Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors report a unique case of an intra-abdominal, epithelioid mesenchymal tumor that had an activating mutation of PDGFRA and a strong PDGFRA immunoreactivity but lacked both c-kit mutation and c-kit protein (CD117) expression. IHC study showed that the tumor cells were diffusely and strongly positive for PDGFRA, vimentin, CD34, and Bcl-2 but completely negative for CD117 as well as for muscle, epithelial, endothelial, endocrine, mesothelial, neural, and melanocytic cell markers. Molecular study revealed a mutation at the juxtamembrane domain of exon 12 in PDGFRA gene with GTC to GAC transition at codon 561 (V561D), as shown in the previous mutational studies on gastrointestinal stromal tumor (GIST). This case likely represents an example of GIST with PDGFRA activating mutation and PDGFRA immunoreactivity without CD117 positivity, which has not been documented in the literature. STI 571 (imatinib mesylate [Gleevec]) might be an effective therapy in this case, since Gleevec targets both PDGFRA and c-kit oncoproteins.
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PMID:Epithelioid gastrointestinal stromal tumor with PDGFRA activating mutation and immunoreactivity. 1589 28

AML1-MTG8 generated by t(8;21) contributes to leukemic transformation, but additional events are required for full leukemogenesis. We examined whether mutations in the receptor tyrosine kinase (RTK) pathway could be the genetic events that cause acute myeloblastic leukemia (AML) harboring t(8;21). Mutations in the second tyrosine kinase domain, juxtamembrane (JM) domain and exon 8 of the C-KIT gene were observed in 10, one and three of 37 AML patients with t(8;21), respectively. Three patients showed an internal tandem duplication in the JM domain of the FLT3 gene. One patient had a mutation in the K-Ras gene at codon 12. As the occurrence of these mutations was mutually exclusive, a total of 18 (49%) patients showed mutations in the RTK pathway. These results suggest that activating mutations in the RTK pathway play a role in part as an additional event leading to the development of t(8;21) AML. The 6-year cumulative incidence of relapse in patients with RTK pathway mutations was 79.8%, compared with 13.5% in patients lacking such mutations (P=0.0029). Furthermore, the 6-year relapse-free survival in patients with mutations was 18% compared to 60% in those without mutations (P=0.0340), indicating that RTK mutations are associated with the clinical outcome in t(8;21) AML.
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PMID:Mutations in the receptor tyrosine kinase pathway are associated with clinical outcome in patients with acute myeloblastic leukemia harboring t(8;21)(q22;q22). 1590 84

Systemic mastocytosis is characterized by abnormal mast cell proliferation in different organs. The 2001 consensus classification distinguishes in separate categories indolent systemic mastocytosis, systemic mastocytosis with concomitant blood disease, aggressive systemic mastocytosis and mast cell leukemia. Clinical manifestations are caused by tissue infiltration by proliferating mastocytes and by release of mediators. The principal organs affected are the skin, bones, digestive tract, liver, spleen and lymph nodes. Diagnosis of mastocytosis is based on appropriate stains (Giemsa, toluidine blue) and immunophenotype features (tryptase, CD117, also known as c-KIT and stem cell factor receptor). Serum tryptase levels reflect the total mast cell burden. Treatment must prevent release of mast cell mediators (histamine antagonists, cromolyn sodium, corticosteroids, or leukotriene-receptor inhibitors), limit bone involvement (bisphosphonates) and reduce the number of circulating mast cells (interferon, cladribine, or tyrosine kinase inhibitors). Enhanced understanding of the pathogenic mechanisms (mutation of c-kit and platelet-derived growth factor receptor alpha has led to the development of targeted treatments, including new inhibitors of tyrosine kinase and of nuclear factor Kappa B.
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PMID:[Systemic mastocytosis]. 1598 48

Gastrointestinal stromal tumors (GISTs): clinical and pathological features. The gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. With immunohistochemical, electron microscope and molecular examinations they can be clearly distinguished in both their genotype and phenotype from other mesenchymal tumors. GIST tumors express the CD 117 receptor in more than 90% independent of histopathological features and clinical behaviour. This is why it is considered as the most important characteristic. The incidence is 10-20 new cases per 1 million annually. The number of incidents is expected to increase by the establishment of CD117 and other new markers (protein kinase C theta, DOG1). Nowadays the establishment of the expected biological behavior and malignancy can be difficult. The best prognostic factors are the tumor size and the mitotic index. Dominantly, due to the mutation of the c-kit proto-oncogene and PGDFRA gene that the high level tyrosine kinase activity generates resulting uncontrolled proliferation and cell growth. The imatinib mesylate is a selective inhibitor of the KIT tyrosine kinase receptor and it also blocks the activity of the PDGFRA kinase. The therapeutic consequence of this is that the majority of advanced GIST tumors which do not react to conventional radio- and chemotherapy respond well to tyrosine kinase inhibitor treatment. As a result, survival and patient's quality of life can significantly improve.
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PMID:[Gastrointestinal stromal tumors (GISTs): clinical and pathological features]. 1605 79

CD117 (KIT) is a type III receptor tyrosine kinase operating in cell signal transduction in several cell types. Normally KIT is activated (phosphorylated) by binding of its ligand, the stem cell factor. This leads to a phosphorylation cascade ultimately activating various transcription factors in different cell types. Such activation regulates apoptosis, cell differentiation, proliferation, chemotaxis, and cell adhesion. KIT-dependent cell types include mast cells, some hematopoietic stem cells, germ cells, melanocytes, and Cajal cells of the gastrointestinal tract, and neoplasms of these cells are examples of KIT-positive tumors. Other KIT-positive normal cells include epithelial cells in skin adnexa, breast, and subsets of cerebellar neurons. KIT positivity has been variably reported in sarcomas such as angiosarcoma, Ewing sarcoma, synovial sarcoma, leiomyosarcoma, and MFH; results of the last three are controversial. The variations in published data may result from incomplete specificity of some polyclonal antibodies, possibly contributed by too high dilutions. Also, KIT is expressed in pulmonary and other small cell carcinomas, adenoid cystic carcinoma, renal chromophobe carcinoma, thymic, and some ovarian and few breast carcinomas. A good KIT antibody reacts with known KIT positive cells, and smooth muscle cells and fibroblasts are negative. KIT deficiency due to hereditary nonsense/missense mutations leads to disruption of KIT-dependent functions such as erythropoiesis, skin pigmentation, fertility, and gastrointestinal motility. Conversely, pathologic activation of KIT through gain-of-function mutations leads to neoplasia of KIT-dependent and KIT-positive cell types at least in three different systems: mast cells/myeloid cells--mastocytosis/acute myeloid leukemia, germ cells--seminoma, and Cajal cells--gastrointestinal stromal tumors (GISTs). KIT tyrosine kinase inhibitors such as imatinib mesylate are the generally accepted treatment of metastatic GISTs, and their availability has prompted an active search for other treatment targets among KIT-positive tumors such as myeloid leukemias and small cell carcinoma of the lung, with variable and often nonconvincing results.
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PMID:KIT (CD117): a review on expression in normal and neoplastic tissues, and mutations and their clinicopathologic correlation. 1608 45

Gastrointestinal stromal tumors (GIST) have been reported to occasionally occur in patients with neurofibromatosis type 1 (NF1). This study aims to describe the phenotypic and genotypic characteristics of GIST in NF1 patients and attempts to elucidate the relationship between them. We analyzed GIST arising in 15 NF1 patients (8 males and 7 females, 19-82 years of age). Eleven patients had multiple GISTs (3 to >100 tumors) ranging from 1 mm to 10 cm in size and predominantly involving the small intestine including the duodenum. Tumors were symptomatic in 8 patients and incidental findings in the remaining 7 patients. Microscopically, the tumors cells were typically spindled and the mitotic rate low; 9 patients had tumors classified as very low or low risk and 6 as intermediate risk GIST. Nine patients were treated surgically and none developed metastases or died of disease. Immunohistochemical stains for CD117 were strongly positive in 47 of 50 GIST; they also accentuated hyperplastic foci (diffuse and focal) of the interstitial cells of Cajal that were often associated with microscopic GIST in the surrounding intestinal muscle wall. No KIT or PDGFRA mutations were detected in 24 GIST from 12 patients using dHPLC analysis and DNA sequencing. We conclude that patients with NF1 have a high risk of developing GIST. NF1-associated GIST are also phenotypically and genotypically distinct from sporadic GIST, indicating that different pathogenetic mechanisms are involved in their evolution.
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PMID:NF1-associated gastrointestinal stromal tumors have unique clinical, phenotypic, and genotypic characteristics. 1609 6

We report a unique case of adenoid cystic carcinoma (ACC) of the maxillary sinus, with gradual histologic transformation from lower-grade ACC (cribriform and tubular types) to high-grade adenocarcinoma (HGA) showing a sequential histologic spectrum via solid-type ACC. A 74-year-old man presented with swelling and mild pain of the right cheek. CT scan showed a mass measuring approximately 4 cm, with marked bone destruction in the right maxillary sinus. A surgically resected specimen revealed that the tumor was comprised of three different components: HGA and solid-type ACC in the central portion and lower-grade ACC in the periphery. The tumor was discriminated from a dedifferentiated carcinoma or hybrid tumor. Autopsy specimens also demonstrated both solid-type ACC and HGA components in the lung and spleen. Immunohistochemically, positive staining of p53 protein was detected on both solid-type ACC and HGA cells, but cyclin D1 and HER2/neu was only seen in HGA cells. Solid-type ACC cells were immunoreactive for CD117 (c-kit), but lower-grade ACC and HGA cells were negative. This case suggests that the overexpression of CD117, p53 protein, cyclin D1, and HER2/neu might be involved in the progression from lower-grade ACC to solid-type ACC and HGA.
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PMID:Adenoid cystic carcinoma of the maxillary sinus with gradual histologic transformation to high-grade adenocarcinoma: a comparative report with dedifferentiated carcinoma. 1613 59

We report on the first case of benign perineurially differentiated peripheral nerve sheath tumor (perineurioma) presenting as a bleeding gastric mass in a 30-year-old, previously healthy woman with no signs or stigmata of von Recklinghausen's disease or other primary tumor at time of presentation. Gastric resection specimen revealed an ulcerated moderately cellular mesenchymal tumor consisting of elongated wavy spindle cells arranged in a fascicular and sheet-like pattern with focal whorling and occasional alternation of dark staining cellular and light staining hypocellular areas. Tumor cells were strongly immunoreactive for epithelial membrane antigen, CD56 (N-CAM), and vimentin, but were negative for S-100-protein and other lineage-specific epithelial, mesenchymal, hematolymphoid, and reticulo-histiocytic markers. CD117 revealed numerous positive staining mast cells, but the lesional cells were not reacting. We presume that the combined histological and immunohistochemical profiles of this unusual gastric neoplasm are consistent with a diagnosis of perineurioma with a probably benign biological behavior. To our knowledge, this is the first report of gastric perineurioma, an extremely rare mesenchymal lesion that should be considered among the differential diagnoses of gastrointestinal stromal tumor, especially the so-called KIT-negative GIST. Gastrointestinal perineuriomas might be under-recognized, as our case was initially diagnosed as a benign GIST.
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PMID:Perineurioma of the stomach. A rare spindle cell neoplasm that should be distinguished from gastrointestinal stromal tumor. 1613 53

Gastrointestinal mesenchymal tumors (GIMTs) are the most common mesenchymal tumors of the gastrointestinal tract. RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is a cancer cell-surface antigen and has been identified as a prognostic factor in several cancer types. It is thought that tumor cells escape immune attack by expressing RCAS1, which induces apoptosis in receptor-positive immune cells. The current study was designed to elucidate the histogenesis of these tumors by using various immunohistochemical markers, and identify parameters that will help to establish the criteria of malignancy in the GIMT. We also discuss the clinicopathological significance of RCAS1 expression in the diagnosis and prognosis of GIMTs. A total of 70 cases of GIMTs were reviewed. Immunohistochemistry was performed between 1990 and 2000, with the avidin-biotin-peroxidase complex method on 3 microm-thick sections of formalin-fixed paraffin-embedded specimens of GIMTs. Antibodies to the following antigens were used: KIT (CD117), CD34 alpha-SMA, Desmin, cytokeratin, S-100 protein, p53, and RCAS1. Recurrence-free survival analysis was done with Stat View-J 5.0 statistical packages. Univariate analysis for a recurrence-free prognosis demonstrated that antibody detection of p53 expression (p=0.0333) and expression of RCAS1 (p=0.0008) is correlated with a significantly higher potential of recurrence. On multivariate analysis, tumor size and RCAS1 expression were independently and inversely correlated with recurrence-free survival. The expression of RCAS1 has not previously been reported in GIMT; indeed, our study suggests that the expression of RCAS1 is correlated with recurrence not only in carcinomas, but also in mesenchymal tumors.
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PMID:A clinical and immunohistochemical study on gastrointestinal mesenchymal tumor (GIMT): RCAS1 as a predictor for recurrence of GIMT. 1621 Dec 75

CD117 (KIT) is expressed in a variety of hematopoietic neoplasms but there are a paucity of data regarding its expression in diffuse large B-cell lymphomas (DLBCL). The purpose of the present paper was to describe the authors' experience of two CD117+ DLBCL (one of follicle center-cell origin and one nasal Epstein-Barr virus (EBV)- plasmablastic lymphoma associated with lytic bone lesions), as determined by tissue immunohistochemistry and flow cytometry. The CD117 expression in DLBCL was further evaluated using tissue microarrays and seven additional plasmablastic lymphomas, using two commercially available anti-CD117 antibodies (Ab-1, Oncogene and A4502, DakoCytomation). Membranous +/- cytoplasmic staining was seen with Ab-1 in 24/65 (37%) DLBCL, including 21/56 microarray DLBCL, two index cases, and 1/7 additional plasmablastic lymphomas, with persistent staining in 13% of microarray DLBCL despite preincubation with KIT peptide. However, A4502 had only membranous staining of the index cases and one additional EBV- plasmablastic lymphoma with medullary disease. The present study suggests that (i) CD117 expression can be detected sporadically in DLBCL of follicle center-cell origin and a subset of plasmablastic lymphomas; (ii) staining for CD117 might help in identifying EBV- plasmablastic lymphomas associated with bone marrow involvement; and (iii) CD117 antibodies should be carefully validated prior to use, because non-specific staining, as observed with Ab-1, could lead to false-positive results.
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PMID:CD117 expression in diffuse large B-cell lymphomas: fact or fiction? 1627 Oct 84


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