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1.
Keith G. Danielson Janice E. Knepper Frances S. Kittrell Janet S. Butel Daniel Medina Elisa M. Durban 《In vitro cellular & developmental biology. Plant》1989,25(6):535-543
Summary Clonal populations were isolated from the mouse mammary cell line, COMMA-D, by transfection with a dominant-selectable gene,
pSV2Neo, which confers resistance to the antibiotic, G418. Seven of twenty-four clones isolated retained the ability of the
parental line to repopulate cleared mammary fat pads in vivo as ductal-alveolar hyperplasias. Two sublines designated CDNR2
and CDNR4 retained hyperplastic growth potential after multiple passages in vitro with low incidence of tumor formation. A
third subpopulation, CDNR1, contained a single integration site for the pSV2Neo plasmid indicating a bonafide clonal origin
for this subline. CDNR1 cells displayed heterogeneous growth phenotypes in vivo including hyperplasia, adenocarcinoma, and
bone formation. Functional differentiation of CDNR1 cells organized as alveolarlike structures in vivo or on floating collagen
gels in vitro was observed as determined by immunoperoxidase staining for the milk-specific protein, casein. Overall, the
results indicate that a subset of cells from the COMMA-D cell line may be functionally analogous to stem cells existing in
the mammary gland.
Supported by NCI research grants CA-38650, CA-33369, CA-39017, and CA-25215. 相似文献
2.
3.
Partial amino acid sequence of rat topoisomerase I: comparison with the predicted sequences for the human and yeast enzymes 总被引:1,自引:0,他引:1
The partial amino acid sequence of rat topoisomerase I was determined by gas-phase microsequencing. Seven tryptic peptides closely matched the sequences deduced from human topoisomerase I cDNA (94.5% homology). Similarity to sequences deduced from baker's yeast and fission yeast genomic DNA were restricted to conserved domains which may represent important sites of interaction with DNA or with other proteins. 相似文献
4.
Mouse submandibular salivary epithelial cell growth and differentiation in long-term culture: Influence of the extracellular matrix 总被引:7,自引:0,他引:7
Elisa M. Durban 《In vitro cellular & developmental biology. Plant》1990,26(1):33-43
Summary The adult mouse submandibular salivary gland provides a good model system to study gene regulation during normal and abnormal
cell behavior because it synthesizes functionally distinct products ranging from growth factors and digestive enzymes to factors
of relevance to homeostatic mechanisms. The present study describes the long-term growth and differentiation of submandibular
salivary epithelial cells from adult male mice as a function of the culture substratum. Using a two-step partial dissociation
procedure, it was possible to enrich for ductal cells of the granular convoluted tubules, the site of epidermal growth factor
synthesis. Long-term cell growth over a period of 2 to 3 mo. with at least 3 serial passages was obtained only within three-dimensional
collagen gels. Cells grew as ductal-type structures, many of which generated lumens with time in culture. Electron microscopic
analysis in reference to the submandibular gland in vivo revealed enrichment for and maintenance of morphologic features of
granular convoluted tubule cells. Reactivity with a keratin-specific monoclonal antibody established the epithelial nature
of the cells that grew within collagen. Maintenance of cell differentiation, using immunoreactivity for epidermal growth factor
as criterion, was determined by both cytochemical and biochemical approaches and was found to be dependent on the collagen
matrix and hormones. Greater than 50% of the cells in primary collagen cultures contained epidermal growth factor only in
the presence of testosterone and triiodothyronine. In contrast, cells initially seeded on plastic or cycled to plastic from
collagen gels were virtually negative for epidermal growth factor. Biochemical analysis confirmed the presence of a protein
with an apparent molecular weight of 6000 which comigrated with purified mouse epidermal growth factor. Epidermal growth factor
was also present in detectable levels in Passage 1 cells. This culture system should permit assessment of whether modulation
of submandibular gland ductal cell growth can be exerted via a mechanism that in itself includes epidermal growth factor and
its receptor and signal transduction pathway.
This work was supported by Public Health Service grant DE07766 from the National Institute of Dental Research, National Institutes
of Health, Bethesda, MD. 相似文献
5.
Basolateral plasma membrane localization of ouabain-sensitive sodium transport sites in the secretory epithelium of the avian salt gland 下载免费PDF全文
The distribution of Na+ pump sites (Na+-K+-ATPase) in the secretory epithelium of the avian salt gland was demonstrated by freeze-dry autoradiographic analysis of [(3)H] ouabain binding sites. Kinetic studies indicated that near saturation of tissue binding sites occurred when slices of salt glands from salt-stressed ducks were exposed to 2.2 μM ouabain (containing 5 μCi/ml [(3)H]ouabain) for 90 min. Washing with label-free Ringer's solution for 90 min extracted only 10% of the inhibitor, an amount which corresponded to ouabain present in the tissue spaces labeled by [(14)C]insulin. Increasing the KCl concentration of the incubation medium reduced the rate of ouabain binding but not the maximal amount bound. In contrast to the low level of ouabain binding to salt glands of ducks maintained on a freshwater regimen, exposure to a salt water diet led to a more than threefold increase in binding within 9-11 days. This increase paralleled the similar increment in Na+-K+-ATPase activity described previously. [(3)H]ouabain binding sites were localized autoradiographically to the folded basolateral plasma membrane of the principal secretory cells. The luminal surfaces of these cells were unlabeled. Mitotically active peripheral cells were also unlabeled. The cell-specific pattern of [(3)H]ouabain binding to principal secretory cells and the membrane-specific localization of binding sites to the nonluminal surfaces of these cells were identical to the distribution of Na+-K+-ATPase as reflected by the cytochemical localization of ouabain-sensitive and K+-dependent nitrophenyl phosphatase activity. The relationship between the nonluminal localization of Na+-K+-ATPase and the possible role of the enzyme n NaCl secretion is considered in the light of physiological data on electrolyte transport in salt glands and other secretory epithelia. 相似文献
6.
Intercellular communication in the rat anterior pituitary gland: an in vivo and in vitro study 总被引:3,自引:1,他引:2 下载免费PDF全文
The concept of "stimulus-secretion coupling" suggested by Douglas and co-workers to explain the events related to monamine discharge by the adrenal medulla (5, 7) may be applied to other endocrine tissues, such as adrenal cortex (36), pancreatic islets (4), and magnocellular hypothalamic neurons (6), which exhibit a similar ion-dependent process of hormone elaboration. In addition, they share another feature, that of joining neighbor cells via membrane junctions (12, 26, and Fletcher, unpublished observation). Given this, and the reports that hormone secretion by the pars distalis also involves a secretagogue-induced decrease in membrane bioelectric potential accompanied by a rise in cellular [Ca++] (27, 34, 41), it was appropriate to test the possibility that cells of the anterior pituitary gland are united by junctions. 相似文献
7.
G L Gianfranceschi E Cardellini G Piccinini M Bramucci A Miano E Maccari D Amici E Durban 《Physiological chemistry and physics and medical NMR》1989,21(4):289-294
Minimum substrate requirements for nuclear NII kinase (casein II kinase) were analyzed with synthetic peptides modeled according to amino acid composition of phosphopeptides isolated from chromatin. Uncharged blocked peptide termini decreased the requirement for acidic clusters neighboring the phosphate acceptor amino acid (serine) such that only one group immediately N-terminal to serine was sufficient for kinase activity. Studies on peptide interaction with DNA showed that the model phosphopeptides bound to DNA only in the phosphorylated form suggesting involvement of phosphorylation in protein-DNA interactions yet to be identified. 相似文献
8.
Tyler JW Robinson Melody Pai Jeff C Liu Frederick Vizeacoumar Thomas Sun Sean E Egan Alessandro Datti Jing Huang Eldad Zacksenhaus 《Cell cycle (Georgetown, Tex.)》2013,12(18):3013-3024
Triple-negative breast cancer (TNBC) represents an aggressive subtype, for which radiation and chemotherapy are the only options. Here we describe the identification of disulfiram, an FDA-approved drug used to treat alcoholism, as well as the related compound thiram, as the most potent growth inhibitors following high-throughput screens of 3185 compounds against multiple TNBC cell lines. The average IC50 for disulfiram was ~300 nM. Drug affinity responsive target stability (DARTS) analysis identified IQ motif-containing factors IQGAP1 and MYH9 as direct binding targets of disulfiram. Indeed, knockdown of these factors reduced, though did not completely abolish, cell growth. Combination treatment with 4 different drugs commonly used to treat TNBC revealed that disulfiram synergizes most effectively with doxorubicin to inhibit cell growth of TNBC cells. Disulfiram and doxorubicin cooperated to induce cell death as well as cellular senescence, and targeted the ESA+/CD24-/low/CD44+ cancer stem cell population. Our results suggest that disulfiram may be repurposed to treat TNBC in combination with doxorubicin. 相似文献
9.
Trevor W. Joyce John W. Durban Diane E. Claridge Charlotte A. Dunn Leigh S. Hickmott Holly Fearnbach Karin Dolan David Moretti 《Marine Mammal Science》2020,36(1):29-46
The vulnerability of beaked whales (Family: Ziphiidae) to intense sound exposure has led to interest in their behavioral responses to mid-frequency active sonar (MFAS, 3–8 kHz). Here we present satellite-transmitting tag movement and dive behavior records from Blainville's beaked whales (Mesoplodon densirostris) tagged in advance of naval sonar exercises at the Atlantic Undersea Test and Evaluation Center (AUTEC) in the Bahamas. This represents one of the largest samples of beaked whales individually tracked during sonar operations (n = 7). The majority of individuals (five of seven) were displaced 28–68 km after the onset of sonar exposure and returned to the AUTEC range 2–4 days after exercises ended. Modeled sound pressure received levels were available during the tracking of four individuals and three of those individuals showed declines from initial maxima of 145–172 dB re 1 μPa to maxima of 70–150 dB re 1 μPa following displacements. Dive behavior data from tags showed a continuation of deep diving activity consistent with foraging during MFAS exposure periods, but also suggested reductions in time spent on deep dives during initial exposure periods. These data provide new insights into behavioral responses to MFAS and have important implications for modeling the population consequences of disturbance. 相似文献
10.
Robert L. Pitman John W. Durban Trevor Joyce Holly Fearnbach Simone Panigada Giancarlo Lauriano 《Marine Mammal Science》2020,36(2):565-594
Long-distance migration in whales has historically been described as an annual, round-trip movement between high-latitude, summer feeding grounds, and low-latitude, winter breeding areas, but there is no consensus about why whales travel to the tropics to breed. Between January 2009 and February 2016, we satellite-tagged 62 antarctic killer whales (Orcinus orca) of four different ecotypes, of which at least three made short-term (6–8 weeks), long-distance (maximum 11,000 km, round trip), essentially nonstop, migrations to warm waters (SST 20°C–24°C), and back. We previously suggested that antarctic killer whales could conserve body heat in subfreezing (to −1.9°C) waters by reducing blood flow to their skin, but that this might preclude normal (i.e., continuous) epidermal molt, and necessitate periodic trips to warm waters for routine skin maintenance (“skin molt migration,” SMM). In contrast to the century-old “feeding/breeding” migration paradigm, but consistent with a “feeding/molting” hypothesis, the current study provides additional evidence that deferred skin molt could be the main driver of long-distance migration for antarctic killer whales. Furthermore, we argue that for all whales that forage in polar latitudes and migrate to tropical waters, SMM might also allow them to exploit rich prey resources in a physiologically challenging environment and maintain healthy skin. 相似文献