Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04626 (erbB-2)
 5,251 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The histopathological characteristics, proto-oncogene amplification, immunohistopathology of the c-erbB-2 product distribution, and the DNA content of nuclei were examined in metastatic brain tumors, which consisted of seven adenocarcinomas, a large cell carcinoma, a squamous cell carcinoma, a renal cell carcinoma and a mucoepidermoid carcinoma. A very high incidence of DNA changes was seen in these tumors. Proto-oncogene amplification and abnormal DNA content in the nuclear portion were found in 64% (7/11) and 67% (6/9) of cases, respectively. We also found double oncogene alteration in three cases metastasizing from lung, esophagus and kidney, and triple oncogene alteration in one case metastasizing from breast. We could not identify the common alterations in the group of metastatic brain tumor cells. These data suggest that the proto-oncogene amplifications and the alteration of DNA ploidy pattern may contribute to the metastatic process.
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PMID:DNA amplifications and elevated expression of proto-oncogene in addition to altered DNA ploidy in metastatic brain tumors. 791 69

Tumorigenesis is the result of sequential or multiple genetic alterations. The overexpression or amplification of various oncogenes in diverse human brain tumors have been observed. While numerous studies on the immunohistochemical demonstration of EGFR-overexpression have been reported, little has been found in the literature about the c-erbB-2 protein in human astrocytic tumors. In the present study, we evaluated the expression of EGFR and c-erbB-2 protein in 33 astrocytic tumors with immunohistochemistry. According to the World Health Organization brain tumor classification, the study included 9 low-grade astrocytomas (grade 2), 15 anaplastic astrocytomas (grade 3), and 9 glioblastomas multiforme (grade 4). The positive EGFR immunoreactivity was detected in 28 (85%) of 33 tumors. The expression of EGFR increased with the grade of malignancy in low-grade astrocytomas (67%), anaplastic astrocytomas (87%), and glioblastomas (100%). For the expression of c-erbB-2 protein, 17 (51.5%) of 33 tumors were positive immunostain, including 3 low-grade astrocytomas (37.5%), 9 anaplastic astrocytomas (81.8%), and 5 glioblastomas (62.5%). Different degrees of immunoreactivity for c-erbB-2 protein were found in variant grades of astrocytomas. However, the positive immunostain of EGFR displayed moderate or strong reactivity. The coexpression of EGFR and c-erbB-2 protein was found in 17 (15.5%) of 33 tumors. The results emphasize that the overexpression of EGFR parallels astrocytoma progession and higher frequency of c-erbB-2 immunoreactivity was seen in snaplastic astrocytomas and glioblastomas than in low-grade astrocytomas.
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PMID:Expression of epidermal growth factor receptors and c-erbB-2 proteins in human astrocytic tumors. 926 Apr 61

There are distinct genetic pathways leading to the glioblastoma, the most malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in older patients and are characterized by epidermal growth factor (EGF) receptor amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in younger patients and frequently contain p53 mutations. In this study, we assessed the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. Single-strand conformation polymorphism followed by direct DNA sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN mutations in seven cases (37%). Homozygous p16 deletion was detected by differential polymerase chain reaction in seven (37%) gliosarcomas. The overall incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive. Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the gliosarcomas showed amplification or overexpression of the EGF receptor. Thus gliosarcomas exhibit a genetic profile similar to that of primary (de novo) glioblastomas, except for the absence of EGFR amplification/overexpression. Identical PTEN mutations in the gliomatous and sarcomatous tumor components were found in two cases. Other biopsies contained p16 deletions, an identical p53 mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly supports the concept of a monoclonal origin of gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.
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PMID:Genetic profile of gliosarcomas. 1066 71

Overactivation of epidermal growth factor receptor (EGFR) signaling has been recognized as an important step in the pathogenesis and progression of multiple forms of cancer of epithelial origin. Reports regarding EGFR family members in brain tumors are sparse and, thus, the significance of EGFR expression in childhood brain tumors is unclear. In this study, the expression of the EGFR family members was analyzed in 22 medulloblastomas. During the immunohistochemical study, a sensitive, four-step, alkaline phosphatase conjugated antigen detection technique was employed. The results demonstrated the presence of c-erbB-2 (HER-2) and c-erbB-4 (HER-4) in 10 to 50% of the neoplastic cells of high-grade glial tumors with high immunoreactivity, while c-erbB-3 (HER-3) was only detected in less than 10% of the neoplastically-transformed cells. In a follow-up, 70% of children, usually under 4 years of age, with c-erbB-2 (HER-2)-positive MEDs/PNETs, succumbed to the cancer. The Kaplan-Meier estimation revealed a significant correlation between c-erbB-2 expression and survival (p = 0.002), suggesting that c-erbB-2 (HER-2) is probably a prognostic marker for limited survival. Medulloblastoma is the most common malignant brain tumor that occurs during childhood. Multimodality treatment regimens have substantially improved survival in this disease; however, the tumor is incurable in about one-third of patients with medulloblastoma, and the current treatment has a detrimental effect on long-term survivors. As such, the results of this study further support the idea that targeting EGFR alone, or in combination with its downstream mediators, represents a promising new approach for the management of childhood brain tumors. Moreover, c-erbB-2 (HER-2) expression may also be of use in better classifying brain tumors.
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PMID:Epidermal growth factor receptor (EGFR) expression in childhood brain tumors. 1609 49

The treatment of glioblastoma is unsatisfactory. Improved understanding of the biological effects of treatment, together with development of new tools to predict outcome of the initiated treatment are therefore of great need. Vandetanib (ZD6474) is mainly a vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) receptor tyrosine kinase inhibitor. This study investigated the pattern of protein expression in brain tumor and normal brain tissue, following treatment with vandetanib in a rat glioma model. BT4C-cells were stereotactically implanted into the brain of BD IX rats. The rats were divided into three different experiments. The treatment schedule for experiments one and two consisted of daily, oral doses of vandetanib from day 6 until day 12 or 20 after implantation, respectively. In the third experiment, each animal received a single dose of vandetanib on day 19 after implantation and was then sacrificed 2, 8 or 24 h thereafter. The protein expression profiles were analyzed by SELDI-TOF-MS and evaluated with multivariate statistical methods. Following treatment with vandetanib, we found significantly altered protein expression pattern in malignant glioma and normal brain. Analyzing protein spectra is an interesting option to assess biological effects induced in brain tissue by signal transduction inhibitors such as vandetanib.
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PMID:Vandetanib alters the protein pattern in malignant glioma and normal brain in the BT4C rat glioma model. 2081 10

The aim of this study is to investigate the anti-cancer effect of the bispecific diphtheria toxin (DT) based immunotoxin DTATEGF, which targets both the epidermal growth factor (EGF) receptor (EGFR) and the urokinase-type plasminogen activator (uPA) receptor (uPAR) in vitro and in vivo when delivered by convection-enhanced delivery (CED) via an osmotic minipump in a human metastatic non-small cell lung cancer (NSCLC) brain tumor mouse xenograft model. The effects of the bispecific immunotoxin DTATEGF, and monospecific DTAT, DTEGF and control DT at various concentrations were tested for their ability to inhibit the proliferation of human metastatic NSCLC PC9-BrM3 cells in vitro by MTT assay. A xenograft model of human metastatic NSCLC intracranial model was established in nude mice using the human NSCLC PC9-BrM3 cell line genetically marked with a firefly luciferase reporter gene. One microgram of DTATEGF in the treatment group or control DT in the control group was delivered intracranially by CED via an osmotic minipump. The bioluminescent imaging (BLI) was performed at day 7, 14, 1 month, 2 months, and 3 months. Kaplan-Meier survival curves for the two groups were generated. The brain tissue samples were stained by hematoxylin and eosin for histopathological assessment. In vitro, DTATEGF could selectively kill PC9-BrM3 cells and showed an IC(50) less than 0.001 nM, representing a more than 100- to 1000-fold increase in activity as compared to monospecific DTAT and DTEGF. In vivo, mice with tumors were treated intracranially with drug via CED where the results showed the treatment was successful in providing a survival benefit with the median survival of mice treated with DTATEGF being significantly prolonged relative to controls (87 vs. 63 days, P = 0.006). The results of these experiments indicate that DTATEGF kills the NSCLC PC9-BrM3 cell line in vitro, and when it is delivered via CED intracranially, it is highly efficacious against metastatic NSCLC brain tumors. DTATEGF is a safe and effective drug where further preclinical and clinical development is warranted for the management of metastatic brain tumors.
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PMID:Intracerebral infusion of the bispecific targeted toxin DTATEGF in a mouse xenograft model of a human metastatic non-small cell lung cancer. 2269 10

The epidermal growth factor (EGF) receptor EGFR is a major receptor tyrosine kinase whose role in gliomagenesis is well established. We have recently identified EHD3 [Eps15 homology (EH) domain-containing protein 3], an endocytic trafficking regulatory protein, as a putative brain tumor suppressor. Here, we investigate the underlying mechanisms, by establishing a novel mechanistic and functional connection between EHD3 and the EGFR signaling pathway. We show that, in response to stimulation with the EGF ligand, EHD3 accelerates the rate of EGFR degradation by dramatically increasing its ubiquitination. As part of this process, EHD3 also regulates EGFR endosomal trafficking by diverting it away from the recycling route into the degradative pathway. Moreover, we found that upon EGF activation, rather than affecting the total MAPK and AKT downstream signaling, EHD3 decreases endosome-based signaling of these two pathways, thus suggesting the contribution of EHD3 in the spatial regulation of EGFR signaling. This function explains the higher sensitivity of EHD3-expressing cells to the growth-inhibitory effects of EGF. In summary, this is the first report supporting a mechanism of EHD3-mediated tumor suppression that involves the attenuation of endosomal signaling of the EGFR oncogene.
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PMID:Spatio-temporal regulation of EGFR signaling by the Eps15 homology domain-containing protein 3 (EHD3). 2781 56