Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells

Blood ◽  
1994 ◽  
Vol 84 (1) ◽  
pp. 229-237 ◽  
Author(s):  
J Laredo ◽  
A Huynh ◽  
C Muller ◽  
JP Jaffrezou ◽  
JD Bailly ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Population ◽  
Inhibitory Effect ◽  
Blast Cell ◽  
Glycoprotein P ◽  
Viability Assay ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
Efflux Kinetics

Abstract The effect of the protein kinase C (PKC) inhibitor staurosporine (ST) on the chemosensitivity of normal (colony-forming unit granulocyte- macrophage [CFU-GM]) and leukemic (acute myeloid leukemia-CFU [AML- CFU]) myeloid progenitors to daunorubicin (DNR) was evaluated. Primary colony inhibition assays allowed us to characterize two distinct groups of AML, a DNR-resistant group (patients no. 1 through 6), which displayed significantly lower DNR sensitivity than normal CFU-GM (D50 = 11.3 +/- 1.4 ng/mL v 1.8 +/- 0.5 ng/mL, after 7 days of exposure, respectively; P < 0.01) and a DNR-sensitive group (patients no. 7 through 12) with D50 = 2.7 +/- 0.4 ng/mL. This classification remained unaltered when assessed by secondary colony inhibition assay (evaluating the self-renewal fraction of AML-CFU) or by viability assay (evaluating the ultimately differentiated blast cell population), suggesting that the DNR sensitivity profile in maintained throughout AML-CFU differentiation. DNR resistance of the differentiated blast cell population was not correlated with the level of P-glycoprotein (P- gp) expression but rather with the ability to extrude rhodamine 123 (Rh123). ST used at subtoxic concentrations induced a twofold to threefold enhancement of DNR cytotoxicity, increased Rh123 accumulation, and decreased Rh123 efflux kinetics in resistant AML cells. These effects were observed for ST concentrations much lower than those required to displace the P-gp-binding probe azidoprazosin, suggesting that ST might act through its PKC inhibitory effect and not through P-gp binding. Finally, this study provides evidence that DNR resistance in AML cells is, at least in part, related to the multidrug- resistance (MDR) phenotype. Because P-gp function can be downregulated by ST, it seems likely that the MDR pheno-type can be functionally regulated by cellular signalization in AML cells.

scholarly journals Effect of the protein kinase C inhibitor staurosporine on chemosensitivity to daunorubicin of normal and leukemic fresh myeloid cells

Blood ◽  
1994 ◽  
Vol 84 (1) ◽  
pp. 229-237
Author(s):  
J Laredo ◽  
A Huynh ◽  
C Muller ◽  
JP Jaffrezou ◽  
JD Bailly ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cell Population ◽  
Inhibitory Effect ◽  
Blast Cell ◽  
Glycoprotein P ◽  
Viability Assay ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
Efflux Kinetics

The effect of the protein kinase C (PKC) inhibitor staurosporine (ST) on the chemosensitivity of normal (colony-forming unit granulocyte- macrophage [CFU-GM]) and leukemic (acute myeloid leukemia-CFU [AML- CFU]) myeloid progenitors to daunorubicin (DNR) was evaluated. Primary colony inhibition assays allowed us to characterize two distinct groups of AML, a DNR-resistant group (patients no. 1 through 6), which displayed significantly lower DNR sensitivity than normal CFU-GM (D50 = 11.3 +/- 1.4 ng/mL v 1.8 +/- 0.5 ng/mL, after 7 days of exposure, respectively; P < 0.01) and a DNR-sensitive group (patients no. 7 through 12) with D50 = 2.7 +/- 0.4 ng/mL. This classification remained unaltered when assessed by secondary colony inhibition assay (evaluating the self-renewal fraction of AML-CFU) or by viability assay (evaluating the ultimately differentiated blast cell population), suggesting that the DNR sensitivity profile in maintained throughout AML-CFU differentiation. DNR resistance of the differentiated blast cell population was not correlated with the level of P-glycoprotein (P- gp) expression but rather with the ability to extrude rhodamine 123 (Rh123). ST used at subtoxic concentrations induced a twofold to threefold enhancement of DNR cytotoxicity, increased Rh123 accumulation, and decreased Rh123 efflux kinetics in resistant AML cells. These effects were observed for ST concentrations much lower than those required to displace the P-gp-binding probe azidoprazosin, suggesting that ST might act through its PKC inhibitory effect and not through P-gp binding. Finally, this study provides evidence that DNR resistance in AML cells is, at least in part, related to the multidrug- resistance (MDR) phenotype. Because P-gp function can be downregulated by ST, it seems likely that the MDR pheno-type can be functionally regulated by cellular signalization in AML cells.

Localization of IP in rabbit kidney and functional role of the PGI2/IP system in cortical collecting duct

2002 ◽  
Vol 283 (4) ◽  
pp. F689-F698 ◽  
Author(s):  
Rania Nasrallah ◽  
Rolf M. Nusing ◽  
Richard L. Hébert
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Functional Role ◽  
Collecting Duct ◽  
Inhibitory Effect ◽  
Rabbit Kidney ◽  
Cortical Collecting Duct ◽  
Kinase C ◽  
Protein Kinase C Inhibitor

To clarify the role of the PGI2/PGI2 receptor (IP) system in rabbit cortical collecting duct (RCCD), we characterized the expression of IP receptors in the rabbit kidney. We show by Northern and Western blotting that IP mRNA and protein was detectable in all three regions of the kidney. To determine how PGI2 signals, we compared the effects of different PGI2 analogs [iloprost (ILP), carba-prostacyclin (c-PGI2), and cicaprost (CCP)] in the isolated perfused RCCD. PGI2 analogs did not increase water flow ( L p). Although PGI2 analogs did not reduce an established L p response to 8-chlorophenylthio-cAMP, they equipotently inhibited AVP-stimulated L p by 45%. The inhibitory effect of ILP and c-PGI2 on AVP-stimulated L p is partially reversed by the protein kinase C inhibitor staurosporine and abolished by pertussis toxin; no effect was obtained with CCP. In fura 2-loaded RCCD, CCP did not alter cytosolic Ca2+concentration ([Ca2+]i), but, in the presence of CCP, individual infusion of ILP and PGE2 increased [Ca2+]i, suggesting that CCP did not cause desensitization to either ILP or PGE2. We concluded that ILP and c-PGI2 activate PKC and the liberation of [Ca2+]i but not CCP. This suggested an important role for phosphatidylinositol hydrolysis in mediating ILP and c-PGI2 effects but not CCP in RCCD.

Osmotic Modulation of the Ouabain-Sensitive (Na++K+)ATPase from Malpighian Tubules of Rhodnius prolixus

1998 ◽  
Vol 53 (9-10) ◽  
pp. 911-917 ◽  
Author(s):  
C. Caruso-Neves ◽  
J. R. Meyer-Fernandes ◽  
A. G. Lopes
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Atpase Activity ◽  
Malpighian Tubule ◽  
Inhibitory Effect ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Maximal Effect ◽  
Kinase C ◽  
Protein Kinase C Inhibitor

The presence and regulation by hyperosmotic medium of the ouabain-sensitive (Na++K+)ATPase of the Malpighian tubule cells of Rhodnius prolixus was investigated. The ouabain-sensitive (Na++K+)ATPase activity was 5.4 ± 0.5 nmol Pi x mg-1 x min-1. Vanadate 100 μM completely abolished this ATPase activity. In hyperosmotic medium, obtained by addition of 180 mᴍ mannitol, the (Na++K+)ATPase activity was inhibited by 60%. When the cell lysates were preincubated in hyperosmotic medium for 30 minutes and the ATPase activity was assayed in isosmotic medium, the (Na++K+)ATPase activity was not modified. Addition of 50 ng/ml sphingosine, a protein kinase C inhibitor, abolished the inhibition of (Na++K+)ATPase activity in hyperosmotic medium. Furtherm ore, phorbol ester (TPA), an activator of protein kinase C, mimicked the effect of hyperosmotic shock on (Na++K+)ATPase activity. The increase in Ca2+ concentration decreased the (Na++K+)ATPase activity by 60% in isosmotic medium, with maximal effect obtained in 10-6 m Ca2+. No effect was observed in hyperosmotic medium. The inhibitory effect of Ca2+ on the (Na++K+)ATPase was not reversed by sphingosine. These results indicate that the ouabain-sensitive (Na++K+) ATPase activity of the Malpighian tubule is regulated by both increasing Ca2+ concentration and by the osmolality of the medium by different and integrative ways.

scholarly journals Protein Kinase C Inhibitor Generates Stable Human Tolerogenic Dendritic Cells

2013 ◽  
Vol 191 (5) ◽  
pp. 2247-2257 ◽  
Author(s):  
Takuya Matsumoto ◽  
Hitoshi Hasegawa ◽  
Sachiko Onishi ◽  
Jun Ishizaki ◽  
Koichiro Suemori ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Tolerogenic Dendritic Cells ◽  
Protein Kinase C Inhibitor

The protein kinase C inhibitor H-7 activates human neutrophils: effect on shape, actin polymerization, fluid pinocytosis and locomotion

1990 ◽  
Vol 96 (1) ◽  
pp. 99-106
Author(s):  
H.U. Keller ◽  
V. Niggli ◽  
A. Zimmermann ◽  
R. Portmann
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Actin Polymerization ◽  
Kinase Inhibitor ◽  
Human Neutrophils ◽  
Kinase C ◽  
Chemotactic Peptides ◽  
Protein Kinase C Inhibitor ◽  
Shape Changes ◽  
Stimulation Of

The present study demonstrates new properties of H-7. The protein kinase inhibitor H-7 is a potent activator of several neutrophil functions. Stimulation of initially spherical nonmotile neutrophils elicits vigorous shape changes within a few seconds, increases in cytoskeletal actin, altered F-actin distribution, increased adhesiveness and a relatively small increase in pinocytic activity. H-7 has also chemokinetic activities. Depending on the experimental condition, H-7 may elicit or inhibit neutrophil locomotion. It failed to induce chemotaxis. Thus, the response pattern elicited by H-7 is different from that of other leukocyte activators such as chemotactic peptides, PMA or diacylglycerols. The finding that H-7 can elicit shape changes, actin polymerization and pinocytosis suggests that these events can occur without activation of protein kinase C (PKC). PMA-induced shape changes and stimulation of pinocytosis were not inhibited by H-7.

Inhibitory Effect of Barbiturates and Local Anaesthetics on Protein Kinase C Activation

1990 ◽  
Vol 18 (2) ◽  
pp. 153-160 ◽  
Author(s):  
K. Mikawa ◽  
N. Maekawa ◽  
H. Hoshina ◽  
O. Tanaka ◽  
J. Shirakawa ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Local Anaesthetics ◽  
Inhibitory Effect ◽  
Kinase C ◽  
Protein Kinase C Activation
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