751
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Kim JR, Irie A, Tsukamoto H, Nishimura Y. A role of kinase inactive ZAP-70 in altered peptide ligand stimulated T cell activation. Biochem Biophys Res Commun 2006; 341:19-27. [PMID: 16412387 DOI: 10.1016/j.bbrc.2005.12.143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 12/21/2005] [Indexed: 12/01/2022]
Abstract
T cell activation signals induced by altered peptide ligands (APLs) are different from those induced by the original agonistic peptide. The characteristics of the former are partial phosphorylation of TCR-zeta and no tyrosine-phosphorylation of zeta-associated protein-70 (ZAP-70). To analyze further those signaling pathways, we introduced a dominant negative (DN) form of ZAP-70 into a human CD4(+) T cell clone in which fully and partially agonistic peptide ligands have been well characterized. We found that some over-expressed partially agonistic ligands (OPALs) induced T cell responses without tyrosine-phosphorylation and kinase activation of ZAP-70. However, those responses were inhibited in T cells expressing DN ZAP-70, which could associate with partially phosphorylated TCR-zeta. In OPAL-stimulated T cells, PLC-gamma1 was phosphorylated and it was suppressed by DN ZAP-70 expression, suggesting that the ZAP-70-TCR-zeta association mediates the activation of PLC-gamma1 leading to T cell responses even in the absence of kinase activation of ZAP-70.
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Affiliation(s)
- Jeong-Ran Kim
- Department of Immunogenetics, Graduate School of Medical Sciences, Kumamoto University, Japan
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752
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Yoeli-Lerner M, Yiu GK, Rabinovitz I, Erhardt P, Jauliac S, Toker A. Akt blocks breast cancer cell motility and invasion through the transcription factor NFAT. Mol Cell 2006; 20:539-50. [PMID: 16307918 DOI: 10.1016/j.molcel.2005.10.033] [Citation(s) in RCA: 321] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 09/22/2005] [Accepted: 10/28/2005] [Indexed: 02/03/2023]
Abstract
The phosphoinositide 3-kinase (PI 3-K) signaling axis is intimately associated with deregulated cancer cell growth, primarily by promoting increased survival through Akt/PKB (protein kinase B). However, there is relatively little information on the role of Akt in cancer cell motility, a key phenotype of invasive carcinomas. Here we report that activation of Akt inhibits carcinoma migration and invasion of breast cancer cells. Conversely, downregulation of Akt using RNA interference increased migration and invasion. Akt blunts invasion by inhibiting the transcriptional activity of NFAT (nuclear factor of activated T cells). Specifically, signaling through Akt reduces NFAT expression levels due to ubiquitination and proteasomal degradation, mediated by the E3 ubiquitin ligase HDM2. These results indicate that while Akt can promote tumor progression through increased cell survival mechanisms, it can block breast cancer cell motility and invasion by a mechanism that depends, at least in part, on the NFAT transcription factor.
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Affiliation(s)
- Merav Yoeli-Lerner
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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753
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Abstract
Overexpression of the ErbB2/Her2 receptor tyrosine kinase in breast cancers is associated with the most aggressive tumors. Experimental studies have revealed that ErbB2 shows many features of a therapeutic target: ErbB2 is able to confer many of the characteristics of a cancerous cell, including uncontrolled proliferation, resistance to apoptosis and increased motility; ErbB2 overexpression is specific to tumor cells; as a cell surface-associated protein, it is easily accessible to drugs and as a kinase it is amenable to targeted inhibition by small molecules. Recent clinical results demonstrate the efficacy of ErbB2-targeting therapy and promise an expanding use of ErbB2-targeting drugs for breast cancer treatment. However, as only a fraction of patients responds successfully to therapy and risks of recurrence are still high, further investigation is required for an improved understanding of the complex network of signaling pathways underlying ErbB2-driven cancer progression.
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Affiliation(s)
- Ali Badache
- UMR599 Inserm, Centre de Recherche en Cancérologie de Marseille, 27 bd Leï Roure, 13009 Marseille, France.
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754
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Ahmad S. Pathway paradox. Nat Rev Mol Cell Biol 2006. [DOI: 10.1038/nrm1848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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755
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Abstract
Akt is well known to enhance malignancy and is recognized as a key target for antineoplastic therapies. However, intriguing findings reported by Yoeli-Lerner et al. in the November 23, 2005 issue of Molecular Cell, suggest a novel, antimetastasis function of Akt: activation of Akt1 inhibited invasion in some cancer cells. One possible mechanism for this surprising phenotype was that Akt activated the E3 ubiquitin ligase HDM2, causing ubiquitination and degradation of NFAT, an invasion-promoting factor. These findings clearly justify further investigations and, if validated in vivo, call for reevaluation of some Akt-targeting therapeutic strategies currently under development.
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Affiliation(s)
- Shannon L Wyszomierski
- Department of Surgical Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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756
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Davanture S, Leignadier J, Milani P, Soubeyran P, Malissen B, Malissen M, Schmitt-Verhulst AM, Boyer C. Selective defect in antigen-induced TCR internalization at the immune synapse of CD8 T cells bearing the ZAP-70(Y292F) mutation. THE JOURNAL OF IMMUNOLOGY 2005; 175:3140-9. [PMID: 16116204 DOI: 10.4049/jimmunol.175.5.3140] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Cbl proteins have been implicated in ligand-induced TCR/CD3 down-modulation, but underlying mechanisms are unclear. We analyzed the effect of mutation of a cbl-binding site on ZAP-70 (ZAP-Y292F) on dynamics, internalization, and degradation of the TCR/CD3 complex in response to distinct stimuli. Naive CD8 T cells expressing the P14 transgenic TCR from ZAP-Y292F mice were selectively affected in TCR/CD3 down-modulation in response to antigenic stimulation, whereas neither anti-CD3 Ab-, and PMA-induced TCR down-modulation, nor constitutive receptor endocytosis/cycling were impaired. We further established that the defect in TCR/CD3 down-modulation in response to Ag was paralleled by an impaired TCR/CD3 internalization and CD3zeta degradation. Analysis of T/APC conjugates revealed that delayed redistribution of TCR at the T/APC contact zone was paralleled by a delay in TCR internalization in the synaptic zone in ZAP-Y292F compared with ZAP-wild-type T cells. Cbl recruitment to the synapse was also retarded in ZAP-Y292F T cells, although F-actin and LFA-1 redistribution was similar for both cell types. This study identifies a step involving ZAP-70/cbl interaction that is critical for rapid internalization of the TCR/CD3 complex at the CD8 T cell/APC synapse.
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Affiliation(s)
- Suzel Davanture
- Centre d'Immunologie de Marseille-Luminy, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université de la Méditerranée, Marseille, Cedex, France
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757
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Najib S, Rodríguez-Baño J, Ríos MJ, Muniain MA, Goberna R, Sánchez-Margalet V. Sam68 is tyrosine phosphorylated and recruited to signalling in peripheral blood mononuclear cells from HIV infected patients. Clin Exp Immunol 2005; 141:518-25. [PMID: 16045742 PMCID: PMC1809455 DOI: 10.1111/j.1365-2249.2005.02867.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Human immunodeficiency virus (HIV) codes for a protein, Rev, that mediates the viral RNA export from the nucleus to the cytoplasm. Recently, it has been found that Sam68, the substrate of Src associated in mitosis, is a functional homologue of Rev, and a synergistic activator of Rev activity. Thus, it has been suggested that Sam68 may play an important role in the post-transcriptional regulation of HIV. Sam68 contains an RNA binding motif named KH [homology to the nuclear ribonucleoprotein (hnRNP) K]. Tyrosine phosphorylation of Sam68 and binding to SH3 domains have been found to negatively regulate its RNA binding capacity. Besides, tyrosine phosphorylation of Sam68 allows the formation of signalling complexes with other proteins containing SH2 and SH3 domains, suggesting a role in signal transduction of different systems in human lymphocytes, such as the T cell receptor, and leptin receptor, or the insulin receptor in other cell types. In the present work, we have found that Sam68 is tyrosine phosphorylated in peripheral blood mononuclear cells (PBMC) from HIV infected subjects, leading to the formation of signalling complexes with p85 the regulatory subunit of PI3K, GAP and STAT-3, and decreasing its RNA binding capacity. In contrast, PBMC from HIV infected subjects have lower expression levels of Sam68 compared with controls. These results suggest that Sam68 may play some role in the immune function of lymphocytes in HIV infection.
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Affiliation(s)
- S Najib
- Department of Clinical Biochemistry, Virgen Macarena University Hospital, Seville, Spain
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758
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Li M, Zhang Z, Hill DL, Chen X, Wang H, Zhang R. Genistein, a Dietary Isoflavone, Down-Regulates the MDM2 Oncogene at Both Transcriptional and Posttranslational Levels. Cancer Res 2005; 65:8200-8. [PMID: 16166295 DOI: 10.1158/0008-5472.can-05-1302] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although genistein has chemopreventive effects in several human malignancies, including cancers of the breast, colon, and prostate, the mechanisms of action are not fully understood. Herein we report novel mechanisms whereby genistein down-regulates the MDM2 oncogene, perhaps explaining some of its anticancer activities. In a dose- and time-dependent manner, genistein reduced MDM2 protein and mRNA levels in human cell lines of breast, colon, and prostate cancer; primary fibroblasts; and breast epithelial cells. The inhibitory effects were found at both transcriptional and posttranslational levels and were independent of tyrosine kinase pathways. We found that the NFAT transcription site in the region between -132 and +33 in the MDM2 P2 promoter was responsive to genistein. At the posttranslational level, genistein induced ubiquitination of MDM2, which led to its degradation. Additionally, genistein induced apoptosis and G2 arrest and inhibited proliferation in a variety of human cancer cell lines, regardless of p53 status. We further showed that MDM2 overexpression abrogated genistein-induced apoptosis in vitro and that genistein inhibited MDM2 expression and tumor growth in PC3 xenografts. In conclusion, genistein directly down-regulates the MDM2 oncogene, representing a novel mechanism of its action that may have implications for its chemopreventive and chemotherapeutic effects.
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Affiliation(s)
- Mao Li
- Department of Pharmacology and Toxicology, Division of Clinical Pharmacology, University of Alabama at Birmingham, 35294, USA
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759
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Dabrowska A, Baczyńska D, Widerak K, Laskowska A, Ugorski M. Promoter analysis of the human alpha1,3/4-fucosyltransferase gene (FUT III). ACTA ACUST UNITED AC 2005; 1731:66-73. [PMID: 16199102 DOI: 10.1016/j.bbaexp.2005.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Revised: 08/24/2005] [Accepted: 08/26/2005] [Indexed: 11/16/2022]
Abstract
alpha1,3/4-Fucosyltransferase (FUT3) is involved in the synthesis of sialyl Le(a) tetrasaccharide, a tumor-associated carbohydrate antigen. Fucosyltransferases are thought to be important regulatory enzymes in the synthesis of fucosylated structures. However, there are conflicting data on the role of FUT3 in the synthesis of this carbohydrate structure and more studies on the regulation of FUT III gene expression are needed. Therefore, as first step, the promoter of FUT III gene was cloned and characterized. Sequencing data showed the absence of TATA, CAAT, and GC boxes, but many binding sites for transcription factors, previously described in colon cancer cells, were identified. Analysis of enhancer and silencing elements of deletion mutants revealed the presence of basal promoter elements of the FUT III gene in the region -636 to -674 bp from the translation initiation site, and positive and negative regulatory elements within the -674 bp to -854 bp and -854 to -1220 regions, respectively. 5'-RACE analysis showed the presence of two transcripts with 5'-ends localized within the exon A. The 5'-end of the longer transcript extended -229 nucleotides from the translation start codon and contained a sequence corresponding to an Inr element, localizing the putative transcription initiation site within this sequence. The strong correlation between the promoter activity of the FUT III gene and the high expression of sialyl Le(a) observed in different colon carcinoma cell lines seem to confirm the important regulatory role of FUT3 in the synthesis of sialyl Le(a).
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Affiliation(s)
- Anna Dabrowska
- Department of Immunochemistry, Institute of Immunology and Experimental Therapy, Polish Academy of Science, Weigla Str. 12, 53-114 Wrocław, Poland
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760
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Lipscomb EA, Mercurio AM. Mobilization and activation of a signaling competent α6β4integrin underlies its contribution to carcinoma progression. Cancer Metastasis Rev 2005; 24:413-23. [PMID: 16258729 DOI: 10.1007/s10555-005-5133-4] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This review examines the hypothesis that the function of the alpha 6beta 4 integrin is altered substantially as normal epithelia undergo malignant transformation and progress to invasive carcinoma and that the functions of this integrin contribute to the behavior of aggressive carcinoma cells. Specifically, alpha 6beta 4 functions primarily as an adhesion receptor in normal epithelia, often as a component of hemidesmosomes and associated with intermediate filaments. Factors in the host-tumor microenvironment have the potential to mobilize alpha 6beta 4 from hemidesmosomes and promote its association with F-actin in lamellae and filopodia, a process that is mediated by PKC-dependent phosphorylation of the beta 4 cytoplasmic domain. Importantly, this altered localization of alpha 6beta 4 appears to be coupled to an activation of its signaling potential, which may occur through its association with growth factor receptors or lipid rafts, possibilities that are not mutually exclusive. The primal signaling event triggered by alpha 6beta 4 appears to be activation of PI3-K and this activation has profound consequences on the migration, invasion and survival of carcinoma cells. Arguably, the ability of alpha 6beta 4 to stimulate the PI3-K-dependent translation of VEGF and possibly other growth factors may be the most significant contribution of this integrin to carcinoma because of the potential autocrine and paracrine effects of these factors.
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Affiliation(s)
- Elizabeth A Lipscomb
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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761
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Du Y, Spence SE, Jenkins NA, Copeland NG. Cooperating cancer-gene identification through oncogenic-retrovirus-induced insertional mutagenesis. Blood 2005; 106:2498-505. [PMID: 15961513 PMCID: PMC1895273 DOI: 10.1182/blood-2004-12-4840] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multiple cooperating mutations that deregulate different signaling pathways are required to induce cancer. Identifying these cooperating mutations is a prerequisite for developing better combinatorial therapies for treating cancer. Here we show that cooperating cancer mutations can be identified through oncogenic-retrovirus-induced insertional mutagenesis. Among 13 myeloid leukemias induced by transplanting into mice bone marrow cells infected in vitro with a replication-defective retrovirus carrying the Sox4 oncogene, 9 contained insertional mutations at known or suspected cancer genes. This likely occurred because rare bone marrow cells, in which the oncogenic retrovirus happened to integrate and in which it mutated a cooperating cancer gene, were selected because the host harbored a cooperating cancer mutation. Cooperativity between Sox4 and another gene, Mef2c, was subsequently confirmed in transplantation studies, in which deregulated Mef2c expression was shown to accelerate the myeloid leukemia induced by Sox4. Insertional mutagenesis of cooperating cancer genes by a defective oncogenic retrovirus provides a new method for identifying cooperating cancer genes and could aid in the development of better therapies for treating cancer.
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Affiliation(s)
- Yang Du
- Mouse Cancer Genetics Program, National Cancer Institute, Center for Cancer Research, Frederick, MD, USA
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762
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Lawn SD, Bekker LG, Miller RF. Immune reconstitution disease associated with mycobacterial infections in HIV-infected individuals receiving antiretrovirals. THE LANCET. INFECTIOUS DISEASES 2005; 5:361-73. [PMID: 15919622 DOI: 10.1016/s1473-3099(05)70140-7] [Citation(s) in RCA: 382] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Immune reconstitution disease (IRD) in HIV-infected patients is an adverse consequence of the restoration of pathogen-specific immune responses during the initial months of highly active antiretroviral treatment (HAART). Previously subclinical infections are "unmasked" or pre-existing opportunistic infections clinically deteriorate as host immunopathological inflammatory responses are "switched on". IRD is most frequently associated with mycobacterial infections. Our literature search identified 166 published cases of IRD associated with mycobacterial infections. We review the underlying immunological mechanisms, difficulties surrounding case definition and diagnosis, the wide diversity of clinical manifestations, and treatment. The importance of screening patients for mycobacterial disease before starting HAART and the critical impact of the timing of commencement of HAART in patients receiving treatment for tuberculosis are highlighted. We also discuss the problem of IRD associated with mycobacterial diseases in developing countries where tuberculosis prevalence is high and access to HAART is currently expanding.
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Affiliation(s)
- Stephen D Lawn
- Desmond Tutu HIV Centre, Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
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763
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Chen M, O'Connor KL. Integrin α6β4 promotes expression of autotaxin/ENPP2 autocrine motility factor in breast carcinoma cells. Oncogene 2005; 24:5125-30. [PMID: 15897878 DOI: 10.1038/sj.onc.1208729] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In advanced breast carcinomas, the alpha6beta4 integrin is associated with a migratory and invasive phenotype. In our current study, we show that expression of the alpha6beta4 integrin in MDA-MB-435 breast carcinoma cells leads to increased expression of the autocrine motility factor autotaxin, as determined by Affymetrix gene chip, real-time quantitative RT-PCR and immunoblot analyses. We further demonstrate that increased autotaxin secretion from integrin alpha6beta4 expressing cells acts to enhance chemotaxis through its ability to convert lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA) and accounts for 80% of the motogenic activity of the conditioned medium. We determine that integrin alpha6beta4-dependent overexpression of autotaxin in MDA-MB-435 cells is mediated by NFAT1, but not NFAT5, through the use of siRNAs that specifically target autotaxin, integrin beta4, NFAT1 and NFAT5. Finally, we show by electrophoretic mobility shift assays that two consensus NFAT binding sites found in the autotaxin promoter strongly and specifically bind NFAT1 from integrin alpha6beta4 expressing cells. In summary, we find that the alpha6beta4 integrin potentiates autotaxin expression through the upregulation and activation of NFAT1. These observations highlight for the first time a mechanism by which NFAT transcription factors can facilitate an invasive and motile phenotype downstream of integrin alpha6beta4 signaling.
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Affiliation(s)
- Min Chen
- Department of Surgery and the Sealy Center for Cancer Cell Biology, University of Texas Medical Branch, 301 University Blvd, Galveston, TX 77555, USA
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764
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Abstract
SRC family kinases are a group of nine cytoplasmic protein tyrosine kinases essential for many cell functions. Some appear to be ubiquitously expressed, whereas others are highly tissue specific. The ability of members of the SRC family to influence ion transport has been recognized for several years. Mounting evidence suggests a broad role for SRC family kinases in the cell response to both hypertonic and hypotonic stress, and in the ensuing regulatory volume increase or decrease. In addition, members of this tyrosine kinase family participate in the mechanotransduction that accompanies cell membrane deformation. Finally, at least one SRC family member operates in concert with the p38 MAPK to regulate tonicity-dependent gene transcription.
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Affiliation(s)
- David M Cohen
- Division of Nephrology, Mailcode PP262, Oregon Health and Science Univ. 3314 SW US Veterans Hospital Rd., Portland, OR 97239, USA.
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765
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Yoon SO, Shin S, Mercurio AM. Hypoxia stimulates carcinoma invasion by stabilizing microtubules and promoting the Rab11 trafficking of the alpha6beta4 integrin. Cancer Res 2005; 65:2761-9. [PMID: 15805276 DOI: 10.1158/0008-5472.can-04-4122] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hypoxia plays a key role in tumor cell survival, invasion, and metastasis. Here we show that hypoxia increases tumor cell invasion by the modulation of Rab11, an important molecule for vesicular trafficking, especially membrane protein recycling and translocation of proteins from trans-Golgi network to plasma membrane. Dominant-negative Rab11 dramatically decreased hypoxia-induced invasion of MDA-MB-231 breast carcinoma cells without affecting cell apoptosis. Hypoxia-induced Rab11 trafficking is regulated by microtubule stability, as evidenced by the findings that hypoxia increases Glu tubulin and that colchicine blocks Rab11 trafficking and invasion. Inhibition of GSK-3beta activity by hypoxia seems to be central to microtubule stabilization and invasion. In fact, expression of a dominant-negative GSK-3beta was sufficient to stimulate invasion in normoxia. One target of Rab11-mediated trafficking that contributes to invasion is the integrin alpha6beta4. Hypoxia induced a significant increase in alpha6beta4 surface expression but it had no effect on the surface expression of alpha3beta1. This increase is dependent on Rab11 and stable microtubules. In summary, we identify vesicle trafficking as a novel target of hypoxic stimulation that is important for tumor invasion.
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Affiliation(s)
- Sang-Oh Yoon
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
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766
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Padma S, Sowjanya AP, Poli UR, Jain M, Rao BN, Ramakrishna G. Downregulation of calcineurin activity in cervical carcinoma. Cancer Cell Int 2005; 5:7. [PMID: 15801986 PMCID: PMC1087859 DOI: 10.1186/1475-2867-5-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Accepted: 04/01/2005] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND: Calcineurin (CaN) is an important serine-threonine phosphatase (PP2B), which plays a crucial role in calcium-calmodulin mediated signal transduction events. Calcineurin has been implicated in pathogenesis of various diseases cardiac hypertrophy, diabetic neuropathy and Alzheimer's, however its role in neoplasia remains unclear. RESULTS: In view of this we evaluated the calcineurin activity in serum and biopsy samples collected from women diagnosed with invasive squamous cell carcinoma of cervix. A significant reduction was observed in the calcineurin activity in cancer cervix patients compared to the control group. However the calcineurin activity remained unaltered in the cervical scrapes obtained from patients diagnosed with low-grade squamous intra epithelial lesions (LSIL). Interestingly the downregulation of calcineurin activity in squamous cell carcinomas was not accompanied by any significant change in DNA-binding affinity of the transcriptional factor NFAT (Nuclear Factor of Activated T-cells). All the squamous cell carcinoma samples used in the present study were positive for high-risk human papillomavirus (HPV) types. CONCLUSION: The present study demonstrates the downregulation of calcineurin activity in squamous cell carcinoma of cervix with high risk HPV infection. We conclude that perturbations in calcineurin-mediated pathway may be involved in development of cervical neoplasia.
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Affiliation(s)
- S Padma
- Centre for DNA Fingerprinting and Diagnostics, Nacharam, Hyderabad, A.P, India
| | - A Pavani Sowjanya
- Centre for DNA Fingerprinting and Diagnostics, Nacharam, Hyderabad, A.P, India
| | - Usha Rani Poli
- M.N.J Institute of Oncology and Regional cancer centre, Hyderabad, A.P, India
| | | | - BN Rao
- M.N.J Institute of Oncology and Regional cancer centre, Hyderabad, A.P, India
| | - Gayatri Ramakrishna
- Centre for DNA Fingerprinting and Diagnostics, Nacharam, Hyderabad, A.P, India
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767
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Wang Y, Ko BCB, Yang JY, Lam TTL, Jiang Z, Zhang J, Chung SK, Chung SSM. Transgenic mice expressing dominant-negative osmotic-response element-binding protein (OREBP) in lens exhibit fiber cell elongation defect associated with increased DNA breaks. J Biol Chem 2005; 280:19986-91. [PMID: 15774462 DOI: 10.1074/jbc.m501689200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Osmotic-response element-binding protein (OREBP), also known as TonEBP or NFAT5, is thought to be responsible for the induction of osmolyte-accumulating genes when cells are under hypertonic stress. Recent studies suggest that OREBP also plays a role in water reabsorption in the kidney, T-cell proliferation, and embryonic development. We developed transgenic mice that express the dominant-negative OREBP (OREBPdn) specifically in the lens because our earlier studies showed that it is particularly sensitive to osmotic stress. The transgenic mice developed nuclear cataract soon after birth, suggesting defects in lens development. The developing transgenic lenses showed incomplete elongation of fiber cells and formation of vacuoles. This is accompanied by evidence of DNA strand breaks, activation of p53, and induction of checkpoint kinase, suggesting that the developing fiber cells lacking OREBP are in a similar physiological state as cells experiencing hypertonic stress. These results indicate that OREBP-mediated accumulation of osmolytes is essential during elongation of the lens fiber cells.
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Affiliation(s)
- Yu Wang
- Department of Chemistry, The University of Hong Kong, China.
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768
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Ye P, Simonian M, Nadkarni MA, Decarlo AA, Chapple CC, Hunter N. Identification of epithelial auto-antigens associated with periodontal disease. Clin Exp Immunol 2005; 139:328-37. [PMID: 15654832 PMCID: PMC1809282 DOI: 10.1111/j.1365-2249.2005.02692.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We previously reported evidence that patients with periodontitis have serum antibodies to oral Gram positive bacteria that are cross-reactive with epithelial antigens. In the present report cross-reactive epithelial antigens including CD24, lactate dehydrogenase A [LDM-A], antioxidant protein 2 [AOP 2] and nuclear factor of activated T cells 5 [NFAT 5], were identified by screening a cDNA expression library with pooled patient sera. Titres of antibodies to CD24 peptide correlated negatively with indices of periodontal disease severity. Strong expression of CD24 in the reactive periodontal epithelium and inflamed gingival attachment contrasted with low to undetectable expression in the external gingival epithelium. In periodontitis, a local action of these auto-reactive antibodies could modulate the regulatory potential associated with expression of CD24 in this epithelium.
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Affiliation(s)
- P Ye
- Institute of Dental Research, Westmead Millennium Institute and Westmead Centre for Oral Health, Westmead, NSW, Australia
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769
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Duque J, Fresno M, Iñiguez MA. Expression and Function of the Nuclear Factor of Activated T Cells in Colon Carcinoma Cells. J Biol Chem 2005; 280:8686-93. [PMID: 15632146 DOI: 10.1074/jbc.m413076200] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Increasing evidence shows a crucial role of the Ca2+/ calcineurin-mediated activation of the nuclear factor of activated T cells (NFAT) in the regulation of a variety of processes in nonimmune cells. Here we provide evidence that NFATc1 and NFATc2 are expressed in human colon carcinoma cell lines. These proteins are translocated from the cytoplasm to the nucleus upon treatment with a combination of phorbol 12-myristate 13-acetate plus the calcium ionophore A23187. Subsequent to translocation to the nucleus, NFATc1 and NFATc2 were able to bind to a NFAT response element in the DNA, regulating transcriptional activation of genes containing a NFAT-responsive element such as cyclooxygenase-2 (COX-2). COX-2 expression and prostaglandin E2 (PGE2) production were induced upon pharmacological stimuli leading to NFAT activation and blunted by inhibition of calcineurin phosphatase with cyclosporin A or tacrolimus (FK506). Expression of NFAT wild type protein or the active catalytic subunit of calcineurin transactivates COX-2 promoter activity, whereas a dominant negative mutant of NFAT inhibited COX-2 induction in colon carcinoma cell lines. Furthermore, mutation or deletion of NFAT binding sites in the human COX-2 promoter greatly diminished its induction by phorbol 12-myristate 13-acetate/calcium ionophore A23187. These findings demonstrate the presence and activation of NFAT in human colon carcinoma cells, with important implications in the regulation of genes involved in the transformed phenotype as COX-2.
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Affiliation(s)
- Javier Duque
- Centro de Biología Molecular Severo Ochoa, Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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770
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Abstract
The ZAP-70 tyrosine kinase has been described more than ten years ago. Its key role in thymocytes development and mature T lymphocytes activation has been illustrated by the characterization of several human immunodeficiencies presenting with mutations in the zap-70 gene resulting in the absence of ZAP-70 expression. More recently, it has been shown that deregulation of ZAP-70 activity can induce autoimmune diseases. Finally, ZAP-70 expression has been shown in some B chronic lymphocytic leukaemia and correlated with bad prognosis of the disease. The diversity of pathologies associated with deregulation of ZAP-70 demonstrates its key role in immune responses. Research aiming at deciphering the different signalling pathways regulated by ZAP-70 will not only shed some lights on these pathologies, but will also help finding new pharmacological tools, targeting ZAP-70, designed to induce immunosuppression or tolerance.
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Affiliation(s)
- Claire Hivroz
- Inserm U.365, Institut Curie, Section Recherche, 26, rue d'Ulm, 75248 Paris Cedex 05, France.
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771
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Alfonso-Jaume MA, Mahimkar R, Lovett DH. Co-operative interactions between NFAT (nuclear factor of activated T cells) c1 and the zinc finger transcription factors Sp1/Sp3 and Egr-1 regulate MT1-MMP (membrane type 1 matrix metalloproteinase) transcription by glomerular mesangial cells. Biochem J 2004; 380:735-47. [PMID: 14979875 PMCID: PMC1224202 DOI: 10.1042/bj20031281] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Revised: 02/06/2004] [Accepted: 02/23/2004] [Indexed: 01/17/2023]
Abstract
The transition of normally quiescent glomerular MCs (mesangial cells) to a highly proliferative phenotype with characteristics of myofibroblasts is a process commonly observed in inflammatory diseases affecting the renal glomerulus, the ultimate result of which is glomerulosclerosis. Generation of proteolytically active MMP (matrix metalloproteinase)-2 by the membrane-associated membrane type 1 (MT1)-MMP is responsible for the transition of mesangial cells to the myofibroblast phenotype [Turck, Pollock, Lee, Marti and Lovett (1996) J. Biol. Chem. 271, 15074-15083]. In the present study, we show that the expression of MT1-MMP within the context of MCs is mediated by three discrete cis -acting elements: a proximal non-canonical Sp1 site that preferentially binds Sp1; an overlapping Sp1/Egr-1-binding site that preferentially binds Egr-1; and a more distal binding site for the NFAT (nuclear factor of activated T cells) that binds the NFAT c1 isoform present in MC nuclear extracts. Transfection with an NFAT c1 expression plasmid, or activation of calcineurin with a calcium ionophore, yielded major increases in NFAT c1 nuclear DNA-binding activity, MT1-MMP transcription and protein synthesis, which were additive with the lower levels of transactivation provided by the proximal Sp1 and the overlapping Sp1/Egr-1 sites. Specific binding of NFAT c1 to the MT1-MMP promoter was confirmed by chromatin immunoprecipitation studies, while MT1-MMP expression was suppressed by treatment with the calcineurin inhibitor, cyclosporin A. These studies are the first demonstration that a specific NFAT isoform enhances transcription of an MMP (MT1-MMP) that plays a major role in the proteolytic events that are a dominant feature of acute glomerular inflammation. Suppression of MT1-MMP by commonly used calcineurin inhibitors may play a role in the development of renal fibrosis following renal transplantation.
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Affiliation(s)
- Maria Alejandra Alfonso-Jaume
- The Department of Medicine, San Francisco VAMC/University of California, 111J Medical Service, 4150 Clement Street, San Francisco, CA 94121, USA
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772
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Liu Z, Dronadula N, Rao GN. A Novel Role for Nuclear Factor of Activated T Cells in Receptor Tyrosine Kinase and G Protein-coupled Receptor Agonist-induced Vascular Smooth Muscle Cell Motility. J Biol Chem 2004; 279:41218-26. [PMID: 15272006 DOI: 10.1074/jbc.m406917200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In addition to their role in cytokine gene regulation in T cells, nuclear factors of activated T cells (NFATs) have been shown to be involved in cardiac development and hypertrophy. We have reported previously that NFATs play an important role in the regulation of vascular smooth muscle cell (VSMC) proliferation by receptor tyrosine kinase (RTK) and G protein-coupled receptor (GPCR) agonists, platelet-derived growth factor-BB (PDGF-BB) and thrombin, respectively. To understand the role of NFATs in vascular disease and development, we have now studied the role of these transcriptional factors in VSMC motility. PDGF-BB and thrombin induced VSMC motility in a dose-dependent manner. Blockade of NFAT activation resulted in substantial reduction in PDGF-BB- and thrombin-induced VSMC motility. PDGF-BB and thrombin also induced interleukin-6 (IL-6) expression in NFAT-dependent manner. Furthermore, IL-6 dose-dependently caused VSMC motility. A neutralizing anti-rat IL-6 antibody inhibited VSMC motility induced by IL-6, PDGF-BB, and thrombin. In addition, exogenous addition of IL-6 rescued both PDGF-BB- and thrombin-induced VSMC motility from inhibition by the blockade of NFAT activation. Together, these results for the first time demonstrate that NFATs mediate both RTK and GPCR agonist-induced VSMC motility via induction of expression of IL-6.
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Affiliation(s)
- Zhimin Liu
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA
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773
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Zaichuk TA, Shroff EH, Emmanuel R, Filleur S, Nelius T, Volpert OV. Nuclear factor of activated T cells balances angiogenesis activation and inhibition. ACTA ACUST UNITED AC 2004; 199:1513-22. [PMID: 15184502 PMCID: PMC2211785 DOI: 10.1084/jem.20040474] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
It has been demonstrated that vascular endothelial cell growth factor (VEGF) induction of angiogenesis requires activation of the nuclear factor of activated T cells (NFAT). We show that NFATc2 is also activated by basic fibroblast growth factor and blocked by the inhibitor of angiogenesis pigment epithelial–derived factor (PEDF). This suggests a pivotal role for this transcription factor as a convergence point between stimulatory and inhibitory signals in the regulation of angiogenesis. We identified c-Jun NH2-terminal kinases (JNKs) as essential upstream regulators of NFAT activity in angiogenesis. We distinguished JNK-2 as responsible for NFATc2 cytoplasmic retention by PEDF and JNK-1 and JNK-2 as mediators of PEDF-driven NFAT nuclear export. We identified a novel NFAT target, caspase-8 inhibitor cellular Fas-associated death domain–like interleukin 1β–converting enzyme inhibitory protein (c-FLIP), whose expression was coregulated by VEGF and PEDF. Chromatin immunoprecipitation showed VEGF-dependent increase of NFATc2 binding to the c-FLIP promoter in vivo, which was attenuated by PEDF. We propose that one possible mechanism of concerted angiogenesis regulation by activators and inhibitors may be modulation of the endothelial cell apoptosis via c-FLIP controlled by NFAT and its upstream regulator JNK.
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Affiliation(s)
- Tetiana A Zaichuk
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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774
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Abstract
Suppression of HIV replication by highly active antiretroviral therapy (HAART) often restores protective pathogen-specific immune responses, but in some patients the restored immune response is immunopathological and causes disease [immune restoration disease (IRD)]. Infections by mycobacteria, cryptococci, herpesviruses, hepatitis B and C virus, and JC virus are the most common pathogens associated with infectious IRD. Sarcoid IRD and autoimmune IRD occur less commonly. Infectious IRD presenting during the first 3 months of therapy appears to reflect an immune response against an active (often quiescent) infection by opportunistic pathogens whereas late IRD may result from an immune response against the antigens of non-viable pathogens. Data on the immunopathogenesis of IRD is limited but it suggests that immunopathogenic mechanisms are determined by the pathogen. For example, mycobacterial IRD is associated with delayed-type hypersensitivity responses to mycobacterial antigens whereas there is evidence of a CD8 T-cell response in herpesvirus IRD. Furthermore, the association of different cytokine gene polymorphisms with mycobacterial or herpesvirus IRD provides evidence of different pathogenic mechanisms as well as indicating a genetic susceptibility to IRD. Differentiation of IRD from an opportunistic infection is important because IRD indicates a successful, albeit undesirable, effect of HAART. It is also important to differentiate IRD from drug toxicity to avoid unnecessary cessation of HAART. The management of IRD often requires the use of anti-microbial and/or anti-inflammatory therapy. Investigation of strategies to prevent IRD is a priority, particularly in developing countries, and requires the development of risk assessment methods and diagnostic criteria.
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Affiliation(s)
- Martyn A French
- Department of Clinical Immunology and Biochemical Genetics, Royal Perth Hospital and School of Surgery and Pathology, University of Western Australia, Perth, Australia.
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775
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Steinberg M, Adjali O, Swainson L, Merida P, Di Bartolo V, Pelletier L, Taylor N, Noraz N. T-cell receptor–induced phosphorylation of the ζ chain is efficiently promoted by ZAP-70 but not Syk. Blood 2004; 104:760-7. [PMID: 15059847 DOI: 10.1182/blood-2003-12-4314] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractEngagement of the T-cell receptor (TCR) results in the activation of Lck/Fyn and ZAP-70/Syk tyrosine kinases. Lck-mediated tyrosine phosphorylation of signaling motifs (ITAMs) in the CD3-ζ subunits of the TCR is an initial step in the transduction of signaling cascades. However, ζ phosphorylation is also promoted by ZAP-70, as TCR-induced ζ phosphorylation is defective in ZAP-70–deficient T cells. We show that this defect is corrected by stable expression of ZAP-70, but not Syk, in primary and transformed T cells. Indeed, these proteins are differentially coupled to the TCR with a 5- to 10-fold higher association of ZAP-70 with ζ as compared to Syk. Low-level Syk-ζ binding is associated with significantly less Lck coupled to the TCR. Moreover, diminished coupling of Lck to ζ correlates with a poor phosphorylation of the positive regulatory tyr352 residue of Syk. Thus, recruitment of Lck into the TCR complex with subsequent ζ chain phosphorylation is promoted by ZAP-70 but not Syk. Importantly, the presence of ZAP-70 positively regulates the TCR-induced tyrosine phosphorylation of Syk. The interplay between Syk and ZAP-70 in thymocytes, certain T cells, and B-chronic lymphocytic leukemia cells, in which they are coexpressed, will therefore modulate the amplitude of antigen-mediated receptor signaling.
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Affiliation(s)
- Marcos Steinberg
- Institut de Génétique Moléculaire de Montpellier, Centre National de la Recherche Scientifique Unité de Recherches 5535/Institut Fédératife de Recherche, F-34293 Montpellier 5, France
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776
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Holzmann K, Kohlhammer H, Schwaenen C, Wessendorf S, Kestler HA, Schwoerer A, Rau B, Radlwimmer B, Döhner H, Lichter P, Gress T, Bentz M. Genomic DNA-chip hybridization reveals a higher incidence of genomic amplifications in pancreatic cancer than conventional comparative genomic hybridization and leads to the identification of novel candidate genes. Cancer Res 2004; 64:4428-33. [PMID: 15231651 DOI: 10.1158/0008-5472.can-04-0431] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Genomic analyses aimed at the detection of high-level DNA amplifications were performed on 13 widely used pancreatic cancer cell lines and 6 pancreatic tumor specimens. For these analyses, array-based comparative genomic hybridization (Matrix-CGH) onto dedicated microarrays was used. In comparison with chromosomal CGH (eight amplifications), a >3-fold number of DNA amplifications was detected (n = 29). The most frequent amplifications mapped to 7p12.3 (three pancreatic cancer cell lines and three pancreatic tumor specimens), 8q24 (four pancreatic cancer cell lines and one pancreatic tumor specimen), 11q13 (three pancreatic cancer cell lines and three pancreatic tumor specimens), and 20q13 (four pancreatic cancer cell lines and three pancreatic tumor specimens). Genes contained in the consensus regions were MYC (8q24), EGFR (7p12.3), and FGF3 (11q13). In six of seven pancreatic cancer cell lines and pancreatic tumor specimens with 20q13 amplifications, the novel candidate gene NFAT C2, which plays a role in the activation of cytokines, was amplified. Other amplifications also affected genes for which a pathogenetic role in pancreatic carcinoma has not been described, such as BCL10 and BCL6, two members of the BCL family. A subset of amplified genes was checked for overexpression by means of real-time PCR, revealing the highest expression levels for BCL6 and BCL10. Thus, Matrix-CGH allows the detection of a high number of amplifications, resulting in the identification of novel candidate genes in pancreatic cancer.
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777
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Saito K, Muto T, Tomimori Y, Maruoka H, Tanaka T, Fukuda Y. Human chymase stimulates Ca2+ signaling in human polymorphonuclear cells. Immunol Lett 2004; 89:161-5. [PMID: 14556974 DOI: 10.1016/s0165-2478(03)00129-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Human chymase is known to function as a chemoattractant for human leukocytes. To investigate the mechanism of the chymase-induced cell migration, change in intracellular calcium concentration ([Ca(2+)]i) was examined in human polymorphonuclear (PMN) cells using Fluo-3 as a fluorescent Ca(2+) indicator. Treatment of PMN cells with human chymase caused [Ca(2+)]i elevation in a concentration-dependent manner. Depletion of extracellular Ca(2+) from the medium partially attenuated the chymase-induced [Ca(2+)]i increase, showing that both Ca(2+) influx and Ca(2+) release from internal stores might be involved in the [Ca(2+)]i response. Pretreatment of the cells with pertussis toxin completely blocked the chymase-induced [Ca(2+)]i signal, suggesting an involvement of G protein in the chymase-mediated [Ca(2+)]i elevation. The data in the present study raise the possibility that the chymase-induced cell migration is mediated by the [Ca(2+)]i elevation, which might be caused by stimulation of a G-protein-coupled receptor such as protease-activated receptors (PARs).
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Affiliation(s)
- Kayo Saito
- Suntory Biomedical Research Limited, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, 618-8503, Osaka, Japan
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778
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Chung J, Yoon SO, Lipscomb EA, Mercurio AM. The Met receptor and alpha 6 beta 4 integrin can function independently to promote carcinoma invasion. J Biol Chem 2004; 279:32287-93. [PMID: 15161909 DOI: 10.1074/jbc.m403809200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It has been proposed that a constitutive, physical association of the Met receptor and the alpha(6)beta(4) integrin exists on the surface of invasive carcinoma cells and that hepatocyte growth factor (HGF)-mediated invasion is dependent on alpha(6)beta(4) (Trusolino, L., Bertotti, A., and Comoglio, P. M. (2001) Cell 107, 643-654). The potential significance of these results prompted us to re-examine this hypothesis. Using three different carcinoma cell lines that express both Met and alpha(6)beta(4), we were unable to detect the constitutive association of these receptors by co-immunoprecipitation. Moreover, carcinoma cells that lacked expression of alpha(6)beta(4) exhibited Met-dependent invasion toward HGF, and increasing Met expression by viral infection of these cells enhanced invasion without inducing alpha(6)beta(4) expression. Although expression of alpha(6)beta(4) in such cells enhanced their invasion to HGF, it also enhanced their ability to invade toward other chemoattractants such as lysophosphatidic acid, and this latter invasion was not inhibited by a function-blocking Met antibody. Finally, depletion of beta(4) by RNA interference in invasive carcinoma cells that express both receptors reduced the ability of these cells to invade toward HGF by approximately 25%, but it did not abrogate their invasion. These data argue that the invasive function of Met can be independent of alpha(6)beta(4) and that alpha(6)beta(4) has a generic influence on the invasion of carcinoma cells that is not specific to Met.
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Affiliation(s)
- Jun Chung
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA
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779
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Ayers M, Symmans WF, Stec J, Damokosh AI, Clark E, Hess K, Lecocke M, Metivier J, Booser D, Ibrahim N, Valero V, Royce M, Arun B, Whitman G, Ross J, Sneige N, Hortobagyi GN, Pusztai L. Gene expression profiles predict complete pathologic response to neoadjuvant paclitaxel and fluorouracil, doxorubicin, and cyclophosphamide chemotherapy in breast cancer. J Clin Oncol 2004; 22:2284-93. [PMID: 15136595 DOI: 10.1200/jco.2004.05.166] [Citation(s) in RCA: 427] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The goal of this study was to examine the feasibility of developing a multigene predictor of pathologic complete response (pCR) to sequential weekly paclitaxel and fluorouracil + doxorubicin + cyclophosphamide (T/FAC) neoadjuvant chemotherapy regimen for breast cancer. PATIENTS AND METHODS All patients underwent one-time pretreatment fine-needle aspiration to obtain RNA from the cancer for transcriptional profiling using cDNA arrays containing 30721 human sequence clones. Analysis was performed after profiling, and 42 patients' clinical results were available, 24 of which were used for predictive marker discovery; 18 patients' results were used as an independent validation set. RESULTS Thirty-one percent of patients had pCR (six discovery and seven validation), defined as disappearance of all invasive cancer in the breast after completion of chemotherapy. We could identify no single marker that was sufficiently associated with pCR to be used as an individual predictor. A multigene model with 74 markers (P <or=.09) was built using data from the discovery samples and tested on the validation samples. Overall, a 78% (14 of 18) predictive accuracy was observed, with a 100% (three of three) positive predictive value for pCR, a 73% (11 of 15) negative predictive value, a sensitivity of 43% (three of seven), and a specificity of 100% (11 of 11). The expected response rate to T/FAC neoadjuvant therapy in unselected patients is 28%. CONCLUSION Our results suggest that transcriptional profiling has the potential to identify a gene expression pattern in breast cancer that may lead to clinically useful predictors of pCR to T/FAC neoadjuvant therapy.
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Affiliation(s)
- M Ayers
- Millennium Pharmaceuticals Inc, Cambridge, MA, USA
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780
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Pulmonary Mycobacterium avium Complex Infection in HIV-Infected Patient After Immune Reconstitution With Highly Active Antiretroviral Therapy. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2004. [DOI: 10.1097/01.idc.0000129849.26885.8c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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781
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Fosmire SP, Dickerson EB, Scott AM, Bianco SR, Pettengill MJ, Meylemans H, Padilla M, Frazer-Abel AA, Akhtar N, Getzy DM, Wojcieszyn J, Breen M, Helfand SC, Modiano JF. Canine malignant hemangiosarcoma as a model of primitive angiogenic endothelium. J Transl Med 2004; 84:562-72. [PMID: 15064773 DOI: 10.1038/labinvest.3700080] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Hemangiosarcoma (HSA) is a common untreatable cancer of dogs that resembles human angiosarcoma. Detailed studies of these diseases have been historically hindered by the paucity of suitable reagents. Here, we show that expression of CD117 (c-Kit) can distinguish primitive (malignant) from mature (benign) proliferative endothelial lesions, and we describe eight independent cell lines derived from canine HSA explants. Endothelial origin was confirmed by sustained expression of surface CD105 (endoglin), CD146 (MUC18), and CD51/CD61 (alpha(v)beta(3) integrin). The cell lines showed anchorage-independent growth and were motile and invasive when cultured on a basement membrane matrix. They required endothelial growth factors for growth and survival, and they could be induced to form tubular structures resembling blood vessels when cultured under low calcium conditions. The formation of vessel-like structures was blocked by nicotine, and restored by FK506, suggesting that 'nuclear factor of activated T cells' activity prevents differentiation of these cells. In summary, these cell lines represent a unique and novel resource to improve our understanding of endothelial cell biology in general and canine HSA in particular.
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Affiliation(s)
- Susan P Fosmire
- AMC Cancer Research Center and Integrated Department of Immunology, University of Colorado Health Sciences Center, Denver, 80214, USA
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782
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Abstract
The pathogenesis of Peyronie's disease (induratio penis plastica) is unclear, but immune phenomena appear likely to be involved. Two cases are presented where the condition developed in temporal association with a virological response to highly active antiretroviral therapy (HAART) in men with HIV infection. It is suggested that this may represent another manifestation of immune restoration disease.
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Affiliation(s)
- G D Rogers
- Health in Human Diversity Unit, Department of General Practice, University of Adelaide, Adelaide, SA 5005, Australia.
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783
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López-Rodríguez C, Antos CL, Shelton JM, Richardson JA, Lin F, Novobrantseva TI, Bronson RT, Igarashi P, Rao A, Olson EN. Loss of NFAT5 results in renal atrophy and lack of tonicity-responsive gene expression. Proc Natl Acad Sci U S A 2004; 101:2392-7. [PMID: 14983020 PMCID: PMC356961 DOI: 10.1073/pnas.0308703100] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The transcription factor NFAT5/TonEBP, a member of the NFAT/Rel family of transcription factors, has been implicated in diverse cellular responses, including the response to osmotic stress, integrin-dependent cell migration, T cell activation, and the Ras pathway in Drosophila. To clarify the in vivo role of NFAT5, we generated NFAT5-null mice. Homozygous mutants were genetically underrepresented after embryonic day 14.5. Surviving mice manifested a progressive and profound atrophy of the kidney medulla with impaired activation of several osmoprotective genes, including those encoding aldose reductase, Na+/Cl--coupled betaine/gamma-aminobutyric acid transporter, and the Na+/myo-inositol cotransporter. The aldose reductase gene is controlled by a tonicity-responsive enhancer, which was refractory to hypertonic stress in fibroblasts lacking NFAT5, establishing this enhancer as a direct transcriptional target of NFAT5. Our findings demonstrate a central role for NFAT5 as a tonicity-responsive transcription factor required for kidney homeostasis and function.
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Affiliation(s)
- Cristina López-Rodríguez
- Department of Pathology, Harvard Medical School and Center for Blood Research, Institute for Biomedical Research, 200 Longwood Avenue, Boston MA 02115, USA
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784
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Ramírez A, Faupel J, Goebel I, Stiller A, Beyer S, Stöckle C, Hasan C, Bode U, Kornak U, Kubisch C. Identification of a novel mutation in the coding region of the grey-lethal geneOSTM1in human malignant infantile osteopetrosis. Hum Mutat 2004; 23:471-6. [PMID: 15108279 DOI: 10.1002/humu.20028] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Autosomal recessive malignant infantile osteopetrosis (ARO) is characterized by severe osteosclerosis, pathologic fractures, hepatosplenomegaly, and pancytopenia. The pathophysiological basis is inadequate bone resorption due to osteoclast dysfunction. In the majority of cases, mutations in either of two human genes cause this fatal disorder: TCIRG1, encoding a subunit of the osteoclast H(+)-ATPase, and the voltage-gated chloride channel gene CLCN7. We excluded both genes in a small inbred family with malignant infantile osteopetrosis and undertook linkage analysis of several candidate loci that are involved in murine osteopetrosis. A region spanning more than 20 cM between the markers D6S1717 and D6S1608 on chromosome 6q21 was found to be homozygous in the affected child. This locus is syntenic to the genomic region harboring the gene for the osteopetrotic mutant mouse grey-lethal (gl). Recently, mutations in a novel gene of unknown function were described in the grey-lethal mouse and in one human patient. Mutation screening of the grey-lethal gene (OSTM1), revealed a homozygous 2-bp deletion in exon 2 (c.415_416delAG) in the affected child. No mutations could be found in six independent ARO patients who had tested negative for mutations in TCIRG1 and CLCN7. In summary, we describe the identification of a novel mutation in the coding sequence of the human grey-lethal gene, which is the second OSTM1 mutation found in human ARO, confirming the involvement of this gene in the pathogenesis of this severe bone disease.
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785
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Wang H, Fu W, Im JH, Zhou Z, Santoro SA, Iyer V, DiPersio CM, Yu QC, Quaranta V, Al-Mehdi A, Muschel RJ. Tumor cell alpha3beta1 integrin and vascular laminin-5 mediate pulmonary arrest and metastasis. J Cell Biol 2004; 164:935-41. [PMID: 15024036 PMCID: PMC2172296 DOI: 10.1083/jcb.200309112] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 02/10/2004] [Indexed: 11/22/2022] Open
Abstract
Arrest of circulating tumor cells in distant organs is required for hematogenous metastasis, but the tumor cell surface molecules responsible have not been identified. Here, we show that the tumor cell alpha3beta1 integrin makes an important contribution to arrest in the lung and to early colony formation. These analyses indicated that pulmonary arrest does not occur merely due to size restriction, and raised the question of how the tumor cell alpha3beta1 integrin contacts its best-defined ligand, laminin (LN)-5, a basement membrane (BM) component. Further analyses revealed that LN-5 is available to the tumor cell in preexisting patches of exposed BM in the pulmonary vasculature. The early arrest of tumor cells in the pulmonary vasculature through interaction of alpha3beta1 integrin with LN-5 in exposed BM provides both a molecular and a structural basis for cell arrest during pulmonary metastasis.
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Affiliation(s)
- Hui Wang
- Dept. of Pathology, Rm. 916D ARC, Children's Hospital of Philadelphia, 3615 Civic Center Blvd., Philadelphia, PA 19104, USA
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786
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Yamaguchi K, Itoh K, Ohnishi N, Itoh Y, Baum C, Tsuji T, Nagao T, Higashitsuji H, Okanoue T, Fujita J. Engineered long terminal repeats of retroviral vectors enhance transgene expression in hepatocytes in vitro and in vivo. Mol Ther 2004; 8:796-803. [PMID: 14599813 DOI: 10.1016/j.ymthe.2003.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
To analyze the important elements for retroviral expression in hepatocytes, cis-acting elements in the U3 region of the long terminal repeat (LTR) of the polycythemic strain of spleen focus-forming virus (SFFVp) were analyzed in a hepatocellular carcinoma cell line. Two cis-acting elements located within the upstream region of the direct repeat, which positively regulated retroviral expression, were identified. Transcription factors NFAT5 and Sp1, which are ubiquitously expressed in a variety of tissues, bound to these elements. To increase specificity without lowering the potency of retroviral expression in hepatocytes, these elements were replaced by a sequence derived from the hepatitis B virus enhancer II region. Novel vectors, SF-Hep3 and SF-Hep5 (SFFVp-based vector for hepatocytes 3 and 5), were developed with these engineered LTRs. The engineered LTRs of these vectors enhanced the retroviral expression only in hepatocellular carcinoma cell lines in vitro. These vectors also increased transgene expression 4- to 9-fold or 3.5- to 5-fold in comparison with a Moloney murine leukemia virus-based vector or a vector containing the wild-type LTR of SFFVp, respectively, in murine hepatocytes in vivo.
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Affiliation(s)
- Kanji Yamaguchi
- Department of Clinical Molecular Biology, Faculty of Medicine, Kyoto University, 606-8507, Kyoto, Japan
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787
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Escher R, Jones A, Hagos F, Carmichael C, Horwitz M, Olopade OI, Scott HS. Chromosome band 16q22-linked familial AML: Exclusion of candidate genes, and possible disease risk modification byNQO1 polymorphisms. Genes Chromosomes Cancer 2004; 41:278-82. [PMID: 15334552 DOI: 10.1002/gcc.20084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Analyses of chromosomal translocation and inversion breakpoints in sporadic acute myeloid leukemias have identified many transcription factors as playing a role in leukemogenesis. Studies of families with a Mendelian predisposition to hematological malignancies have identified the gene coding for the transcription factor RUNX1 as a leukemia-predisposing gene involved in the first steps of leukemogenesis. Using two families, another autosomal dominant familial leukemia locus was linked to chromosome band 16q22 where the CBFB gene maps. Although CBFB forms a core-binding factor transcriptional complex with RUNX1, previous analyses have excluded the CBFB gene as the leukemia-predisposing gene in these families. In the current study, we performed an extended molecular analysis in these families of the four other transcription factor genes in the 16q22 critical region as well as of two other genes with a known association with leukemia. Several previously undescribed but nonpathogenic sequence variants were identified. We demonstrated that the transcription factors E2F4, CTCF, NFATC3, and NFAT5, and the genes coding for NAD(P)H:quinone oxido-reductase 1 (NQO1) and for E-cadherin are not responsible for the leukemia susceptibility in these families. The presence of NQO1 polymorphisms may suggest a role for this gene in disease risk modification in these families.
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Affiliation(s)
- Robert Escher
- Genetics and Bioinformatics Division, the Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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788
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Berger P, Lepidi H, Drogoul-Vey MP, Poizot-Martin I, Drancourt M. Mycobacterium avium brain abscess at the initiation of highly active antiretroviral therapy. Eur J Clin Microbiol Infect Dis 2003; 23:142-4. [PMID: 14689317 DOI: 10.1007/s10096-003-1070-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- P Berger
- Unité des Rickettsies CNRS UMR 6020, IFR 48, Faculté de Médecine, 27 Boulevard Jean Moulin, 13385 Marseille Cédex 05, France
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789
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Lipscomb EA, Dugan AS, Rabinovitz I, Mercurio AM. Use of RNA interference to inhibit integrin (alpha6beta4)-mediated invasion and migration of breast carcinoma cells. Clin Exp Metastasis 2003; 20:569-76. [PMID: 14598892 DOI: 10.1023/a:1025819521707] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The application of small interfering RNA (siRNA) oligonucleotides to silence gene expression has profound implications for the intervention of human diseases including cancer. Using this technique, we explored the possibility that the alpha6beta4 integrin, a laminin adhesion receptor with a recognized role in the invasive phenotype of many carcinomas, represents a potential therapeutic target to inhibit the migration and invasion of carcinoma cells. We found that siRNA oligonucleotides targeted to either subunit of the alpha6beta4 integrin reduced cell surface expression of this integrin and resulted in decreased invasion of MDA-MB-231 breast carcinoma cells. Interestingly, reduced alpha6beta4 expression also promoted decreased migration on non-laminin substrata indicating that this integrin can function in a ligand-independent manner. In addition, the absence of beta4 expression in these cells augmented the formation of alpha6beta1 heterodimers and increased adhesion to laminin-1. Taken together, these results substantiate the importance of the alpha6beta4 integrin in invasion and migration that has been demonstrated previously by expression of the beta4 subunit in beta4-deficient cell lines and by function blocking antibodies. Furthermore, these data suggest that the utilization of siRNA oligonucleotides to reduce the expression of the alpha6beta4 integrin may be a useful approach to prevent carcinoma cell progression.
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Affiliation(s)
- Elizabeth A Lipscomb
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215, USA
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790
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Lee SD, Colla E, Sheen MR, Na KY, Kwon HM. Multiple domains of TonEBP cooperate to stimulate transcription in response to hypertonicity. J Biol Chem 2003; 278:47571-7. [PMID: 12970349 DOI: 10.1074/jbc.m308795200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tonicity-responsive enhancer binding protein (TonEBP), also known as NFAT5, belongs to the Rel family of transcriptional activators. In the kidney medulla and thymus, TonEBP plays a major role in protecting renal cells and T cells from the deleterious effects of ambient hypertonicity. TonEBP is stimulated by hypertonicity via several pathways: increased expression of protein, nuclear translocation, and increased transactivation. In this study, we identified five domains of TonEBP involved in transactivation. The two conserved glutamine repeats were not involved in transactivation. There were three activation domains that could stimulate transcription independently. In addition, there were two modulation domains that potentiated the activity of the activation domains. One of the activation domains is unique to a splice isoform that is more active than others, indicating that alternative splicing can affect the activity of TonEBP. Another activation domain and one of the modulation domains were stimulated by hypertonicity. All the five domains acted in synergy in every combination. Although overall phosphorylation of TonEBP increased in response to hypertonicity, phosphorylation of the activation and modulation domains did not increase in isolation. In sum, TonEBP possesses far more elaborate domains involved in transactivation compared with other Rel proteins.
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Affiliation(s)
- Sang Do Lee
- Department of Medicine, University of Maryland, Baltimore, Maryland 21201, USA
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791
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Zhang Z, Ferraris JD, Brooks HL, Brisc I, Burg MB. Expression of osmotic stress-related genes in tissues of normal and hyposmotic rats. Am J Physiol Renal Physiol 2003; 285:F688-93. [PMID: 12824075 DOI: 10.1152/ajprenal.00028.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
TonEBP is a transcription factor that, when activated by hypertonicity, increases transcription of genes, including those involved in organic osmolyte accumulation. Surprisingly, it is expressed in virtually all tissues, including many never normally exposed to hypertonicity. We measured TonEBP mRNA (real-time PCR) and protein (Western blot analysis) in tissues of control (plasma osmolality 294 +/- 1 mosmol/kgH2O) and hyposmotic (dDAVP infusion plus water loading for 3 days, 241 +/- 2 mosmol/kgH2O) rats to test whether the ubiquitous expression of TonEBP mRNA is osmotically regulated around the normal plasma osmolality. TonEBP protein is reduced by hyposmolality in thymus and liver, but not in brain, and is not detected in heart and skeletal muscle. TonEBP mRNA decreases in brain and liver but is unchanged in other tissues. There are no general changes in mRNA of TonEBP-mediated genes: aldose reductase (AR) does not change in any tissue, betaine transporter (BGT1) decreases only in liver, taurine transporter (TauT) only in brain and thymus, and inositol transporter (SMIT) only in skeletal muscle and liver. Heat shock protein (Hsp)70-1 and Hsp70-2 mRNA increase greatly in most tissues, which cannot be attributed to decreased TonEBP activity. The conclusions are as follows: 1) TonEBP protein or mRNA expression is reduced by hyposmolality in thymus, liver, and brain. 2) TonEBP protein and mRNA expression are differentially regulated in some tissues. 3) Although AR, SMIT, BGT1, and TauT are regulated by TonEBP in renal medullary cells, other sources of regulation may predominate in other tissues. 4) TonEBP abundance and activity are regulated by factors other than tonicity in some tissues.
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Affiliation(s)
- Zheng Zhang
- Laboratory of Kidney and Electrolyte Metabolism, National Heart Lung and Blood Institute, Bethesda, MD 20892, USA.
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792
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Hogan PG, Chen L, Nardone J, Rao A. Transcriptional regulation by calcium, calcineurin, and NFAT. Genes Dev 2003; 17:2205-32. [PMID: 12975316 DOI: 10.1101/gad.1102703] [Citation(s) in RCA: 1497] [Impact Index Per Article: 71.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Patrick G Hogan
- The Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA
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793
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Zhou W, König R. T cell receptor-independent CD4 signalling: CD4-MHC class II interactions regulate intracellular calcium and cyclic AMP. Cell Signal 2003; 15:751-62. [PMID: 12781868 DOI: 10.1016/s0898-6568(03)00037-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
CD4 is a coreceptor on T helper (Th) cells that interacts with MHC class II molecules (MHCII). The mechanisms mediating the effects of CD4 on responses by T helper cells to stimulation of the antigen-specific T cell receptor (TCR) are still poorly understood. Here, we demonstrate T cell costimulation via CD4 signalling independent of T cell receptor-mediated signals. Incubation of T helper cells with peptide mimetics of the CD4-binding region on the MHC class II beta2 domain caused intracellular calcium mobilization in the absence of antigen or other T cell receptor stimuli. Engagement of CD4 by peptide mimetics or wild-type MHC class II, but not by mutant MHC class II molecules incapable of engaging CD4, inhibited the T cell receptor-mediated increase in cyclic AMP (cAMP) concentrations in T helper cells. CD4-mediated signals activated cyclic AMP phosphodiesterases (PDEs) and inhibited adenylyl cyclase. Full activation and clonal expansion of antigen-stimulated T helper cells required the CD4-mediated regulation of cyclic AMP. Our results suggest a costimulatory mechanism of CD4 function that acts on the second messengers, calcium and cyclic AMP.
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Affiliation(s)
- Wenhong Zhou
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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794
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Robertson P, Scadden DT. Immune reconstitution in HIV infection and its relationship to cancer. Hematol Oncol Clin North Am 2003; 17:703-16, vi. [PMID: 12852652 DOI: 10.1016/s0889-8588(03)00047-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
HIV infection results in formidable immune dysfunction, widely affecting the immune system, but typified by T lymphopenia. This dysfunction includes a perturbed immune response to several persistent viruses that have a propensity to cause tumors. Effective control of HIV replication by highly active antiretroviral therapy (HAART) results in regeneration of the damaged immune system, and recent advances have allowed this immune reconstitution to be better defined. This article describes the immunodeficiency caused by HIV and the response of the immune system to HAART, with specific reference to the immune response to cancers associated with HIV infection.
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Affiliation(s)
- Paul Robertson
- AIDS Research Center, Massachusetts General Hospital, Harvard Medical School 149, 13th Street, Room 5212, Boston, MA 02109, USA
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795
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Abstract
NFAT5/TonEBP, the most recently described member of the rel/NFkappaB/NFAT family of signal-dependent transcription factors, is activated by extracellular hypertonicity-a cellular stress of particular and perhaps unique physiologic relevance to cells of the renal medulla. Accumulating evidence suggests that NFAT5/TonEBP also functions in vivo under isotonic conditions as part of a ubiquitous regulatory mechanism that senses and adjusts available intracellular volume during cell growth to establish an intracellular environment appropriate for optimal cell proliferation.
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Affiliation(s)
- Steffan N Ho
- Department of Pathology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0644, USA.
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796
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Neal JW, Clipstone NA. A constitutively active NFATc1 mutant induces a transformed phenotype in 3T3-L1 fibroblasts. J Biol Chem 2003; 278:17246-54. [PMID: 12598522 DOI: 10.1074/jbc.m300528200] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The calcineurin/nuclear factor of activated T cells (NFAT) signaling pathway is best known for its role in T lymphocyte activation. However, it has become increasingly apparent that this signaling pathway is also involved in the regulation of cell growth and development in a wide variety of different tissues and cell types. Here we have investigated the effects of sustained NFATc1 signaling on the growth and differentiation of the murine 3T3-L1 preadipocyte cell line. Remarkably, we find that expression of a constitutively active NFATc1 mutant (caNFATc1) in these immortalized cells inhibits their differentiation into mature adipocytes and causes them to adopt a transformed cell phenotype, including loss of contact-mediated growth inhibition, reduced serum growth requirements, protection from growth factor withdrawal-induced apoptosis, and formation of colonies in semisolid media. Furthermore, we find that caNFATc1-expressing cells acquire growth factor autonomy and are able to proliferate even in the complete absence of serum. We provide evidence that this growth factor independence is caused by the NFATc1-dependent production of a soluble heat-labile autocrine factor that is capable of promoting the growth and survival of wild type 3T3-L1 cells as well as potently inhibiting their differentiation into mature adipocytes. Finally, we demonstrate that cells expressing caNFATc1 form tumors in nude mice. Taken together, these results indicate that deregulated NFATc1 activity is able to induce the immortalized 3T3-L1 preadipocyte cell line to acquire the well established hallmarks of cellular transformation and thereby provide direct evidence for the oncogenic potential of the NFATc1 transcription factor.
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Affiliation(s)
- Joel W Neal
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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797
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Bommireddy R, Saxena V, Ormsby I, Yin M, Boivin GP, Babcock GF, Singh RR, Doetschman T. TGF-beta 1 regulates lymphocyte homeostasis by preventing activation and subsequent apoptosis of peripheral lymphocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:4612-22. [PMID: 12707339 DOI: 10.4049/jimmunol.170.9.4612] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TGF-beta1 plays an important role in the maintenance of immune homeostasis and self-tolerance. To determine the mechanism by which TGF-beta1 prevents autoimmunity we have analyzed T cell activation in splenic lymphocytes from TGF-beta1-deficient mice. Here we demonstrate that unlike wild-type splenic lymphocytes, those from Tgfb1(-/-) mice are hyporesponsive to receptor-mediated mitogenic stimulation, as evidenced by diminished proliferation and reduced IL-2 production. However, they have elevated levels of IFN-gamma and eventually undergo apoptosis. Receptor-independent stimulation of Tgfb1(-/-) T cells by PMA plus ionomycin induces IL-2 production and mitogenic response, and it rescues them from anergy. Tgfb1(-/-) T cells display decreased CD3 expression; increased expression of the activation markers LFA-1, CD69, and CD122; and increased cell size, all of which indicate prior activation. Consistently, mutant CD4(+) T cells have elevated intracellular Ca(2+) levels. However, upon subsequent stimulation in vitro, increases in Ca(2+) levels are less than those in wild-type cells. This is also consistent with the anergic phenotype. Together, these results demonstrate that the ex vivo proliferative hyporesponsiveness of Tgfb1(-/-) splenic lymphocytes is due to prior in vivo activation of T cells resulting from deregulated intracellular Ca(2+) levels.
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Affiliation(s)
- Ramireddy Bommireddy
- Department of Molecular Genetics, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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798
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Kohler JJ, Tuttle DL, Coberley CR, Sleasman JW, Goodenow MM. Human immunodeficiency virus type 1 (HIV-1) induces activation of multiple STATs in CD4+ cells of lymphocyte or monocyte/macrophage lineages. J Leukoc Biol 2003; 73:407-16. [PMID: 12629155 DOI: 10.1189/jlb.0702358] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) impacts the activation state of multiple lineages of hematopoietic cells. Chronic HIV-1 infection among individuals with progressive disease can be associated with increased levels of activated signal transducers and activators of transcription (STATs) in peripheral blood mononuclear cells. To investigate interactions between HIV-1 and CD4(+) cells, activated, phosphorylated STAT proteins in nuclear extracts from lymphocytic and promonocytic cell lines as well as primary monocyte-derived macrophages were measured. Levels of activated STATs increased six- to tenfold in HUT78 and U937 cells within 2 h following exposure to virions. The response to virus was dose-dependent, but kinetics of activation was delayed relative to interleukin-2 or interferon-gamma. Activation of STAT1, STAT3, and STAT5 occurred with diverse viral envelope proteins, independent of coreceptor use or viral replication. Envelope-deficient virions had no effect on STAT activation. Monoclonal antibody engagement of CD4 identified a novel role for CD4 as a mediator in the activation of multiple STATs. Results provide a model for HIV-1 pathogenesis in infected and noninfected hematopoietic cells.
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Affiliation(s)
- James J Kohler
- Department of Pathology, Immunology, and Laboratory Medicine, Division of Immunology and Infectious Diseases, College of Medicine, University of Florida, Gainesville 32610, USA
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799
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Abstract
Although they were used initially as non-specific immunosuppressants in transplantation, CD3-specific monoclonal antibodies have elicited renewed interest owing to their capacity to induce immune tolerance. In mouse models of autoimmune diabetes, CD3-specific antibodies induce stable disease remission by restoring tolerance to pancreatic beta-cells. This phenomenon was extended recently to the clinic--preservation of beta-cell function in recently diagnosed patients with diabetes was achieved by short-term administration of a CD3-specific antibody. CD3-specific antibodies arrest ongoing disease by rapidly clearing pathogenic T cells from the target. Subsequently, they promote long-term T-cell-mediated active tolerance. Recent data indicate that transforming growth factor-beta-dependent CD4+CD25+ regulatory T cells might have a central role in this effect.
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Affiliation(s)
- Lucienne Chatenoud
- Centre de l'Association Claude Bernard sur les Maladies Autoimmunes and Hôpital Necker Enfants Malades IRNEM, 161 Rue de Sèvres, 75015 Paris, France.
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800
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Scimeca JC, Quincey D, Parrinello H, Romatet D, Grosgeorge J, Gaudray P, Philip N, Fischer A, Carle GF. Novel mutations in the TCIRG1 gene encoding the a3 subunit of the vacuolar proton pump in patients affected by infantile malignant osteopetrosis. Hum Mutat 2003; 21:151-7. [PMID: 12552563 DOI: 10.1002/humu.10165] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fifty percent of the infantile malignant osteopetrosis (IMO) cases reported in the literature present mutations in the TCIRG1 gene encoding the 116-kDa osteoclast specific subunit of the vacuolar proton ATPase (ATP6I). In this study, we identified four novel mutations in a series of six IMO patients. All of these mutations correspond to single nucleotide changes and affect splice acceptor or donor sites, resulting in aberrant transcription products. We report also a missense mutation, G405R, previously described in several Costa Rican patients. This independent finding suggests that the highly conserved residue at amino acid 405 plays a critical role in the a3 subunit function. Finally, the results of this study were used to provide a prenatal diagnosis to one of the families.
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MESH Headings
- Chromosomes, Human, Pair 11/genetics
- Female
- Genes, Recessive/genetics
- Genetic Markers/genetics
- Genotype
- Haplotypes/genetics
- Humans
- Infant
- Infant, Newborn
- Infant, Newborn, Diseases/diagnosis
- Infant, Newborn, Diseases/genetics
- Infant, Newborn, Diseases/mortality
- Male
- Mutation/genetics
- Organ Specificity/genetics
- Osteoclasts/classification
- Osteoclasts/metabolism
- Osteopetrosis/diagnosis
- Osteopetrosis/genetics
- Osteopetrosis/mortality
- Pedigree
- Prenatal Diagnosis
- Protein Subunits/genetics
- Vacuolar Proton-Translocating ATPases/genetics
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Affiliation(s)
- Jean-Claude Scimeca
- Instabilité et Altérations des Génomes, UMR6549 CNRS/UNSA, Faculté de Médecine de l'Université de Nice-Sophia Antipolis, Nice, France
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