scholarly journals Different secretory response of pancreatic islets and insulin secreting cell lines INS-1 and INS-1E to osmotic stimuli

2008 ◽  
pp. 935-945
Author(s):  
M Orečná ◽  
R Hafko ◽  
Z Bačová ◽  
J Podskočová ◽  
D Chorvát ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Tumor Cell ◽  
Pancreatic Islets ◽  
Cell Lines ◽  
Insulin Response ◽  
Cell Types ◽  
Secretory Response ◽  
Induced Response ◽  
Tumor Cell Lines ◽  
Hypertonic Medium

Objective of this study was to characterize osmotically-induced insulin secretion in two tumor cell lines. We compared response of freshly isolated rat pancreatic islets and INS-1 and INS-1E tumor cell lines to high glucose, 30 % hypotonic medium and 20 % hypertonic medium. In Ca(2+)-containing medium glucose induced insulin release in all three cell types. Hypotonicity induced insulin secretion from islets and INS-1 cells but not from INS-1E cells, in which secretion was inhibited despite similar increase in cell volume in both cell types. GdCl(3) (100 micromol/l) did not affect insulin response from INS-1E cells to hypotonic challenge. Hypertonic medium inhibited glucose-induced insulin secretion from islets but not from tumor cells. Noradrenaline (1 micromol/l) inhibited glucose-induced but not swelling-induced insulin secretion from INS-1 cells. Surprisingly, perifusion with Ca(2+)-depleted medium showed distinct secretory response of INS-1E cells to hypotonicity while that of INS-1 cells was partially inhibited. Functioning glucose-induced insulin secretion is not sufficient prerequisite for hypotonicity-induced response in INS-1E cells suggesting that swelling-induced exocytosis is not essential step in the mechanism mediating glucose-induced insulin secretion. Both cell lines are resistant to inhibitory effect of hyperosmolarity on glucose-induced insulin secretion. Response of INS-1E cells to hypotonicity is inhibited by the presence of Ca(2+) in medium.

Ethanol and urea affect insulin secretion from islets and insulinoma cells by different mechanisms

Biologia ◽  
2009 ◽  
Vol 64 (5) ◽  
Author(s):  
Roman Hafko ◽  
Martina Orecna ◽  
Zuzana Bacova ◽  
Jana Kirchnerova ◽  
Dušan Chorvat ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Tumor Cell ◽  
Pancreatic Islets ◽  
Tumor Cells ◽  
Insulin Release ◽  
Cell Lines ◽  
Opposite Effect ◽  
Cell Swelling ◽  
Tumor Cell Lines ◽  
Insulinoma Cells

AbstractSecretion of insulin could be stimulated by several ways. Comparison of glucose- and swelling-induced mechanisms in pancreatic islets revealed the involvement of a novel signal transduction pathway with specific features of osmotically stimulated peptide hormone release including Ca2+ independence and resistance to noradrenalin (NA) inhibition. Cell swelling can be induced by hypotonicity or small permeant molecules (e.g. ethanol, urea). Our experiments were aimed to compare the effect of these permeants on insulin secretion from natural system — freshly isolated pancreatic islets and rat insulinoma cell lines INS-1 and INS-1E. As expected glucose and both permeants (80 mM ethanol and urea in isosmotic medium) induced insulin release from islets and NA did not inhibit permeant-induced secretion. Although ethanol and urea induced similar swelling of tumor cells, they produced opposite effect on insulin secretion; while exposure to ethanol led to stimulation of insulin secretion, exposure to urea led to suppression in both types of neoplastic cells. Surprisingly, stimulating effect of ethanol was completely suppressed by NA in both tumor cell lines. Ethanol in hyperosmotic medium failed to stimulate and even inhibited insulin release from both tumor cell lines in present study indicating thus involvement of an osmotic component. In conclusion, the opposite effect of ethanol and urea on insulin secretion from insulinoma cells and sensitivity of ethanol stimulation to NA indicate utilization of different cellular signaling pathways in tumor cells as compared to natural β-cells. Participation of permeant effect in the mechanism of ethanol stimulation remains to be clarified.

scholarly journals Expression of the MyoD1 muscle determination gene defines differentiation capability but not tumorigenicity of human rhabdomyosarcomas.

1989 ◽  
Vol 9 (11) ◽  
pp. 4722-4730 ◽  
Author(s):  
A L Hiti ◽  
E Bogenmann ◽  
F Gonzales ◽  
P A Jones
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Cell Types ◽  
Chain Gene ◽  
Tumor Cell Lines ◽  
Myosin Heavy Chain Gene ◽  
Mouse Muscle ◽  
Primary Explants ◽  
Rhabdomyosarcoma Cell ◽  
Multinucleated Myotubes

Several human rhabdomyosarcoma cell lines, cultured primary tumor explants, and biopsies of tumor and normal skeletal muscle tissue expressed a 2.0-kilobase transcript that hybridized to the mouse muscle determination gene MyoD1. This transcript was found in tumor cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines derived from other mesenchymal tumor cell types. Expression of the human homolog of MyoD1 therefore can define a tumor as a rhabdomyosarcoma. Transfection of the mouse MyoD1 gene into the human rhabdomyosarcoma cell line RD increased the ability of the tumor cells to differentiate into multinucleated myotubes and enhanced myosin heavy-chain gene expression but did not decrease tumorigenicity in nude mice.

scholarly journals Cathepsin B activity in human lung tumor cell lines: ultrastructural localization, pH sensitivity, and inhibitor status at the cellular level.

1994 ◽  
Vol 42 (7) ◽  
pp. 917-929 ◽  
Author(s):  
E Spiess ◽  
A Brüning ◽  
S Gack ◽  
B Ulbricht ◽  
H Spring ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Tumor Cell ◽  
Enzymatic Activity ◽  
Cell Lines ◽  
Cathepsin B ◽  
Lung Tumor ◽  
Cell Types ◽  
Cellular Level ◽  
Tumor Cell Lines

We investigated the appearance and activity of the cysteine proteinase cathepsin B and its physiological inhibitors, stefins A and B, at the cellular level in human tumor cell lines HS-24, derived from a primary lung tumor (squamous cell), and SB-3, derived from a metastasis (lung adenocarcinoma). In addition to cathepsin B, these tumor cells also expressed the immunologically and functionally related cathepsin L, but not cathepsin H. Stefin A was found in HS-24 but not in SB-3 cells; stefin B was found in both cell types. Using a specific fluorogenic cytochemical assay, the intracellular activity of the enzyme was localized and quantified. Thus, the cellular cathepsin B kinetics for the synthetic substrates Z-Arg-Arg-4M beta NA and Z-Val-Lys-Lys-Arg-4M beta NA, its pH dependence and inhibition by E64, stefins A and B, and cystatin C could be determined. From these measurements it appeared that the enzyme exhibited different cleavage rates for these substrates in the different cell types, showed considerable cleavage activity at neutral pH, which was stable under these conditions for extended time periods, and was highly sensitive to the inhibitors E64 and cystatin C but was considerably less sensitive to stefins, particularly stefin A. By conventional light microscopy, confocal laser scanning microscopy, and electron microscopy the enzymatic activity was localized in lysosomes, as expected, but also in the endoplasmic reticulum, nuclear membrane, and plasma membrane. The endoplasmic reticulum is a site at which only pre-mature enzyme forms exist, which are usually not active. The appearance of enzymatic activity at the plasma membrane confirms earlier biochemical and immunofluorescence microscopic investigations. The different sites of localization within the cells make it likely that different forms of the enzyme are expressed simultaneously, which follow alternate ways of processing and sorting. Taken together, the results support an involvement of the enzyme under extracellular conditions in degradative processes.

scholarly journals Mechanism of Ethanol-Induced Insulin Secretion from INS-1 and INS-1E Tumor Cell Lines

2009 ◽  
Vol 24 (5-6) ◽  
pp. 441-450 ◽  
Author(s):  
Roman Hafko ◽  
Martina Orečná ◽  
Zuzana Bačová ◽  
Gabriela Kolláriková ◽  
Igor Lacík ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Tumor Cell ◽  
Cell Lines ◽  
Tumor Cell Lines

scholarly journals Inheritance of gene density–related higher order chromatin arrangements in normal and tumor cell nuclei

2003 ◽  
Vol 162 (5) ◽  
pp. 809-820 ◽  
Author(s):  
Marion Cremer ◽  
Katrin Küpper ◽  
Babett Wagler ◽  
Leah Wizelman ◽  
Johann v. Hase ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Radial Distribution ◽  
Normal Cell ◽  
Cell Types ◽  
Higher Order ◽  
Gene Density ◽  
Tumor Cell Lines ◽  
Cell Nuclei ◽  
Significant Difference

A gene density–related difference in the radial arrangement of chromosome territories (CTs) was previously described for human lymphocyte nuclei with gene-poor CT #18 located toward the nuclear periphery and gene-dense CT #19 in the nuclear interior (Croft, J.A., J.M. Bridger, S. Boyle, P. Perry, P. Teague, and W.A. Bickmore. 1999. J. Cell Biol. 145:1119–1131). Here, we analyzed the radial distribution of chromosome 18 and 19 chromatin in six normal cell types and in eight tumor cell lines, some of them with imbalances and rearrangements of the two chromosomes. Our findings demonstrate that a significant difference in the radial distribution of #18 and #19 chromatin is a common feature of higher order chromatin architecture in both normal and malignant cell types. However, in seven of eight tumor cell lines, the difference was less pronounced compared with normal cell nuclei due to a higher fraction of nuclei showing an inverted CT position, i.e., a CT #18 located more internally than a CT #19. This observation emphasizes a partial loss of radial chromatin order in tumor cell nuclei.

Expression of the MyoD1 muscle determination gene defines differentiation capability but not tumorigenicity of human rhabdomyosarcomas

1989 ◽  
Vol 9 (11) ◽  
pp. 4722-4730
Author(s):  
A L Hiti ◽  
E Bogenmann ◽  
F Gonzales ◽  
P A Jones
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Cell Types ◽  
Chain Gene ◽  
Tumor Cell Lines ◽  
Myosin Heavy Chain Gene ◽  
Mouse Muscle ◽  
Primary Explants ◽  
Rhabdomyosarcoma Cell ◽  
Multinucleated Myotubes

Several human rhabdomyosarcoma cell lines, cultured primary tumor explants, and biopsies of tumor and normal skeletal muscle tissue expressed a 2.0-kilobase transcript that hybridized to the mouse muscle determination gene MyoD1. This transcript was found in tumor cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines and primary explants that developed multinucleated myotubes but was absent in Wilms' tumors or cell lines derived from other mesenchymal tumor cell types. Expression of the human homolog of MyoD1 therefore can define a tumor as a rhabdomyosarcoma. Transfection of the mouse MyoD1 gene into the human rhabdomyosarcoma cell line RD increased the ability of the tumor cells to differentiate into multinucleated myotubes and enhanced myosin heavy-chain gene expression but did not decrease tumorigenicity in nude mice.

Effect of Cellular Cholesterol Changes on Insulin Secretion by Tumor Cell Lines

2012 ◽  
Vol 8 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Bacova Z. ◽  
Hafko R. ◽  
Orecna M. ◽  
Kohut P. ◽  
Hapala I. ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Tumor Cell ◽  
Cell Lines ◽  
Tumor Cell Lines ◽  
Cellular Cholesterol

scholarly journals Interaction of a Cyclin E Fragment with Ku70 Regulates Bax-Mediated Apoptosis

2007 ◽  
Vol 27 (9) ◽  
pp. 3511-3520 ◽  
Author(s):  
Suparna Mazumder ◽  
Dragos Plesca ◽  
Michael Kinter ◽  
Alexandru Almasan
Keyword(s):  
Cell Cycle ◽  
Tumor Cell ◽  
Cell Lines ◽  
Cyclin E ◽  
Critical Role ◽  
Genotoxic Stress ◽  
Cell Types ◽  
Tumor Cell Lines ◽  
Cdk2 Complex ◽  
Apoptotic Effect

ABSTRACT The cyclin E/Cdk2 complex plays an essential role in the G1/S cell cycle transition and DNA replication. Earlier we showed that in hematopoietic tumor cells, caspase-mediated cleavage of cyclin E generates p18-cyclin E, which is unable to interact with Cdk2 and therefore plays a role independent of the cell cycle. The expression of a cleavage-resistant cyclin E mutant greatly diminishes apoptosis, indicating the critical role of cyclin E cleavage. p18-cyclin E expression can induce apoptosis or sensitization to apoptotic stimuli in many cell types. Here we identify Ku70 as a specific p18-cyclin E-interacting partner. In hematopoietic tumor cell lines, the association of p18-cyclin E with Ku70 induces the dissociation of Bax from Ku70, followed by Bax activation. This mechanism of Bax activation leads to the amplification of the apoptosis signal in all tumor cell lines examined. N-terminal Ku70 deletion mutants are unable to bind to p18-cyclin E to regulate its apoptotic effect. p18-cyclin E-mediated amplification of apoptosis is dependent on Bax and Ku70 being greatly diminished in Ku70−/− and Bax−/− mouse embryo fibroblasts and in hematopoietic cells where Bax knockdown was achieved by short interfering RNA. The p18-cyclin E/Ku70 and Bax/Ku70 interactions provide a balance between apoptosis and the survival of cells exposed to genotoxic stress.

Interaction of Human Tumor Cells with Human Platelets and the Coagulation System

1983 ◽  
Vol 50 (03) ◽  
pp. 726-730 ◽  
Author(s):  
Hamid Al-Mondhiry ◽  
Virginia McGarvey ◽  
Kim Leitzel
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Lines ◽  
Human Tumor ◽  
Human Platelets ◽  
Factor Vii ◽  
Coagulation System ◽  
Breast Adenocarcinoma ◽  
Activate Factor ◽  
Tumor Cell Lines

SummaryThis paper reports studies on the interaction between human platelets, the plasma coagulation system, and two human tumor cell lines grown in tissue culture: Melanoma and breast adenocarcinoma. The interaction was monitored through the use of 125I- labelled fibrinogen, which measures both thrombin activity generated by cell-plasma interaction and fibrin/fibrinogen binding to platelets and tumor cells. Each tumor cell line activates both the platelets and the coagulation system simultaneously resulting in the generation of thrombin or thrombin-like activity. The melanoma cells activate the coagulation system through “the extrinsic pathway” with a tissue factor-like effect on factor VII, but the breast tumor seems to activate factor X directly. Both tumor cell lines activate platelets to “make available” a platelet- derived procoagulant material necessary for the conversion of prothrombin to thrombin. The tumor-derived procoagulant activity and the platelet aggregating potential of cells do not seem to be inter-related, and they are not specific to malignant cells.

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