Characterization of normal human embryo cells grown to over 100 population doublings

In Vitro ◽  
1978 ◽  
Vol 14 (5) ◽  
pp. 405-412 ◽  
Author(s):  
J. A. Poiley ◽  
R. F. Schuman ◽  
R. J. Pienta
Keyword(s):  
Human Embryo ◽  
Embryo Cells ◽  
Normal Human ◽  
Population Doublings

Cyclic Dipeptides with 1-Aminocyclopropane-1-carboxylic Acid

1997 ◽  
Vol 62 (6) ◽  
pp. 941-947 ◽  
Author(s):  
Evžen Kasafírek ◽  
Jaroslav Moural ◽  
Jarmila Vinšová ◽  
Antonín Šturc ◽  
Jan Taimr
Keyword(s):  
Carboxylic Acid ◽  
Human Embryo ◽  
Antiproliferative Activity ◽  
Leukemia Cells ◽  
Cyclic Dipeptides ◽  
Embryo Cells ◽  
Normal Human

Cyclic dipeptides of the formula cyclo(-Acc-X-), where Acc = 1-aminocyclopropane-1-carboxylic acid, X = Gly, Ala, Val, Leu, Phe or Tyr, were synthesized. The prepared 2,5-piperazinediones showed no proliferative or antiproliferative activity on normal human embryo cells as well as on HL60 leukemia cells. Results of trace memory assays in mice were negative.

Hypoxia Relieves X-Ray-Induced Delayed Effects in Normal Human Embryo Cells

2000 ◽  
Vol 154 (6) ◽  
pp. 659-666 ◽  
Author(s):  
Kanaklata Roy ◽  
Seiji Kodama ◽  
Keiji Suzuki ◽  
Kazuaki Fukase ◽  
Masami Watanabe
Keyword(s):  
Human Embryo ◽  
X Ray ◽  
Delayed Effects ◽  
Embryo Cells ◽  
Normal Human

Dose-Dependent Biphasic Accumulation of TP53 Protein in Normal Human Embryo Cells after X Irradiation

2000 ◽  
Vol 153 (3) ◽  
pp. 305-311 ◽  
Author(s):  
Jagadish C. Ghosh ◽  
Yuko Izumida ◽  
Keiji Suzuki ◽  
Seiji Kodama ◽  
Masami Watanabe
Keyword(s):  
Human Embryo ◽  
Embryo Cells ◽  
X Irradiation ◽  
Normal Human ◽  
Dose Dependent ◽  
Tp53 Protein

hTERT alone immortalizes epithelial cells of renal proximal tubules without changing their functional characteristics

2008 ◽  
Vol 295 (5) ◽  
pp. F1365-F1375 ◽  
Author(s):  
Matthias Wieser ◽  
Guido Stadler ◽  
Paul Jennings ◽  
Berthold Streubel ◽  
Walter Pfaller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Biology ◽  
Replicative Senescence ◽  
Ectopic Expression ◽  
Immortalized Cells ◽  
Normal Human ◽  
Population Doublings ◽  
Camp Induction ◽  
Renal Origin

Telomere-dependent replicative senescence is one of the mechanisms that limit the number of population doublings of normal human cells. By overexpression of telomerase, cells of various origins have been successfully immortalized without changing the phenotype. While a limited number of telomerase-immortalized cells of epithelial origin are available, none of renal origin has been reported so far. Here we have established simple and safe conditions that allow serial passaging of renal proximal tubule epithelial cells (RPTECs) until entry into telomere-dependent replicative senescence. As reported for other cells, senescence of RPTECs is characterized by arrest in G1 phase, shortened telomeres, staining for senescence-associated β-galactosidase, and accumulation of γ-H2AX foci. Furthermore, ectopic expression of the catalytic subunit of telomerase (TERT) was sufficient to immortalize these cells. Characterization of immortalized RPTEC/TERT1 cells shows characteristic morphological and functional properties like formation of tight junctions and domes, expression of aminopeptidase N, cAMP induction by parathyroid hormone, sodium-dependent phosphate uptake, and the megalin/cubilin transport system. No genomic instability within up to 90 population doublings has been observed. Therefore, these cells are proposed as a valuable model system not only for cell biology but also for toxicology, drug screening, biogerontology, as well as tissue engineering approaches.

Purification and characterization of the yeast-expressed erythropoietin mutant Epo (R103A), a specific inhibitor of human primary hematopoietic cell erythropoiesis

Blood ◽  
2002 ◽  
Vol 99 (12) ◽  
pp. 4400-4405 ◽  
Author(s):  
Suzanne Burns ◽  
Murat O. Arcasoy ◽  
Li Li ◽  
Elizabeth Kurian ◽  
Katri Selander ◽  
...  
Keyword(s):  
Animal Models ◽  
Specific Inhibitor ◽  
Competitive Inhibitor ◽  
Erythropoietin Receptor ◽  
Single Amino Acid ◽  
Human Cd34 ◽  
Unit Formation ◽  
Dependent Cell ◽  
Normal Human

A drug that specifically inhibits erythropoiesis would be clinically useful. The erythropoietin (Epo) mutant Epo (R103A) could potentially be used for this purpose. Epo (R103A) has a single amino acid substitution of alanine for arginine at position 103. Because of this mutation, Epo (R103A) is only able to bind to one of the 2 subunits of the erythropoietin receptor (EpoR) homodimer and is thus a competitive inhibitor of Epo activity. To produce large quantities of Epo (R103A) to test in animal models of thalassemia and sickle cell disease, we expressed and purified recombinant Epo (R103A) from the yeast Pichia pastoris. Using this method milligram quantities of highly purified Epo (R103A) are obtained. The yeast-expressed Epo (R103A) is properly processed and glycosylated and specifically inhibits Epo-dependent cell growth and125I-Epo binding. Epo (R103A) does not, however, directly induce apoptosis in 32D cells expressing EpoR. Epo (R103A) inhibits erythropoiesis of human CD34+ hematopoietic cells and completely blocks erythroid burst-forming unit formation in normal human bone marrow colony assays. Yeast-expressed Epo (R103A) is a specific inhibitor of primary erythropoiesis suitable for testing in animal models.

Architectural and Immunohistochemical Characterization of Biliary Ductules in Normal Human Liver

2009 ◽  
Vol 18 (10) ◽  
pp. 1417-1422 ◽  
Author(s):  
Katalin Dezső ◽  
Sándor Paku ◽  
Veronika Papp ◽  
Eszter Turányi ◽  
Peter Nagy
Keyword(s):  
Human Liver ◽  
Normal Human Liver ◽  
Normal Human

scholarly journals Characterization of an activated human ros gene.

1986 ◽  
Vol 6 (9) ◽  
pp. 3109-3116 ◽  
Author(s):  
C Birchmeier ◽  
D Birnbaum ◽  
G Waitches ◽  
O Fasano ◽  
M Wigler
Keyword(s):  
Gene Transfer ◽  
Protein Kinases ◽  
Transmembrane Domain ◽  
Extracellular Domain ◽  
Kinase Domain ◽  
Specific Protein ◽  
Normal Human

A human oncogene, mcf3, previously detected by a combination of DNA-mediated gene transfer and a tumorigenicity assay, derives from a human homology of the avian v-ros oncogene. Both v-ros and mcf3 can encode a protein with homology to tyrosine-specific protein kinases, and both mcf3 and v-ros encode a potential transmembrane domain N terminal to the kinase domain. mcf3 probably arose during gene transfer from a normal human ros gene by the loss of a putative extracellular domain. There do not appear to be any other gross rearrangements in the structure of mcf3.

Transformation of hamster embryo cells by chymotrypsin-treated and untreated polyoma virus: characterization of transformants

1985 ◽  
Vol 31 (4) ◽  
pp. 356-360
Author(s):  
Vera Chlumecky ◽  
Donald C. Stranks ◽  
John S. Colter
Keyword(s):  
Common Species ◽  
Soft Agar ◽  
T Antigen ◽  
Polyoma Virus ◽  
Large T Antigen ◽  
T Antigens ◽  
Hamster Embryo Cells ◽  
Embryo Cells

The ability of chymotrypsin-treated (chymo+) and untreated (chymo−) polyoma virus to transform cultured hamster embryo fibroblasts was examined. The data show that exposure to this protease reduces the ability of the virus to transform non-permissive cells to essentially the same extent as it reduces its ability to replicate in permissive cells. Twenty-five lines of transformed cells were established from colonies growing in soft agar, and after 20 in vitro passages, cells of all lines were characterized with respect to their ability to form colonies in soft agar and their tumorigenicity in hamsters. While the studies showed that there are striking differences among the lines with respect to colony-forming ability, and real, though less striking differences in tumorigenicity, they failed to reveal any obvious differences between the groups of cell lines transformed by chymo− and chymo+ polyoma virus. Of 13 lines examined, all were found to express both middle and small polyoma T antigens, none express significant levels of large T antigen, and 11 express some form of what is probably a truncated large T antigen, the most common species having a molecular weight of 67 000.

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