Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P10721 (c-kit)
 6,575 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal (GI) tract. The c-kit receptor tyrosine kinase (KIT) is expressed by practically all GISTs, and gain-of-function mutations of KIT are present in most GISTs. Interstitial cells of Cajal (ICC) are the pacemaker of the peristaltic movement of the GI tract. Since signals through KIT are essential for development of ICC and since multiple GISTs develop from the hyperplastic lesion of ICCs in familial GIST patients with germline mutations of KIT, GISTs are considered to originate from ICC. Imatinib mesylate, which was developed for treatment of chronic myeloid leukemia (CML), was found to be useful for treatment of GISTs. Imatinib mesylate inhibits BCR-ABL fused tyrosine kinase that causes CML. Imatinib mesylate also inhibits the mutated KIT observed in most GISTs, and this explains the effectiveness of Imatinib mesylate on GISTs. GISTs appear to serve as a model for molecule-based diagnosis and treatment of solid tumors.
 ...
PMID:Gastrointestinal stromal tumors (GIST): a model for molecule-based diagnosis and treatment of solid tumors. 1282 97

Imatinib mesylate (Gleevec) inhibits the BCR-ABL tyrosine kinase in chronic granulocytic leukemia. Previous studies have demonstrated that imatinib mesylate also inhibits the survival and functions of normal mast cells by interfering with the receptor tyrosine kinase for stem cell factor (SCF), c-kit, which is expressed by mast cells. Because mast cells extensively surround many types of cancer and contain powerful anticoagulants such as heparin, we investigated the effects of imatinib mesylate on blood clotting and tumor growth within subcutaneous implants of a mammary adenocarcinoma cell line (4T1) in BALB/c mice. After 5 days of oral treatment with 10 mg/kg of the drug, the average mass of the tumors in treated mice (198 +/- 42 mg, n = 5) was significantly (p < 0.05) greater than the average mass of the tumors from untreated (control) mice (60 +/- 23 mg, n = 5). Moreover, the tumors in the treated mice were frequently surrounded by large lakes of clotted blood that were not evident in tumors from the control mice. Accelerated growth and blood clotting were also observed in tumor-bearing mice treated with heparinase I enzyme to destroy endogenous mast cell heparin and in NDST-2 knockout mice in which there is a targeted disruption in the gene coding for mast cell heparin synthesis. We conclude that imatinib mesylate accelerated the growth and peri-tumoral blood clotting of implants of mammary adenocarcinoma in mice. These results suggest that imatinib mesylate may have significant effects on mast cells infiltrating tumors, in addition to its other biologic activities. Our results also indicate that the mechanism of this effect may be related to the anticoagulant properties of mast cell heparin.
 ...
PMID:Acceleration of tumor growth and peri-tumoral blood clotting by imatinib mesylate (Gleevec). 1286 22

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors. The molecular etiology is the result of mutations in the c-Kit gene. The mutant c-Kit proteins, which are activated without a stem cell factor, contribute to the tumor development. STI571 selectively inhibits c-Kit, BCR-ABL, and PDGFR tyrosine kinases. Based on this potential to inhibit critical c-Kit function in GISTs, case studies have reported effective outcomes following treatment with STI571. This case report describes a highly effective use of STI571 in a 54-year-old woman with multiple liver metastases from a GIST originating in the duodenum.
 ...
PMID:Effect of a tyrosine kinase inhibitor STI571 in a patient with hepatic metastases from a duodenal gastrointestinal stromal tumor. 1289 63

Imatinib mesylate is a 2-phenylaminopyrimidine tyrosine kinase inhibitor with specific activity for ABL, platelet-derived growth factor receptor, and c-kit receptor. The pharmacological basis of this interaction has been elucidated by crystallographic studies. Imatinib mesylate binds to the amino acids of the BCR-ABL tyrosine kinase ATP binding site and stabilizes the inactive, non-ATP-binding form of BCR-ABL, thereby preventing tyrosine autophosphorylation, and in turn, phosphorylation of its substrates. This process ultimately results in a "switch-off" of the downstream signaling pathways that promote leukemogenesis. Despite high rates of hematologic and cytogenetic responses to imatinib therapy, the emergence of resistance to imatinib has been recognized as a major problem in the treatment of Ph-positive leukemia. Considerable progress has been made in developing therapeutic agents that are effective against molecular targets specifically expressed in CML cells. It is important to emphasize that BCR-ABL is the ideal target for therapy even at relapse; at least one general mechanism of resistance involves maintenance of an active BCR-ABL kinase inside leukemic cells. It is also notable that the high frequency of BCR-ABL mutations and amplifications represents the high degree of heterogeneity in patients with advanced CML, in whom multiple leukemic clones may exist. For these reasons, a single inhibitor is unlikely to be able to block all mutants described so far.
 ...
PMID:[Molecular-target therapy of Ph-positive leukemia by imatinib (tyrosine kinase inhibitor)]. 1293 59

Gastrointestinal stromal tumours (GISTs) are rare gastro-intestinal, mesenchymal tumours characterized by the expression of a receptor with tyrosine kinase activity called c-kit. A new drug, Imatinib, is a potent inhibitor of a subgroup of the tyrosine kinase family comprising BCR-ABL, platelet-derived growth factor, and c-kit. Imatinib represents the first systemic treatment with a clinical effect on patients with metastatic or unresectable GISTs, which are known to be resistant to chemo and radiotherapy. In the first phase I and II studies confirmed partial responses were seen in 53% and 59% of the patients respectively.
 ...
PMID:[Imatinib--a breakthrough in the treatment of gastrointestinal stromal tumors (GIST)]. 1453 49

The new knowledge in molecular biology and pathophysiology of chronic myeloid leukemia enabled the development of imatinib mesylate (Glivec, formerly STI571). Imatinib potently inhibits several protein tyrosine kinases, including BCR-ABL, c-Kit, and PDGF receptor. Imatinib blocks the phosphorylation of downstream target proteins and interrupts the malignant transformation leading to the development of CML. Phase I and II studies demonstrated that imatinib is highly effective and well tolerated in all phase of CML. We got our experience with imatinib on more than two-year monitoring 34 patients within the Expanded Access Study CST1571 0113. Imatinib 400 mg/d was administered orally to 10 women and 24 men in median age of 53 years (22-70) who were hematologically (n = 9) or cytogenetically (n = 13) resistant, cytogenetically refractory (n = 3) or intolerant (n = 9) to interferon alpha. The median follow-up time was 97.5 weeks (23-115), the median time from CML diagnosis to the start of the study was 32.3 months (6-140.5). Complete hematologic response was achieved in 33 of 34 (97%) pts, total major cytogenetic response (complete plus major) in 21 of 33 (63%) pts. Cytogenetic relapse was observed in 2 of 33 pts (6%), cytogenetic progression in 4 (12%) pts. Non-hematologic toxicity was mild (grade 1 or 2) and no patient was excluded from the study due to it. Hematological toxicity grade 3 limited dose of imatinib in 26% of patients and probably caused lower rate of cytogenetic responses in heavy pretreated patients. Both quantitative RT-PCR methods (competitive RT-PCR and real-time RT-PCR Light-Cycler) were found useful to monitor patients with CML on imatinib therapy. Our results confirmed high efficacy and safety of imatinib in late-chronic phase CML patients failing prior interferon therapy. The lower incidence of hematological toxicity and higher rate of cytogenetic responses in patients treated with imatinib in early-chronic phase CML justify according to our opinion the recommendation to administer imatinib early after the diagnosis of CML in patients who are not indicated for allogeneic transplantation.
 ...
PMID:[Imatinib mesylate (Glivec) in treatment of chronic phase chronic myeloid leukemia]. 1501 23

Myeloid leukaemias are frequently associated with translocations and mutations of tyrosine kinase genes. The products of these oncogenes, including BCR-ABL, TEL-PDGFR, Flt3 and c-Kit, have elevated tyrosine kinase activity and transform haematopoietic cells, mainly by augmentation of proliferation and enhanced viability. Activated ABL kinases are associated with chronic myeloid leukaemia. Mutations in platelet-derived growth factor receptor beta are associated with chronic myelomonocytic leukaemia. Flt3 or c-Kit cooperate with other types of oncogenes to create fully transformed acute leukaemias. Elevated activity of these tyrosine kinases is crucial for transformation, thus making the kinase domain an ideal target for therapeutic intervention. Tyrosine kinase inhibitors for various kinases are currently being evaluated in clinical trials and are potentially useful therapeutic agents in myeloid leukaemias. Here, the authors review the signalling activities, mechanism of transformation and therapeutic targeting of several tyrosine kinase oncogenes important in myeloid leukaemias.
 ...
PMID:Targeting mutated tyrosine kinases in the therapy of myeloid leukaemias. 1516 29

Mutations of the c-kit gene have been reported in myeloproliferative disorders. We describe here a case of Ph+ (b2a2) chronic myelogenous leukemia that, during the course of disease, showed an unusual bone marrow mast-cell infiltration. A mutational screening for the c-kit gene, performed on DNA routinely cryopreserved during the follow-up, evidenced the D816Y-activating mutation as an additional genetic abnormality. Treatment with imatinib mesylate resulted in a substantial decrease of the BCR-ABL/ABL ratio and in the absence of c-kit mutation. It is likely that the superimposed c-kit mutation, in this case, may account for the transient bone marrow mastocytosis.
 ...
PMID:Chronic myelogenous leukemia with acquired c-kit activating mutation and transient bone marrow mastocytosis. 1516 15

Imatinib mesylate (Gleevec/Glivec, Novartis, Basel, Switzerland), formerly called STI571, is a specific and potent inhibitor of the BCR-ABL tyrosine kinase, the molecular hallmark of chronic myeloid leukaemia. Several clinical trials have demonstrated the efficacy of imatinib in different phases of this disease. On the other hand, imatinib is also active against other tyrosine kinases, such as ABL, the stem cell factor receptor (c-kit) and the platelet-derived growth factor receptor, whose inhibition might have potential implications for the treatment of several malignancies. In this regard, imatinib has already shown a remarkable activity in patients with hypereosinophilic syndrome and gastrointestinal stromal tumours. Imatinib is an example of how a better understanding of the pathogenetic mechanisms of a neoplastic disease can lead to the development of a molecular-targeted therapy.
 ...
PMID:Imatinib mesylate (Gleevec/Glivec) a molecular-targeted therapy for chronic myeloid leukaemia and other malignancies. 1520 9

Chronic myeloid leukaemia is associated with a specific translocation between chromosomes 9 and 22 that results in the formation of a chimaeric gene. This gene, when transcribed, produces the BCR-Abl oncoprotein which has tyrosine kinase activity and the ability to prevent apoptosis, but has no effect on cellular proliferation. Imatinib mesylate, an inhibitor of the BCR-Abl transcript modelled on the ATP binding pocket of the Abl oncoprotein, prevents phosphorylation of effector molecules and induces apoptosis. Imatinib has limited effectiveness when BCR-Abl cells are in the quiescent cell-cycle state of G0. A life-long regimen of imatinib should reduce the risk of relapse from cells leaving G0. Up-regulation of BCR-Abl expression, ATP binding pocket mutations, up-regulation of MDR1 and over-expression of Pgp are all thought to limit the effectiveness of imatinib. Advanced BCR-Abl positivity is associated with complex mutations, which are thought to have a cumulative effect on the BCR-Abl oncoprotein in disrupting normal signal transduction, making these cells refractory to monotherapy alone. Combination therapy is thought to overcome this. Research studies have identified imatinib as a potential treatment option for a diverse range of malignancies associated with BCR-Abl, platelet-derived growth factor receptor (PDGFr) and c-Kit pathways. This may extend the application of this special therapy in the future.
 ...
PMID:Use and limitations of imatinib mesylate (Glivec), a selective inhibitor of the tyrosine kinase Abl transcript in the treatment of chronic myeloid leukaemia. 1525 Jun 77


<< Previous 1 2 3 4 5 6 7 Next >>