodents. Their origin is known only in mice, where the mouse mammary tumour virus (MMTV) gives rise to them. Sexual hormones are involved in the development of mammary tumours; in women, oestrogen is important and most studied whereas progesterone is more important in the dog, where spaying at early age prevents mammary tumo...

The objectives of this study were to determine the effects of ovariectomy and growth hormone on mammary epithelial cell proliferation and estrogen receptor α (ERα) expression within the bovine mammary gland. Two experiments were performed. In the first experiment, eight Holstein heifer calves aged between 1 and 3 mo were ovariectomized, while six calves served as controls. At 6 mo of age, calve...

Recent studies in dairy cows have demonstrated that serotonergic ligands affect milk yield and composition. Correspondingly, serotonin (5-HT) has been demonstrated to be an important local regulator of lactational homeostasis and involution in mouse and human mammary cells. We determined the mRNA expression of bovine 5-HT receptor (HTR) subtypes in bovine mammary tissue (BMT) and used pharmacol...