Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidermal growth factor receptor (EGFR) is expressed in many cancers and is associated with poor prognosis. EGFR activation pathways have been well characterised using tumour cell lines and are known to involve EGFR activation through autophosphorylation. Phosphorylation of downstream signalling molecules, such as ERK1/2 (extra-cellular regulated kinase 1 and 2) and PKB/Akt (protein kinase B), leads to enhanced tumour cell survival and proliferation. Although EGFR expression has been determined in neuroendocrine tumour tissue, its activation and subsequent effects on the downstream signalling molecules, ERK1/2 and Akt, have not been studied. We therefore planned to determine the role of EGFR in neuroendocrine tumours (NETs) by determining its pattern of expression and activation, and the subsequent activation of downstream signalling molecules ERK1/2 and Akt. Paraffin-embedded tumour tissue was available from 98 patients with NETs (39 foregut, 42 midgut, four hindgut, five paragangliomas, and four of unknown origin). Immunohistochemical evaluation was performed for the expression of EGFR, p-EGFR, p-Akt, and p-ERK1/2. Ninety-six percent of tumour samples were positive for EGFR expression; 63% were positive for activated EGFR; 76% were positive for activated Akt; and 96% were positive for activated ERK1/2. Importantly, the histological score for the activation of Akt and ERK1/2 correlated with the histological score for activated EGFR. These data provide a rationale for considering EGFR inhibitors in the treatment of NETs. Additionally, direct inhibition of Akt and ERK1/2 may provide further therapeutic options in the treatment of NETs in the future.
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PMID:Epidermal growth factor receptor expression and activation in neuroendocrine tumours. 1662 34

The most frequent alterations found in astrocytomas are two major groups of signaling proteins: the cell cycle and the growth factor-regulated signaling pathways. The aim of our study was to detect changes in expression of the following proteins: the tumor suppressors PTEN, p53, and p21Waf1/Cip1, glial fibrillary acidic protein (GFAP, as a marker of astroglial differentiation), the phosphorylated form of protein kinase B/Akt (PKB/Akt), which is downstream to the epidermal growth factor receptor (EGFR), and MDM2, which degrades p53. Paraffin-embedded astrocytoma tissue samples from 89 patients were divided into low grade (grade I-II; 42 samples) and high grade astrocytomas (grade III-IV; 47 samples). Mouse monoclonal antibodies against GFAP, PTEN, PKB/Akt phosphorylated on serine 473, EGFR, p53, p21Waf1/Cip1 and MDM2 were used, followed by standard indirect immunohistochemical method. EGFR protein was detected in 29 % of low grade and in 60 % of high grade astrocytomas. The expression of phosphorylated PKB/Akt was found in roughly the same proportions: in 86% of low grade and in 79% of high grade astrocytomas. PTEN was not found in most of astrocytomas, 64% of low grade and 74% of high grade tumors showed no PTEN staining. Overexpression of the mutated form of p53 or loss of p53 expression, however, was found in about 63% in both groups of astrocytomas with no differences between them. GFAP expression was decreased in tumor astrocytes compared to normal astrocytes and this decreased with grading. GFAP positive tumor cells were detected in only 50% of low grade, and 32% of high grade astrocytomas. The level of MDM2 expression was similar in both grades. Loss of p21Waf1/Cip1 expression was shown in 20% of low and in 45% of high grade tumors. In the subgroup of high grade tumors with wild type p53, 86% showed p21Waf1/Cip1 expression, whereas in the subgroup of high grade tumors with altered p53, only 35% displayed p21Waf1/Cip1. We conclude that EGFR expression increases with astrocytoma grading. EGFR activation may subsequently lead to stimulation of the PKB/Akt survival pathway. PTEN defects may also participate in aggressive tumor behaviour through activation of the PKB/Akt pathway. The alteration of p53 supports the finding that the cell cycle regulation is also disrupted during development of astrocytomas. The changes in PTEN and p53 expression, and activation of PKB/Akt are events in the early stages of astrocytomagenesis. EGFR is one of the factors, which drives the progression of astrocytomas from low to high grade stage.
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PMID:Could changes in the regulation of the PI3K/PKB/Akt signaling pathway and cell cycle be involved in astrocytic tumor pathogenesis and progression? 1782 24

Atypical chronic myeloid leukemia (aCML) as defined by the WHO classification is a rare hematopoietic stem cell disorder, which shows both myeloproliferative as well as myelodysplastic features. Because of the presence of neutrophilic leukocytosis, aCML may resemble chronic myelogenous leukemia. However, in contrast with the latter, aCML lacks a Philadelphia chromosome or the BCR/ABL fusion gene. The molecular pathogenesis of aCML and its relationship to other myeloproliferative neoplasms is unknown. To clarify these points, the presence of JAK2 V617F was examined by a retrospective analysis of archival specimens obtained from two large medical institutions. Paraffin-embedded bone marrow (BM) trephines and clot sections were examined by an allele-specific TaqMan PCR suitable for use with decalcified tissue. Fifty-nine cases of Philadelphia (Ph) chromosome negative chronic myeloproliferative neoplasms (CMPN) and normal bone marrows (BM) served as controls. None of the nine amplifiable cases of aCML and none of the normal BM controls showed a JAK2 V617F mutation, in contrast to 45/59 (76%) of the Ph chromosome negative CMPN cases. Atypical CML should therefore be considered as a JAK2 negative chronic myeloid neoplasm that remains properly categorized, alongside chronic myelomonocytic leukemia and juvenile myelomonocytic leukemia, within the WHO group of myelodysplastic/myeloproliferative neoplasms.
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PMID:Atypical chronic myeloid leukemia as defined in the WHO classification is a JAK2 V617F negative neoplasm. 1942 35

Bronchioloalveolar carcinoma (BAC) is classified as a subset of lung adenocarcinoma but has a distinct clinical presentation, tumor biology, response to therapy, and prognosis compared with other subtypes of lung adenocarcinoma. This study was designed to investigate the clinicopathological differences between BAC and adenocarcinoma and the expression of focal adhesion kinase (FAK) and phosphatase and tensin homologue (PTEN) and their clinical significance in BAC and adenocarcinoma. A retrospective analysis was performed on 77 patients with BAC and 172 patients with pure adenocarcinoma seen during the period from January 1998 to December 2000. All patients underwent lobectomy or pneumonectomy and systematic lymph node dissection. Paraffin-embedded tissue blocks from these patients were obtained and expressions of PTEN and FAK were evaluated by using immunohistochemical staining. Clinicopathological characteristics and survival outcome were reviewed and compared between patients with BAC and adenocarcinoma. Lymph node status, clinical symptoms, CT appearance and expression of FAK were different between BAC and adenocarcinoma. The overall survival of BAC was better than that of adenocarcinoma. In patients with FAK(-), the overall survival was not different between BAC and adenocarcinoma. In patients with adenocarcinoma, the overall survival was better for FAK(-) compared with FAK(+). Expression of PTEN had a prognostic significance in patients with BAC and adenocarcinoma. BAC and adenocarcinoma have different clinicopathological presentations. Expression of FAK has some effect on such differences and affects survival of lung adenocarcinoma. Expression of PTEN can predict outcome of resected lung adenocarcinoma and BAC.
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PMID:Expression of FAK and PTEN in bronchioloalveolar carcinoma and lung adenocarcinoma. 1940 43

Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) characterized by JAK2 mutation. The exon 14 V617F mutation is present in almost all patients with PV and in approx. 60% of patients with ET and PMF. The importance of JAK2V617F in the differential diagnostic considerations is still unclear and here the BM morphology examination still represents an important diagnostic tool. In the WHO classification of Ph1-negative MPNs, the identification of JAK2 mutations represents a major diagnostic criterion of these diseases. Therefore we decided to implement the examination of JAK2V617F mutation in formalin-fixed paraffin-embedded biopsy specimens of patients with Ph1-negative MPN using allele-specific PCR. In addition, in all JAK2 V617F negative patients with PV we sequenced the whole JAK2 exon 12. Until now we examined up to 200 patients with clinically confirmed MPN and our results in all three categories PV, ET and PMF are in agreement with earlier published data. Paraffin embedded tissues represent a valuable source of DNA which can be used in the diagnostics of both JAK2 exon 12 and exon 14 mutations. It is of particular importance if the fresh material is not available and there is a clinical and/or research utility for the performance of PCR on archival bone marrow samples with PV, ET or PMF suspicion.
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PMID:[Our experience with detection of JAK2 mutations in paraffin-embedded trephine bone marrow biopsies of patients with chronic myeloproliferative disorders]. 2188 28