Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
1.
Blood Cancer J ; 6(7): e446, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27421095

RESUMO

Multiple myeloma (myeloma in short) is an incurable cancer of antibody-producing plasma cells that comprise 13% of all hematological malignancies. The proteasome inhibitor bortezomib has improved treatment significantly, but inherent and acquired resistance to the drug remains a problem. We here show that bortezomib-induced cytotoxicity was completely dampened when cells were supplemented with cysteine or its derivative, glutathione (GSH) in ANBL-6 and INA-6 myeloma cell lines. GSH is a major component of the antioxidative defense in eukaryotic cells. Increasing intracellular GSH levels fully abolished bortezomib-induced cytotoxicity and transcriptional changes. Elevated intracellular GSH levels blocked bortezomib-induced nuclear factor erythroid 2-related factor 2 (NFE2L2, NRF2)-associated stress responses, including upregulation of the xCT subunit of the Xc- cystine-glutamate antiporter. INA-6 cells conditioned to increasing bortezomib doses displayed reduced bortezomib sensitivity and elevated xCT levels. Inhibiting Xc- activity potentiated bortezomib-induced cytotoxicity in myeloma cell lines and primary cells, and re-established sensitivity to bortezomib in bortezomib-conditioned cells. We propose that intracellular GSH level is the main determinant of bortezomib-induced cytotoxicity in a subset of myeloma cells, and that combined targeting of the proteasome and the Xc- cystine-glutamate antiporter can circumvent bortezomib resistance.


Assuntos
Antineoplásicos/farmacologia , Bortezomib/farmacologia , Glutationa/metabolismo , Mieloma Múltiplo/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Análise por Conglomerados , Cisteína/metabolismo , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Humanos , Espaço Intracelular/metabolismo , Mieloma Múltiplo/genética , Fator 2 Relacionado a NF-E2/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Estresse Fisiológico
2.
Blood Cancer J ; 5: e299, 2015 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-25794135

RESUMO

In this study, we analyzed the prevalence and clone size of BRAF V600E mutation in 209 patients with multiple myeloma and related the results to clinical phenotype, response and survival. Biopsies were screened for BRAF V600E by allele-specific real-time PCR (AS-PCR). Positive results were confirmed by immunohistochemistry, Sanger sequencing and, in three patients from whom we had stored purified myeloma cells, whole-exome sequencing. Eleven patients (5.3%) were BRAF V600E mutation positive by AS-PCR and at least one other method. The fraction of mutated cells varied from 4 to 100%. BRAF V600E-positive patients had no characteristic clinical phenotype except for significantly higher levels of serum creatinine (125 versus 86 µmol/l) Seven of eleven patients responded with at least very good partial response to alkylators, immunomodulatory agents or proteasome inhibitors. Progression-free and overall survival were similar in patients with and without the mutation. By this integrated approach, we found that patients with BRAF V600E mutation responded very well to broad acting drugs and there was no relation to prognosis in early-stage myeloma. In particular, a large mutated cell fraction did not correlate with aggressive disease.


Assuntos
Antineoplásicos/administração & dosagem , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Adulto , Idoso , Biomarcadores Farmacológicos , Intervalo Livre de Doença , Exoma/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/patologia , Mutação , Estadiamento de Neoplasias
3.
Blood Cancer J ; 4: e196, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24658374

RESUMO

Multiple myeloma is a malignancy of plasma cells predominantly located in the bone marrow. A number of bone morphogenetic proteins (BMPs) induce apoptosis in myeloma cells in vitro, and with this study we add BMP-9 to the list. BMP-9 has been found in human serum at concentrations that inhibit cancer cell growth in vitro. We here show that the level of BMP-9 in serum was elevated in myeloma patients (median 176 pg/ml, range 8-809) compared with healthy controls (median 110 pg/ml, range 8-359). BMP-9 was also present in the bone marrow and was able to induce apoptosis in 4 out of 11 primary myeloma cell samples by signaling through ALK2. BMP-9-induced apoptosis in myeloma cells was associated with c-MYC downregulation. The effects of BMP-9 were counteracted by membrane-bound (CD105) or soluble endoglin present in the bone marrow microenvironment, suggesting a mechanism for how myeloma cells can evade the tumor suppressing activity of BMP-9 in multiple myeloma.

4.
Leukemia ; 26(5): 1073-80, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21941367

RESUMO

Bone morphogenetic proteins (BMPs) have been shown to induce apoptosis and growth arrest in myeloma cells. However, the molecular mechanisms behind these events are not known. The MYC oncogene is a master regulator of cell growth and protein synthesis and MYC overexpression has been proposed to be associated with the progression of multiple myeloma. Here, we show that BMP-induced apoptosis in myeloma cells is dependent on downregulation of MYC. Moreover, the results suggest that targeting the MYC addiction in multiple myeloma is an efficient way of killing a majority of primary myeloma clones. We also found that myeloma cells harboring immunoglobulin (IG)-MYC translocations evaded BMP-induced apoptosis, suggesting a novel way for myeloma cells to overcome potential tumor suppression by BMPs.


Assuntos
Apoptose/fisiologia , Proteínas Morfogenéticas Ósseas/fisiologia , Genes myc , Mieloma Múltiplo/patologia , Proteínas Smad/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/genética , Reação em Cadeia da Polimerase em Tempo Real
5.
Oncogene ; 30(28): 3198-206, 2011 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-21478911

RESUMO

Multiple myeloma (MM) is a paradigm for a malignant disease that exploits external stimuli of the microenvironment for growth and survival. A thorough understanding of the complex interactions between malignant plasma cells and their surrounding requires a detailed analysis of the transcriptional response of myeloma cells to environmental signals. We determined the changes in gene expression induced by interleukin (IL)-6, tumor necrosis factor-α, IL-21 or co-culture with bone marrow stromal cells in myeloma cell lines. Among a limited set of genes that were consistently activated in response to growth factors, a prominent transcriptional target of cytokine-induced signaling in myeloma cells was the gene encoding the serine/threonine kinase serum/glucocorticoid-regulated kinase 1 (SGK1), which is a down-stream effector of PI3-kinase. We could demonstrate a rapid, strong and sustained induction of SGK1 in the cell lines INA-6, ANBL-6, IH-1, OH-2 and MM.1S as well as in primary myeloma cells. Pharmacologic inhibition of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway abolished STAT3 phosphorylation and SGK1 induction. In addition, small hairpin RNA (shRNA)-mediated knock-down of STAT3 reduced basal and induced SGK1 levels. Furthermore, downregulation of SGK1 by shRNAs resulted in decreased proliferation of myeloma cell lines and reduced cell numbers. On the molecular level, this was reflected by the induction of cell cycle inhibitory genes, for example, CDKNA1/p21, whereas positively acting factors such as CDK6 and RBL2/p130 were downregulated. Our results indicate that SGK1 is a highly cytokine-responsive gene in myeloma cells promoting their malignant growth.


Assuntos
Citocinas/farmacologia , Proteínas Imediatamente Precoces/genética , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Proteínas Serina-Treonina Quinases/genética , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Citocinas/metabolismo , Regulação para Baixo/genética , Humanos , Proteínas Imediatamente Precoces/deficiência , Janus Quinases/metabolismo , Mieloma Múltiplo/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Interferência de RNA , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
7.
Eur J Haematol ; 81(5): 380-3, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18691255

RESUMO

OBJECTIVES: Hepatocyte growth factor (HGF) is a potential key factor in multiple myeloma. Conversion of pro-HGF to its active form is a critical limiting step for its biological effects. We aimed to examine the levels of the most potent activator, the hepatocyte growth factor activator (HGFA), in serum and bone marrow plasma of patients with multiple myeloma. METHODS: The activated form of HGFA was measured by an enzyme-linked immunosorbent assay in serum (n = 49) and bone marrow plasma (n = 16) from multiple myeloma patients, and in serum from healthy controls (n = 24). RESULTS: The median concentrations of activated HGFA in myeloma and control sera were 39.7 (range 6.2-450.0) and 17.6 ng/mL (range 4.8-280.6), respectively. The difference was statistically significant (P = 0.037). The median concentration of activated HGFA in bone marrow plasma was 6.1 ng/mL (range 3.5-30.0). CONCLUSION: We here show for the first time that the activated form of HGFA is present at high levels in serum and bone marrow of myeloma patients, thus providing a necessary prerequisite for the activation of HGF.


Assuntos
Fator de Crescimento de Hepatócito/sangue , Mieloma Múltiplo/sangue , Precursores de Proteínas/sangue , Serina Endopeptidases/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Noruega , Estudos Retrospectivos
8.
Leukemia ; 20(6): 1138-44, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16617319

RESUMO

Multiple myeloma (MM) is an incurable B-cell malignancy characterized by accumulation of malignant plasma cells in bone marrow (BM) and recurrent or persistent infections. Toll-like receptors (TLRs) are essential in the host defense against infections and today 10 human TLRs (TLR1-TLR10) and one TLR-homolog (RP105) have been characterized. B cells express several TLRs (mainly TLR1, 6, 7, 9, 10 and RP105) and TLR-initiated responses in B cells include proliferation, anti-apoptosis effect and plasma cell (PC) differentiation. The present study was designed to analyze the role of TLRs in MM. We show that frequent expressions of TLRs were detected in cell lines from MM patients (minimum six TLRs in each). In comparison, only few TLRs (mainly TLR1 and or RP105) were found expressed in PCs from BM of healthy donors. In addition, TLR-specific ligands induce increased proliferation and survival of the MM cell lines, partially due to an autocrine interleukin-6 production. Importantly, we demonstrate that also PC from MM patients proliferates in response to TLR-specific ligands. In conclusion, TLR-ligands may contribute to increased growth and survival of MM cells in MM patients.


Assuntos
Proliferação de Células , Mieloma Múltiplo/imunologia , Receptores Toll-Like/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Dipeptídeos/farmacologia , Flagelina/farmacologia , Perfilação da Expressão Gênica , Humanos , Imidazóis/farmacologia , Interleucina-6/antagonistas & inibidores , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Ligantes , Lipopeptídeos , Lipopolissacarídeos/farmacologia , Lipoproteínas/farmacologia , Glicoproteínas de Membrana/efeitos dos fármacos , Glicoproteínas de Membrana/imunologia , Mieloma Múltiplo/genética , Oligodesoxirribonucleotídeos/farmacologia , Oligopeptídeos/farmacologia , Poli I-C/farmacologia , Proteoglicanas/efeitos dos fármacos , Proteoglicanas/imunologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sindecanas , Receptores Toll-Like/efeitos dos fármacos , Receptores Toll-Like/genética
9.
Curr Drug Targets ; 6(6): 701-11, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16178802

RESUMO

One of the most characteristic features of multiple myeloma is the development of osteolytic bone lesions. Myeloma-associated bone disease is caused by an increase in osteoclastic bone resorption and a decrease in osteoblastic new bone formation. Insight into the molecular mechanisms of osteoclastogenesis has been provided by the detection of receptor activator of NF-kappaB ligand (RANKL), its specific receptor (RANK) and its decoy receptor antagonist osteoprotegerin (OPG). The RANK signaling system is abnormally regulated in multiple myeloma and targeting this system may ameliorate myeloma bone disease. Less is known about the development of osteoblastic dysfunction, and further knowledge about the interaction between myeloma cells and osteoblasts is required. The aim of this review is to focus on the principles of bone biology for a better understanding of the development of myeloma bone disease and to identify possible therapeutic targets.


Assuntos
Mieloma Múltiplo/complicações , Osteólise/tratamento farmacológico , Remodelação Óssea , Reabsorção Óssea/prevenção & controle , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/sangue , Diferenciação Celular , Difosfonatos/uso terapêutico , Glicoproteínas/sangue , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/sangue , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Osteoclastos/fisiologia , Osteólise/sangue , Osteólise/etiologia , Osteoprotegerina , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores Citoplasmáticos e Nucleares/sangue , Receptores do Fator de Necrose Tumoral/sangue
10.
Heart ; 91(3): 299-304, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15710705

RESUMO

OBJECTIVES: To test the hypothesis that heat shock protein (Hsp) 70 may be released into the circulation after acute myocardial infarction (AMI) by exploring the kinetics of Hsp70 release and the relations between Hsp70 and markers of inflammation and myocardial damage in AMI. DESIGN: Blood samples from 24 patients were prospectively collected through to the first day after AMI. Hsp70, interleukin (IL) 6, IL-8, and IL-10 in serum were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: Median Hsp70 concentrations in AMI patients measured at arrival, six hours thereafter, and the following morning were 686, 868, and 607 pg/ml, respectively. These concentrations were all significantly different from those of the control patients with angina with a median serum Hsp70 concentration of 306 pg/ml. Peak Hsp70 correlated with creatine kinase (CK) MB (r = 0.62, p < 0.01) and cardiac troponin T (r = 0.58, p < 0.01). Furthermore, serum Hsp70 correlated with IL-6 and IL-8 at six hours (r = 0.60, p < 0.01 and r = 0.59, p < 0.01, respectively). CONCLUSIONS: In this study, Hsp70 was rapidly released into the circulation after AMI. Circulating Hsp70 is suggested as a marker of myocardial damage. In addition, Hsp70 may have a role in the inflammatory response after AMI.


Assuntos
Proteínas de Choque Térmico HSP70/sangue , Isquemia Miocárdica/sangue , Biomarcadores/sangue , Creatina Quinase/sangue , Feminino , Humanos , Interleucina-10/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/patologia , Isquemia Miocárdica/patologia , Miocárdio/patologia , Necrose , Estudos Prospectivos , Troponina/sangue
11.
Scand J Immunol ; 60(1-2): 74-81, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15238075

RESUMO

Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a cytotoxic member of the TNF family. Some reports have shown that TRAIL is released from cells in a soluble form. In this work, we have investigated the mechanism of release of TRAIL from monocytes. First, we show that whole gram-positive, gram-negative and mycoplasmal bacteria as well as lipopolysaccharide (LPS), interferon-alpha (IFN-alpha), -beta and -gamma all induced upregulation of TRAIL on the surface of human monocytes. Next, we show that IFN-alpha, -beta and -gamma all induced a dose-dependent release of TRAIL, giving significant amounts of soluble TRAIL after 2 days. Of the bacteria, only the Group B streptococcus COH-1 (GBS) induced release of TRAIL and concomittantly induced IFN-alpha. Monocytes stimulated with GBS or IFN-alpha also showed extensive cell death. When monocyte apoptosis was prevented by interleukin-1, GM-CSF, LPS or the caspase inhibitor zVADfmk, the IFN-alpha-induced release of TRAIL was reduced, whereas agents inducing necrosis caused increased release of TRAIL. LPS also prevented release of TRAIL from GBS-stimulated monocytes. The release of TRAIL from IFN-alpha-stimulated monocytes was reduced by inhibitors of both cysteine and metalloproteases. We conclude that bacteria and IFN induce upregulation of membrane TRAIL and that release of TRAIL is associated with cell death.


Assuntos
Interferons/imunologia , Leucina/análogos & derivados , Glicoproteínas de Membrana/imunologia , Monócitos/imunologia , Streptococcus agalactiae/imunologia , Fator de Necrose Tumoral alfa/imunologia , Clorometilcetonas de Aminoácidos/farmacologia , Apoptose/imunologia , Proteínas Reguladoras de Apoptose , Testes Imunológicos de Citotoxicidade , Citometria de Fluxo , Humanos , Leucina/farmacologia , Leupeptinas/farmacologia , Lipopolissacarídeos/imunologia , Ativação Linfocitária/imunologia , Monócitos/microbiologia , Inibidores de Proteases/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF , Regulação para Cima
12.
Int Arch Allergy Immunol ; 131(3): 201-8, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12876411

RESUMO

BACKGROUND: A reduction of IL-12 production by lung macrophages may partly explain the presumed adjuvant effect of diesel exhaust particles (DEP) in allergy and asthma. IL-12 stimulates T helper type 1 (Th1) lymphocytes, which inhibit Th2 cells via Th1-specific cytokines. The aim of this study was to investigate the influence of DEP on the production of IL-12 p40 in lipopolysaccharide (LPS)-activated monocytes. METHODS: The human monocytic cell line Mono-Mac-6 was stimulated with LPS (200 ng/ml) and grown with DEP (0-200 microg/ml) for 0, 6 or 24 h. IL-12 p40 and the pro-inflammatory cytokine TNF were analysed in the cell supernatants by ELISA and a cell assay, respectively. RESULTS: Levels of IL-12 p40 correlated inversely with the DEP exposure concentrations, whereas TNF increased in parallel to the DEP concentrations. At a DEP concentration of 200 microg/ml, the amount of IL-12 p40 was 35% of that observed without DEP. The corresponding TNF value was 230% of the control. Reduced viability, binding of cytokines to DEP or endotoxin in the DEP samples cannot fully explain the changes in the concentrations of these two cytokines. CONCLUSION: DEP seem to inhibit the production of IL-12 p40 and stimulate that of TNF in activated monocytes. This may partly explain the presumed adjuvant effect of DEP in atopy; by altering the Th1/Th2 balance via down-regulation of IL-12, the Th2 response characteristic of allergy and asthma may be favoured.


Assuntos
Regulação para Baixo , Interleucina-12/biossíntese , Monócitos/imunologia , Subunidades Proteicas/biossíntese , Emissões de Veículos/efeitos adversos , Asma/imunologia , Asma/fisiopatologia , Linhagem Celular , Humanos , Hipersensibilidade Imediata/imunologia , Hipersensibilidade Imediata/fisiopatologia , Lipopolissacarídeos/farmacologia , Tamanho da Partícula , Fator de Necrose Tumoral alfa/biossíntese
13.
Scand J Rheumatol ; 30(4): 229-34, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11578019

RESUMO

Rheumatic diseases are often associated with changes in bone metabolism. Excessive production and release of cytokines and other growth factors due to inflammation, e.g. tumor necrosis factor-alpha (TNF-alpha), receptor activator of NF-kappaB ligand (RANKL), interleukins such as IL-1 and IL-6, may cause alterations in bone homeostasis leading to bone degradation. Other components such as osteoprotegerin (OPG) and possibly the ligand-receptor pair hepatocyte growth factor (HGF) and c-met may counteract this destruction, we have measured the levels of OPG, and HGF c-met, in serum, synovial fluid (SF), and cartilage from patients with rheumatoid arthritis (RA) and other arthritides. We found a) elevated levels of both OPG and HGF in SF from RA patients relative to arthritides of other causes, b) increased levels of both OPG and HGF in SF from seropositive RA patients (RA+) compared to seronegative RA patients (RA-), c) elevated levels or both OPG and HGF in serum from RA patients compared to healthy controls, d) no correlation between severity of inflammation and levels of OPG or HGF, and e) presence of HGF c-met in both cartilage and synovial tissue. The most significant elevations of OPG and HGF were found in patients with RA, the rheumatic disease most frequently associated with the development of secondary osteoporosis.


Assuntos
Artrite Reumatoide/sangue , Glicoproteínas/sangue , Fator de Crescimento de Hepatócito/sangue , Receptores Citoplasmáticos e Nucleares/sangue , Adulto , Cartilagem Articular/química , Ensaio de Imunoadsorção Enzimática , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/sangue , Osteoprotegerina , Receptores do Fator de Necrose Tumoral , Espondilite Anquilosante/sangue , Líquido Sinovial/química
14.
Blood ; 98(7): 2269-71, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11568016

RESUMO

Osteoprotegerin (OPG), the neutralizing decoy receptor for the osteoclast activator RANK ligand, was measured in serum taken from patients with multiple myeloma at the time of diagnosis. Median OPG was lower in the patients with myeloma (7.4 ng/mL; range, 2.6-80; n = 225) than in healthy age- and sex-matched controls (9.0 ng/mL; range 5.1-130; n = 40; P =.02). Importantly, OPG levels were associated with degree of radiographically assessed skeletal destruction (P =.01). The median OPG level in patients lacking osteolytic lesions was 9.1 ng/mL, as compared with 7.6 ng/mL and 7.0 ng/mL, respectively, in patients with minor or advanced osteolytic disease. Furthermore, OPG levels were associated with World Health Organization performance status (P =.003) and correlated to serum levels of carboxy-terminal propeptide of type I procollagen (PICP; P <.001) but not with clinical stage or survival. These findings suggest impaired OPG function in myeloma and give a rationale for OPG as a therapeutic agent against myeloma bone disease.


Assuntos
Glicoproteínas/sangue , Mieloma Múltiplo/sangue , Mieloma Múltiplo/complicações , Osteólise/etiologia , Receptores Citoplasmáticos e Nucleares/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Indicadores Básicos de Saúde , Humanos , Pessoa de Meia-Idade , Osteólise/sangue , Osteoprotegerina , Receptores do Fator de Necrose Tumoral
15.
J Leukoc Biol ; 69(3): 474-81, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11261796

RESUMO

Human Toll-like receptor 2 (TLR2) is a receptor for a variety of microbial products and mediates activation signals in cells of the innate immune system. We have investigated expression and regulation of the TLR2 protein in human blood cells and tissues by using two anti-TLR2 mAbs. Only myelomonocytic cell lines expressed surface TLR2. In tonsils, lymph nodes, and appendices, activated B-cells in germinal centers expressed TLR2. In human blood, CD14+ monocytes expressed the highest level of TLR2 followed by CD15+ granulocytes, and CD19+ B-cells, CD3+ T-cells, and CD56+ NK cells did not express TLR2. The level of TLR2 on monocytes was after 20 h up-regulated by LPS, GM-CSF, IL-1, and IL-10 and down-regulated by IL-4, IFN-gamma, and TNF. On purified granulocytes, LPS, GM-CSF, and TNF down-regulated, and IL-10 modestly increased TLR2 expression after 2 h. These data suggest that TLR2 protein expression in innate immune cells is differentially regulated by inflammatory mediators.


Assuntos
Proteínas de Drosophila , Granulócitos/metabolismo , Tecido Linfoide/metabolismo , Glicoproteínas de Membrana/biossíntese , Monócitos/metabolismo , Receptores de Superfície Celular/biossíntese , Anticorpos Monoclonais , Citometria de Fluxo , Regulação da Expressão Gênica/fisiologia , Granulócitos/fisiologia , Humanos , Linfonodos/citologia , Linfonodos/metabolismo , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Monócitos/fisiologia , Tonsila Palatina/citologia , Tonsila Palatina/metabolismo , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor 2 Toll-Like , Receptores Toll-Like , Células Tumorais Cultivadas
16.
Blood ; 97(2): 516-22, 2001 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-11154231

RESUMO

Bone morphogenetic proteins (BMPs) can be isolated from organic bone matrix and are able to initiate de novo cartilage and bone formation. Here it is shown that BMP-4 inhibited DNA synthesis in a dose-dependent manner in 3 IL-6-dependent multiple myeloma (MM) cell lines (OH-2, IH-1, and ANBL-6). In contrast, no effect on DNA synthesis was observed in 3 IL-6-independent MM cell lines (JJN-3, U266, and RPMI 8226). BMP-4 induced cell cycle growth arrest in the G(0)/G(1) phase in OH-2 and ANBL-6 cells but not in IH-1 cells. BMP-4 induced apoptosis in OH-2 and IH-1 cells, but not significantly in ANBL-6 cells. Furthermore, BMP-4 induced apoptosis in freshly isolated MM cells from 4 of 13 patients. In the OH-2 and ANBL-6 cell lines and in a patient sample, immunoblotting showed that BMP-4 down-regulated IL-6-induced tyrosine phosphorylation of Stat3, suggesting a mechanism for the apparent antagonism between IL-6 and BMP-4. BMP-4 or analogues may be attractive therapeutic agents in MM because of possible beneficial effects on both tumor burden and bone disease.


Assuntos
Apoptose/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/farmacologia , Proteínas Morfogenéticas Ósseas/fisiologia , Mieloma Múltiplo/patologia , Idoso , Idoso de 80 Anos ou mais , Proteína Morfogenética Óssea 4 , Técnicas de Cultura de Células , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Humanos , Interleucina-6/antagonistas & inibidores , Pessoa de Meia-Idade , Mieloma Múltiplo/fisiopatologia , Inibidores da Síntese de Ácido Nucleico/farmacologia , Fosforilação/efeitos dos fármacos , Receptores de Interleucina-6/fisiologia , Fator de Transcrição STAT3 , Transativadores/metabolismo , Células Tumorais Cultivadas
17.
Infect Immun ; 68(12): 6770-6, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11083794

RESUMO

Lipopolysaccharide (LPS) and related bacterial products can be recognized by host inflammatory cells in a particulate, bacterium-bound form, as well as in various soluble, released forms. In the present study we have compared the mechanisms used by LPS, detoxified LPS (DLPS), and mannuronic acid polymers (M-polymers), in solution or covalently linked to particles, in stimulating monocytes to tumor necrosis factor (TNF) production. The addition of recombinant LPS binding protein (LBP) and/or soluble CD14 (sCD14) enhanced the production of TNF from monocytes stimulated with soluble LPS, DLPS, or M-polymer, but did not affect the response to M-polymer or DLPS attached to particles. Treatment of monocytes with antibody to CD14, CD18, or CD11b showed that CD14, but not CR3 (CD11b/CD18), mediated monocyte TNF production in response to the soluble antigens. In contrast, anti-CD14, anti-CD11b and anti-CD18 monoclonal antibodies all inhibited the response to the particulate stimuli. On the other hand, B975, a synthetic analog of Rhodobacter capsulatus lipid A, completely abrogated the monocyte TNF response induced by LPS but did not affect the TNF induction by DLPS or M-polymer, either in soluble or particulate forms. These data demonstrate that the engagement of immune receptors by bacterial products such as LPS, DLPS, and M-polymer is dependent upon the presentation form of their constituent carbohydrates, and that factors such as aggregation state, acylation, carbohydrate chain length, and solid versus liquid phase of bacterial ligands influence the mechanisms used by cells in mediating proinflammatory responses.


Assuntos
Proteínas de Fase Aguda , Alginatos/farmacologia , Antígenos CD18/fisiologia , Receptores de Lipopolissacarídeos/fisiologia , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana , Animais , Células CHO , Proteínas de Transporte/fisiologia , Cricetinae , Ácido Glucurônico , Ácidos Hexurônicos , Antígeno de Macrófago 1/fisiologia , Monócitos/efeitos dos fármacos , Fator de Necrose Tumoral alfa/biossíntese
18.
Blood ; 96(9): 3139-46, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11049995

RESUMO

Syndecan-1 is a heparan sulfate proteoglycan expressed on the surface of, and actively shed by, myeloma cells. Hepatocyte growth factor (HGF) is a cytokine produced by myeloma cells. Previous studies have demonstrated elevated levels of syndecan-1 and HGF in the serum of patients with myeloma, both of negative prognostic value for the disease. Here we show that the median concentrations of syndecan-1 (900 ng/mL) and HGF (6 ng/mL) in the marrow compartment of patients with myeloma are highly elevated compared with healthy controls and controls with other diseases. We show that syndecan-1 isolated from the marrow of patients with myeloma seems to exist in an intact form, with glucosaminoglycan chains. Because HGF is a heparan-sulfate binding cytokine, we examined whether it interacted with soluble syndecan-1. In supernatants from myeloma cells in culture as well as in pleural effusions from patients with myeloma, HGF existed in a complex with soluble syndecan-1. Washing myeloma cells with purified soluble syndecan-1 could effectively displace HGF from the cell surface, suggesting that soluble syndecan-1 can act as a carrier for HGF in vivo. Finally, using a sensitive HGF bioassay (interleukin-11 production from the osteosarcoma cell line Saos-2) and intact syndecan-1 isolated from the U-266 myeloma cell line, we found that the presence of high concentrations of syndecan-1 (more than 3 microg/mL) inhibited the HGF effect, whereas lower concentrations potentiated it. HGF is only one of several heparin-binding cytokines associated with myeloma. These data indicate that soluble syndecan-1 may participate in the pathology of myeloma by modulating cytokine activity within the bone marrow.


Assuntos
Células da Medula Óssea/patologia , Fator de Crescimento de Hepatócito/análise , Glicoproteínas de Membrana/análise , Mieloma Múltiplo/patologia , Proteoglicanas/análise , Biópsia por Agulha , Células da Medula Óssea/citologia , Neoplasias Ósseas , Membrana Celular/patologia , Meios de Cultivo Condicionados , Citometria de Fluxo , Fator de Crescimento de Hepatócito/isolamento & purificação , Fator de Crescimento de Hepatócito/fisiologia , Humanos , Interleucina-11/metabolismo , Glicoproteínas de Membrana/isolamento & purificação , Glicoproteínas de Membrana/farmacologia , Osteossarcoma , Proteoglicanas/isolamento & purificação , Proteoglicanas/farmacologia , Valores de Referência , Sindecana-1 , Sindecanas , Células Tumorais Cultivadas
19.
Br J Haematol ; 109(4): 815-22, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10929035

RESUMO

Binding of urokinase (uPA) to its receptor (uPAR; CD87) focuses proteolytic activity on the cell surface and this system is of importance in malignant matrix degradation and tumour invasion. By immunocytochemistry and flow cytometry, we found that primary myeloma cells and myeloma cell lines expressed uPA and uPAR. Soluble uPA was present in cell line supernatants and lysates in low concentrations. In cell lines, uPA and uPAR were located both on the cell surface and intracellularly, but the expression of both proteins was low. Higher levels of uPAR was detected on the cell surface of primary myeloma cells. When primary myeloma cells were gated by CD45 expression, stronger expression was found on immature CD45+ cells than on mature CD45-/dim cells. Finally, both myeloma cell lines and primary cells were able to cleave a uPA-specific substrate showing that the uPA system is functionally active. We conclude that myeloma cells are able to produce uPA and uPAR. This opens up a possible role of the uPA system in myeloma cell invasion and in the proteolytic digestion of bone matrix.


Assuntos
Mieloma Múltiplo/metabolismo , Ativadores de Plasminogênio/análise , Receptores de Superfície Celular/análise , Ativador de Plasminogênio Tipo Uroquinase/análise , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Receptores de Ativador de Plasminogênio Tipo Uroquinase , Células Tumorais Cultivadas
20.
J Immunol ; 164(4): 2064-9, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10657659

RESUMO

Human Toll like receptor (TLR) 2 has been implicated as a signaling receptor for LPS from Gram-negative bacteria and cell wall components from Gram-positive organisms. In this study, we investigated whether TLR2 can signal cell activation by the heat-killed group B streptococci type III (GBS) and Listeria monocytogenes (HKLM). HKLM, but not GBS, showed a time- and dose-dependent activation of Chinese hamster ovary cells transfected with human TLR2, as measured by translocation of NF-kappaB and induction of IL-6 production. A mAb recognizing a TLR2-associated epitope (TL2.1) was generated that inhibited IL-6 production from Chinese hamster ovary-TLR2 cells stimulated with HKLM or LPS. The TL2.1 mAb reduced HKLM-induced TNF production from human monocytes by 60%, whereas a CD14 mAb (3C10) reduced the TNF production by 30%. However, coadministrating TL2.1 and 3C10 inhibited the TNF response by 80%. In contrast to this, anti-CD14 blocked LPS-induced TNF production from monocytes, whereas anti-TLR2 showed no inhibition. Neither TL2.1 nor 3C10 affected GBS-induced TNF production. These results show that TLR2 can function as a signaling receptor for HKLM, possibly together with CD14, but that TLR2 is unlikely to be involved in cell activation by GBS. Furthermore, although LPS can activate transfected cell lines through TLR2, this receptor does not seem to be the main transducer of LPS activation of human monocytes. Thus, our data demonstrate the ability of TLR2 to distinguish between different pathogens.


Assuntos
Proteínas de Drosophila , Lipopolissacarídeos/imunologia , Listeria monocytogenes/imunologia , Glicoproteínas de Membrana/fisiologia , Monócitos/imunologia , Monócitos/microbiologia , Receptores de Superfície Celular/fisiologia , Streptococcus agalactiae/imunologia , Animais , Anticorpos Monoclonais/biossíntese , Reações Antígeno-Anticorpo , Células CHO , Cricetinae , Relação Dose-Resposta Imunológica , Epitopos/imunologia , Temperatura Alta , Humanos , Interleucina-6/antagonistas & inibidores , Interleucina-6/biossíntese , Receptores de Lipopolissacarídeos/fisiologia , Lipopolissacarídeos/antagonistas & inibidores , Ativação de Macrófagos , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Receptores de Superfície Celular/imunologia , Receptor 2 Toll-Like , Receptores Toll-Like , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...