RUNX1 encodes a RUNX family transcription factor (TF) and was recently identified as a novel mutated gene in human luminal breast cancers. We found that Runx1 is expressed in all subpopulations of murine mammary epithelial cells (MECs) except the secretory alveolar luminal cells. Conditional knockout of Runx1 in MECs by MMTV-Cre led to a decrease in luminal MECs, largely due to a profound reduc...

PURPOSE Human epidermal growth factor receptor 2 (HER2)-positive luminal B type comprises estrogen receptor (ER)-positive and HER2-positive cancers, and HER2-negative luminal B type comprises ER-positive cancers showing a Ki-67 labeling index ≥14% or progesterone receptor (PR) expression of <20% according to the St. Gallen consensus 2013. The current study aimed to classify intrinsic subtypes a...

The existence of slow-cycling luminal cells in the prostate has been suggested, but their identity and functional properties remain unknown. Using a bigenic mouse model to earmark, isolate, and characterize the quiescent stem-like cells, we identify a label-retaining cell (LRC) population in the luminal cell layer as luminal progenitors. Molecular and biological characterizations show that thes...

Mammary epithelia are composed of luminal and myoepithelial/basal cells whose neoplastic transformations lead to distinct types of breast cancers with diverse clinical features. We report that mice deficient for the CDK4/6 inhibitor p18(Ink4c) spontaneously develop ER-positive luminal tumors at a high penetrance. Ink4c deletion stimulates luminal progenitor cell proliferation at pubertal age an...

An exchange of Na(+) for H(+) has been proposed to explain why jejunal Na(+) absorption is influenced by luminal concentrations of H(+) and HCO(3) (-). We studied the influence of luminal Na(+) concentration on net HCO(3) (-) absorption by perfusing rat jejunum in vivo. When Na(+) was omitted from the perfusion fluid, HCO(3) (-) absorption diminished by a fixed amount over a range of initial HC...

Luminal epithelial cells in the breast gradually alter gene and protein expression with age, appearing to lose lineage-specificity by acquiring myoepithelial-like characteristics. We hypothesize that the luminal lineage is particularly sensitive to microenvironment changes, and age-related microenvironment changes cause altered luminal cell phenotypes. To evaluate the effects of different micro...

  SUMMARY The testes of five wistar rats 2 months after bilateral vasectomy was compared with those of sham­operated controls. Aims were to determine whether there are any changes in the wistar rat testis after vasectomy. Two testis in the vasectomized group displayed histological changes, which consisted of depletion of germ cells, vacuolation in the epithelium, folding of basement membrane ...

The present in vitro microperfusion study examined the effect of luminal angiotensin II on proximal convoluted tubule (PCT) volume absorption and bicarbonate transport. Neither 10-11 M, 10-10 M, nor 2 × 10-8 M luminal angiotensin II significantly affected PCT transport. When tubules were first perfused with enalaprilat to inhibit endogenous angiotensin II production, addition of 10-10 M luminal...