Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myoepithelial and secretory cells from the mammary gland of the lactating rat have been isolated, purified, and characterized. Mammary tissue was dissociated with collagenase into basket-like networks of myoepithelial cells and single secretory cells. Because of their larger size, the myoepithelial cell networks could be separated from other mammary and blood cells by differential centrifugation. Isolated secretory cells were purified by isopycnic centrifugation in 25% bovine serum albumin. The purified myoepithelial and secretory cells were viable, as shown by the incorporation of 32P into distinct macromolecules that were separable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both myoepithelial and secretory cells retained their characteristic morphology after isolation and purification, as shown by light, transmission, and scanning electron microscopies. The isolated myoepithelial cells were unique and, thus, distinguishable from other mammary cells in a number of respects; they 1) contracted in response to the addition of oxytocin, 2) bound [3H]oxytocin specifically, 3) accounted for the content of alkaline phosphatase and [Na+ + K+]ATPase in mammary tissue, and 4) reacted specifically with antiserum prepared against purified myoepithelial cells. The purified secretory cells were unique in possessing glucose-6-phosphate dehydrogenase activity. The different cell markers not only gave independent estimates of the purity of the cell fractions, but they also may be helpful in identifying mammary cells in stages of differentiation and neoplastic transformation.
 ...
PMID:Purification and characterization of mammary myoepithelial and secretory cells from the lactating rat. 624 56

Several strategies have been described for the primary culture of human myometrial cells. However, primary cultures of myometrial cells have a limited life span, making continual tissue acquisition and cell isolation necessary. Recent studies have demonstrated that cell culture life span is related to chromosomal telomere length, and cellular senescence results from progressive telomere shortening and the lack of telomerase expression. Transfection of cells with expression vectors containing the human telomerase reverse transcriptase (hTERT) maintains telomere length and effectively gives normal cells an unlimited life span in culture. In addition, hTERT extends the life span of cultured cells far beyond normal senescence without causing neoplastic transformation. In the present study, we developed a cell line from hTERT-infected myometrial cells (hTERT-HM). Cells were isolated from myometrial tissue obtained from women undergoing hysterectomy, and retroviral infection was used to express the catalytic subunit of telomerase in myometrial cells. Cells expressing hTERT have been in continuous culture for >10 mo, whereas the control culture senesced after approximately 2 mo. Telomerase activity was monitored in cells with a polymerase chain reaction-based telomerase activity assay. Telomerase-expressing cells contained mRNA for alpha smooth muscle actin, smoothelin, oxytocin receptor, and estrogen receptor alpha, but the estrogen receptor beta receptor was lost. Immunoblotting analysis identified the expression of calponin, caldesmon, alpha smooth muscle actin, and oxytocin receptor. Although estrogen receptor expression was below the level of detection with immunoblotting, transfection experiments performed with reporter constructs driven by estrogen response elements demonstrated estrogen responsiveness in the hTERT-HM. In addition, treatment of hTERT-HM with oxytocin caused a concentration-dependent increase in intracellular calcium levels, confirming the presence of functional oxytocin receptors. Myometrial cells immortalized with hTERT retained markers of differentiation that are observed in primary cultures of smooth muscle cells. The expression of various smooth muscle/myometrium cell markers suggests that these cells may be an appropriate model system to study certain aspects of human myometrial function.
 ...
PMID:Telomerase immortalization of human myometrial cells. 1213 89

Membrane-bound peptidases play a key role in the control of growth, differentiation, and signal transduction of many cellular systems by degrading bioactive peptides. Thus, abnormal changes in their expression pattern and catalytic function result in altered peptide activation, which contributes to neoplastic transformation or progression. In this review, we describe our recent findings along with work from other groups on the expression and biological functions of membrane-bound peptidases in cancer, focusing on the regulatory roles of three peptidases, aminopeptidase A (APA), neutral endopeptidase (NEP) and placental leucine aminopeptidase (P-LAP), in the progression of gynecologic malignancies. APA, NEP and P-LAP are differentially expressed and localized in various gynecologic malignancies including cervical cancer, endometrial cancer, ovarian cancer and choriocarcinoma in a tumor-type specific pattern. The expression levels are up- or down-regulated depending on histological grade or disease progression. These peptidases play regulatory roles in tumor cell proliferation, invasion or angiogenesis via degradation/inactivation of target peptides such as angiotensin II, endothelin-1 and oxytocin, which act on cancer cells as stimulatory or inhibitory factors. Thus, membrane-bound peptidases may become not only a new diagnostic/prognostic marker, but also a novel molecular target for the treatment of gynecologic malignancies.
 ...
PMID:Regulatory role of membrane-bound peptidases in the progression of gynecologic malignancies. 1544 4