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)

GIST are stromal tumors and the gastrointestinal tract (GIT) and some other organs of spindle-cell or epithelioid-cell structure expressing CD117 (C-kit, KIT), as well as those at different rates and in different combinations, CD34, smooth muscle and/or neurogenic differentiation antigens. It should be taken into account that CD117 are also expressed by melanomas, vascular, and some other tumors. The c-kit gene mutations leading to the expression and autoactivation of the tyrosine kinase receptor KIT underlie the oncogenesis of GIST, which results in enhanced proliferative activity and inhibited apoptosis. This is supported by successful chemotherapy for GIST with a KIT receptor inhibitor. The histogenesis of GIST is associated with GIT somatic stem, the Cajal cell precursors. Many GISTs behave like sarcomas and they are characterized by an infiltrating growth, hematogenic (mainly into the liver) and implantational (along the peritoneum) cancer spread. There are opinions that all such neoplasms are potentially malignany and small-sized GISTs are benign and have the minimum mitotic activity.
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PMID:[Clinical and morphological characteristics of gastrointestinal stromal tumors]. 1807 24

Imatinib mesylate (imatinib) inhibits the c-Kit-dependent tyrosine kinase activities and highly effective in the treatment of CML and GIST patients. Although pancreatic cancer is reported to express c-Kit, imatinib does not effectively inhibit pancreatic cancer cell growth at physiological concentrations. Therefore, we investigated the mechanism of resistance of pancreatic cancer to imatinib treatment. Imatinib inhibited growth of pancreatic cancer cell lines in concentration and time-dependent fashion regardless of c-Kit expression. However, 5 microM imatinib, which is almost a mean maximal plasma concentration in clinical setting, failed to suppress pancreatic cancer cell growth. Western blot analysis demonstrated that 5 microM imatinib treatment for 1h activated the MEK-MAPK pathway and the activation was independent of Ras activation. Administration of 5 microM imatinib and 1 microM U0126 (MEK inhibitor) significantly suppressed pancreatic cell growth. Our results indicate that a combination therapy of imatinib and MEK inhibitor can be a new therapeutic strategy to suppress the progression of pancreatic cancer.
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PMID:MEK inhibitor enhances the inhibitory effect of imatinib on pancreatic cancer cell growth. 1834 44

GIST is the most common mesenchymal tumor of the gastrointestinal tract. The discovery of KIT proto-oncogene mutations in the pathogenesis of this tumor, and the development of imatinib mesylate, a specific inhibitor of KIT tyrosine kinase function have revolutionized the treatment of GIST. We present the clinical case of a patient with an upper digestive bleeding secondary to a jejunal GIST. Therapeutic options are highlighted.
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PMID:[Diagnosis and satisfactory surgical treatment of a jejunal stromal tumor]. 1879 72

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. Until today, there have been few markers specific for the tumor. This has complicated the differential diagnosis of the neoplasm from tumors of smooth muscle origin. Recently, the proto-oncogene c-kit has been shown to be a very relevant marker as it almost invariably is expressed in gastrointestinal stromal tumors. Radiation exposure, hormonal and genetic factors, particularly neurofibromatosis 2, have been implicated in their development and growth. GIST initiation, either in NF2-associated or in sporadic cases, is linked to inactivation of members of the proteins 4.1 superfamily. The majority of the mutations identified in the NF2 gene result in a truncated protein and are clinically associated with a severe phenotype. Occasionally, missense mutations associated with a mild phenotype may occur. We compared NF2 gene expression in 5 cases with gastrointestinal stromal tumors by quantitative real-time polymerase chain reaction analysis. NF2 gene mRNA expression was assessed in fresh tissue of stomach from 5 consecutive patients. We detected no alterations in NF2 gene expression in the quantitative analyses of the 5 tumors.
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PMID:NF2 expression levels of gastrointestinal stromal tumors: a quantitative real-time PCR study. 1882 92

Neoadjuvant imatinib therapy used to treat locally advanced or metastatic gastrointestinal stromal tumors (GI ST) remains under active investigation. We studied three cases of locally advanced gastric GISTs treated with imatinib on a neoadjuvant basis, followed by a complete surgical resection. Three patients were diagnosed with locally advanced unresectable GIST of the stomach and were started on imatinib 400 mg/day. After the imatinib treatment, partial responses were achieved in all patients and the tumors were considered resectable. Surgical resection was done after 7, 11, and 8 months of imatinib therapy, respectively. In one case, a metastatic liver lesion was detected during the imatinib treatment using computed tomography scans, so the imatinib therapy was maintained for 11 months postoperatively. In the other two patients without distant metastasis, imatinib treatment was not restarted after surgery. Mutational analysis revealed a mutation in exon 11 of the c-kit gene in two patients, and wild-type c-kit and PDGFRA in one patient. During pathology review of all three cases, we noted several features common to imatinib treatment. There was no evidence of tumor recurrence in all three patients at respective follow-up visits of 22, 15, and 7 months. These results suggest that the neoadjuvant imatinib therapy is a potentially curative approach for selected patients with locally advanced GIST.
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PMID:Neoadjuvant imatinib in locally advanced gastrointestinal stromal tumors of the stomach: report of three cases. 1977 Dec 79

Many gastrointestinal stromal tumors( GISTs) were treated according to the guidelines in Japan. In this paper, our procedure of the local resection, minimal invasive surgery, the jejunal graft patching and an attractive new method of treating duodenal GISTs was reported. A 50-year-old woman with duodenal submucosal tumor was referred to our hospital. The gastrointestinal endoscopic examination, the computed-tomographic images, and the magnetic resonance images showed a 3.5 cm hyper vascular tumor at the posterior superior aspect of the pancreatic head. PET-CT images revealed accumulations only in the duodenal tumor. The endoscopic ultra-sonographic images and biopsy revealed that the tumor was positive for c-kit, as a periampullary GIST of the duodenum presumed pancreatic invasion. The authors showed a" conventional and safe" local resection and duodenoplastic surgical technique for duodenal GISTs, although some reports declared the efficacy of the Roux-en Y duodeno-jejunostomy in Japan.
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PMID:[Local resection and jejunal patch duodeno-plasty for the duodenal gastrointestinal stromal tumor--a case report]. 2003 18

An 18-year-old girl presented with abdominal pain and a tumor was subsequently detected in the jejunum. We therefore carried out a wedge resection of the jejunum. The diagnosis of GIST was confirmed histologically, and a mutation in exon 9 of the c-kit gene was observed. GISTs are rare in pediatric populations and pediatric GISTs occur predominantly in females and are characterized by a multifocal gastric location and a wild-type phenotype for the c-kit genes. The features of pediatric GISTs of the small intestine have not yet been categorized, and to date, only 11 cases in patients younger than 18 years have been reported. These cases did not occur primarily in females and tended to present as single tumors with mutations in the c-kit gene. This suggests that these cases do not have the same features as pediatric gastric GISTs, but instead are similar to adult GISTs. In pediatric populations, GISTs of the small intestine were expected to show a better response to imatinib treatment than gastric GISTs because of the alterations in the c-kit gene.
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PMID:Gastrointestinal stromal tumors of the small intestine in pediatric populations: a case report and literature review. 2040 78

The introduction of novel targeted therapies into the clinic in recent years has had a considerable impact on the management of several neoplastic diseases--such as gastrointestinal stromal tumors, hepatocellular carcinomas and renal cell carcinomas--considered until recently refractory to systemic therapies. We describe here two such novel biological agents, sunitinib and sorafenib, as a paradigm of the successful clinical application of new concepts. Sunitinib and sorafenib are small molecule tyrosine kinase inhibitors that target vascular endothelial growth factor receptor, platelet-derived growth factor receptor, C-Kit and others. Both agents are administered orally; sunitinib is tyically given in cycles for 4 consecutive weeks with 2 weeks off, while sorafenib is given continually. Side effects occur in most patients, similar for both agents; they may affect several systems and organs but are mostly mild and easily manageable, rarely requiring discontinuation of the drug. However, these toxicities mandate prompt attention and intervention. The most frequently observed effects are hypertension, nausea, anorexia, asthenia and cutaneous manifestations; cardiac abnormalities may include congestive failure. Sunitinib, and markedly less frequently sorafenib, may cause thyroid gland dysfunction, mainly hypothyroidism. Antitumor activity has been shown for renal cell carcinoma in pivotal trials, for sunitinib as first-line treatment and for sorafenib in previously treated patients as second-line. Sunitinib is now approved as second-line therapy for patients with GIST refractory to imatinib; sorafenib has resulted in a significant prolongation in median survival in patients with hepatocellular carcinoma. Ongoing clinical trials will further define the spectrum of these agents' antitumor activity, their role in combination with other drugs, as well as their optimal dose and schedule of administration.
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PMID:Novel multitargeted anticancer oral therapies: sunitinib and sorafenib as a paradigm. 2109 May 21

We report a case of a 48-year-old Indian male who presented with swelling and firmness in his left upper part of the abdomen of one month duration with anorexia and weight loss. Initial examination revealed an intra abdominal mass of around 16.8x11.0x24.5cm with minimal left sided pleural effusion. A biopsy from the mass confirmed the diagnosis of gastrointestinal stromal tumour (GISTs) as supported by immmunohistochemistry results which showed strong positivity for c-kit while stains for smooth muscle actin, desmin, myoglobin, S100 Protein and cytokerstin remained negative. The patient was not suitable for surgical intervention in view of advanced tumor, and Imatinib Mesylate 400mg daily was started with the aim of making the tumor operable. Such therapy lasted for twenty months and was tolerated well by the patient. It then resulted in gradual tumor regression, following which the patient underwent successful tumor resection. Post surgical resection patient had no radiological evidence of intra abdominal tumor but mild left sided pleural effusion with left lower lobe atelectasis. The patient had uneventful post operative recovery and he is currently on Imatinib mesylate and tolerating treatment well with mild skin rash. The experience with preoperative imatinib on surgical resection rates and post operative outcomes is limited especially with primary locally advanced GISTs. In our case successful surgical resection was possible for a huge locally advanced GIST with unusually prolonged treatment of twenty months with imatinib preoperatively.
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PMID:Successful surgical resection of advanced gastrointestinal stromal tumor post neoadjuvent therapy. 2148 16

A biomarker is defined as "a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic/pharmacodynamic responses to a therapeutic intervention". Various assays, including immunohistochemistry, gene constitution such as amplification, mutation, and rearrangement, gene and protein expression analysis such as single gene or protein expression, exhaustive analysis and gene or protein signature and single nucleotide polymorphism have been used to identify biomarkers in recent years. No therapeutic effects have yet been predicted based on the results of such exhaustive gene analysis because of low reproducibility although some correlate with the prognosis of patients. Biomarkers such as HER2 for breast cancer or EGFR mutation for lung cancer and KRAS mutation in colon cancer have contributed to identify a patient population that might show a good and bad treatment response, respectively. On the other hand, other biomarkers such as bcr-abl, c-kit gene mutation and CD20 expression, which are positive for CML, GIST and B cell lymphoma, respectively, have crucial biological significance but have not necessarily been used for practical clinical screening since pathological diagnosis coincide with finding of biomarkers. Hence, much work remains to be done in many areas of biomarker research.
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PMID:Critical comments for roles of biomarkers in the diagnosis and treatment of cancer. 2165 49


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