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)

Integrin receptors and the growth factor, scatter factor (SF; also known as hepatocyte growth factor) have been shown to modulate similar cellular processes including embryogenesis, wound healing and tumour invasion. The purpose of this study was to examine the role of SF in the regulation of integrin expression, migration and adhesion in normal human oral keratinocytes (NHK). Integrin expression was examined using flow cytometry, SF did not alter levels of expression but had a dramatic effect on cell morphology, inducing migratory filopodia and lamellipodia. SF selectively induced migration towards fibronectin, but not towards collagen I. Integrin function was further investigated by measuring the ability of NHK to adhere and migrate on various integrin ligands. SF reduced adhesion of NHK to collagen types I and IV, laminins 1 and 5 and fibronectin. The inclusion of function-blocking antibodies revealed that SF mediated upregulation of migration through alpha(5)beta(1) integrin and downregulation of adhesion through alpha(v) integrins. SF increased tyrosine phosphorylation of FAK protein in NHK after a 30-min treatment. These results show that SF can affect keratinocyte behaviour by modifying integrin function but not expression.
Arch Dermatol Res 2003 Jun
PMID:Scatter factor regulation of integrin expression and function on oral epithelial cells. 1275 Sep 24

Natural killer and natural killer-like T cell lymphomas represent a rare type of non-Hodgkin's lymphoma originally described to involve the upper aerodigestive tract. This malignancy has been increasingly observed in other extranodal sites, particularly in the skin. Patients with cutaneous natural killer cell lymphoma generally have a poor prognosis; however, the etiology and the underlying molecular pathogenesis remain unclear. This study aimed to investigate comprehensively genomic changes in blastic natural killer and extranodal natural killer-like T cell lymphoma with cutaneous involvement. Comparative genomic hybridization showed chromosome imbalances in six of eight cases studied (75%). The mean number of chromosome imbalances per sample was 2.18+/-1.63 with similar number of gains (1.18+/-1.17) and losses (1.00+/-1.34). The most frequent DNA copy number changes observed were losses of 9/9p (83%), followed by loss of 13q and gain of 7 (67%). Similar patterns of chromosome imbalances were observed in both blastic natural killer and cutaneous natural killer-like T cell lymphomas. Loss of the RB1 gene at 13q14.2 was detected in one blastic natural killer cell lymphoma with 13q loss using a gene dosage assay, and in one cutaneous natural killer-like T cell lymphoma without 13q loss using fluorescent in situ hybridization. Genomic microarray analysis identified oncogene copy number gains of PAK1 and JUNB in three of four cases studied, and gains of RAF1, CTSB, FGFR1, and BCR in two cases. Real-time polymerase chain reaction detected amplification of CTSB and RAF1 in four of five cases analyzed, JUNB and MYCN in three cases, and REL and YES1 in two cases, respectively. In conjunction with this study, an extensive literature search for the published G-banded karyotypes of four subsets of natural killer cell lymphomas was conducted, which showed a nonrandom pattern of multiple chromosome aberrations. These results reveal consistent genetic alterations in cutaneous natural killer cell lymphomas, and provide a basis for further investigation of molecular pathogenesis in this malignancy.
J Invest Dermatol 2003 Sep
PMID:Genomic alterations in blastic natural killer/extranodal natural killer-like T cell lymphoma with cutaneous involvement. 1292 24

Cowden disease, also known as multiple hamartoma syndrome, is a rare disease inherited in an autosomal dominant pattern, which confers a high risk of developing breast and thyroid carcinomas. Mutations in PTEN, a tumor suppressor gene located on chromosome 10q23, have been identified in patients with Cowden disease. In this work, the direct sequencing of all coding regions of the PTEN gene led us to the identification of N48K, a new germline PTEN missense mutation, in a patient suffering from Cowden disease. The genetic analysis of 200 chromosomes from healthy individuals revealed that the variant was not common in our population. Moreover, by functional analysis we found that the ability of PTEN N48K mutant protein to inhibit the activation of the proto-oncogene PKB/Akt was impaired, supporting the involvement of N48K mutation in Cowden disease. Loss of heterozygosity using three microsatellites (D10S215, D10S541, and D10S564) and the complete sequence analysis of PTEN exons in breast and endometrial tumor samples from the same patient were also carried out in an attempt to identify additional PTEN somatic mutations. The lack of loss of heterozygosity or additional mutations in tumor samples suggests that abnormalities of the regulatory regions of the PTEN gene or haplo-insufficiency might occur in tumors from Cowden disease patients.
J Invest Dermatol 2003 Dec
PMID:A novel loss-of-function mutation (N48K) in the PTEN gene in a Spanish patient with Cowden disease. 1467 82

Circulating malignant Sezary cells are a clonal proliferation of CD4+CD45RO+ T lymphocytes primarily involving the skin. To study the biology of these malignant T lymphocytes, we tested their ability to migrate in chemotaxis assays. Previously, we had shown that the neuropeptide neurotensin (NT) binds to freshly isolated Sezary malignant cells and induces through NT1 receptors the cell migration of the cutaneous T cell lymphoma cell line Cou-L. Here, we report that peripheral blood Sezary cells as well as the Sezary cell line Pno fail to migrate in response to neurotensin although they are capable of migrating to the chemokine stromal-cell-derived factor 1 alpha. This is in contrast with normal circulating CD4+ or CD8+ lymphocytes, which respond to both types of chemoattractants except after ex vivo short-time anti-CD3 monoclonal antibody activation, which abrogates the neurotensin-induced lymphocyte migration. Furthermore, we demonstrate that neurotensin-responsive T lymphocytes express the functional NT1 receptor responsible for chemotaxis. In these cells, but not in Sezary cells, neurotensin induces recruitment of phosphatidylinositol-3 kinase, and redistribution of phosphorylated cytoplasmic tyrosine kinase focal adhesion kinase and filamentous actin. Taken together, these results, which show functional distinctions between normal circulating lymphocytes and Sezary syndrome cells, contribute to further understanding of the physiopathology of these atypical cells.
J Invest Dermatol 2004 Jan
PMID:Sezary syndrome cells unlike normal circulating T lymphocytes fail to migrate following engagement of NT1 receptor. 1496 98

Molluscum contagiosum mainly affects children, but in adults the advent of HIV has modified its clinical spectrum. Our study is designed to ascertain the clinical profile of molluscum contagiosum in children and adults and to discover the effects of underlying HIV infection. During the study period of September 2000 to June 2002, 150 cases of molluscum contagiosum are screened and recruited at the Department of Dermatology and STD, JIPMER, Pondicherry. These include 137 children (85 male, 52 female) and 13 adults (10 male, 3 female). In children molluscum contagiosum is most commonly seen in the 5-10-year age group (58 cases), followed by the 1-5-year age group (53 cases), the 10-14-year age group (23 cases), and the younger-than-1-year age group (3 cases). In adults molluscum contagiosum is most commonly seen in the 14-20-year age group, followed by 2 cases each in the age groups 20-26 years, 26-34 years, and 34-40 years. The male-to-female sex ratio was 1.6:1 in children and 3.3:1 in adults. In both children and adults the most common sites affected are the head and neck, followed by trunk, upper extremity, genitalia, and lower extremity. It appears that the distribution of molluscum in our patients is significantly affected by the high proportion of HIV-positive adults in our sample. Seropositivity for HIV by ELISA is found in 1 of 137 children and 8 of 13 adults. In these HIV-positive patients, 2 cases of giant molluscum and one furuncle-like presentation are seen.
Dermatol Online J 2003 Dec
PMID:Clinical profile of molluscum contagiosum in children versus adults. 1499 74

Expression of nNOS mRNA was found in normal human and mouse skin tissue. Upon wounding, we observed a rapid downregulation of nNOS mRNA and protein in wounds of mice; however, when repair continued, nNOS mRNA was strongly upregulated and nNOS protein expression peaked at late stages of healing. Immunohistochemistry revealed wound keratinocytes as the cellular source of nNOS. In line with the in vivo situation, we found a basal expression of nNOS in the human keratinocyte cell line HaCaT. A marked stimulation of nNOS expression in the cells was achieved with epidermal growth factor receptor (EGFR) ligands such as epidermal growth factor (EGF), heparin-binding EGF, transforming growth factor-alpha and two alternate splicing forms of the neuregulin gene. EGF-induced induction of nNOS was completely inhibited by the specific EGFR antagonist PD153035 and by the EGFR and Janus kinase 2/3 inhibitor AG490. Activation of EGFR might contribute to the observed upregulation of nNOS also in skin repair, as we found a spatial and temporal correlation of phosphorylated EGFR (Y1173) with nNOS expression at the wound site. Thus, in addition to the inducible- and endothelial-type NOS isoforms, also nNOS expression is regulated in the process of cutaneous wound repair.
J Invest Dermatol 2004 Jul
PMID:The neuronal nitric oxide synthase is upregulated in mouse skin repair and in response to epidermal growth factor in human HaCaT keratinocytes. 1519 53

Carcinogenesis is considered as a multistep process involving functional changes in the hemidesmosomal organization. In normal skin keratinocytes, expression of the alpha(6)beta(4) integrin is restricted to the proliferative basal layer and mediates stable adhesion to the underlying basement membrane. Observations in carcinoma cells show a functional and spatial dissociation of the alpha(6)beta(4) integrin from the hemidesmosomal complex, which stimulates cell migration and, therefore, may contribute to carcinoma invasion. We now have evaluated the adhesion behavior of epithelial cells at different stages of transformation in response to activation of the beta(4) integrin. It is demonstrated that ligation of the beta(4) integrin augmented adhesion of carcinoma and pre-carcinoma cells to non-modified plastic. In contrast, adhesion behavior of normal human keratinocytes was not influenced by ligation of the beta(4) integrin. In order to explain the mechanism of beta(4)-mediated adhesion, the hypothesis of an "inside-out" activation of integrins was tested. Evidence is given that for cells expressing the alpha(6)beta(4) integrin, ligation of the beta(4) integrin increased beta(1) integrin-mediated adhesion. Furthermore, ligation of the beta(4) integrin led to phosphorylation of PKB/Akt at both phosphorylation sites. Functional blocking of PKB/Akt by dominant-negative overexpression decreased cell adhesion in response to beta(4) integrin ligation. Taken together, the present data establish a link between the ligation of the beta(4) integrin and beta(1) integrin-mediated cell adhesion in carcinoma and pre-carcinoma cells. Hence, these findings provide further insight into the conversion processes during carcinogenesis and show the beta(4) integrin to be a key regulator of cellular adhesion.
J Invest Dermatol 2004 Sep
PMID:Ligation of the beta4 integrin triggers adhesion behavior of human keratinocytes by an "inside-out" mechanism. 1530 80

Stem cell factor (SCF) and its receptor, KIT, are essential to the migration and differentiation of melanocytes during embryogenesis. We previously demonstrated that apoptosis is induced by blocking survival function of the SCF/KIT interaction in a mouse neural crest cell (NCC) primary culture. Using the NCCmelb4 cell line, we investigated the occurrence of apoptosis in the cultured cells when KIT receptors were blocked by the monoclonal anti-KIT antibody (ACK2). Apoptosis following treatment with ACK2 was detected by DNA fragmentation assay, in situ apoptosis detection, and electron microscopy. We noted a decrease in extracellular signal-related kinase (ERK) and ribosomal S6 kinase (RSK) protein expression following ACK2 incubation. Western blot analysis and real-time quantitative RT-PCR revealed an apparent time-dependent reduction in Bcl-2 protein levels with respect to ACK2 within the NCCmelb4 cells. In terms of Bax expression, a difference was not found. Fas and caspase8 proteins increased time-dependently in proportion to ACK2 incubation. We noted apoptotic cell death upon addition of ACK2, with evidence of possible involvement of Bcl-2 and Fas in the induction of apoptosis. In contrast, no significant correlation between Fas ligand (Fas-L) expression and ACK2 was found. Fas activation appears to occur independent of Fas-L during ACK2-induced cell death. Therefore, we propose that Fas-L expression in NCCmelb4 cells does not play a major role in facilitating apoptosis. Furthermore, we hypothesize that these molecules combined with SCF/KIT play an important role in regulating the induction of vertebrate NCC apoptosis during embryogenesis.
J Invest Dermatol 2005 Jan
PMID:Bcl-2 reduced and fas activated by the inhibition of stem cell factor/KIT signaling in murine melanocyte precursors. 1565 78

The interaction of the urokinase-type plasminogen activator (uPA) receptor (uPAR) with integrins plays a critical role in the regulation of cell adhesion and migration. However, the molecular events underlying the modulation of the interaction of uPAR and integrin are poorly understood. Gangliosides are thought to regulate epithelial cell adhesion and migration by inhibiting alpha(5)beta(1) integrin and epidermal growth factor receptor (EGFR) signaling. We report here that increases in the expression of ganglioside NeuAcalpha2-->3Galbeta1-->3GalNAcbeta1-->4(NeuAcalpha2-->8NeuAcalpha2-->3)Galbeta1-->4Glcbeta1-Cer (GT1b) or NeuAcalpha2-->3Galbeta1-->4Glcbeta1-Cer (GM3) inhibit uPA-dependent cell migration by preventing the association of uPAR with alpha(5)beta(1) integrin or uPAR/alpha(5)beta(1) integrin with the EGFR, respectively. As a result, uPA-dependent focal adhesion kinase (FAK) and integrin-mediated EGFR signaling are suppressed. Both gangliosides inhibit uPAR signaling-stimulated migration; however, GM3 inhibits uPA-induced EGFR phosphorylation by blocking the crosstalk between integrin and EGFR, whereas GT1b suppresses both uPA-induced FAK and EGFR activation by preventing the activation of integrin alpha(5)beta(1).
J Invest Dermatol 2005 Apr
PMID:Gangliosides inhibit urokinase-type plasminogen activator (uPA)-dependent squamous carcinoma cell migration by preventing uPA receptor/alphabeta integrin/epidermal growth factor receptor interactions. 1581 44

Most of the cultured scleroderma fibroblasts have been reported to be myofibroblasts that have the ability to express alpha smooth muscle actin (alphaSMA). It is reported that, in human lung fibroblasts, alphaSMA is induced by transforming growth factor-beta (TGF-beta), which requires focal adhesion kinase (FAK) phosphorylation on its Tyr-397 site. In this study, we investigated how alphaSMA expression is upregulated in cultured scleroderma fibroblasts. 4-amino-5-(4-chlorophenyl)-7-(butyl)pyrazolo[3,4-d]pyrimidine, which is a pharmacologic inhibitor of FAK/Src, markedly diminished upregulated alphaSMA expression in scleroderma fibroblasts as well as in normal fibroblasts stimulated with TGF-beta. Likewise, alphaSMA expression was significantly reduced in sclerderma fibroblasts transfected with kinase-deficient FAK mutant. FAK phosphorylation levels on Tyr-397 in scleroderma fibroblasts were significantly higher than those in normal fibroblasts. Both alphaSMA expression and FAK phosphorylation levels in scleroderma fibroblasts were markedly diminished by the treatment with TGF-beta antisense oligonucleotide. These results indicate that the constitutive phosphorylation of FAK, which is possibly because of the autocrine TGF-beta signaling, may play an important role in alphaSMA expression in scleroderma fibroblasts.
J Invest Dermatol 2005 May
PMID:Constitutive phosphorylation of focal adhesion kinase is involved in the myofibroblast differentiation of scleroderma fibroblasts. 1585 26


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