201
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Tang DG, Guan KL, Li L, Honn KV, Chen YQ, Rice RL, Taylor JD, Porter AT. Suppression of W256 carcinosarcoma cell apoptosis by arachidonic acid and other polyunsaturated fatty acids. Int J Cancer 1997; 72:1078-87. [PMID: 9378543 DOI: 10.1002/(sici)1097-0215(19970917)72:6<1078::aid-ijc24>3.0.co;2-#] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Serum-cultured rat W256 carcinosarcoma cells of the monocytoid origin undergo rapid apoptosis in response to the lipoxygenase inhibitor NDGA (nordihydroguaiaretic acid). Exogenous arachidonic acid (AA), in a time- and dose-dependent fashion, suppressed NDGA-induced W256 cell apoptosis as well as DNA fragmentation, with the maximal effect observed at approximately 25 microM. Mobilization of endogenous AA by calcium ionophore A23187 provided an even stronger and longer-lasting protection against NDGA-caused cell death. The A23187 effect on AA release as well as W256 cell death can be blocked by bromophenacyl bromide, thus suggesting involvement of phospholipase A2 activation. Serum withdrawal similarly caused W256 cells to undergo typical apoptosis, which was not rescued by several growth factors commonly found in serum. However, exogenous AA suppressed serum starvation-induced W256 cell apoptosis and significantly extended cell survival in a dose-dependent manner. Lipoxygenase products, 12(S)- and 15(S)-, but not 5(S)-hydroxyeicosatetraenoic acid (HETE), in a dose-dependent fashion, also prevented both NDGA- and serum-starvation-induced W256 cell apoptosis. AA appears to suppress W256 cell apoptosis via distinct signaling pathway(s) since it does not prevent cell death triggered by several other inducers. Examination of a panel of polyunsaturated fatty acids revealed that alpha-linolenic and linoleic acid can also suppress NDGA-induced W256 cell apoptosis. Our data suggest that AA and other polyunsaturated fatty acids and/or their metabolites may enhance tumor growth not only by promoting cell proliferation but also by suppressing apoptosis.
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Affiliation(s)
- D G Tang
- Department of Radiation Oncology, Wayne State University, Detroit, MI 48202, USA.
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202
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Abstract
The integrin alphaIIb beta3 is a membrane receptor which was considered to be expressed only in cells of megakaryocytic lineage. We have shown that alphaIIb beta3 is expressed in mouse melanoma B16a cells, and in human prostate adenocarcinoma cells. The purpose of this study was to determine whether the megakaryocytic product alphaIIb beta3 was functionally expressed in other non-megakaryocyte lineage tumor cells. By using the reverse transcription polymerase chain reaction (RT-PCR), we have obtained data demonstrating that alphaIIb beta3 is expressed in a variety of tumor cell lines (17) derived from different species (human, rat and mouse) and of different histological origins (skin, blood, lung, liver, kidney, cervix, colon, bladder, breast and prostate). Immunostaining of tumor cells with a monoclonal antibody (MAb) to alphaIIb beta3 demonstrates that alphaIIb beta3 protein is also expressed in tumor cells. A protein kinase C activator PMA stimulates adhesion of tumor cells to fibronectin and fibrinogen, and this stimulated adhesion is blocked by a function-blocking MAb directed to alphaIIb beta3. Our results indicate that the megakaryocytic gene product alphaIIb beta3 integrin is widely expressed among tumor cells of non-megakaryocytic lineage, suggesting that ectopic expression of this integrin may play an important role in tumor progression.
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Affiliation(s)
- Y Q Chen
- Department of Pathology, Wayne State University, Detroit, MI 48202, USA
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203
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Chen M, Cheng A, Chen YQ, Hymel A, Hanson EP, Kimmel L, Minami Y, Taniguchi T, Changelian PS, O'Shea JJ. The amino terminus of JAK3 is necessary and sufficient for binding to the common gamma chain and confers the ability to transmit interleukin 2-mediated signals. Proc Natl Acad Sci U S A 1997; 94:6910-5. [PMID: 9192665 PMCID: PMC21258 DOI: 10.1073/pnas.94.13.6910] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
JAK3 is a protein tyrosine kinase that specifically associates with the common gamma chain (gammac), a shared subunit of receptors for interleukin (IL) 2, 4, 7, 9, and 15. Patients deficient in either JAK3 or gammac presented with virtually identical forms of severe combined immunodeficiency (SCID), underscoring the importance of the JAK3-gammac interaction. Despite the key roles of JAK3 and gammac in lymphocytic development and function, the molecular basis of this interaction remains poorly understood. In this study, we have characterized the regions of JAK3 involved in gammac association. By developing a number of chimeric JAK3-JAK2 constructs, we show that the binding specificity to gammac can be conferred to JAK2 by transferring the N-terminal domains of JAK3. Moreover, those JAK3-JAK2 chimeras capable of binding gammac were also capable of reconstituting IL-2 signaling as measured by inducible phosphorylation of the chimeric JAK3-JAK2 protein, JAK1, the IL-2 receptor beta chain, and signal transducer and activator of transcription 5A. Subsequent deletion analyses of JAK3 have identified the N-terminal JH7-6 domains as a minimal region sufficient for gammac association. Furthermore, expression of the mutant containing only the JH7-6 domains effectively competed with full-length JAK3 for binding to gammac. We conclude that the JH7-6 domains of JAK3 are necessary and sufficient for gammac association. These studies offer clues toward a broader understanding of JAK-mediated cytokine signaling and may provide a target for the development of novel therapeutic modalities in immunologically mediated diseases.
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Affiliation(s)
- M Chen
- Lymphocyte Cell Biology Section, Arthritis-Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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204
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Sheikh MS, Chen YQ, Smith ML, Fornace AJ. Role of p21Waf1/Cip1/Sdi1 in cell death and DNA repair as studied using a tetracycline-inducible system in p53-deficient cells. Oncogene 1997; 14:1875-82. [PMID: 9150394 DOI: 10.1038/sj.onc.1201004] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Postulated roles for p21(Waf1/Cip1/Sdi1) (p21) in DNA repair and apoptosis remain controversial. Studies suggest both stimulatory and inhibitory effects of p21 in DNA repair. p21 has also been implicated in induction or protection from apoptosis. Using the tetracycline inducible expression system, we studied the role of p21 in DNA repair and apoptosis in wild-type p53 deficient DLD1 colorectal carcinoma cells. These cells displayed marked heterogeneity in their ability to tolerate higher levels of exogenous p21. The majority of the p21 overexpressing cells grew slower and did not exhibit apoptotic phenotype, some cells underwent apoptotic death within 5-8 days following p21 induction while other became giant cells prior to undergoing cell death. Induction of p21 transgene neither sensitized to nor protected from adriamycin-induced acute cell death. p21 also did not alter the clonogenic survival following adriamycin treatment. Clonogenic survival after u.v.-irradiation was, however, increased when p21 expression was transiently induced a few hours before and after u.v.-irradiation. Consistent with its effect on clonogenic survival, p21 also enhanced the cellular capacity to repair three different exogenously introduced u.v.-damaged reporter plasmids. Taken together our results demonstrate that p21 may modulate the nucleotide excision repair process to facilitate the repair of u.v.-type DNA damage even in the absence of wild-type p53.
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Affiliation(s)
- M S Sheikh
- Laboratory of Molecular Pharmacology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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205
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Abstract
The catalytic site of all dihydrofolate reductases contains an invariant carboxylic acid, equivalent to Asp-27 in Escherichia coli dihydrofolate reductase (ecDHFR). It has been found that various kinetic and ligand binding properties of ecDHFR show a pH profile with a pKa of about 6.5. The group responsible for this pKa is often assumed to be carboxyl group of Asp-27. To determine the ionization state of this carboxyl and its pKa, we have employed a novel method, based on Raman difference spectroscopy, to obtain its vibrational spectrum in situ. The method is general for the study of protein carboxyl groups, which are often significantly implicated in protein function and structure; this study establishes the method's limits and problems. The Raman difference spectrum between wild-type ecDHFR and the Asp-27 to serine mutant (D27S) in the pH range 5.6-9.0 has been taken. No protonation of the carboxyl group was detected, implying that its pKa is probably less than 5.0. We did, however, detect a pH dependence in the intensity of Raman bands in the difference spectrum with a pKa of 6.3, indicating that the apo enzyme undergoes a pH-dependent conformational change. Because the carboxyl group of Asp-27 at the active site is the only ionizable group in the binding site, other groups, away from the catalytic site, must be responsible for the pH behavior of ecDHFR.
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Affiliation(s)
- Y Q Chen
- Department of Physics, City College of City University of New York, New York 10031, USA
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206
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Oakes SA, Candotti F, Johnston JA, Chen YQ, Ryan JJ, Taylor N, Liu X, Hennighausen L, Notarangelo LD, Paul WE, Blaese RM, O'Shea JJ. Signaling via IL-2 and IL-4 in JAK3-deficient severe combined immunodeficiency lymphocytes: JAK3-dependent and independent pathways. Immunity 1996; 5:605-15. [PMID: 8986719 DOI: 10.1016/s1074-7613(00)80274-5] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Both IL-2 and IL-4 bind to receptors containing the common gamma chain and JAK3. Although JAK3 is required for proper lymphoid development, the precise roles of this kinase in IL-2 and IL-4 signaling in lymphocytes have not been defined. Here, we have studied IL-2 and IL-4 signaling in B cell lines lacking JAK3. Although IL-2-induced phosphorylation of IL-2R beta, JAK1, and STAT5 all required the presence of JAK3, IL-4-mediated phosphorylation of JAK1, STAT6, and insulin receptor substrates 1 and 2 did not. However, IL-4-induced effects were clearly improved following JAK3 expression. These data indicate that IL-4 signaling occurs in the absence of of JAK3, but is comparatively inefficient. These findings may help in understanding the pathogenesis of the immunodeficiency that occurs with mutations of JAK3 and may suggest a mechanism for the pleiotropic effects of IL-4.
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Affiliation(s)
- S A Oakes
- Howard Hughes Medical Institute, National Institutes of Health, Research Scholars Program, Bethesda, Maryland 20892, USA
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207
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Bai JZ, Bian JG, Chai ZW, Chen GP, Chen HF, Chen JC, Chen SM, Chen Y, Chen YB, Chen YQ, Cheng BS, Cheng ZD, Cui XZ, Ding HL, Ding WY, Du ZZ, Fan XL, Fang J, Gao CS, Gao ML, Gao SQ, Gu JH, Gu SD, Gu WX, Gu YF, Guo YN, Han SW, Han Y, He J, He JT, He M, Hu GY, Hu JL, Hu QH, Hu T, Hu XQ, Huang XP, Huang YZ, Jiang CH, Jin S, Jin Y, Kang SH, Ke ZJ, Lai YF, Lan HB, Lang PF, Li J, Li PQ, Li Q, Li RB, Li W, Li WD, Li WG, Li XH, Li XN, Lin SZ, Liu HM, Liu J, Liu JH, Liu Q, Liu RG, Liu Y, Liu ZA, Lu F. Structure Analysis of the fJ(1710) in the Radiative Decay J/ psi --> gamma K+K-. Phys Rev Lett 1996; 77:3959-3962. [PMID: 10062352 DOI: 10.1103/physrevlett.77.3959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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208
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Hagmann W, Gao X, Timar J, Chen YQ, Strohmaier AR, Fahrenkopf C, Kagawa D, Lee M, Zacharek A, Honn KV. 12-Lipoxygenase in A431 cells: genetic identity, modulation of expression, and intracellular localization. Exp Cell Res 1996; 228:197-205. [PMID: 8912711 DOI: 10.1006/excr.1996.0317] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human A431 epidermoid carcinoma cells express 12-lipoxygenase enzymatic activity. However, the isoform identity based on cDNA sequence data is not known. Further, the simultaneous characterization of the intracellular distribution of 12-lipoxygenase protein and activity is lacking. Here we report that the cDNA sequence from RT-PCR-amplified 12-lipoxygenase mRNA is identical with the platelet-type 12-lipoxygenase isoform, and the leukocyte-type isoform of 12-lipoxygenase is not expressed in A431 cells. The predominant amount (78%) of 12-lipoxygenase protein resides in the cytosol. In contrast, the predominant (98%) 12-lipoxygenase activity is localized in the membrane fraction. Western blot and immunofluorescence data demonstrate that epidermal growth factor increases total cellular 12-lipoxygenase protein and enhances the association of 12-lipoxygenase protein with perinuclear or nuclear membrane sites. In addition, epidermal growth factor stimulates 12-lipoxygenase activity resulting in generation of 12(S)-hydroxyeicosatetraenoic acid from cellular arachidonate. In contrast, both 12-lipoxygenase protein and activity decrease approximately 80% within 24 h during serum starvation. The recovery of 12-lipoxygenase expression in serum-deprived cells can be induced by readdition of epidermal growth factor or serum. Further, the basal expression of 12-lipoxygenase depends on signal pathways requiring protein tyrosine kinase activity, since genistein, herbimycin A, and tyrphostin 25 reduce the expression of 12-lipoxygenase protein in A431 cells.
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Affiliation(s)
- W Hagmann
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan 48202, USA
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209
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210
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211
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Zhang K, Kim JP, Woodley DT, Waleh NS, Chen YQ, Kramer RH. Restricted expression and function of laminin 1-binding integrins in normal and malignant oral mucosal keratinocytes. Cell Adhes Commun 1996; 4:159-74. [PMID: 8969862 DOI: 10.3109/15419069609014220] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Squamous cell carcinoma of the oral cavity spreads by initial invasion of the laminin-rich basement membrane. We examined the adhesion and motility of human oral SCC cells and normal mucosal keratinocytes and found that the SCC cells readily attached and migrated on laminin 1 substrates but migrated poorly on collagen type I and fibronectin. The normal keratinocytes, however, adhered poorly to and were non-motile on laminin 1 yet readily and preferentially attached and migrated on fibronectin and collagen type I. Analysis with blocking anti-integrin antibodies showed that the SCC cells used the alpha 6 beta 1 complex to attach and migrate on laminin 1 and that this activity was confined to the E8 long arm fragment of laminin. Affinity chromatography on laminin-Sepharose columns revealed that the SCC cells, but not normal keratinocytes, expressed high levels of the alpha 6 beta 1 laminin 1 receptor. Metabolic pulse-chase analysis indicated that in contrast to the SCC cells, keratinocytes did not have a stable pool of beta 1 subunit precursor. Preferential pairing of alpha 6 with beta 4 and the deficiency in pre-beta 1 levels appear to account for the failure of keratinocytes to form significant alpha 6 beta 1 complex. Additionally, the presence of laminin 1 in co-coating experiments blocked keratinocyte adhesion to other immobilized ligands, such as collagen type I or fibronectin. This anti-adhesive effect seemed to reflect a general paralysis of cell adhesive function, since laminin 1 also diminished the adhesion of keratinocytes to substrates coated with immobilized anti-integrin subunit antibody. The inhibitory activity of laminin 1 resided in the E1' and E8 fragments, and not in the E3, E4 or G domains. Collectively, our results indicate that laminin 1 is a restrictive ligand for normal keratinocytes, apparently because of their failure to assemble and express the alpha 6 beta 1 complex or other functional laminin receptors and their sensitivity to the anti-adhesive activity of laminin itself. The elevated expression of alpha 6 beta 1 following malignant conversion of muscosal keratinocytes promotes their migration on laminin, a process important during invasion and metastasis.
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Affiliation(s)
- K Zhang
- Department of Anatomy, University of California, San Francisco 94143, USA
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212
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Clyman RI, Goetzman BW, Chen YQ, Mauray F, Kramer RH, Pytela R, Schnapp LM. Changes in endothelial cell and smooth muscle cell integrin expression during closure of the ductus arteriosus: an immunohistochemical comparison of the fetal, preterm newborn, and full-term newborn rhesus monkey ductus. Pediatr Res 1996; 40:198-208. [PMID: 8827767 DOI: 10.1203/00006450-199608000-00004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Anatomical closure of the ductus arteriosus requires normally quiescent luminal endothelial cells and medial smooth muscle cells to migrate into the subendothelial space forming intimal mounds that eventually coalesce and occlude the vessel's lumen. The migration of endothelial cells and smooth muscle cells requires the presence of integrin receptors that interact with the surrounding matrix. We used immunohistochemical staining to examine the repertoires of integrins expressed by endothelial cells and smooth muscle cells during postnatal closure of the ductus arteriosus in full-term and preterm rhesus monkeys. In the fetal ductus, luminal endothelial cells have a limited repertoire of integrins. During postnatal ductus closure, luminal endothelial cells, of both term and preterm monkeys, change their phenotype and express the full repertoire of integrins found on growing capillary endothelial cells (alpha 1 beta 1, alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 1, alpha v beta 1, alpha 6 beta 4, and alpha v beta 5). Similarly, during ductus closure, smooth muscle cells of both term and preterm monkeys expand their integrin repertoire to include the alpha 5 beta 1 and alpha v beta 3 integrins; these two integrins have been shown to be essential for smooth muscle cell migration in vitro. These changes in integrin profile occur at the same time the endothelial and smooth muscle cells invade their neighboring compartments. In contrast, preterm monkeys with a persistently patent ductus lumen fail to develop these changes in integrin expression and fail to develop neointimal mounds. No evidence of intimal thickening occurs in the absence of changes in integrin expression. Therefore, endothelial cells and smooth muscle cells change phenotypes to produce the intimal thickening required for ductus closure.
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Affiliation(s)
- R I Clyman
- Cardiovascular Research Institute, University of California, San Francisco 94143-0544, USA
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213
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Abstract
Previous work from this and other laboratories has demonstrated that the vasoconstrictor peptide angiotensin II results in hypertrophy of rat aortic smooth muscle cells that is associated with an increase in transcription of the early growth response gene c-fos. To explore the molecular mechanism responsible for c-fos induction in rat aortic smooth muscle cells, we used a series of reporter constructs linked to the chloramphenicol acetyl transferase gene in transient transfection experiments in rat aortic smooth muscle cells. Constructs containing both the serum response element and cAMP response element exhibited a 20-fold increase in chloramphenicol acetyl transferase activity in response to either serum or angiotensin II, whereas no increase was seen in vehicle-treated cells. Mutations in either the serum response element or cAMP response element alone, which have been demonstrated to inactivate these elements in other cell types, had no effect on chloramphenicol acetyl transferase inducibility. In contrast, if both elements were mutated, inducibility was almost abolished. Electrophoretic mobility shift assays with oligonucleotides corresponding to either serum response element or cAMP response element demonstrated that these oligonucleotides are capable of forming specific complexes with proteins from rat aortic smooth muscle cell nuclear extracts. One of the proteins binding to the serum response element is the previously described serum response factor, since it was supershifted by a monospecific antibody. These studies demonstrate that c-fox induction in smooth muscle occurs by a dual mechanism that can activate transcription via the serum response element or cAMP response element. These elements appear to act equally and independently, involving a distinct set of transacting factors.
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Affiliation(s)
- Y Q Chen
- Department of Medicine, Division of Cardiology, Vanderbilt University, Nashville, TN 37232-2170, USA
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214
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Abstract
Arachidonic acid (AA) metabolites derived from both cyclooxygenase (COX) and lipoxygenase (LOX) pathways transduce a variety of signals related to cell growth. Here, we report that the AA LOX pathway also functions as a critical regulator of cell survival and apoptosis. Rat Walker 256 (W256) carcinosarcoma cells express 12-LOX and synthesize 12(S)- and 15(S)-hydroxyeicosatetraenoic acids as their major LOX metabolites. W256 cells transfected with 12-LOX-specific antisense oligonucleotide or antisense oligonucleotides directed to conserved regions of LOXs underwent time- and dose-dependent apoptosis. Likewise, treatment of W256 cells with various LOX but not COX inhibitors induced apoptotic cell death, which could be partially inhibited by exogenous 12(S)- or 15(S)-hydroxyeicosatetraenoic acids. The W256 cell apoptosis induced by antisense oligos and LOX inhibitors was followed by a rapid downregulation of bcl-2 protein, a dramatic decrease in the bcl-2/bax ratio, and could be suppressed by bcl-2 overexpression. In contrast, p53, which is wild type in W256 cells, did not undergo alterations during apoptosis induction. The results suggest that the LOX pathway plays an important physiological role in regulating apoptosis.
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Affiliation(s)
- D G Tang
- Department of Radiation Oncology, Wayne State University, Detroit, MI 48202, USA
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215
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Bai JZ, Bian JG, Chen GP, Chen HF, Chen SJ, Chen SM, Chen Y, Chen YQ, Chen YB, Cheng BS, Cui XZ, Ding HL, Ding WY, Du ZZ, Fan XL, Fang J, Gao CS, Gao ML, Gao SQ, Gu JH, Gu SD, Gu WX, Gu YF, Guo YN, Han SW, Han Y, He J, He M, Hu GY, Hu T, Hu XQ, Huang DQ, Huang T, Huang YZ, Jiang CH, Jin S, Jin Y, Kang SH, Ke ZJ, Lai YF, Lan HB, Lang PF, Li F, Li J, Li PQ, Li Q, Li RB, Li W, Li WD, Li WG, Li XH, Li XN, Lin SZ, Liu HM, Liu J, Liu JH, Liu Q, Liu RG, Liu Y, Liu ZA, Lu JG, Luo SQ, Luo Y, Ma AM. Studies of xi (2230) in J/ psi radiative decays. Phys Rev Lett 1996; 76:3502-3505. [PMID: 10060984 DOI: 10.1103/physrevlett.76.3502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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216
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Chen YQ, Oakes RJ. Hyperfine spin splittings in heavy quarkonia. Phys Rev D Part Fields 1996; 53:5051-5057. [PMID: 10020502 DOI: 10.1103/physrevd.53.5051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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217
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Bernstein EF, Chen YQ, Kopp JB, Fisher L, Brown DB, Hahn PJ, Robey FA, Lakkakorpi J, Uitto J. Long-term sun exposure alters the collagen of the papillary dermis. Comparison of sun-protected and photoaged skin by northern analysis, immunohistochemical staining, and confocal laser scanning microscopy. J Am Acad Dermatol 1996; 34:209-18. [PMID: 8642084 DOI: 10.1016/s0190-9622(96)80114-9] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Long-term solar irradiation produces both morphologic and functional changes in affected skin. Because collagen is the major structural component of skin, any alteration in its production or degradation could have profound effects on cutaneous functional integrity. OBJECTIVE Our purpose was to investigate alterations in the production and morphology of collagen fibers brought about by long-term sun exposure. METHODS We compared collagen and collagenase gene expression and collagen immunohistochemical staining and used confocal laser scanning microscopy for morphologic examination of dermal collagen fibers in photodamaged compared with sun-protected skin from the same persons. RESULTS Despite a large increase in elastin messenger RNA in sun-damaged skin, collagen and collagenase gene expression remained essentially unchanged. However, striking alterations in the papillary dermis of photoaged skin were found, which revealed large, abnormally clumped elastic fibers and deformed collagen fibers of various diameters, replacing the normal architecture of the papillary dermis. CONCLUSION Our data provide evidence for normal collagen gene expression in sun-damaged skin and suggest that degradation and remodeling of collagen take place in the papillary dermis accompanied by deposition of other matrix components, predominantly abnormal elastic fibers.
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Affiliation(s)
- E F Bernstein
- Department of Dermatology, Jefferson Medical College, Philadelphia, PA 19107-5541, USA
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218
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Gulli LF, Palmer KC, Chen YQ, Reddy KB. Epidermal growth factor-induced apoptosis in A431 cells can be reversed by reducing the tyrosine kinase activity. Cell Growth Differ 1996; 7:173-8. [PMID: 8822200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A431 cells overexpress epidermal growth factor receptors (EGF-Rs) and are inhibited by EGF. We show that treatment of A431 cells with 10 nM EGF induced a 15-fold increase in EGF-R autophosphorylation, leading to inhibition of cell proliferation and morphological features of apoptosis. However, at a lower concentration of EGF (0.01 nM), there is a 2-fold increase in EGF-R autophosphorylation and increased cell proliferation when compared to untreated cells. EGF treatment is associated with increased expression of c-myc and decreased expression of mutant p53 and p21/WAF protein. When A431 cells were simultaneously treated with 10 nM EGF and EGF-R antibody, there was a significant reduction in EGF-R autophosphorylation that was associated with increased cell proliferation. Based on these results, we postulate that overexpression of EGF-R could allow for selective growth advantage for tumor cells in the presence of normal or decreased ligand availability. However, excessive ligand binding would result in deregulated growth signaling, leading to growth inhibition and programmed cell death.
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Affiliation(s)
- L F Gulli
- Department of Pathology, Wayne State University, Detroit, Michigan 48201, USA
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219
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220
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Bai JZ, Bardon O, Becker-Szendy RA, Blum I, Breakstone A, Burnett T, Chen GP, Chen HF, Chen J, Chen SJ, Chen SM, Chen Y, Chen YB, Chen YQ, Cheng BS, Cowan RF, Cui HC, Cui XZ, Ding HL, Du ZZ, Dunwoodie W, Fan XL, Fang J, Gao CS, Gao ML, Gao SQ, Gao WX, Gratton P, Gu JH, Gu SD, Gu WX, Gu YF, Guo YN, Han SW, Han Y, Harris FA, Hatanaka M, He J, He KR, He M, Hitlin DG, Hu GY, Hu T, Hu XQ, Huang DQ, Huang YZ, Izen JM, Jia QP, Jiang CH, Jiang ZZ, Jin S, Jin Y, Jones L, Kang SH, Ke ZJ, Kelsey MH, Kim BK, Lai YF, Lan HB, Lang PF, Lankford A, Li F, Li J, Li PQ. Measurement of the mass of the tau lepton. Phys Rev D Part Fields 1996; 53:20-34. [PMID: 10019769 DOI: 10.1103/physrevd.53.20] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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221
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Tortolani PJ, Lal BK, Riva A, Johnston JA, Chen YQ, Reaman GH, Beckwith M, Longo D, Ortaldo JR, Bhatia K, McGrath I, Kehrl J, Tuscano J, McVicar DW, O'Shea JJ. Regulation of JAK3 expression and activation in human B cells and B cell malignancies. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.155.11.5220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Members of the Janus family (JAK) of protein tyrosine kinases are critical enzymes in signaling pathways via hematopoietin receptors. We have cloned JAK3, which unlike other known family members (JAK1, JAK2, and TYK2) is preferentially expressed in hematopoietic cells but not in a variety of other cells. Functionally, JAK3 and JAK1 are coupled to the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15 in T cells and NK cells. Because of the importance of IL-2, IL-4, and IL-7 in B cell physiology, we sought to determine whether JAK3 was also present in B lymphocytes and whether it was involved in signaling via cytokines that are important for B cell development and function. In this report, we demonstrate that JAK3 is expressed in normal human peripheral blood B cells at levels that are comparable to those in T cells. In addition, the levels were found to be markedly up-regulated following stimulation with staphylococcal protein A Cowan and anti-CD40 Abs. In addition, IL-4 and IL-7 induced the rapid tyrosine phosphorylation of JAK3 and JAK1, and IL-4 activated both JAK3 and JAK1 phosphotransferase activity. JAK3 protein was also detected in immature B cell lines, but not in more well differentiated cell lines. Additionally, JAK3 was detected in lysates from bone marrow lymphoblasts of patients with B cell precursor acute lymphocytic leukemia and cell lines derived from human B cell lymphomas. Together, these data suggest that the regulation of JAK3 expression and activity is likely to be important in B cell development and function.
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Affiliation(s)
- P J Tortolani
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - B K Lal
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - A Riva
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - J A Johnston
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - Y Q Chen
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - G H Reaman
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - M Beckwith
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - D Longo
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - J R Ortaldo
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - K Bhatia
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - I McGrath
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - J Kehrl
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - J Tuscano
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - D W McVicar
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
| | - J J O'Shea
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
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222
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Tortolani PJ, Lal BK, Riva A, Johnston JA, Chen YQ, Reaman GH, Beckwith M, Longo D, Ortaldo JR, Bhatia K, McGrath I, Kehrl J, Tuscano J, McVicar DW, O'Shea JJ. Regulation of JAK3 expression and activation in human B cells and B cell malignancies. J Immunol 1995; 155:5220-6. [PMID: 7594533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Members of the Janus family (JAK) of protein tyrosine kinases are critical enzymes in signaling pathways via hematopoietin receptors. We have cloned JAK3, which unlike other known family members (JAK1, JAK2, and TYK2) is preferentially expressed in hematopoietic cells but not in a variety of other cells. Functionally, JAK3 and JAK1 are coupled to the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15 in T cells and NK cells. Because of the importance of IL-2, IL-4, and IL-7 in B cell physiology, we sought to determine whether JAK3 was also present in B lymphocytes and whether it was involved in signaling via cytokines that are important for B cell development and function. In this report, we demonstrate that JAK3 is expressed in normal human peripheral blood B cells at levels that are comparable to those in T cells. In addition, the levels were found to be markedly up-regulated following stimulation with staphylococcal protein A Cowan and anti-CD40 Abs. In addition, IL-4 and IL-7 induced the rapid tyrosine phosphorylation of JAK3 and JAK1, and IL-4 activated both JAK3 and JAK1 phosphotransferase activity. JAK3 protein was also detected in immature B cell lines, but not in more well differentiated cell lines. Additionally, JAK3 was detected in lysates from bone marrow lymphoblasts of patients with B cell precursor acute lymphocytic leukemia and cell lines derived from human B cell lymphomas. Together, these data suggest that the regulation of JAK3 expression and activity is likely to be important in B cell development and function.
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Affiliation(s)
- P J Tortolani
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD 20892, USA
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223
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Upadhyay S, Li G, Liu H, Chen YQ, Sarkar FH, Kim HR. bcl-2 suppresses expression of p21WAF1/CIP1 in breast epithelial cells. Cancer Res 1995; 55:4520-4. [PMID: 7553620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The tumor suppressor gene p53 regulates G1 checkpoint prior to the initiation of DNA synthesis, which can either induce G1 arrest or signal apoptosis. The involvement of p53 in apoptosis may also be related to its ability to down-regulate transcription of the bcl-2 gene. The bcl-2 gene product prevents most types of apoptotic cell death, suggesting that bcl-2 interferes with an essential signaling molecule involved in the apoptotic cell death pathway. Although the bcl-2 protein is shown to be overexpressed in many types of human tumor including breast cancer, its biochemical or pathological consequences are poorly understood. To determine the effects of bcl-2 overexpression on apoptosis and transformation of breast epithelial cells and to investigate whether bcl-2 interferes with the p53 pathway, we introduced the bcl-2 expression vector into MCF10A cells, which were derived from diploid human breast epithelial cells containing the wild-type p53 gene. Overexpression of bcl-2 prevented free radical-induced apoptosis and induced a partially transformed phenotype in MCF10A cells. Although overexpression of bcl-2 did not affect the expression of the p53 gene, p53-dependent gene transcription such as p21WAF1/CIP1 was suppressed. These results suggest that bcl-2 may inhibit p53 functional activity and is involved in the regulation of an early commitment step either to proliferate or suicide.
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Affiliation(s)
- S Upadhyay
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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224
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Chen YQ, Cipriano SC, Arenkiel JM, Miller FR. Tumor suppression by p21WAF1. Cancer Res 1995; 55:4536-9. [PMID: 7553623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The p21WAF1 gene encodes a cyclin-dependent kinase inhibitor and mediates tumor suppressor gene p53-induced cell cycle arrest. To directly test whether p21WAF1 can act as a tumor suppressor, we have expressed the p21WAF1 cDNA in several human tumor cell lines using a tetracycline-inducible system. Overexpression of p21WAF1 suppresses proliferation and soft agar growth of tumor cells in vitro, as well as tumorigenicity in vivo. Our data provide direct evidence for the tumor-suppressive activity of p21WAF1.
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Affiliation(s)
- Y Q Chen
- Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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225
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Gao X, Chen YQ, Wu N, Grignon DJ, Sakr W, Porter AT, Honn KV. Somatic mutations of the WAF1/CIP1 gene in primary prostate cancer. Oncogene 1995; 11:1395-8. [PMID: 7478562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The WAF1/CIP1 gene, a potential tumor suppressor gene, has recently been cloned and identified as a p53 mediator and an inhibitor for G1 cyclin-dependent kinases (CDKs). We undertook this study to investigate the possible role of the WAF1/CIP1 gene in human prostatic carcinoma. Matched normal and cancer tissues from 18 patients with prostate cancer were screened for WAF1/CIP1 mutation by nested reverse transcription-polymerase chain reaction/single strand conformational polymorphism (RT-PCR/SSCP) and DNA sequencing. Shifted bands from three tumor, but not the matched normal specimens, were observed. Subsequent direct DNA sequencing of the PCR fragments identified four sequence alterations including a cytosine (C) to adenine (A) transversion and a guanine (G) to A transition and two A insertions. Our results demonstrated that mutations of the WAF1/CIP1 gene occur and may be important during the pathogenesis of human prostate cancer. This is the first report of WAF1/CIP1 mutation in a primary human cancer.
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Affiliation(s)
- X Gao
- Department of Radiation Oncology [Cancer Biology Division], Wayne State University School of Medicine, Detroit, Michigan 48202, USA
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226
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Bai JZ, Bardon O, Blum I, Breakstone A, Burnett T, Chen GP, Chen HF, Chen J, Chen SJ, Chen SM, Chen Y, Chen YB, Chen YQ, Cheng BS, Cowan RF, Cui HC, Cui XZ, Ding HL, Du ZZ, Dunwoodie W, Fan XL, Fang J, Fero M, Gao CS, Gao ML, Gao SQ, Gao WX, Gratton P, Gu JH, Gu SD, Gu WX, Gu YF, Guo YN, Han SW, Han Y, Harris FA, Hatanaka M, He J, He KR, He M, Hitlin DG, Hu GY, Hu HB, Hu T, Hu XQ, Huang DQ, Huang YZ, Izen JM, Jia QP, Jiang CH, Jin Y, Jones L, Kang SH, Kelsey MH, Kim BK, Lai YF, Lan HB, Lang PF, Lankford A, Li F, Li J, Li PQ, Li Q, Li RB. Direct measurement of the Ds branching fraction to phi pi. Phys Rev D Part Fields 1995; 52:3781-3784. [PMID: 10019603 DOI: 10.1103/physrevd.52.3781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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227
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Johnston JA, Bacon CM, Finbloom DS, Rees RC, Kaplan D, Shibuya K, Ortaldo JR, Gupta S, Chen YQ, Giri JD. Tyrosine phosphorylation and activation of STAT5, STAT3, and Janus kinases by interleukins 2 and 15. Proc Natl Acad Sci U S A 1995; 92:8705-9. [PMID: 7568001 PMCID: PMC41035 DOI: 10.1073/pnas.92.19.8705] [Citation(s) in RCA: 309] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The cytokines interleukin 2 (IL-2) and IL-15 have similar biological effects on T cells and bind common hematopoietin receptor subunits. Pathways that involve Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) have been shown to be important for hematopoietin receptor signaling. In this study we identify the STAT proteins activated by IL-2 and IL-15 in human T cells. IL-2 and IL-15 rapidly induced the tyrosine phosphorylation of STAT3 and STAT5, and DNA-binding complexes containing STAT3 and STAT5 were rapidly activated by these cytokines in T cells. IL-4 induced tyrosine phosphorylation and activation of STAT3 but not STAT5. JAK1 and JAK3 were tyrosine-phosphorylated in response to IL-2 and IL-15. Hence, the JAK and STAT molecules that are activated in response to IL-2 and IL-15 are similar but differ from those induced by IL-4. These observations identify the STAT proteins activated by IL-2 and IL-15 and therefore define signaling pathways by which these T-cell growth factors may regulate gene transcription.
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Affiliation(s)
- J A Johnston
- Lymphocyte Cell Biology Section, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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228
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Gao X, Grignon DJ, Chbihi T, Zacharek A, Chen YQ, Sakr W, Porter AT, Crissman JD, Pontes JE, Powell IJ. Elevated 12-lipoxygenase mRNA expression correlates with advanced stage and poor differentiation of human prostate cancer. Urology 1995; 46:227-37. [PMID: 7624992 DOI: 10.1016/s0090-4295(99)80198-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer death in males in the United States. The mortality is due mainly to distant metastasis. Therefore, predicting the prognosis of prostate cancer patients is an important clinical problem. Previously, we demonstrated that a 12-lipoxygenase (12-LOX) metabolite of arachidonic acid, 12(S)-hydroxyeicosatetraenoic acid, enhances the invasiveness of prostate cancer cells and that a 12-LOX-selective inhibitor [N-benzyl-N-hydroxy-5-phenylpentanamide] reduces experimental metastasis in animal model systems. In this study, we investigated the potential of 12-LOX as a predictor for the aggressiveness of prostate cancer. METHODS The mRNA expression level of 12-LOX in 122 matching prostate normal and cancerous tissues were measured by quantitative reverse transcription- polymerase chain reaction. Possible association between 12-LOX expression and histologic grade, pathologic and clinical stage, margin positivity, age, and race was analyzed. RESULTS 12-LOX mRNA levels were elevated in cancer cells and the expression associated with poor differentiation and invasiveness of prostate cancer. Overall, 46 (38%) of 122 evaluable patients showed elevated levels of 12-LOX mRNA in prostate cancer tissues compared with the matching normal tissues. A statistically significantly greater number of cases were found to have an elevated level of 12-LOX among T3, high grade, and surgical margin-positive than T2, intermediate, and low grade, and surgical margin-negative prostatic adenocarcinomas. CONCLUSIONS Our data suggest that elevation of 12-LOX mRNA expression occurs more frequently in advanced stage, high-grade prostate cancer and that 12-LOX may serve as an indicator for progression and prognosis of prostate cancer. This enzyme also may be a novel target for the development of anti-invasive and antimetastatic agents.
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Affiliation(s)
- X Gao
- Department of Radiation Oncology, Wayne State University School of Medicine, Harper Hospital, Michigan, USA
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229
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Rafi MA, Luzi P, Chen YQ, Wenger DA. A large deletion together with a point mutation in the GALC gene is a common mutant allele in patients with infantile Krabbe disease. Hum Mol Genet 1995; 4:1285-9. [PMID: 7581365 DOI: 10.1093/hmg/4.8.1285] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Galactocerebrosidase (GALC) activity is deficient in all patients with globoid cell leukodystrophy (GLD). While most patients have the severe infantile form of this autosomal recessive disorder (Krabbe disease), patients up to 50 years of age have been diagnosed in this laboratory. With the cloning of the GALC cDNA and availability of information regarding the gene organization, patients can be evaluated for their disease-causing mutations. We now report that a large deletion, together with a polymorphic C to T transition at position 502 of cDNA (counting from the A of the initiation codon), is responsible for a large number of disease-causing alleles in patients with Krabbe disease. Of 48 patients evaluated, 10 were found to be homozygous for the 502/del allele, five patients were heterozygous for this allele, 21 patients were heterozygous for the 502 mutation (presence of the deletion could not be confirmed), and one infantile patient was homozygous for the 502 mutation but at least one allele was not deleted. No patient was found to have the deletion without the 502 polymorphism. The delineation of mutations causing infantile Krabbe disease will provide new information regarding structure-function relationships in this multi-subunit enzyme and will improve the identification of patients and carriers in some families.
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Affiliation(s)
- M A Rafi
- Department of Medicine (Medical Genetics), Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA
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230
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231
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Bai JZ, Bardon O, Blum I, Breakstone A, Burnett T, Chen GP, Chen HF, Chen J, Chen SJ, Chen SM, Chen Y, Chen YB, Chen YQ, Cheng BS, Cowan RF, Cui HC, Cui XZ, Ding HL, Du ZZ, Dunwoodie W, Fan XL, Fang J, Fero M, Gao CS, Gao ML, Gao SQ, Gao WX, Gratton P, Gu JH, Gu SD, Gu WX, Gu YF, Guo YN, Han SW, Han Y, Harris FA, Hatanaka M, He J, He KR, He M, Hitlin DG, Hu GY, Hu HB, Hu T, Hu XQ, Huang DQ, Huang YZ, Izen JM, Jia QP, Jiang CH, Jin Y, Jones L, Kang SH, Kelsey MH, Kim BK, Lai YF, Lan HB, Lang PF, Lankford A, Li F, Li J, Li PQ, Li Q, Li RB. Direct measurement of the pseudoscalar decay constant, fDs. Phys Rev Lett 1995; 74:4599-4602. [PMID: 10058551 DOI: 10.1103/physrevlett.74.4599] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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232
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Mauviel A, Santra M, Chen YQ, Uitto J, Iozzo RV. Transcriptional regulation of decorin gene expression. Induction by quiescence and repression by tumor necrosis factor-alpha. J Biol Chem 1995; 270:11692-700. [PMID: 7744809 DOI: 10.1074/jbc.270.19.11692] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Decorin, a leucine-rich proteoglycan with ubiquitous tissue distribution, may play essential biological roles during inflammation and cancer growth through its ability to bind extracellular matrix constituents and growth factors. In this study, we demonstrate that decorin gene expression is greatly enhanced after normal diploid fibroblasts reach confluency and cease to proliferate. Elevation of decorin mRNA steady state levels was maintained for up to 16 days postconfluency. In vitro transcription analyses indicated enhanced transcriptional activity in quiescent fibroblasts when compared to cells harvested in their logarithmic phase of growth. This phenotypic trait was reversed by the exogenous addition of tumor necrosis factor-alpha (TNF-alpha). Furthermore, transforming growth factor-beta (TGF-beta) down-regulated decorin gene expression in an additive manner with TNF-alpha. Transient cell transfection assays using plasmid constructs harboring the decorin promoter linked to the chloramphenicol acetyltransferase reporter gene demonstrated a dose-dependent transcriptional repression by TNF-alpha. These findings were further corroborated by in vitro transcription experiments using nuclear extracts from control and TNF-alpha-treated quiescent fibroblasts. In contrast, the decorin promoter constructs failed to respond to TGF-beta, thus suggesting either post-transcriptional regulation by this growth factor or lack of TGF-beta-responsive elements. Further experiments with 5' deletion constructs showed two TNF-alpha response elements, one residing within the 5'-untranslated region (exon Ib), the other one between residues -188 and -140 of the decorin promoter. Collectively, our results indicate that TNF-alpha, through its ability to transcriptionally inhibit decorin gene expression in growth-arrested cells, may be a key modulator of the biological functions of this proteoglycan.
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Affiliation(s)
- A Mauviel
- Department of Dermatology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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233
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Chen YQ. Erratum: Perturbative QCD predictions for the fragmentation functions of the P-wave mesons with two heavy quarks. Phys Rev D Part Fields 1994; 50:6013. [PMID: 10021667 DOI: 10.1103/physrevd.50.6013.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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234
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Chang CH, Chen YQ. Erratum: Production of Bc or B-barc mesons associated with two heavy-quark jets in Z0 decay. Phys Rev D Part Fields 1994; 50:6013. [PMID: 10018260 DOI: 10.1103/physrevd.50.6013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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235
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236
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Chen YQ, Dai KR, Qiu SJ, Zhu ZA. Bone remodelling after internal fixation with different stiffness plates: ultrastructural investigation. Chin Med J (Engl) 1994; 107:766-70. [PMID: 7835104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Forty adult New Zealand rabbits were used in this experiment. Four rabbits served as control and the rest 36 being divided into 3 groups, each of which was fixed respectively with methylmethacrylate, titanium alloy and stainless steel plate on the left intact tibiae. The cortical bone beneath the plate was harvested at 2, 4, 8 and 12 weeks after operation and observed by means of using transmission electron microscope. The major ultrastructural changes after internal fixation with different stiffness plates were alteration of osteocyte life cycle, perilacunar matrix and disorder of osteoblast and osteoblast coupling. The greater the stiffness of the plate, the greater the ultrastructural change.
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Affiliation(s)
- Y Q Chen
- Department of Orthopaedics, Ninth People's Hospital Shanghai Second Medical University
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237
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Bernstein EF, Chen YQ, Tamai K, Shepley KJ, Resnik KS, Zhang H, Tuan R, Mauviel A, Uitto J. Enhanced elastin and fibrillin gene expression in chronically photodamaged skin. J Invest Dermatol 1994; 103:182-6. [PMID: 8040608 DOI: 10.1111/1523-1747.ep12392693] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cutaneous aging consists of chronologic aging as well as actinic damage, referred to as photoaging. Most of the morphologic changes associated with an aged appearance result from actinic damage to the skin. The morphologic changes in sun-damaged skin are associated with accumulation of material having the staining characteristics of elastin, known as solar elastosis, in the superficial dermis. Previous studies have demonstrated the presence of elastin within areas of solar elastosis; however, little is known about the mechanisms leading to elastin accumulation in photoaged skin. In addition, fibrillin, the fibrillar component of elastic fibers, has been found in small amounts in solar elastosis. In this study we demonstrate increased elastin mRNA levels in photoaged skin, as well as increased elastin and fibrillin mRNAs in skin explant-derived fibroblasts using Northern hybridizations, compared with controls from sun-protected sites of the same individual. Increased elastin mRNA levels result from transcriptional upregulation of the gene, as demonstrated by transient transfections with a human elastin promoter/chloramphenicol acetyltransferase construct. Elevated mRNA levels were also correlated with increased elastin and fibrillin deposition in paired biopsy specimens from photodamaged and non-sun-exposed skin, as demonstrated by immunohistochemical staining. Thus, approaches to counteract transcriptional activation of elastin gene expression may be useful in preventing the changes associated with cutaneous photoaging.
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Affiliation(s)
- E F Bernstein
- Department of Dermatology, Jefferson Medical College, Philadelphia, PA 19107-5541
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238
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Johnston JA, Kawamura M, Kirken RA, Chen YQ, Blake TB, Shibuya K, Ortaldo JR, McVicar DW, O'Shea JJ. Phosphorylation and activation of the Jak-3 Janus kinase in response to interleukin-2. Nature 1994; 370:151-3. [PMID: 8022485 DOI: 10.1038/370151a0] [Citation(s) in RCA: 494] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Interleukin-2 is an autocrine growth factor for T cells which also activates other cells including B cells and natural killer cells. The subunits of the interleukin-2 receptor (IL-2R) lack intrinsic enzymatic activity, but protein tyrosine phosphorylation is a critical event following ligand binding and src family kinases, such as Lck, are known to be activated by IL-2 (refs 5-9). However, IL-2 signalling can occur in the absence of receptor interaction with Lck, suggesting that other protein tyrosine kinases might be important. Here we report that a new member of the Janus family of kinases (Jak-3) is coupled to the IL-2R in human peripheral blood T cells and natural killer cells.
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Affiliation(s)
- J A Johnston
- Leukocyte Cell Biology Section, PRI/DynCorp, Frederick, Maryland
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239
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Kawamura M, McVicar DW, Johnston JA, Blake TB, Chen YQ, Lal BK, Lloyd AR, Kelvin DJ, Staples JE, Ortaldo JR, O'Shea JJ. Molecular cloning of L-JAK, a Janus family protein-tyrosine kinase expressed in natural killer cells and activated leukocytes. Proc Natl Acad Sci U S A 1994; 91:6374-8. [PMID: 8022790 PMCID: PMC44204 DOI: 10.1073/pnas.91.14.6374] [Citation(s) in RCA: 219] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Protein-tyrosine kinases (PTKs) are critical enzymes for receptor-mediated signaling in lymphocytes. Because natural killer (NK) cells are large granular lymphocytes with specialized effector function, we set out to identify PTKs preferentially expressed in these cells. One such PTK was identified and molecularly cloned. The predicted amino acid sequence shows that this kinase lacks SH2 or SH3 domains typical of src family kinases but has tandem nonidentical catalytic domains, indicating that it is a member of the Janus family of PTKs. Immunoprecipitation using antiserum generated against a peptide corresponding to the deduced amino acid sequence of this gene revealed a kinase with a molecular weight of approximately 125,000. The pattern of expression of this kinase contrasted sharply with that of other Janus kinases, which are ubiquitously expressed. The kinase described in the present study was found to be more limited in its expression; expression was found in NK cells and an NK-like cell line but not in resting T cells or in other tissues. In contrast, stimulated and transformed T cells expressed the gene, suggesting a role in lymphoid activation. Because of its homology and tissue expression, we have tentatively termed this PTK gene L-JAK for leukocyte Janus kinase.
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Affiliation(s)
- M Kawamura
- Leukocyte Cell Biology Section, Program Resources, Inc./DynCorp, National Cancer Institute, Frederick, MD 21702-1201
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240
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McVicar DW, Lal BK, Lloyd A, Kawamura M, Chen YQ, Zhang X, Staples JE, Ortaldo JR, O'Shea JJ. Molecular cloning of lsk, a carboxyl-terminal src kinase (csk) related gene, expressed in leukocytes. Oncogene 1994; 9:2037-44. [PMID: 7516063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Regulation of the activity of src-family kinases is thought to occur, in part, through the phosphorylation of conserved carboxyl-terminal tyrosine residues. Although the src-family includes several molecules with tissue or cell-type restricted expression, the only kinase implicated in the regulatory phosphorylation of these enzymes is p50csk. Herein we report the molecular cloning of a tissue specific p50csk-related gene. Like p50csk, the deduced protein sequence of this novel cDNA includes a tyrosine kinase catalytic domain, SH2 and SH3 domains, a short amino terminus, and no autophosphorylation or carboxyl-terminal tyrosine residues. Additionally, neither this novel kinase nor p50csk contain the amino-terminal myristoylation site characteristic of the src-family. However, whereas csk is ubiquitously expressed, mRNA corresponding to this novel gene is expressed in brain, natural killer (NK) cells, and activated T cells but not in a variety of other tissues and cell lines. In agreement with the mRNA expression pattern, antiserum reactive with the predicted carboxyl-terminus of the cDNA recognizes a 57 kDa polypeptide in immunoblots of NK cells and PHA-activated T cells. Because of its limited expression and high homology to p50csk, we named this gene lsk; leukocyte carboxyl-terminal src kinase related gene. Identification of a molecule like lsk suggests the existence of tissue specific src-regulatory pathways that function in activated lymphocytes.
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Affiliation(s)
- D W McVicar
- Leukocyte Cell Biology Section, Inc./DynCorp, National Cancer Institute, Frederick Cancer Research and Development Center, Maryland 21702-1201
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Chen YQ, Kraut J, Blakley RL, Callender R. Determination by Raman spectroscopy of the pKa of N5 of dihydrofolate bound to dihydrofolate reductase: mechanistic implications. Biochemistry 1994; 33:7021-6. [PMID: 8003467 DOI: 10.1021/bi00189a001] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Dihydrofolate reductase (DHFR) catalyzes the reduction of dihydrofolate (H2folate) to tetrahydrofolate by NADPH, and this requires that the pteridine ring be protonated at N5. A long-standing puzzle has been how, at physiological pH, the enzyme can protonate N5 in view of its solution pKa of 2.6 and the fact that the only proton-donating group in the pterdine binding site, Asp-27, hydrogen bonds not to N5 but to the 2-amino group and N3 of the pterin ring. We have determined the pKa of N5 of dihydrofolate in the Escherichia coli DHFR/NADP+/H2folate ternary complex by Raman difference spectroscopy and found that the value is 6.5. In contrast, the pKa of N5 is less than 4.0 in either the binary complex, the ternary complex with an analogue of NADPH (H2NADPH), or the Asp27 to serine mutant DHFR (D27S) ternary complex with NADP+. Thus, one need not invoke proton donation from Asp-27 to N5 via a series of bound water molecules and/or pteridine-ring substituents. We propose instead that the N5 protonated form of H2folate is stabilized directly at the active site in the DHFR/NADPH/H2folate complex by specific interactions that form only in the ternary complex, involving perhaps a bound water molecule, the carboxamide moiety of the coenzyme, and/or the local electrostatic field of the enzyme molecule, to which an important contribution may be made by Asp-27.
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Affiliation(s)
- Y Q Chen
- Department of Physics, City College, City University of New York, New York 10031
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Clyman RI, Tannenbaum J, Chen YQ, Cooper D, Yurchenco PD, Kramer RH, Waleh NS. Ductus arteriosus smooth muscle cell migration on collagen: dependence on laminin and its receptors. J Cell Sci 1994; 107 ( Pt 4):1007-18. [PMID: 8056826 DOI: 10.1242/jcs.107.4.1007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During permanent closure of the ductus arteriosus, smooth muscle cells migrate through the extracellular matrix (ECM) to form intimal mounds that occlude the vessel's lumen. Smooth muscle cells (SMC) migrate over surfaces coated with collagen in vitro. During the migration SMC also synthesize fibronectin (FN) and laminin (LN). Antibodies against FN and LN inhibit migration on collagen by 30% and 67%, respectively. Because of the apparent importance of LN in migration, we examined how SMC interact with LN and LN fragments (P1, E8, P1′, E1′, E3, E4, and G). Ductus SMC adhere to high concentrations of LN and two fragments of the molecule: P1 and E8. They use a unique set of integrin receptors to bind to LN (alpha 1 beta 1, alpha 6 beta 1 and alpha v beta 3), to P1 (alpha 1 beta 1, alpha v beta 3), and to E8 (alpha 6 beta 1, alpha v beta 3). The alpha v beta 3 integrin binds to the P1 fragment of LN in an RGD peptide-dependent manner, and to the E8 fragment in an RGD-independent manner; the RGD site on the P1 fragment probably is not available to the cell in intact LN. Antibodies against beta 1 integrins completely inhibit SMC adhesion to LN; antibodies against the alpha v beta 3 integrin do not block SMC adhesion to LN, but do prevent cell spreading. LN is also capable of interfering with SMC adhesion to other ECM components. The antiadhesive effect of LN is located in the E1′ domain. Both exogenous and endogenous LN increase SMC motility on collagen I. The locomotion-promoting activity of LN resides in the E1′ antiadhesive domain, and not in its adhesive (P1, E8) domains. LN causes a decrease in the number of focal contacts on collagen I. This might enable SMC to alter their mobility as they move through the extracellular matrix to occlude the ductus arteriosus lumen.
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Affiliation(s)
- R I Clyman
- Cardiovascular Research Institute, Department of Pediatrics, San Francisco, CA 94143-0544
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Chen YQ, Duniec ZM, Liu B, Hagmann W, Gao X, Shimoji K, Marnett LJ, Johnson CR, Honn KV. Endogenous 12(S)-HETE production by tumor cells and its role in metastasis. Cancer Res 1994; 54:1574-9. [PMID: 7511046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
12(S)-Hydroxyeicosatetraenoic acid [12(S)-HETE] is the 12-lipoxygenase metabolite of arachidonic acid. Previously, we have demonstrated that exogenous 12(S)-HETE can activate protein kinase C, increase cell surface expression of integrins, enhance adhesion, induce endothelial cell retraction, and increase experimental metastasis of tumor cells. Because of these prominent effects of exogenous 12(S)-HETE on tumor cell metastatic potential, it is important to determine whether there is endogenous 12(S)-HETE production by tumor cells. In the present study, mRNAs from human, rat, and mouse platelets as well as human colon carcinoma (Clone A), rat Walker carcinoma (W256), and mouse melanoma (B16a) and lung carcinoma (3LL) were reverse transcribed and amplified by polymerase chain reaction with platelet 12-lipoxygenase specific primers. Identity of the polymerase chain reaction fragments was confirmed by sequencing. 12-Lipoxygenase protein was detected by Western blotting. Tumor cell-derived 12-HETE was determined by reverse phase-high performance liquid chromatography analysis. In addition, the effect of endogenous 12(S)-HETE on tumor cells was studied by using a platelet-type 12-lipoxygenase selective inhibitor (N-benzyl-N-hydroxy-5-phenylpentanamide). Our results suggest that some tumor cells express platelet-type 12-lipoxygenase mRNA, protein and metabolize arachidonic acid to 12(S)-HETE and that endogenous 12(S)-HETE, like the exogenous 12(S)-HETE, may play an important role in tumor cell adhesion to matrix in vitro and lung colonization in vivo.
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MESH Headings
- 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
- Amino Acid Sequence
- Animals
- Arachidonate 12-Lipoxygenase/analysis
- Arachidonate 12-Lipoxygenase/physiology
- Base Sequence
- Blotting, Western
- Carcinoma, Squamous Cell/enzymology
- Carcinoma, Squamous Cell/metabolism
- Carcinoma, Squamous Cell/pathology
- Cell Adhesion/physiology
- Chromatography, High Pressure Liquid/methods
- Extracellular Matrix/physiology
- Humans
- Hydroxyeicosatetraenoic Acids/biosynthesis
- Hydroxyeicosatetraenoic Acids/physiology
- Lipoxygenase Inhibitors
- Lung Neoplasms/secondary
- Male
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Neoplasm Metastasis/physiopathology
- Neoplasms, Experimental/enzymology
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Polymerase Chain Reaction/methods
- RNA-Directed DNA Polymerase/metabolism
- Rats
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Affiliation(s)
- Y Q Chen
- Department of Radiation Oncology, Wayne State University, Detroit, Michigan 48202
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Chen YQ, Mauviel A, Ryynänen J, Sollberg S, Uitto J. Type VII collagen gene expression by human skin fibroblasts and keratinocytes in culture: influence of donor age and cytokine responses. J Invest Dermatol 1994; 102:205-9. [PMID: 8106749 DOI: 10.1111/1523-1747.ep12371763] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Type VII collagen is the predominant, if not the exclusive, component of the anchoring fibrils. In this study, we have examined the expression of the type VII collagen gene in human skin fibroblasts and keratinocytes in culture by Northern analyses and immunocytochemistry. Type VII collagen gene expression was greatly enhanced in all cell strains studied after stimulation by transforming growth factor-beta (TGF-beta). However, no definitive correlation between the donor age and the magnitude of TGF-beta response could be made. In contrast, the basal expression of the type VII collagen gene was shown to decrease in an age-dependent manner in fibroblasts. The pro-inflammatory cytokines interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) were shown to elevate type VII collagen mRNA levels in a dose-dependent manner. This response was inversely related to the donor age of the cell cultures. The attenuated response of cells from older individuals to TNF-alpha and IL-1 beta was specific for type VII collagen gene expression, because, in the same experiments, collagenase gene expression was strongly elevated by the two cytokines. Our data suggest that type VII collagen gene expression is subject to modulation by the cytokine network, which may play a role in controlling anchoring fibril assembly in normal skin and in pathologic conditions characterized by altered deposition of type VII collagen.
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Affiliation(s)
- Y Q Chen
- Department of Dermatology, Jefferson Medical College, Philadelphia, PA 19107
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Chen YQ, Miao JZ, Zhang XZ. [Determination of antibody of Borrelia burgdorferi in the serum of patients with sarcoidosis and its significance]. Zhonghua Nei Ke Za Zhi 1994; 33:15-7. [PMID: 8045180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The level of antibody of Borrelia Burgdorferi in the serum of 40 patient, 23 with sarcoidosis and 17 without sarcoidosis was determined by using ELISA method. Antibody of BB was positive in the serum of 18 patients with sarcoidosis (78.3%). It is possible that sarcoidosis might be a disease of autoimmune abnormality and antibody of BB in the serum an auto-antibody resulting from the stimuli of certain unknown antigens. Cross reactivity may be present between the serological tests for sarcoidosis and those for rheumatic disease, tuberculosis, tumour and Lyme disease. But another case might be that antigen of BB is a mixture. Different antibodies of different disease react with different component of antigen of BB. Therefore, antibody of BB can not be considered as a specific test in the diagnosis of sarcoidosis.
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Clyman RI, Peters KG, Chen YQ, Escobedo J, Williams LT, Ives HE, Wilson E. Phospholipase C gamma activation, phosphotidylinositol hydrolysis, and calcium mobilization are not required for FGF receptor-mediated chemotaxis. Cell Adhes Commun 1994; 1:333-42. [PMID: 8081884 DOI: 10.3109/15419069409097264] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Basic fibroblast growth factor (FGF) is a potent angiogenic factor that stimulates several cell types to migrate along a chemotactic gradient. Most chemoattractant receptors appear to share a common mechanism that involves activation of phospholipase C (PLC), hydrolysis of phosphotidylinositol, and mobilization of intracellular calcium. We transfected two different cell lines with either human FGF receptor-1 cDNA or chimeric FGF receptor cDNA. Ligand stimulation induced chemotaxis, activation of PLC gamma, phosphotidylinositol hydrolysis, and calcium mobilization in both wild-type receptor cell lines. No such response was elicited in control cells. Mutation of the two fibroblast growth factor receptors at residue 766, replacing tyrosine with phenylalanine, made the receptors incapable of associating with and activating PLC gamma following ligand stimulation. These mutant receptors also failed to mediate phosphotidylinositol hydrolysis and calcium mobilization. However, cells transfected with the mutant fibroblast growth factor receptors were as chemotactically responsive to the appropriate ligand as were cells transfected with the wild-type receptors. These findings demonstrate that the ability of the fibroblast growth factor receptor to promote chemotaxis is not dependent on increased activation of PLC gamma, increased hydrolysis of phosphotidylinositol, or increased global mobilization of calcium.
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Affiliation(s)
- R I Clyman
- Department of Pediatrics, University of California, San Francisco 94143
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Cannizzaro LA, Chen YQ, Rafi MA, Wenger DA. Regional mapping of the human galactocerebrosidase gene (GALC) to 14q31 by in situ hybridization. Cytogenet Cell Genet 1994; 66:244-5. [PMID: 8162701 DOI: 10.1159/000133703] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The cDNA for human galactocerebrosidase (GALC) has recently been cloned and expressed. A portion of this cDNA was used for in situ hybridization, and the region of strongest signal corresponded to human chromosome region 14q31. This agrees with recent linkage studies that localized Krabbe disease (globoid cell leukodystrophy) to the same region. This information will be useful in future studies for mapping this gene in animal models of GALC deficiency.
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Chen YQ. Perturbative QCD predictions for the fragmentation functions of the P- wave mesons with two heavy quarks. Phys Rev D Part Fields 1993; 48:5181-5189. [PMID: 10016177 DOI: 10.1103/physrevd.48.5181] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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