Inhibition of c-kit receptor tyrosine kinase activity by STI 571, a selective tyrosine kinase inhibitor

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 925-932 ◽  
Author(s):  
Michael C. Heinrich ◽  
Diana J. Griffith ◽  
Brian J. Druker ◽  
Cecily L. Wait ◽  
Kristen A. Ott ◽  
...  

STI 571 (formerly known as CGP 57148B) is a known inhibitor of the c-abl, bcr-abl, and platelet-derived growth-factor receptor (PDGFR) tyrosine kinases. This compound is being evaluated in clinical trials for the treatment of chronic myelogenous leukemia. We sought to extend the activity profile of STI 571 by testing its ability to inhibit the tyrosine kinase activity of c-kit, a receptor structurally similar to PDGFR. We treated a c-kit expressing a human myeloid leukemia cell line, M-07e, with STI 571 before stimulation with Steel factor (SLF). STI 571 inhibited c-kit autophosphorylation, activation of mitogen-activated protein (MAP) kinase, and activation of Akt without altering total protein levels of c-kit, MAP kinase, or Akt. The concentration that produced 50% inhibition for these effects was approximately 100 nmol/L. STI 571 also significantly decreased SLF-dependent growth of M-07e cells in a dose-dependent manner and blocked the antiapoptotic activity of SLF. In contrast, the compound had no effect on MAP kinase activation or cellular proliferation in response to granulocyte-macrophage colony-stimulating factor. We also tested the activity of STI 571 in a human mast cell leukemia cell line (HMC-1), which has an activated mutant form of c-kit. STI 571 had a more potent inhibitory effect on the kinase activity of this mutant receptor than it did on ligand-dependent activation of the wild-type receptor. These findings show that STI 571 selectively inhibits c-kit tyrosine kinase activity and downstream activation of target proteins involved in cellular proliferation and survival. This compound may be useful in treating cancers associated with increased c-kit kinase activity.

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 925-932 ◽  
Author(s):  
Michael C. Heinrich ◽  
Diana J. Griffith ◽  
Brian J. Druker ◽  
Cecily L. Wait ◽  
Kristen A. Ott ◽  
...  

Abstract STI 571 (formerly known as CGP 57148B) is a known inhibitor of the c-abl, bcr-abl, and platelet-derived growth-factor receptor (PDGFR) tyrosine kinases. This compound is being evaluated in clinical trials for the treatment of chronic myelogenous leukemia. We sought to extend the activity profile of STI 571 by testing its ability to inhibit the tyrosine kinase activity of c-kit, a receptor structurally similar to PDGFR. We treated a c-kit expressing a human myeloid leukemia cell line, M-07e, with STI 571 before stimulation with Steel factor (SLF). STI 571 inhibited c-kit autophosphorylation, activation of mitogen-activated protein (MAP) kinase, and activation of Akt without altering total protein levels of c-kit, MAP kinase, or Akt. The concentration that produced 50% inhibition for these effects was approximately 100 nmol/L. STI 571 also significantly decreased SLF-dependent growth of M-07e cells in a dose-dependent manner and blocked the antiapoptotic activity of SLF. In contrast, the compound had no effect on MAP kinase activation or cellular proliferation in response to granulocyte-macrophage colony-stimulating factor. We also tested the activity of STI 571 in a human mast cell leukemia cell line (HMC-1), which has an activated mutant form of c-kit. STI 571 had a more potent inhibitory effect on the kinase activity of this mutant receptor than it did on ligand-dependent activation of the wild-type receptor. These findings show that STI 571 selectively inhibits c-kit tyrosine kinase activity and downstream activation of target proteins involved in cellular proliferation and survival. This compound may be useful in treating cancers associated with increased c-kit kinase activity.


1985 ◽  
Vol 5 (1) ◽  
pp. 204-213 ◽  
Author(s):  
R L Davis ◽  
J B Konopka ◽  
O N Witte

The v-abl protein of Abelson murine leukemia virus is a tyrosine-specific kinase. Its normal cellular homolog, murine c-abl, does not possess detectable tyrosine kinase activity in vitro. Previously, we have detected tyrosine kinase activity in vitro for an altered c-abl gene product (c-abl P210) in the K562 human chronic myelogenous leukemia cell line. The expression of this variant c-abl gene product correlates with chromosomal translocation and amplification of the c-abl gene in K562 cells. Like v-abl, c-abl P210 is a fusion protein containing non-abl sequences near the amino terminus of c-abl. We compared the in vitro tyrosine kinase activity of c-abl P210 with that of wild-type murine v-abl. The remarkable similarities of these two proteins with respect to cis-acting autophosphorylation, trans-acting phosphorylation of exogenous substrates, and kinase inhibition, using site-directed abl-specific antisera, suggested that c-abl P210 could function similarly to v-abl in vivo. In addition, c-abl P210 possessed an associated serine kinase activity in immunoprecipitates. The serine kinase activity was not inhibited by site-directed, abl-specific antisera that inhibit the tyrosine kinase activity, suggesting that the serine kinase activity is not an intrinsic property of c-abl P210. Thus, the activation of the c-abl gene in a human leukemia cell line may have functional consequences analogous to activation of the c-abl gene in Abelson murine leukemia virus.


Blood ◽  
2002 ◽  
Vol 99 (11) ◽  
pp. 4122-4130 ◽  
Author(s):  
Jason A. Wertheim ◽  
Kevin Forsythe ◽  
Brian J. Druker ◽  
Daniel Hammer ◽  
David Boettiger ◽  
...  

The t(9;22) chromosomal translocation results in expression of P210BCR-ABL, a fusion protein necessary for the development of chronic myelogenous leukemia (CML). The constitutive activation of the P210BCR-ABL tyrosine kinase results in phosphorylation of multiple signaling pathways leading to the transformed phenotype. Additionally, extracellular interactions between P210BCR-ABL–expressing progenitor cells and bone marrow stroma may provide external signals that facilitate CML development. In contrast to the intracellular signaling pathways involved in CML, little is known about how P210BCR-ABLexpression modifies cell-cell and cell-substratum interactions. To investigate the role of P210BCR-ABL in modulating cellular adhesion, we used a highly sensitive and quantitative cell detachment apparatus that measures the strength of association between a population of cells and an adhesive matrix. Our findings show that P210BCR-ABL expression increased adhesion nearly 2-fold between the myeloblastic cell line, 32D, and fibronectin compared to a control vector. We then investigated whether abnormal adhesion due to P210BCR-ABL expression was caused by its tyrosine kinase activity. A quantitative analysis of cell-fibronectin adhesion found that neither expression of a kinase-inactive P210BCR-ABL mutant in 32D cells or attenuation of kinase activity by STI571 (imatinib mesylate) in 32D cells transduced with wild-type P210BCR-ABL could correct the nearly 2-fold increase in cell-fibronectin adhesion. Similarly, STI571 treatment of Meg-01 cells, a P210BCR-ABL–expressing cell line derived from a patient in blast crisis, failed to inhibit adhesion to fibronectin. Together, our results indicate that changes in adhesion induced by P210BCR-ABL are independent of its tyrosine kinase activity.


1985 ◽  
Vol 5 (1) ◽  
pp. 204-213
Author(s):  
R L Davis ◽  
J B Konopka ◽  
O N Witte

The v-abl protein of Abelson murine leukemia virus is a tyrosine-specific kinase. Its normal cellular homolog, murine c-abl, does not possess detectable tyrosine kinase activity in vitro. Previously, we have detected tyrosine kinase activity in vitro for an altered c-abl gene product (c-abl P210) in the K562 human chronic myelogenous leukemia cell line. The expression of this variant c-abl gene product correlates with chromosomal translocation and amplification of the c-abl gene in K562 cells. Like v-abl, c-abl P210 is a fusion protein containing non-abl sequences near the amino terminus of c-abl. We compared the in vitro tyrosine kinase activity of c-abl P210 with that of wild-type murine v-abl. The remarkable similarities of these two proteins with respect to cis-acting autophosphorylation, trans-acting phosphorylation of exogenous substrates, and kinase inhibition, using site-directed abl-specific antisera, suggested that c-abl P210 could function similarly to v-abl in vivo. In addition, c-abl P210 possessed an associated serine kinase activity in immunoprecipitates. The serine kinase activity was not inhibited by site-directed, abl-specific antisera that inhibit the tyrosine kinase activity, suggesting that the serine kinase activity is not an intrinsic property of c-abl P210. Thus, the activation of the c-abl gene in a human leukemia cell line may have functional consequences analogous to activation of the c-abl gene in Abelson murine leukemia virus.


Diabetes ◽  
1985 ◽  
Vol 34 (4) ◽  
pp. 347-352 ◽  
Author(s):  
T. Yamanouchi ◽  
T. Tsushima ◽  
Y. Akanuma ◽  
M. Kasuga ◽  
H. Mizoguchi ◽  
...  

2004 ◽  
Vol 154 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Hyuk-Chan Kwon ◽  
Sung-Hyun Kim ◽  
Jae-Seok Kim ◽  
Hoon Han ◽  
Mee Sook Roh ◽  
...  

1997 ◽  
Vol 110 (14) ◽  
pp. 1655-1663
Author(s):  
G.G. Skouteris ◽  
C.H. Schroder

The hepatocyte growth factor/scatter factor (HGF/SF) receptor which is a transmembrane protein encoded by the Met oncogene, possesses intrinsic tyrosine kinase activity which transduces the mitogenic, morphogenic and the scattering effect of HGF/SF. The pluripotent signal of HGF/SF is transduced through association of the Met receptor with various intracellular adaptors. Phosphorylation of cytosolic phospholipase A2 (cPLA2) is associated with activation of this molecule which in turn leads to arachidonic acid production followed by release of prostaglandins and related compounds exerting their roles onto cell proliferation, chemotaxis and vascular motility. Arachidonic acid and its metabolites were shown to be involved in processes like liver regeneration where growth factor receptors possessing tyrosine kinase activity are implicated. In this study we examined whether stimulation of the HGF/SF-receptor's tyrosine kinase activity would involve changes in the phosphorylation state and the activity of cPLA2 in MDCK cells, where HGF/SF is known to induce scattering responses rather than mitogenesis. The activated p145betaMET was shown to associate with and to phosphorylate cPLA2 on tyrosine residues, this leading to subsequent release of arachidonic acid. cPLA2 was also phosphorylated in serine residues and such a role has been so far assigned to the mitogen activated protein (MAP) kinase. Our data have also shown that MAP kinase is associated and phosphorylated on tyrosine by the activated p145betaMET. Immunodepletion of MAP kinase via electroporation of an anti-MAP kinase antibody, did not significantly decrease arachidonic acid release in HGF/SF-stimulated MDCK cells. It is therefore emerging that phosphorylation of cPLA2 on tyrosine by the HGF/SF receptor kinase is capable of triggering arachidonic acid release and that MAP kinase is contributing to full, but does not drive, the activity of cPLA2. The release of arachidonic acid by MDCK cells following HGF/SF stimulation is establishing this fatty acid and its metabolites as major components involved in the transduction of MET-driven signals and at the same time in the amplification of such signals.


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