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Yoon SK, Ahn YH, Han K. Enhancement of recombinant erythropoietin production in CHO cells in an incubator without CO(2) addition. Cytotechnology 2008; 37:119-32. [PMID: 19002908 DOI: 10.1023/a:1019905319224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The effect of low levels of carbon dioxide (CO(2)) in the gas phase on the production of recombinant human erythropoietin (EPO)in CHO cells was explored. A T-flask culture in an incubator without CO(2) addition showed a slow cell growth initially followed by the cessation of growth, while other cultures incubated under 0.5-5% CO(2) concentrations grew normally at the same rate during the entire period of cultivation. Interestingly, the production of EPO in the culture incubated under no CO(2) supply was highest among the tested cultures. The cell specific secretion rate of EPO (q(EPO)) of the culture under no CO(2) supply was about 3 times higher than that of the culture under 5% CO(2) supply. Western blot analysis and in vivo bioassay of EPO showed no apparent changes in EPO quality between the two cases of different CO(2) environments (air vs. 5% CO(2)), suggesting robust glycosylation of EPO by CHO cells even under very reduced CO(2) environment. Various combinations of the two extreme cases, with 5% CO(2) supply (suitable for cell growth) and no CO(2) addition (better for EPO production), were made in order to maximize the volumetric productivity of EPO secretion (P(V)) in CHO cells. The P(V) of the cultures programmed with initial incubation under 5% CO(2) followed by no CO(2) supply was about 2 times superior to that of the culture incubated only under no CO(2) supply. The P(V) of the culture under no CO(2) supply was slightly lower than that of culture grown under 5% CO(2). However, the q(EPO) of the no CO(2) supply case was more than 5 times higher than that of the culture under 5% CO(2) supply. In conclusion, we have demonstrated that a simple programming of CO(2) supply to an incubator can enhance the production of EPO in CHO cells remarkably, without any apparent change of the EPO quality.
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Affiliation(s)
- S K Yoon
- Life Science R&D, LG Chemical Investment, Yu Song, Science Town, Daejeon, Korea
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Dutton RL, Scharer J, Moo-Young M. Cell cycle phase dependent productivity of a recombinant Chinese hamster ovary cell line. Cytotechnology 2007; 52:55-69. [PMID: 19002865 DOI: 10.1007/s10616-006-9041-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 12/22/2006] [Indexed: 11/26/2022] Open
Abstract
A Chinese Hamster Ovary cell line, CHO1-15(500), producing recombinant human tissue type plasminogen activator (tPA) via the dihydrofolate reductase (DHFR) amplification system, was studied in batch culture. In this system both DHFR and tPA are under the control of the strong constitutive viral SV40 early promoter. Employing the cumulative viable cell-hour approach, the specific productivity of tPA had maxima in the lag (0.065 pg cell(-1 )h(-1)) and early decline (0.040 pg cell(-1 )h(-1)) population growth phases. The viable population was assigned into four subpopulations (G1, S, G2/M phase, and Apoptotic cells) using flow cytometric analysis. As expected, intracellular DHFR was maximally expressed during the S cell cycle phase. The production of tPA, however, was found to be a direct linear function of the G1 phase, with a subpopulation specific productivity of 0.080 pg c-h(-1). Productivity maxima in the lag and early decline corroborate the flow cytometric data, indicative that this recombinant tPA production occurs primarily in the G1 cell cycle phase, not the S phase. This suggests that endogenous regulatory mechanisms are important controlling influences on the production of recombinant tPA in this ovarian cell line. Productivity from recombinant cell lines cannot be inferred from either the plasmid construct or the host cell alone. Elucidation of the relationship between expression of recombinant protein and the cell cycle phases of the host cell is a major component of the characterization of the animal cell production system. This information facilitates rational process design, including operating mode, modelling and control, and medium formulation.
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Affiliation(s)
- Roshni L Dutton
- BioProcess Assist (BPA) Ltd, 8 Maple Leaf Lane , Aberfoyle, ON, Canada, N1H 6H9,
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Gu MB, Todd P, Kompala DS. Foreign gene expression (?-galactosidase) during the cell cycle phases in recombinant CHO cells. Biotechnol Bioeng 1993; 42:1113-23. [DOI: 10.1002/bit.260420914] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Clowes AW, Clowes MM, Au YP, Reidy MA, Belin D. Smooth muscle cells express urokinase during mitogenesis and tissue-type plasminogen activator during migration in injured rat carotid artery. Circ Res 1990; 67:61-7. [PMID: 2114227 DOI: 10.1161/01.res.67.1.61] [Citation(s) in RCA: 212] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Although the level of plasminogen activator (PA) expression has been correlated with cellular proliferation and migration in vitro, this relation has not been established in tissue undergoing repair. In a rat model of arterial injury, we have measured the expression of PAs by vascular smooth muscle cells (SMCs) during entry into the growth cycle (0-24 hours) and subsequent migration from the media to the intima (starting at approximately 4 days). In normal rat carotid, low levels of urokinase-type PA (uPA) and tissue-type PA (tPA) are present; after removal of the endothelium, only uPA is detected in the media. uPA activity in extracts of carotid arteries increases and reaches a maximum between 16 and 24 hours after injury; uPA mRNA increases steadily and is maximal at 7 days. tPA activity appears at 3 days and is maximal at 7 days; tPA mRNA is present in normal vessels and reaches a maximum by 7 days. Most of the tPA in the media is associated with SMC and not with regenerating endothelium. Furthermore, tPA is present in the media before the SMCs migrate into the intima. These results demonstrate that PA expression by vascular SMCs is differentially regulated, with uPA present during mitogenesis and tPA during migration.
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Affiliation(s)
- A W Clowes
- Department of Surgery, University of Washington, School of Medicine, Seattle 98195
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Abstract
When human diploid fibroblasts were seeded onto the surface of blood clots, lysis of the clot occurred as a result of the release of cellular plasminogen activator. A number of aspects of this lysis were studied. 1. There was no significant difference in rates of lysis of whole blood clots, platelet-rich plasma clots, and platelet-poor plasma clots brought about by the same number of fibroblasts. 2. Clot lysis was promoted by nondividing cells and by proliferating cells. 3. Using cycloheximide to block protein synthesis it was found that the plasminogen activator released by fibroblasts had an active half-life of less than an hour. 4. When clots were washed prior to the addition of cells then lysis occurred at an increased rate. This was probably due to the removal of alpha 2-antiplasmin from the clots, since when antisera to alpha 2-antiplasmin was added to clots, lysis also proceeded at an increased rate. 5. Medium conditioned by fibroblasts did not promote clot lysis even when antiplasmin was removed by washing or by addition of antisera. 6. Cells had to be in direct contact with the clot in order to bring about lysis; when cells were separated from clots by permeable membranes there was no lysis. 7. When cross-linking of fibrin was reduced by the inhibition of transglutaminase, the rate of clot lysis was increased.
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Affiliation(s)
- P Knox
- Department of Biochemistry, St. George's Hospital Medical School, London, U.K
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Pepper MS, Vassalli JD, Montesano R, Orci L. Urokinase-type plasminogen activator is induced in migrating capillary endothelial cells. J Biophys Biochem Cytol 1987; 105:2535-41. [PMID: 3121633 PMCID: PMC2114714 DOI: 10.1083/jcb.105.6.2535] [Citation(s) in RCA: 221] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Cellular migration is an essential component of invasive biological processes, many of which have been correlated with an increase in plasminogen activator production. Endothelial cell migration occurs in vivo during repair of vascular lesions and angiogenesis, and can be induced in vitro by wounding a confluent monolayer of cells. By combining the wounded monolayer model with a substrate overlay technique, we show that cells migrating from the edges of an experimental wound display an increase in urokinase-type plasminogen activator (uPA) activity, and that this activity reverts to background levels upon cessation of movement, when the wound has closed. Our results demonstrate a direct temporal relationship between endothelial cell migration and uPA activity, and suggest that induction of uPA activity is a component of the migratory process.
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Affiliation(s)
- M S Pepper
- Institute of Histology and Embryology, University of Geneva Medical Center, Switzerland
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Crutchley D, Smariga P. Monovalent cation dependence of tissue plasminogen activator synthesis by HeLa cells. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61462-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Grimaldi G, Di Fiore P, Locatelli EK, Falco J, Blasi F. Modulation of urokinase plasminogen activator gene expression during the transition from quiescent to proliferative state in normal mouse cells. EMBO J 1986; 5:855-61. [PMID: 2424752 PMCID: PMC1166874 DOI: 10.1002/j.1460-2075.1986.tb04295.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have investigated the regulation of urokinase (u-PA) mRNA in quiescent mouse fibroblasts and keratinocytes stimulated to divide by the addition of serum or epidermal growth factor (EGF), respectively. Serum stimulation of quiescent fibroblasts (BALB/c 3T3 or Swiss 3T3) results in an early and transient increase of u-PA mRNA level, which precedes by several hours the onset of DNA synthesis. A similar response is elicited by EGF stimulation of quiescent keratinocytes. The increase of u-PA mRNA parallels that of c-myc mRNA, does not require protein synthesis and is at least in part due to increase in template activity of the u-PA gene. Induction of terminal differentiation of mouse keratinocytes results in a decrease of u-PA mRNA which parallels the decrease of thymidine incorporation. In conclusion, variation in the level of u-PA mRNA is seen during G0/G1 transition and correlates with the proliferative state of these normal mouse cells.
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Plasminogen activation and regulation of pericellular proteolysis. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 823:35-65. [PMID: 2413894 DOI: 10.1016/0304-419x(85)90014-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Buckley AR, Putnam CW, Russell DH. In vivo induction of rat hepatic ornithine decarboxylase and plasminogen activator by 12-O-tetradecanoylphorbol 13-acetate. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 841:127-30. [PMID: 4040399 DOI: 10.1016/0304-4165(85)90282-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Rapid and substantial elevations in ornithine decarboxylase and plasminogen activator have been linked to tumor promotion in mouse epidermis and in vitro. Systemic administration of 12-O-tetradecanoylphorbol 13-acetate (TPA) rapidly increased both enzymic activities in rat liver. Pretreatment with either cycloheximide or actinomycin D attenuated both enzyme inductions. It is concluded that: (1) systemic TPA rapidly induces plasminogen activator and ornithine decarboxylase activities in rat liver; and (2) both inductions reflect de novo enzyme synthesis.
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Ogawa K, Miki M, Hirata M, Funahara Y, Kitaguchi H. Plasminogen activator activity of cultured endothelial cells derived from canine coronary vessel and human umbilical artery and vein. Thromb Res 1985; 37:411-22. [PMID: 3922081 DOI: 10.1016/0049-3848(85)90070-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The present study was undertaken to determine which cells participate in plasminogen activator (PA) release from the vascular wall. Canine coronary vessel was confirmed to release PA when various agents were administered in perfusion experiments. Endothelial cells from the coronary vessel were then isolated and cultured for 2 days. PA activity was observed in lysates of the cultured cells, and the medium used for the cultivation was found to contain little PA activity. This suggests that the endothelial cells participate in PA release from the vascular wall. In addition, the PA synthesis was also studied in cultured endothelial cells from human umbilical artery and vein. Both contained little PA activity, indicating that vascular endothelial cells may vary in PA synthesis and release according to the vessel.
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Danø K, Andreasen PA, Grøndahl-Hansen J, Kristensen P, Nielsen LS, Skriver L. Plasminogen activators, tissue degradation, and cancer. Adv Cancer Res 1985; 44:139-266. [PMID: 2930999 DOI: 10.1016/s0065-230x(08)60028-7] [Citation(s) in RCA: 1816] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Bazer FW, Roberts RM. Biochemical aspects of conceptus--endometrial interactions. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1983; 228:373-83. [PMID: 6363610 DOI: 10.1002/jez.1402280220] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Mammalian conceptuses must provide a chemical signal to the maternal system to insure maintenance of corpus luteum (CL) function and of progesterone production and continuation of uterine endometrial secretory activity. These events insure that the developing conceptus is provided with appropriate nutrients, regulatory enzymes and endocrine state to allow successful establishment and maintenance of pregnancy. Pig blastocysts begin to produce estrogens by Day 11 of pregnancy, which prevents secretion of the uterine luteolytic factor (PGF2 alpha) in an endocrine direction, but allows secretion in an exocrine direction, i.e., into the uterine lumen. Therefore, CL are "protected." Blastocyst estrogens also trigger secretion of a group of proteins, including uteroferrin, an iron transport protein, and a family of protease inhibitors whose biosynthesis within the uterine glandular epithelium is under the control of progesterone. Estrogen also appears to promote accumulation of glucose and fructose within the uterine lumen. A complex in vivo "culture medium" is thereby established to promote conceptus development. Pig blastocysts do not undergo invasive implantation within the uterine lumen although they produce the protease, plasminogen activator. Invasion may be prevented by endometrial secretion of progesterone-induced protease inhibitors which are produced in large amounts. In addition to estrogens of conceptus origin, calcium and prostaglandins PGF2 alpha and E2 may affect the uterine vasculature, water and electrolyte transport, capillary permeability, conceptus steroid production, and related events during pregnancy. The blastocysts of the large domestic animals also secrete proteins which include a large glycoprotein (Mr approximately 600,000) and a small acidic protein (Mr approximately 17,000). The latter has been purified from sheep and named ovine trophoblast protein I. These proteins may play unique roles in early pregnancy with respect to establishment and maintenance of pregnancy in the ewe, sow, mare, and cow.
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Ito R, Statland BE. Selected Hemostatic Abnormalities Associated with Neoplastic Disease. Clin Lab Med 1982. [DOI: 10.1016/s0272-2712(18)31032-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Abstract
The distribution of protein and ribonucleic acid (RNA) synthesized by telencephalon slices was determined by radioautography at the light microscope level. Previous studies had shown that, in telencephalon slices, the cells associated with the cerebral microvasculature were synthesizing protein at very high rates compared to other cerebral cells such as neurons. In this study, therefore, particular emphasis was placed on the distribution of newly synthesized protein and RNA among the various cell types of the microvasculature. Rat telencephalon slices were incubated with either [3H] leucine or [3H] uridine for 1 h. The 3H-protein that was found in association with microvessels was present in endothelial cells, pericytes and smooth muscles cells. There was also extensive labeling of cellular processes adjacent to the abluminal side of the basement membrane and extending as far as 15 micrometer from the lumen. The latter processes may have been astrocyte glial projections. All [3H] RNA found associated with microvessels was, however, restricted to endothelial cells and pericytes. This data is discussed in relation to the induction of a 71,000 dalton protein which occurs within minutes of the preparation of tissue slices, and requires the synthesis of new RNA.
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Goldsmith GH, Ziats NP, Robertson AL. Studies on plasminogen activator and other proteases in subcultured human vascular cells. Exp Mol Pathol 1981; 35:257-64. [PMID: 7026274 DOI: 10.1016/0014-4800(81)90065-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Crook RB, Kasagami H, Prusiner SB. Culture and characterization of epithelial cells from bovine choroid plexus. J Neurochem 1981; 37:845-54. [PMID: 6119356 DOI: 10.1111/j.1471-4159.1981.tb04470.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Epithelial cells were isolated from choroid plexus, which plays a major role in cerebrospinal fluid production and regulation. Incubation of bovine choroid plexuses with pronase released cells which attached to plastic dishes with a plating efficiency of 5%. The cells were predominantly polygonal as judged by phase-contrast microscopy. These polygonal cells undergo limited cell division and survive for 1-2 weeks in culture before being overgrown by fibroblasts. The fibroblastic cells could be selectively removed from the cultures but the addition of 100 microgram/ml cis-hydroxyproline to the medium for several days. The specific activities of three membrane-bound enzymes, gamma-glutamyl transpeptidase, alkaline phosphatase, and leucine aminopeptidase were compared in selective cultures of polygonal cells and fibroblasts. Polygonal cells were found to have 4-5 times the gamma-glutamyl transpeptidase of fibroblasts, whereas fibroblasts have 2-3 times the alkaline phosphatase of polygonal cells. Leucine aminopeptidase levels in the two cultures were roughly equivalent. The polygonal cells rapidly lost gamma-glutamyl transpeptidase activity over a 4-day period in culture but acquired increased levels of leucine aminopeptidase. Alkaline phosphatase remained roughly constant. Under similar conditions fibroblasts showed a 3- to 4-fold increase in the specific activities of all three enzymes; these changes coincided with a substantial increase in cell density. Based on morphology, resistance to cis-hydroxyproline, absence of antihemophilic factor antigen, and enzymatic characteristics, we believe the polygonal cells to be of epithelial origin.
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Jaken S, Black PH. Correlation between a specific molecular weight form of plasminogen activator and metabolic activity of 3T3 cells. J Cell Biol 1981; 90:721-6. [PMID: 7197279 PMCID: PMC2111885 DOI: 10.1083/jcb.90.3.721] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
In quiescent cultures of 3T3 cells, plasminogen activator (PA) is found predominantly as a 75,000 dalton species. When quiescent cells are exposed to mitogenic agents such as phorbol myristate acetate, Ca++, or 25% serum, the absolute levels of PA in cell lysates may either increase or decrease. However, a consistent observation is that in the stimulated cultures PA is found predominantly as a 49,000 dalton species. This also is the predominant form of PA in growing and transformed cells. Concomitant with the mitogen-induced stimulation of the 49,000 dalton PA in quiescent cultures is a change in morphology to one that is characteristic of growing and transformed cells. The data suggest that PA is not operative in causing the morphological change that occurs with activation; however, the 49,000 dalton PA in particular is closely related to the pleiotypic response accompanying growth stimulation and transformation.
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Jaken S, Black PH. Regulation of plasminogen activator in 3T3 cells: effect of phorbol myristate acetate on subcellular distribution and molecular weight. J Cell Biol 1981; 90:727-31. [PMID: 7197280 PMCID: PMC2111890 DOI: 10.1083/jcb.90.3.727] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The tumor promoter, phorbol myristate acetate (PMA), stimulates plasminogen activator production and extracellular release in confluent Swiss 3T3 cells. Coordinated with the increased extracellular release is a redistribution of the activity into plasma membrane-enriched fractions and a shift in the predominant molecular weight species from 75,000 to 49,000 daltons. The evidence suggests that PMA induces the formation of the 49,000 dalton species which is preferentially located in plasma membrane-enriched fractions.
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Levin EG, Loskutoff DJ. Serum-mediated suppression of cell-associated plasminogen activator activity in cultured endothelial cells. Cell 1980; 22:701-7. [PMID: 6780198 DOI: 10.1016/0092-8674(80)90546-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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21
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Hince TA, Roscoe JP. Differences in pattern and level of plasminogen activator production between a cloned cell line from an ethylnitrosourea-induced glioma and one from normal adult rat brain. J Cell Physiol 1980; 104:199-207. [PMID: 7190976 DOI: 10.1002/jcp.1041040209] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The production of plasminogen activator (PA) by two cloned cell lines, one from an ethylnitrosourea-induced glioma (A15A5) and the other from normal adult rat brain (ARBO C9), has been investigated. Three assays were used to detect and measure PA in harvest fluids, cells and cell lysates. Similar levels were detected in harvest fluids from both cell lines. However, the cell and lysate assays indicated much higher levels in the tumor line. When actively growing cells were compared A15A5 cells had approximately 16X more fibrinolytic activity than the control cells with a limit of detection in the order of 10(3) cells or 1 microgram protein (cell lysate). In contrast for the control cells PA could only be detected when upwards of 10(4) cells or 5-10 micrograms protein were assayed. Plaminogen activator in as few as 10(3) tumor cells could be detected in the presence of 10(4) non-tumor cells. Plasminogen activator in 26 micrograms protein of A15A5 cell lysate could also be detected in the presence of 44 micrograms protein from ARBO C9 lysates indicating no inhibitory activity in the control cell lysates. Levels of PA in both harvest fluids and cell lysates were determined as cultures progressed through the growth cycle. For cell lysates this showed a build-up of PA in the normal cell line as the cells approached and attained confluence. A much higher level was measured in the tumor cells soon after seeding and maintained to confluence. No differences in growth cycle-associated changes in secreted PA could be determined in harvest fluids: both cell lines showing similar levels at confluence.
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Levin EG, Loskutoff DJ. Comparative studies of the fibrinolytic activity of cultured vascular cells. Thromb Res 1979; 15:869-78. [PMID: 494183 DOI: 10.1016/0049-3848(79)90195-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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