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

Protein tyrosine kinases have been implicated in tumor initiation and progression. Here we used Northern blotting to study expression of their genes in cultured normal melanocytes and 19 melanoma cell lines from different stages of tumor progression. We detected transcripts for 2 cytoplasmic (ABL and FES) and 6 receptor (ECK, ERB-B2, FGF-R4, IGFI-R, KDR and TIE) kinases but not for receptors RET or TRK-A. Genes for ECK, FGF-R4 and TIE were expressed ectopically in melanomas (not in normal melanocytes). Similarly, ECK protein was detected by immunoblotting in metastatic melanomas but not in normal melanocytes. ECK mRNA levels tended to increase again during late melanoma progression. ECK and TIE mRNAs were also detected in highly metastatic variant cells but not in the corresponding poorly metastatic parental lines. Conversely, FES and KDR gene expression was lost in most advanced primary and metastatic melanomas. These findings suggest positive and negative roles for specific tyrosine kinases during progression.
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PMID:Abnormal protein tyrosine kinase gene expression during melanoma progression and metastasis. 781 45

To identify the novel receptor tyrosine kinases (RTKs) critical to the proliferation of hematopoietic stem cells, we performed polymerase chain reaction-based cloning from highly purified murine hematopoietic stem cells. Lineage marker-negative, c-KIT-positive, and Ly6A/E- or Sca-1-positive (Lin-c-KIT+Sca-1+) cells were sorted by a fluorescence-activated cell sorter. Two sets of degenerate oligonucleotide primers were directed to the conserved sequences of the catalytic domain, and were used to amplify cDNAs that encode protein tyrosine kinases (PTKs). One hundred cDNA clones were sequenced and 8 RTKs were identified, as well as 12 non-RTKs and 2 serine/threonine kinases. Sixteen cDNAs were identical to the known kinase genes (PKC beta, JAK-1, JAK-2, TYK-2, HCK, FGR, FYN, BLK, c-FES, FER, c-ABL, c-KIT, FLK-1, FLK-2, IGF1R, and ECK). Six novel cDNA sequences (stk series) were identified. However, three of them turned out to be BPK, RYK, and TEK. The remaining three showed high homology to S6 kinase II, JAK-2, and v-SEA/c-MET, respectively. Characterization of full-length cDNA sequence of the v-SEA/cMET-related gene showed that this was a novel RTK gene and we named this gene STK (stem cell-derived tyrosine kinase). We identified two distinct forms of STK cDNA; the short one encoded a putative truncated protein that lacked most of the extracellular domain. STK was expressed at various stages of hematopoietic cells, including stem cells, but we could not detect any apparent expression in other adult tissues. The expression of the truncated form of mRNA was more predominant than that of the complete form. STK was assigned by fluorescent in situ hybridization to the R-positive F1 band of chromosome 9, the same region to which hepatic growth factor-like protein has been assigned. Characterization of these PTKs, including STK, will be helpful to elucidate the molecular mechanism of the growth regulation of hematopoietic stem cells.
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PMID:Molecular cloning of a novel receptor tyrosine kinase gene, STK, derived from enriched hematopoietic stem cells. 819 52

Protein tyrosyl phosphorylation is an essential component in intracellular signalling, with diverse and crucial functions including mediation of cell proliferation, survival, death, differentiation, migration and attachment. It is regulated by the balance between the activities of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases. A number of PTKs are encoded by proto-oncogenes or viral oncogenes, and are thus strongly implicated in cancer. While a role for PTKs in human melanoma is less firmly established, human melanomas or melanoma cells have been reported to contain more tyrosine phosphate than normal melanocytes, and some receptor PTKs (EPH-A2/ ECK and EPH-B3) are overexpressed in over 90% of melanoma cell lines. Other specific PTKs are also frequently overexpressed, including KDR and fibroblast growth factor receptor-4 (FGF-R4), while, interestingly, yet others, such as KIT and FES, are consistently downregulated in melanoma cell lines. All of these differentially expressed PTKs are candidates for gene products important in melanoma development. In addition, PTKs expressed in significant amounts in both benign and malignant melanocytes, such as insulin-like growth factor-1 receptor (IGF1-R), FGF-R1, HER2/NEU and FAK, are likely to play a role in melanoma genesis and progression.
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PMID:Protein tyrosine kinases in malignant melanoma. 1109

Ephrins and Eph receptors are involved in axon guidance and cellular morphogenesis. An interaction between ephrin and Eph receptors elicits neuronal growth-cone collapse through cytoskeletal disassembly. When NIH3T3 cells were plated onto an ephrinA1-coated surface, the cells both adhered and spread. Adhesion and spreading proceeded concomitantly with changes in both the actin and microtubule cytoskeleton. EphA2, focal adhesion kinase (FAK) and p130(cas) were identified as the major ephrin-dependent phosphotyrosyl proteins during the ephrin-induced morphological changes. Mouse embryonic fibroblasts (MEFs) derived from FAK(-/-) and p130(cas-/-) mice had severe defects in ephrinA1-induced cell spreading, which were reversed after re-expression of FAK or p130(cas), respectively. Expression of a constitutively active EphA2 induced NIH3T3 cells to undergo identical, but ligand-independent, morphological changes. These data show that ephrinA1 can induce cell adhesion and actin cytoskeletal changes in fibroblasts in a FAK- and p130(cas)-dependent manner, through activation of the EphA2 receptor. The finding that ephrin Eph signalling can result in actin cytoskeletal assembly, rather than disassembly, has many implications for ephrin Eph responses in other cell types.
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PMID:EphrinA1-induced cytoskeletal re-organization requires FAK and p130(cas). 1213 57

The molecular analysis of tumors, such as melanoma, has benefited significantly from microarray technology that can facilitate the classification of tumors based on the differential expression of genes. The data summarized in this review describe the molecular profile of aggressive cutaneous and uveal melanoma cells as that of multiple phenotypes similar to a pluripotent, embryonic-like stem cell. A noteworthy example of the plasticity of the aggressive melanoma cell phenotype is demonstrated by the ability of these tumor cells to engage in vasculogenic mimicry and neovascularization. A review of the current evidence demonstrating important cellular and molecular determinants of melanoma vasculogenic mimicry is presented. In addition, novel signaling pathways are discussed, involving VE-cadherin, EphA2, FAK, and PI 3-kinase, which promote cell migration, invasion, and matrix remodeling. The observations summarized in this review describe some of the key molecular events that regulate the process of melanoma vasculogenic mimicry and identify new signal transduction pathways that can serve as putative targets for therapeutic intervention.
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PMID:Molecular plasticity of human melanoma cells. 1278 82

The Eph tyrosine kinases interact with ligands of the Ephrin family and have diverse cellular functions. EphA2 has been recognized to be an oncoprotein of importance in a range of cancers. Here, we examine the effect of EphA2 overexpression and ligation by chimeric Ephrin A1-Fc on the invasive phenotype of pancreatic adenocarcinoma cells. We show that EphA2 overexpression induces a FAK-dependent increase in MMP-2 expression and invasiveness. EphA2 ligation induces proteosomal degradation of EphA2, attenuates the invasive phenotype, and decreases both FAK phosphorylation and MMP-2 expression. EphA2 appears to represent a rational therapeutic target and ligation by Ephrin A1-Fc is one strategy to modulate levels of this oncoprotein.
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PMID:Ligation of EphA2 by Ephrin A1-Fc inhibits pancreatic adenocarcinoma cellular invasiveness. 1524 2

Overexpression and enhanced activation of the epidermal growth factor (EGF) receptor are frequent events in human cancers that correlate with poor prognosis. Anti-phosphotyrosine and anti-EGFr affinity chromatography, isotope-coded muLC-MS/MS, and immunoblot methods were combined to describe and measure signaling networks associated with EGF receptor activation and pharmacological inhibition. The squamous carcinoma cell line HN5, which overexpresses EGF receptor and displays sustained receptor kinase activation, was used as a model system, where pharmacological inhibition of EGF receptor kinase by erlotinib markedly reduced auto and substrate phosphorylation, Src family phosphorylation at EGFR Y845, while increasing total EGF receptor protein. Diverse sets of known and poorly described functional protein classes were unequivocally identified by affinity selection, comprising either proteins tyrosine phosphorylated or complexed therewith, predominantly through EGF receptor and Src family kinases, principally 1) immediate EGF receptor signaling complexes (18%); 2) complexes involved in adhesion and cell-cell contacts (34%); and 3) receptor internalization and degradation signals. Novel and known phosphorylation sites could be located despite the complexity of the peptide mixtures. In addition to interactions with multiple signaling adaptors Grb2, SHC, SCK, and NSP2, EGF receptors in HN5 cells were shown to form direct or indirect physical interactions with additional kinases including ACK1, focal adhesion kinase (FAK), Pyk2, Yes, EphA2, and EphB4. Pharmacological inhibition of EGF receptor kinase activity by erlotinib resulted in reduced phosphorylation of downstream signaling, for example through Cbl/Cbl-B, phospholipase Cgamma (PLCgamma), Erk1/2, PI-3 kinase, and STAT3/5. Focal adhesion proteins, FAK, Pyk2, paxillin, ARF/GIT1, and plakophillin were down-regulated by transient EGF stimulation suggesting a complex balance between growth factor induced kinase and phosphatase activities in the control of cell adhesion complexes. The functional interactions between IGF-1 receptor, lysophosphatidic acid (LPA) signaling, and EGF receptor were observed, both direct and/or indirectly on phospho-Akt, phospho-Erk1/2, and phospho-ribosomal S6.
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PMID:Phosphotyrosine signaling networks in epidermal growth factor receptor overexpressing squamous carcinoma cells. 1565 67

Breast cancer is the second-leading cause of death among Mexican women >35 years of age. At the molecular level, changes in many genetic pathways have been reported to be associated with this neoplasm. To analyze these changes, we determined gene expression profiles and chromosomal structural alterations in tumors from Mexican women. We obtained mRNA to identify expression profiles with microarray technology, and DNA to determine amplifications and deletions, in 10 fresh sporadic breast tumor biopsies without treatment, as well as in 10 nonaffected breast tissues. Expression profiles were compared with genetic changes observed by comparative genomic hybridization (CGH). We compared the expression profiles against the structural alterations from the studied genes by means of microarrays; at least 17 of these genes correlated with DNA copy number alterations. We found that the following genes were overexpressed: LAMC1, PCTK3, CCNC, CCND1, FGF3, PCTK2, L1CAM, BGN, and PLXNB3 (alias PLEXR). Underexpressed genes included CASP9, FGR, TP73, HSPG2, and ERCC1; genes turned off included FRAP1, EPHA2 (previously ECK), IL12A, E2F5, TNFRSF10B, TNFRSF10A, EFNB3, and BCL2. The results will allow us, in the near future, to outline genes that could serve as diagnostic, prognostic, or target therapy markers for the Mexican population.
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PMID:Genetic expression profiles and chromosomal alterations in sporadic breast cancer in Mexican women. 1701 86

Eph receptors, the largest receptor tyrosine kinases, and their ephrin ligands play important roles in axon guidance and cell migration during development of the nervous system. Recently, these molecules are also found involved in tumorigenesis of different kinds of cancers. In this study, we demonstrated that expression of ephrin-A1 was dramatically down-regulated in glioma cell lines and in primary gliomas compared to the matched normal tissues. Forced expression of ephrin-A1 attenuated cell migration, cell proliferation, and adhesion-independent growth in human glioma U251 cells. EphA2, a receptor for ephrin-A1 and an oncoprotein, was greatly decreased in ephrin-A1-transfected glioma cells. Overexpression of ephrin-A1 stimulated activation of EphA2 by phosphorylation and led to its degradation. Furthermore, focal adhesion kinase (FAK), a known downstream molecule of EphA2, was also down-regulated in the ephrin-A1 transfected cells. These results suggested that ephrin-A1 serves as a critical negative regulator in the tumorigenesis of gliomas by down-regulating EphA2 and FAK, which may provide potential valuable targets for therapeutic intervention.
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PMID:Ephrin-A1 is a negative regulator in glioma through down-regulation of EphA2 and FAK. 1733 25

Eph receptors and ephrin ligands are widely expressed in epithelial cells and mediate cell repulsive motility through heterotypic cell-cell interactions. Several Ephs, including EphA2, are greatly overexpressed in certain tumors, in correlation with poor prognosis and high vascularity in cancer tissues. The ability of several Eph receptors to regulate cell migration and invasion likely contribute to tumor progression and metastasis. We report here that in prostatic carcinoma cells ephrinA1 elicits a repulsive response that is executed through a Rho-dependent actino/myosin contractility activation, ultimately leading to retraction of the cell body. This appears to occur through assembly of an EphA2-associated complex involving the two kinases Src and focal adhesion kinase (FAK). EphrinA1-mediated repulsion leads to the selective phosphorylation of Tyr-576/577 of FAK, enhancing FAK kinase activity. The repulsive response elicited by ephrinA1 in prostatic carcinoma cells is mainly driven by a Rho-mediated phosphorylation of myosin light chain II, in which Src and FAK activation are required steps. Consequently, Src and FAK are upstream regulators of the overall response induced by ephrinA1/EphA2, instructing cells to retract the cell body and to move away, probably facilitating dissemination and tissue invasion of ephrin-sensitive carcinomas.
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PMID:EphrinA1 activates a Src/focal adhesion kinase-mediated motility response leading to rho-dependent actino/myosin contractility. 1744 13


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