Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.1 (ERK)
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Biopsy specimens of 19 human gliomas (10 glioblastomas, 2 anaplastic astrocytomas, 4 astrocytomas, one mixed glioma, one oligodendroglioma and one ependymoma) were examined for amplification of tumour-related genes located on chromosome 7: the proto-oncogene c-erb-B1 (encoding the epidermal growth factor receptor (EGFR], the proto-oncogene c-met, the platelet-derived growth factor A-chain gene, and the plasminogen activator inhibitor type-1 gene. Gene amplification was observed in 6 glioblastomas, and the EGFR gene was the only chromosome-7-gene examined that was amplified. The selective EGFR gene amplification in human glioblastomas suggests its potential role in the progression of some of these tumours.
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PMID:Amplification of the epidermal growth factor receptor gene in human gliomas. 177 45

Ependymomas are glial cell-derived tumors. They are, in contrast to other gliomas (astrocytomas, oligodendrogliomas, and oligoastrocytomas), ill-defined with respect to the genes and chromosomal segments important in their tumorigenesis. In this study, we extensively screened 17 ependymomas for genetic changes characteristic of other gliomas. Allelic loss was detected on chromosome arm 22q in three tumors; on chromosome 10 in two tumors; on chromosome arm 17p in two tumors; and on chromosome arms 6q, 9p, 13q, and 19q, each in one tumor. No allelic losses were found on chromosome arms 1p and 16q. None of the tumors had EGFR gene amplification. In each case, the chromosomal segment affected by the deletion included the region known to harbor a tumor suppressor gene important in glioma tumorigenesis. We conclude that ependymomas resemble the other glial neoplasms with respect to type and location of the chromosomal changes involved. Given the relatively infrequent occurrence of these genetic changes, ependymomas should be considered genetically as low-grade gliomas.
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PMID:Molecular analysis of genetic changes in ependymomas. 754 35

We have used the polymerase chain reaction to clone and characterize growth factor receptor tyrosine kinases (RTKs) expressed in 3 pathologically distinct pediatric brain tumors, an anaplastic ependymoma, a glioblastoma multiforme and a primitive neuroectodermal tumor (PNET). These neoplasms are presumed to be derived from embryonic neuroepithelial precursor cells of the central nervous system. This cloning demonstrated expression of 24 distinct kinase genes: 16 receptor type kinases and 8 nonreceptor type kinases. The expression of 6 receptors, including Hek2, IRR, Ryk, FGFR3, and 2 members of the newly identified cell adhesion kinase receptor family, DDR and TKT, in such tumors has not been reported previously. Northern analysis of mRNA levels revealed DDR expression in 6 of 7 pediatric brain tumors including an ependymoma, PNET, glioblastoma and astrocytoma, and also in an adult pheochromocytoma. Thus, the DDR cell adhesion kinase may be widely expressed in pediatric brain tumors. Also, PCR cloning may be an effective procedure for characterizing RTKs in clinical tissue samples and revealing the expression of novel RTK species.
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PMID:Pediatric brain tumors express multiple receptor tyrosine kinases including novel cell adhesion kinases. 907 49

Astrocytic tumors occasionally arise in the central nervous system following radiotherapy. It is not clear if these gliomas represent a unique molecular genetic subset. We identified nine cases in which an astrocytoma arose within ports of previous radiation therapy, with total doses ranging from 2400 to 5500 cGy. Irradiated primary lesions included craniopharyngioma, pituitary adenoma, Hodgkin's lymphoma, ependymoma, pineal neoplasm, rhabdomyosarcoma, and three cases of lymphoblastic malignancies. Patients ranged from 9 to 60 years of age and developed secondary tumors 5 to 23 years after radiotherapy. The 9 postradiation neoplasms presented as either anaplastic astrocytoma (3 cases) or glioblastoma multiforme (6 cases). Two of the latter contained malignant mesenchymal components. We performed DNA sequence analysis, differential polymerase chain reaction (PCR), and quantitative PCR on DNA from formalin-fixed, paraffin-embedded tumors to evaluate possible alterations of p53, PTEN, K-ras, EGFR, MTAP, and p16 (MTS1/CDKN2) genes. By quantitative PCR, we found EGFR gene amplification in 2 of 8 tumors. One of these demonstrated strong immunoreactivity for EGFR. Quantitative PCR showed chromosome 9p deletions including p16 tumor suppressor gene (2 of 7 tumors) and MTAP gene (3 of 7). Five of 9 tumors demonstrated diffuse nuclear immunoreactivity for p53 protein. Sequencing of the p53 gene in these 9 cases revealed a mutation in only one of these cases, a G-to-A substitution in codon 285 (exon 8). Somewhat unexpectedly, no mutations were identified in PTEN, a commonly altered tumor suppressor gene in de novo glioblastoma multiformes. Unlike some radiation-induced tumors, no activating point mutations of the K-ras proto-oncogene or base pair deletions of tumor suppressor genes were noted. These radiation-induced tumors are distinctive in their high histological grade at clinical presentation. The spectrum of molecular genetic alterations appears to be similar to that described in spontaneous high grade astrocytomas, especially those of the de novo type.
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PMID:Molecular genetic alterations in radiation-induced astrocytomas. 1032 96

Overexpression of EGFR secondary to EGFR gene amplification is a common feature in primary malignant gliomas. To correctly assess EGFR protein and gene level as possible prognostic and predictive markers in gliomas, straightforward assays, which can be used routinely in the pathology laboratory to evaluate EGFR status, becomes critical. EGFR gene amplification and chromosome 7 aneuploidy was detected in 34 formalin-fixed, paraffin-embedded benign and malignant gliomas by chromogenic in situ hybridization (CISH) using digoxigenin-labeled EGFR and biotin-labeled chromosome 7 centromeric probes. The results were evaluated by bright-field microscopy under a 40x objective lens. EGFR protein level was detected by immunohistochemistry (IHC) using monoclonal antibody 31G7. Five cases, 3 astrocytoma grade III (33%) and 2 glioblastoma multiforme (GBM) (33%), had EGFR amplification displayed as diaminobenzidine-stained multiple dots suggesting the pattern of double-minute chromosomes. Chromosome 7 polysomy was found in 68% gliomas, 100% GBM, 67% astrocytoma grade III, 42% astrocytoma grade II, 50% astrocytoma grade I, 100% ependymoma, and the 1 case of mixed glioma III. High expression of EGFR protein was present in 62% gliomas and displayed membrane and cytoplasmic staining. All tumors with EGFR gene amplification showed EGFR high expression. High expression of EGFR without gene amplification was observed in all grades of gliomas. Simultaneous detection of EGFR gene copies or chromosome 7 centromere signals along with tissue morphology allows us to compare CISH results easily with IHC results. Our results show that CISH is an objective, practical, and accurate assay to screen for EGFR gene status in gliomas.
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PMID:Evaluation of epidermal growth factor receptor (EGFR) by chromogenic in situ hybridization (CISH) and immunohistochemistry (IHC) in archival gliomas using bright-field microscopy. 1516 2

Ependymomas are primary tumors of the central nervous system that typically originate from the walls of the cerebral ventricles or from the spinal canal. The pathogenesis of these tumors is poorly understood, and prognostic assessment based on histologic features and clinical parameters is difficult. The aim of this study was to investigate the molecular heterogeneity of ependymomas. We used cDNA microarrays and RT-PCR to examine gene expression in 47 ependymomas. We present results for five comparisons: (1) tumors from children and adults with poor versus favorable outcome, (2) tumors from children with poor versus favorable outcome, (3) tumors with high versus low proliferation indices, (4) subependymomas versus myxopapillary ependymomas, and (5) spinal versus intracranial ependymomas. For patients with an overall survival >10 years after diagnosis, we identified 27 genes associated with favorable prognosis. In contrast, overexpression of BNIP3, MRC1, EPHB3, GLIS3, CDK4, COL4A2, EBP, NRCAM, and CCNA1 genes in tumors with high proliferation indices was associated with a poor outcome. Thirty genes, including ETV6, YWHAE, TOP2A, TLR2, IRAK1, TIA1, and UFD1L were found to be highly expressed in subependymomas but not myxopapillary ependymomas. Also, 30 genes were differentially expressed in spinal versus intracranial ependymomas. There was no relationship between expression profiles and tumor grade, patient age, and patient gender. Our results provide insight into specific molecular events underlying ependymoma tumorigenesis and may contribute to more accurate diagnosis and prediction of clinical outcome.
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PMID:Ependymoma gene expression profiles associated with histological subtype, proliferation, and patient survival. 1726 49

Pediatric ependymomas are enigmatic tumors, and their clinical management remains one of the more difficult in pediatric oncology. The identification of biological correlates of outcome and therapeutic targets remains a significant challenge in this disease. We therefore analyzed a panel of potential biological markers to determine optimal prognostic markers. We constructed a tissue microarray from 97 intracranial tumors from 74 patients (WHO grade II-III) and analyzed the candidate markers nucleolin, telomerase catalytic subunit (hTERT; antibody clone 44F12), survivin, Ki-67, and members of the receptor tyrosine kinase I (RTK-I) family by immunohistochemistry. Telomerase activity was determined using the in vitro-based telomere repeat amplification protocol assay, and telomere length was measured using the telomere restriction fragment assay. Primary tumors with low versus high nucleolin protein expression had a 5-year event-free survival of 74%+/-13% and 31%+/-7%, respectively. Multivariate analysis identified low nucleolin expression to be independently associated with a more favorable prognosis (hazard ratio=6.25; 95% confidence interval, 1.6-24.2; p=0.008). Ki-67 and survivin correlated with histological grade but not with outcome. Immunohistochemical detection of the RTK-I family did not correlate with grade or outcome. Telomerase activity was evident in 19 of 22 primary tumors, with telomere lengthening and/or maintenance occurring in five of seven recurrent cases. Low nucleolin expression was the single most important biological predictor of outcome in pediatric intracranial ependymoma. Furthermore, telomerase reactivation and maintenance of telomeric repeats appear necessary for childhood ependymoma progression. These findings require corroboration in a clinical trial setting.
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PMID:Multifactorial analysis of predictors of outcome in pediatric intracranial ependymoma. 1870 11

Three human leucine-rich repeats and immunoglobulin-like domains (LRIG1-3) genes and proteins have recently been characterized. LRIG1 has been shown to be a suppressor of tumor growth by counteracting the signaling of epidermal growth factor receptor (EGFR) family members, including EGFR (ERBB1). Expression of LRIG proteins seems to be of importance in the pathogenesis of astrocytic tumors. In this study, the expression of LRIG1-3 was evaluated in 51 human ependymomas by immunohistochemistry. LRIG proteins were detected in all ependymomas analyzed, however, with a pronounced heterogeneity in expression and subcellular localization. Higher cytoplasmic immunoreactivity of LRIG1 correlated with older patient age and higher LRIG1 nuclear immunoreactivity with lower WHO Grade. LRIG1 displayed a stronger immunoreactivity in the cytoplasm and nuclei in spinal ependymomas than in the posterior fossa or supratentorial ependymomas, while perinuclear LRIG3 was more highly expressed in supratentorial than in infratentorial ependymomas. The indications that expression and subcellular localization of LRIG proteins could be pathogenetically associated with specific clinicopathological features of ependymoma tumors might be of importance in the carcinogeneses and tumor progression of human ependymomas.
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PMID:Expression of leucine-rich repeats and immunoglobulin-like domains (LRIG) proteins in human ependymoma relates to tumor location, WHO grade, and patient age. 1921 16

Ependymomas account for 2-9% of all neuroepithelial tumors, amounting to 6-12% of all intracranial tumors in children and up to 30% of those in children younger than 3 years. Recent findings provide evidence that intracranial and spinal ependymomas share similar molecular profiles with the radial glia of their corresponding locations. The management of intracranial ependymoma is still not optimal. The 5-year progression-free survival for children with ependymoma ranges between 30 and 50% with a worse prognosis for patients with residual disease after surgery. The prognostic relevance of most factors are still being debated. Recent studies, in which the current WHO classification criteria were applied, reported the relationship between histological grade and outcome. Biomolecular studies have identified that gain of 1q25 and EGFR overexpression correlate to poor prognosis, whereas low expression of nucleolin correlated with a favorable outcome. Ependymomas have been considered a 'surgical disease', where completeness of excision can be reached in approximately half of the cases. At present the standard treatment is radiation therapy for all patients after gross-total or near-total resection. For high-risk patients, with residual tumor, an interesting, although experimental, approach could be chemotherapy followed by secondary surgery and postoperative conformal irradiation.
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PMID:Intracranial ependymoma: factors affecting outcome. 1928 79

Myxopapillary ependymoma (MEPN) generally can be cured by gross total surgical resection and usually manifest a favorable prognosis. However, surgery is less curative in tumors that are large, multifocal or extend outside the thecal sac. Late recurrences may occur, particularly in pediatric patients. The role of adjuvant therapy is unclear in the clinical management of recurrent tumors. Clinical trial design requires a better understanding of tumor biology. Unique molecular features of MEPN were investigated by using microarray technology to compare the gene expression of five pediatric MEPN to 24 pediatric intracranial ependymoma (EPN). The upregulation of three genes of interest, homeobox B13 (HOXB13), neurofilament, light polypeptide (NEFL) and PDGFR alpha, was further studied by immunohistochemistry in a larger cohort that included adult MEPN and EPN specimens. Protein expression in MEPN was compared to subependymoma, spinal EPN, intracranial EPN and normal fetal and adult ependyma. Immunoreactivity for HOXB13, NEFL and PDGFR alpha was strongest in MEPN and virtually absent in subependymoma. Spinal and intracranial EPN generally expressed weak or focal staining. MEPN manifests unique gene and protein expression patterns compared to other EPNs. Aberrant expression of HOXB13 suggests possible recapitulation of developmental pathways in MEPN tumorigenesis. PDGFR alpha may be a potential therapeutic target in recurrent MEPN.
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PMID:Unique molecular characteristics of pediatric myxopapillary ependymoma. 1979 39


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