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1.
BMJ Open ; 13(3): e067794, 2023 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-36868593

RESUMO

BACKGROUND: One of the most severe complications in laparoscopic cholecystectomy (LC) is intraoperative bile duct injury (BDI). Despite its low incidence, the medical implications for the patient can be serious. Besides, BDI can also generate significant legal issues in healthcare. Different techniques have been described to reduce the incidence of this complication, and near-infrared fluorescence cholangiography with indocyanine green (NIRFC-ICG) is one of the latest additions. In spite of the great interest aroused by this procedure, there are currently great disparities in the usage or administration protocols of ICG. METHODS AND ANALYSIS: This is a randomised, multicentre, per-protocol analysis, open clinical trial with four arms. The estimated duration of the trial is 12 months. The aim of the study is to analyse whether there are differences between the dose and administration ICG intervals to obtain good-quality NIRFC during LC. The primary outcome is the degree of identification of critical biliary structures during LC. In addition, different factors will be analysed that may have an influence on the results of this technique. ETHICS AND DISSEMINATION: The trial will be conducted according to the recommendations for Clinical Trials in the Declaration of Helsinki Ethical Principles for Medical Research Involving Human Subjects and the recommendations of the Spanish Agency of Medicines and Medical Devices (AEMPs) for clinical trials. This trial was approved by the local institutional Ethics Committee and the AEMPs. The results of the study will be presented to the scientific community through publications, conferences or other means. EUDRACT NUMBER: 2022-000904-36. PROTOCOL VERSION: V.1.4, 2 June 2022 TRIAL REGISTRATION NUMBER: NCT05419947.


Assuntos
Colecistectomia Laparoscópica , Verde de Indocianina , Humanos , Fluorescência , Gerenciamento do Tempo , Colangiografia , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Multicêntricos como Assunto
2.
Vaccine ; 39(3): 554-563, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33334613

RESUMO

TRIAL DESIGN: An interventional, phase 4, single group assignment, without masking (open label), preventive clinical trial was carried out in health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B. METHODS: 67 health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B, were enrolled in the Clinical Trial. All participants were from 18 years up to 64 years old. INCLUSION CRITERIA: NHS workers -including university students doing their internships in health centres dependent on the National Health System (inclusion of students is regulated and limited by specific instructions on labour prevention in each autonomous community)- classified as non-responders. The criteria defining them as non-responders to the conventional hepatitis B vaccine is anti HBsAb titers < 10 mUI/ml following the application of six doses of conventional vaccine at 20 µg doses (two complete guidelines). The objective of this study was to provide Health workers-staff with an additional protection tool against hepatitis B infection, and to evaluate the efficacy of the adjuvanted vaccine in healthy non-responders to conventional hepatitis B vaccine. The primary outcome was the measurement of antibody antiHBs before the first Fendrix® dose and a month after the administration of each dose. Other outcome was collection of adverse effects during administration and all those that could be related to the vaccine and that occur within 30 days after each dose. In this study, only one group was assigned. There was no randomization or masking. RESULTS: The participants were recruited between April 13, 2018 and October 31, 2019. 67 participants were enrolled in the Clinical Trial and included the analyses. The primary immunisation consists of 4 separate 0.5 ml doses of Fendrix®, administered at the following schedule: 1 month, 2 months and 6 months from the date of the first dose. Once the positivity was reached in any of the doses, the participant finished the study and was not given the following doses. 68.66% (46 out 67) had a positive response to first dose of Fendrix®. 57.14% (12 out 21) had a positive response to second dose of Fendrix®. 22.22% (2 out 9) had a positive response to third dose of Fendrix and 42.96% (3 out 7) had a positive response to last dose of Fendrix®. Overall, 94.02% (64 out 67) of participants had a positive response to Fendrix®. No serious adverse event occurred. CONCLUSIONS: The use of Fendrix®, is a viable vaccine alternative for NHS workers classified as "non-responders". Revaccination of healthy non-responders with Fendrix®, resulted in very high proportions of responders without adverse events. TRIAL REGISTRATION: The trial was registered in the Spanish National Trial Register (REEC), ClinicalTrials.gov and inclusion has been stopped (identifier NCT03410953; EudraCT-number 2016-004991-23). FUNDING: GRS 1360/A/16: Call for aid for the financing of research projects in biomedicine, health management and socio-health care to be developed in the centres of the Regional Health Management of Autonomous Community of Castile-Leon. In addition, this work has been supported by the Spanish Platform for Clinical Research and Clinical Trials, SCReN (Spanish Clinical Research Network), funded by the Subdirectorate General for Research Evaluation and Promotion of the Carlos III Health Institute (ISCIII), through the project PT13/0002/0039 and project PT17/0017/0023 integrated in the State Plan for R&D&I 2013-2016 and co-financed by and the European Regional Development Fund (ERDF).


Assuntos
COVID-19 , Hepatite B , Atenção à Saúde , Hepatite B/prevenção & controle , Vacinas contra Hepatite B , Humanos , SARS-CoV-2 , Vacinação
3.
Front Pharmacol ; 11: 533, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32410997

RESUMO

Colorectal cancer (CRC) is one of the most common and recurrent types of cancer, with high mortality rates. Several clinical trials and meta-analyses have determined that the use of pharmacological inhibitors of cyclooxygenase 2 (COX-2), the enzyme that catalyses the rate-limiting step in the synthesis of prostaglandins (PG) from arachidonic acid, can reduce the incidence of CRC as well as the risk of recurrence of this disease, when used together with commonly used chemotherapeutic agents. These observations suggest that inhibition of COX-2 may be useful in the treatment of CRC, although the current drugs targeting COX-2 are not widely used since they increase the risk of health complications. To overcome this difficulty, a possibility is to identify genes regulated by COX-2 activity that could give an advantage to the cells to form tumors and/or metastasize. The modulation of those genes as effectors of COX-2 may cancel the beneficial effects of COX-2 in tumor transformation and metastasis. A review of the available databases and literature and our own data have identified some interesting molecules induced by prostaglandins or COX-2 that have been also described to play a role in colon cancer, being thus potential pharmacological targets in colon cancer. Among those mPGES-1, DUSP4, and 10, Programmed cell death 4, Trop2, and many from the TGFß and p53 pathways have been identified as genes upregulated in response to COX-2 overexpression or PGs in colon carcinoma lines and overexpressed in colon tumor tissue. Here, we review the available evidence of the potential roles of those molecules in colon cancer in the context of PG/COX signaling pathways that could be critical mediators of some of the tumor growth and metastasis advantage induced by COX-2. At the end, this may allow defining new therapeutic targets/drugs against CRC that could act specifically against tumor cells and would be effective in the prevention and treatment of CRC, lacking the unwanted side effects of COX-2 pharmacological inhibitors, providing alternative approaches in colon cancer.

4.
Cancers (Basel) ; 11(11)2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717606

RESUMO

Cell contact inhibition (CCI) is deregulated in cancer. Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. We found that dual-specificity phosphatase 10 (DUSP10) is involved in CRC. DUSP10 overexpression increased the growth of CRC cell lines and mouse xenografts, while the opposite phenotype was observed by DUSP10 silencing. High cell density (HD) induced DUSP10 expression in CRC cell lines, particularly within the nucleus. Yes-associated protein 1 (YAP1) is activated by dephosphorylation, controlling organ growth and CCI, both processes being deregulated in CRC. Expression levels and localization of DUSP10 matched with YAP1 levels in CRC cell lines. DUSP10 and YAP1 co-immunoprecipitated and their interaction was dependent on YAP1 Ser397. The existence of DUSP10 and YAP1 pathway in vivo was confirmed by using a transgenic Drosophila model. Finally, in CRC patients' samples, high levels of nuclear DUSP10 correlated with nuclear YAP1 in epithelial tumor tissue. Strong nuclear DUSP10 staining also correlated with high tumor stage and poor survival. Overall, these findings describe a DUSP10-YAP1 molecular link in CRC cell lines promoting cell growth in HD. We present evidence suggesting a pro-tumorigenic role of nuclear DUSP10 expression in CRC patients.

5.
Oncotarget ; 6(37): 39941-59, 2015 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-26498686

RESUMO

Cyclooxygenase2 (COX2) has been associated with cell growth, invasiveness, tumor progression and metastasis of colorectal carcinomas. However, the downstream prostaglandin (PG)-PG receptor pathway involved in these effects is poorly characterized.We studied the PG-pathway in gene expression databases and we found that PTGS2 (prostaglandin G/H synthase and cyclooxygenase) and PTGES (prostaglandin E synthase) are co-expressed in human colorectal tumors. Moreover, we detected that COX2 and microsomal Prostaglandin E2 synthase 1 (mPGES1) proteins are both up-regulated in colorectal human tumor biopsies.Using colon carcinoma cell cultures we found that COX2 overexpression significantly increased mPGES1 mRNA and protein. This up-regulation was due to an increase in early growth response 1 (EGR1) levels and its transcriptional activity. EGR1 was induced by COX2-generated PGF2α. A PGF2α receptor antagonist, or EGR1 silencing, inhibited the mPGES1 induction by COX2 overexpression. Moreover, using immunodeficient mice, we also demonstrated that both COX2- and mPGES1-overexpressing carcinoma cells were more efficient forming tumors.Our results describe for the first time the molecular pathway correlating PTGS2 and PTGES in colon cancer progression. We demonstrated that in this pathway mPGES1 is induced by COX2 overexpression, via autocrine PGs release, likely PGF2α, through an EGR1-dependent mechanism. This signaling provides a molecular explanation to PTGS2 and PTGES association and contribute to colon cancer advance, pointing out novel potential therapeutic targets in this oncological context.


Assuntos
Neoplasias Colorretais/metabolismo , Ciclo-Oxigenase 2/metabolismo , Oxirredutases Intramoleculares/metabolismo , Prostaglandinas/metabolismo , Proteínas Repressoras/metabolismo , Animais , Western Blotting , Células CACO-2 , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Ciclo-Oxigenase 2/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Oxirredutases Intramoleculares/genética , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Microscopia Confocal , Microssomos/enzimologia , Prostaglandina-E Sintases , Interferência de RNA , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo , Regulação para Cima
6.
J Immunol Methods ; 384(1-2): 171-6, 2012 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-22835433

RESUMO

In this report we show that combining double-chemically modified carrier proteins and hetero-functional cross-linkers allows preparing tailor-made hapten-protein carrier conjugates. Accordingly, a new carrier protein has been designed where carboxylic groups were transformed into highly reactive primary amino groups by reaction with ethylendiamine after activation with EDCI. The aminated protein carrier is then modified by different cross-linkers (hyper-activated proteins) at different conditions in order to control the conjugation ratio from 1 to >12 molecules of hapten per carrier protein. Finally, this novel strategy has been successfully used to develop antibodies against a short specific peptide corresponding to a point mutation (D816V) of cKIT, which is a clinically relevant mutation related to mastocytosis and gastrointestinal stroma tumor.


Assuntos
Anticorpos Monoclonais/imunologia , Proteínas de Transporte/imunologia , Mutação de Sentido Incorreto , Proteínas Proto-Oncogênicas c-kit/imunologia , Animais , Anticorpos/sangue , Anticorpos/imunologia , Proteínas de Transporte/química , Bovinos , Reagentes de Ligações Cruzadas/química , Eletroforese em Gel Bidimensional , Ensaio de Imunoadsorção Enzimática , Etilenodiaminas/química , Tumores do Estroma Gastrointestinal/genética , Tumores do Estroma Gastrointestinal/imunologia , Imunoconjugados/química , Imunoconjugados/imunologia , Maleimidas/química , Mastocitose/genética , Mastocitose/imunologia , Camundongos , Modelos Químicos , Modelos Moleculares , Estrutura Molecular , Peptídeos/genética , Peptídeos/imunologia , Conformação Proteica , Proteínas Proto-Oncogênicas c-kit/química , Proteínas Proto-Oncogênicas c-kit/genética , Soroalbumina Bovina/química , Soroalbumina Bovina/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
7.
PLoS One ; 6(11): e27583, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22132115

RESUMO

Multiple myeloma (MM) is a hematological disease characterized by an abnormal accumulation of plasma cells in the bone marrow. These cells have frequent cytogenetic abnormalities including translocations of the immunoglobulin heavy chain gene and chromosomal gains and losses. In fact, a singular characteristic differentiating MM from other hematological malignancies is the presence of a high degree of aneuploidies. As chromosomal abnormalities can be generated by alterations in the spindle assembly checkpoint (SAC), the functionality of such checkpoint was tested in MM. When SAC components were analyzed in MM cell lines, the RNA levels of most of them were conserved. Nevertheless, the protein content of some key constituents was very low in several cell lines, as was the case of MAD2 or CDC20 in RPMI-8226 or RPMI-LR5 cells. The recovery of their cellular content did not substantially affect cell growth, but improved their ability to segregate chromosomes. Finally, SAC functionality was tested by challenging cells with agents disrupting microtubule dynamics. Most of the cell lines analyzed exhibited functional defects in this checkpoint. Based on the data obtained, alterations both in SAC components and their functionality have been detected in MM, pointing to this pathway as a potential target in MM treatment.


Assuntos
Pontos de Checagem da Fase M do Ciclo Celular , Mieloma Múltiplo/patologia , Aneuploidia , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Instabilidade Genômica/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Proteínas Mad2 , Mieloma Múltiplo/genética , Nocodazol/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Repressoras/metabolismo , Retroviridae/efeitos dos fármacos , Retroviridae/genética , Transdução Genética
8.
Gene ; 419(1-2): 16-26, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18547747

RESUMO

We have identified sequential changes in the gene expression pattern of human myeloid leukaemia HL-60 cells during their neutrophil differentiation induced by dimethyl sulfoxide (DMSO) that account for the acquisition of mature neutrophil phenotypic hallmarks. Following 1-day DMSO treatment, HL-60 cells were committed to neutrophil differentiation with loss of their proliferative capacity, and gene expression changes were mostly related to transcription and cell cycle, including up-regulation of inhibitor of DNA binding (Id) genes and down-regulation of cyclins, CDC kinases and MCM proteins. After 3-4-day DMSO treatment, zinc finger proteins 266 and 51 (BCL-6) were dramatically up-regulated, and additional gene expression changes, involving functional and signalling proteins as well as genes involved in RNA processing, apoptosis, and protein degradation, correlated with acquisition of the mature neutrophil phenotype. Our data define changes in the gene expression pattern of a rather restricted number of genes during the differentiation process that seem to regulate neutrophil maturation, providing a molecular basis for the acquisition of neutrophil phenotype. Peripheral blood mature neutrophils showed a qualitatively similar expression profile for these selected genes. These results show changes in gene expression during the transformation of a proliferating leukaemic cell into an end apoptotic-prone cell, which might be of importance to get a molecular insight for the use of differentiation therapy in leukaemia.


Assuntos
Regulação da Expressão Gênica , Neutrófilos/metabolismo , Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Apoptose , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células , Citocinas/genética , Citocinas/metabolismo , Dimetil Sulfóxido/farmacologia , Perfilação da Expressão Gênica , Células HL-60 , Humanos , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Processamento Pós-Transcricional do RNA , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Transdução de Sinais/genética , Transcrição Gênica
9.
Haematologica ; 93(6): 851-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18443272

RESUMO

BACKGROUND: c-Kit is expressed in the plasma cells from 30% of patients with multiple myeloma. Two different isoforms of c-Kit, characterized by the presence or absence of the tetrapeptide sequence GNNK in the extracellular domain, have been described. However, their expression and function in myeloma cells are unknown. We explored the function and expression of these c-Kit isoforms in myeloma cells. DESIGN AND METHODS: Expression of c-Kit isoforms was investigated by reverse transcriptase polymerase chain reaction in fresh plasma cells from patients and cell lines. The function of these c-Kit isoforms was analyzed upon expression in myeloma cells. Signaling was investigated by western blotting using antibodies specific for activated forms of several signaling proteins. The impact of c-Kit on the action of drugs commonly used in the treatment of multiple myeloma was investigated by MTT proliferation assays. RESULTS: Fresh plasma cells from patients as well as myeloma cell lines expressed the two isoforms of c-Kit. Retroviral infection of myeloma cells with vectors that code for c-Kit-GNNK+ or c-Kit-GNNK- forms demonstrated differences in the kinetics of phosphorylation between these isoforms. Stem cell factor-induced activation of the GNNK- form was faster and more pronounced than that of the GNNK+ form, whose activation, however, lasted for longer. The c-Kit receptors weakly activated the Erk1/2 and Erk5 pathways. Both receptors, however, efficiently coupled to the PI3K/Akt pathway, and stimulated p70S6K activation. The latter was sensitive to the mTOR inhibitor, rapamycin. Studies of drug sensitivity indicated that cells expressing the GNNK- form were more resistant to the anti-myeloma action of bortezomib and melphalan. CONCLUSIONS: Our data indicate that c-Kit expression in multiple myeloma cells is functional, and coupled to survival pathways that may modulate cell death in response to therapeutic compounds used in the treatment of this disease.


Assuntos
Regulação Neoplásica da Expressão Gênica , Mieloma Múltiplo/metabolismo , Proteínas Proto-Oncogênicas c-kit/biossíntese , Proteínas Proto-Oncogênicas c-kit/química , Antineoplásicos/farmacologia , Ácidos Borônicos/farmacologia , Bortezomib , Morte Celular , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Imunofenotipagem , Melfalan/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Isoformas de Proteínas , Proteínas Quinases/metabolismo , Pirazinas/farmacologia , Transdução de Sinais , Sirolimo/farmacologia , Serina-Treonina Quinases TOR
10.
BMC Genomics ; 8: 2, 2007 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-17201911

RESUMO

BACKGROUND: A promising application of the huge amounts of genetic data currently available lies in developing a better understanding of complex diseases, such as cancer. Analysis of publicly available databases can help identify potential candidates for genes or mutations specifically related to the cancer phenotype. In spite of their huge potential to affect gene function, no systematic attention has been paid so far to the changes that occur in untranslated regions of mRNA. RESULTS: In this study, we used Expressed Sequence Tag (EST) databases as a source for cancer-related sequence polymorphism discovery at the whole-genome level. Using a novel computational procedure, we focused on the identification of untranslated region (UTR)-localized non-coding Single Nucleotide Polymorphisms (UTR-SNPs) significantly associated with the tumoral state. To explore possible relationships between genetic mutation and phenotypic variation, bioinformatic tools were used to predict the potential impact of cancer-associated UTR-SNPs on mRNA secondary structure and UTR regulatory elements. We provide a comprehensive and unbiased description of cancer-associated UTR-SNPs that may be useful to define genotypic markers or to propose polymorphisms that can act to alter gene expression levels. Our results suggest that a fraction of cancer-associated UTR-SNPs may have functional consequences on mRNA stability and/or expression. CONCLUSION: We have undertaken a comprehensive effort to identify cancer-associated polymorphisms in untranslated regions of mRNA and to characterize putative functional UTR-SNPs. Alteration of translational control can change the expression of genes in tumor cells, causing an increase or decrease in the concentration of specific proteins. Through the description of testable candidates and the experimental validation of a number of UTR-SNPs discovered on the secreted protein acidic and rich in cysteine (SPARC) gene, this report illustrates the utility of a cross-talk between in silico transcriptomics and cancer genetics.


Assuntos
Genoma Humano/genética , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Regiões não Traduzidas/genética , Biologia Computacional/métodos , Bases de Dados Genéticas , Etiquetas de Sequências Expressas , Humanos , Leucemia Mieloide Aguda/genética , Conformação de Ácido Nucleico , Osteonectina/genética , RNA Mensageiro/química , RNA Mensageiro/genética , Regiões não Traduzidas/química
11.
Cancer Res ; 66(11): 5781-9, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16740717

RESUMO

Multiple myeloma represents an incurable disease, for which development of new therapies is required. Here, we report the effect on myeloma cells of LBH589, a new hydroxamic acid-derived histone deacetylase inhibitor. LBH589 was a potent antimyeloma agent (IC(50) < 40 nmol/L) on both cell lines and fresh cells from multiple myeloma patients, including cells resistant to conventional chemotherapeutic agents. In addition, LBH589 potentiated the action of drugs, such as bortezomib, dexamethasone, or melphalan. Using gene array, quantitative PCR, and Western analyses, we observed that LBH589 affected a large number of genes involved in cell cycle and cell death pathways. LBH589 blocked cell cycle progression, and this was accompanied by p21, p53, and p57 up-regulation. LBH589 induced cell death through an increase in the mitochondrial outer membrane permeability. LBH589 favored apoptosome formation by inducing cytochrome c release, Apaf-1 up-regulation, and caspase-9 cleavage. In addition, LBH589 stimulated a caspase-independent pathway through the release of AIF from the mitochondria. LBH589 down-regulated Bcl-2 and particularly Bcl-X. Moreover, overexpression of Bcl-X in multiple myeloma cells prevented LBH589-induced cell death. All these data indicate that LBH589 could be a useful drug for the treatment of multiple myeloma patients.


Assuntos
Inibidores de Histona Desacetilases , Mieloma Múltiplo/tratamento farmacológico , Acetilação/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Ácidos Borônicos/administração & dosagem , Ácidos Borônicos/farmacologia , Bortezomib , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Dexametasona/administração & dosagem , Dexametasona/farmacologia , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/administração & dosagem , Ácidos Hidroxâmicos/farmacologia , Indóis , Melfalan/administração & dosagem , Melfalan/farmacologia , Mieloma Múltiplo/enzimologia , Mieloma Múltiplo/patologia , Panobinostat , Pirazinas/administração & dosagem , Pirazinas/farmacologia , Proteína bcl-X/biossíntese
12.
Acta Haematol ; 114 Suppl 1: 23-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16166769

RESUMO

DNA methylation is involved in malignancy and is seen, in progression, in more than 80% of all solid tumours. Methylation is one of the main physiological processes to induce silencing of gene expression. Much work has focused on the suppressor gene p16, which acts as a negative cell cycle regulator, while its inhibition (via methylation) will have a positive effect on the cell cycle advance. The methylation status of the p16 gene was analysed in a group of 159 patients. Methylation of the p16 gene was seen in 41/98 (42%) patients with multiple myeloma and 4/5 (80%) patients with primary plasma cell leukaemias. This data favours the importance of p16 methylation on cell cycle regulation in multiple myeloma. In a proposed mechanism, methylated CpG islands attract a protein, MeCP2, which recruits a transcriptional inhibitory complex that includes histone deacetylases. The deacetylated lysine tails of the histones closely interact with DNA, resulting in a transcriptionally repressed chromatin with inhibited gene transcription, providing potential synergy between demethylating drugs and histone deacetylase inhibitors. Based on the knowledge of epigenetic mechanisms, the potential application of demethylating agents should be further investigated. Multiple myeloma remains an incurable disease, so new treatment strategies are needed to improve the outcome of patients.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Mieloma Múltiplo/metabolismo , Animais , Ciclo Celular , Linhagem Celular Tumoral , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Ilhas de CpG , DNA de Neoplasias/genética , DNA de Neoplasias/metabolismo , Proteínas de Ligação a DNA/metabolismo , Inibidores Enzimáticos/uso terapêutico , Inibidores de Histona Desacetilases , Histona Desacetilases/metabolismo , Humanos , Proteína 2 de Ligação a Metil-CpG , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Proteínas Repressoras/metabolismo , Transcrição Gênica
13.
Haematologica ; 90(7): 906-13, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15996928

RESUMO

BACKGROUND AND OBJECTIVES: Analysis of IgH rearrangements in B-cell malignancies has provided clinical researchers with a wide range of information during the last few years. However, only a few studies have contributed to the characterization of these features in multiple myeloma (MM), and they have been focused on the analysis of the expressed IgH allele only. Comparison between the expressed and the non-functional IgH alleles allows further characterizion of the selection processes to which pre-myeloma cells are submitted. DESIGN AND METHODS: We analyzed a cohort of 84 untreated MM patients in order to characterize their functional VDJH and non-functional DJH rearrangements. The pattern of mutations and gene segment usage for both types of rearrangements was analyzed by polymerase chain reaction and sequencing. RESULTS: VH3 and VH1 family members were over- and under-represented, respectively. VH3-30 and VH3-15 segments were the most frequently used, whereas VH4-34 was found only in non-functional or heavily mutated VDJH rearrangements. DH2 and DH3 family members were over-represented in both VDJH and DJH repertoires, while the DH1 family was under-represented only in the productive VDJH rearrangements. Finally, DH3-22 and DH2-21 gene segments were found to be over-represented in the functional repertoire while segments commonly used by less mature B-cell malignancies, such as DH6-19 or DH3-3, were under-represented. INTERPRETATION AND CONCLUSIONS: Data reported here help to identify the clonogenic MM cell as a post-germinal center B cell that has undergone selection processes during the germinal center reaction.


Assuntos
Rearranjo Gênico de Cadeia Pesada de Linfócito B , Genes de Imunoglobulinas/genética , Mieloma Múltiplo/genética , Diversidade de Anticorpos , Linfócitos B , Saúde da Família , Rearranjo Gênico , Humanos , Região de Junção de Imunoglobulinas , Região Variável de Imunoglobulina , Mieloma Múltiplo/imunologia , Ácidos Nucleicos Heteroduplexes/química , Reação em Cadeia da Polimerase
14.
Blood ; 105(11): 4492-9, 2005 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-15692064

RESUMO

Multiple myeloma is characterized by the accumulation of terminally differentiated B cells in the bone marrow, due to increased proliferation and restricted apoptosis of the myelomatous clone. Here we have studied the participation of a novel mitogen-activated protein kinase (MAPK) route, the extracellular signal-regulated kinase 5 (Erk5) pathway, in the regulation of myeloma cell proliferation and apoptosis. Erk5 was expressed in cells isolated from patients and in myeloma cell lines. The myeloma growth factor interleukin 6 (IL-6) activated Erk5, and this activation was independent of Ras and Src. Expression of a dominant-negative form of Erk5 restricted the proliferation of myeloma cells and inhibited IL-6-dependent cell duplication. This dominant-negative form also sensitized myeloma cells to the proapoptotic action of dexamethasone and PS341. The latter compound caused a profound decrease in the amount of endogenous Erk5 and was less effective in inducing apoptosis when the level of Erk5 was increased by transfection of Erk5. These results place the Erk5 route as a new regulatory signaling pathway that affects multiple myeloma proliferation and apoptosis.


Assuntos
Proteína Quinase 7 Ativada por Mitógeno/fisiologia , Mieloma Múltiplo/enzimologia , Antineoplásicos/farmacologia , Apoptose , Ácidos Borônicos/farmacologia , Bortezomib , Proliferação de Células , Dexametasona/farmacologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Interleucina-6/farmacologia , Proteína Quinase 7 Ativada por Mitógeno/análise , Mieloma Múltiplo/etiologia , Mieloma Múltiplo/patologia , Pirazinas/farmacologia , Transdução de Sinais , Células Tumorais Cultivadas
15.
Rev. venez. oncol ; 16(4): 213-220, oct.-dic. 2004. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-421942

RESUMO

Determinar la utilidad de la punción aspiración con aguja fina como método de diagnóstico en pacientes con lesiones óseas. Se evaluaron los resultados obtenidos en los pacientes que ingresaron al Servicio de Tumores Mixtos del Instituto de Oncología Dr. Miguel Pérez Carreño, entre enero de 2000 y febrero de 2004, portadores de lesiones óseas y, a quienes se les realizó punción aspiración con aguja fina, biopsia por trocar y biopsia incisional o excisional. Se compararon los resultados, con la biopsia definitiva. Se obtuvieron otros datos como edad, sexo y localización de la lesión. Se realizaron 21 punciones con aguja fina, en 15 de ellos se obtuvo material adecuado para diagnóstico: 11 tumores primarios, 7 malignos, benignos, 3 de comportamientos incierto, 3 lesiones metastásicas y 1 lesión reactiva. La sensibilidad fue de 71,4 por ciento. La punción aspiración con aguja fina representa un método fácil, poco riesgoso y seguro para el diagnóstico en pacientes con lesiones óseas diferente origen


Assuntos
Masculino , Humanos , Feminino , Biópsia por Agulha , Neoplasias Ósseas , Venezuela , Oncologia
16.
Br J Haematol ; 118(4): 1034-40, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12199782

RESUMO

In order to gain further insights into the role of the p16 gene in cell cycle regulation and the prognostic implications of its inactivation, we investigated the methylation status of the p16 gene in 98 untreated patients using a polymerase chain reaction assay based on the inability of some restriction enzymes to digest methylated sequences. Forty-one patients showed a p16 methylated gene (42%). The percentage of S-phase plasma cells (PC) in these patients was almost three times higher than in those with an unmethylated p16 gene (4.16% +/- 3.37%vs 1.5% +/- 1.41%, P < 0.001). The presence of p16 methylation also correlated with both elevated beta2-microglobulin serum levels and high C-reactive protein values. Patients with a p16 methylated gene had shorter overall and progression-free survival than those patients without p16 methylation. However, this feature did not retain independent prognostic influence on multivariate analysis, probably due to its association with the S-phase PC, which had more potent statistical significance in the Cox model. These findings showed methylation of the p16 gene was a frequent event inMM patients at diagnosis, and was associated with an increased proliferative rate of plasma cells and a poor prognosis, indicating an important role for p16 gene in the cell cycle regulation of multiple myeloma tumour cells, and thus in the clinical outcome of the disease.


Assuntos
Metilação de DNA , Genes p16 , Mieloma Múltiplo/genética , Plasmócitos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Divisão Celular/genética , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/patologia , Análise Multivariada , Reação em Cadeia da Polimerase/métodos , Prognóstico
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