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1.
Gut ; 68(7): 1190-1199, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30279238

RESUMO

OBJECTIVE: Loss of the Crohn's disease predisposing NOD2 gene results in an intestinal microenvironment conducive for colonisation by attaching-and-effacing enteropathogens. However, it remains elusive whether it relies on the intracellular recruitment of the serine-threonine kinase RIPK2 by NOD2, a step that is required for its activation of the transcription factor NF-κB. DESIGN: Colonisation resistance was evaluated in wild type and mutant mice, as well as in ex-germ-free (ex-GF) mice which were colonised either with faeces from Ripk2-deficient mice or with bacteria with similar preferences for carbohydrates to those acquired by the pathogen. The severity of the mucosal pathology was quantified at several time points postinfection by using a previously established scoring. The community resilience in response to infection was evaluated by 16S ribosomal RNA gene sequence analysis. The control of pathogen virulence was evaluated by monitoring the secretion of Citrobacter-specific antibody response in the faeces. RESULTS: Primary infection was similarly outcompeted in ex-GF Ripk2-deficient and control mice, demonstrating that the susceptibility to infection resulting from RIPK2 deficiency cannot be solely attributed to specific microbiota community structures. In contrast, delayed clearance of Citrobacter rodentium and exacerbated histopathology were preceded by a weakened propensity of intestinal macrophages to afford innate lymphoid cell activation. This tissue protection unexpectedly required the regenerating family member 3ß by instigating interleukin (IL) 17A-mediated neutrophil recruitment to the intestine and subsequent phosphorylation of signal transducer and activator of transcription 3. CONCLUSIONS: These results unveil a previously unrecognised mechanism that efficiently protects from colonisation by diarrhoeagenic bacteria early in infection.


Assuntos
Doença de Crohn/microbiologia , Doença de Crohn/patologia , Infecções por Enterobacteriaceae/prevenção & controle , Interleucina-17/fisiologia , Infiltração de Neutrófilos/fisiologia , Proteína Adaptadora de Sinalização NOD2/fisiologia , Animais , Proteínas Adaptadoras de Sinalização CARD/fisiologia , Citrobacter rodentium , Modelos Animais de Doenças , Infecções por Enterobacteriaceae/patologia , Mucosa Intestinal/patologia , Camundongos , Proteína Serina-Treonina Quinase 2 de Interação com Receptor , Proteína Serina-Treonina Quinases de Interação com Receptores/fisiologia , Transdução de Sinais
2.
Oncology ; 85(5): 306-11, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24217364

RESUMO

OBJECTIVES: The rapid fatality of pancreatic cancer is, in large part, the result of diagnosis at an advanced stage in the majority of patients. Identification of individuals at risk of developing pancreatic adenocarcinoma would be useful to improve the prognosis of this disease. There is presently no biological or genetic indicator allowing the detection of patients at risk. Our main goal was to identify copy number variants (CNVs) common to all patients with sporadic pancreatic cancer. METHODS: We analyzed gene CNVs in leukocyte DNA from 31 patients with sporadic pancreatic adenocarcinoma and from 93 matched controls. Genotyping was performed with the use of the GeneChip Human Mapping 500K Array Set (Affymetrix). RESULTS: We identified 431 single nucleotide polymorphism (SNP) probes with abnormal hybridization signal present in the DNA of all 31 patients. Of these SNP probes, 284 corresponded to 3 or more copies and 147 corresponded to 1 or 0 copies. Several cancer-associated genes were amplified in all patients. Conversely, several genes supposed to oppose cancer development were present as single copy. CONCLUSIONS: These data suggest that a set of 431 CNVs could be associated with the disease. This set could be useful for early diagnosis.


Assuntos
Adenocarcinoma/genética , Dosagem de Genes , Mutação em Linhagem Germinativa , Neoplasias Pancreáticas/genética , Polimorfismo de Nucleotídeo Único , Idoso , Estudos de Casos e Controles , DNA de Neoplasias/análise , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Análise Serial de Tecidos
3.
J Cell Physiol ; 226(12): 3442-51, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21344397

RESUMO

p8 is a stress gene whose activity is necessary for tumor development and progression. The acquisition of invasive properties by transformed cells is a key event in tumor development. In order to establish whether p8 is involved or not in this phenomenon, we assessed the capacity of p8 at influencing cell adhesion, migration, invasion, and tumorigenesis of pancreatic cancer cells. p8 expression was knocked down by a small interfering RNA (siRNA) in pancreatic cancer-derived Panc-1 and MiaPaCa-2 cells and subsequent changes in cell adhesion, migration, invasion, and tumorigenesis were assessed. Influence of p8 silencing on gene expression was analyzed using cDNA microarrays. The influence of inhibiting CDC42, one of the genes most over-expressed in p8-silenced cells, on the changes observed in p8-silenced cells was also evaluated. Finally, the tumorigenic capacities of Panc-1 cells transfected with control siRNA or p8 siRNA were compared by assessing their ability to form colonies in soft agar and to grow as xenografts in nude mice. Knocking-down p8 in pancreatic cancer cells in vitro decreased migration and invasion while increasing cell adhesion; over-expression produced the opposite effect. Knocking down CDC42 reversed almost completely the effects of silencing p8 in vitro. Finally, cells transfected with p8 siRNA were almost unable to form colonies in soft agar. In addition, p8-deficient Panc-1 cells did not develop tumors when injected subcutaneously in nude mice. In conclusion, p8 expression controls pancreatic cancer cell migration, invasion and adhesion, three processes required for metastasis, at least in part, through CDC42, a major regulator of cytoskeleton organization.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Adesão Celular , Proliferação de Células , Quimiotaxia , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Nus , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Interferência de RNA , Fatores de Tempo , Transfecção , Carga Tumoral , Ensaio Tumoral de Célula-Tronco , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
4.
J Cell Physiol ; 221(3): 594-602, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19650074

RESUMO

The stress protein p8 is a small, highly basic, unfolded, and multifunctional protein. We have previously shown that most of its functions are exerted through interactions with other proteins, whose activities are thereby enhanced or repressed. In this work we describe another example of such mechanism, by which p8 binds and negatively regulates MSL1, a histone acetyl transferase (HAT)-associated protein, which in turn binds the DNA-damage-associated 53BP1 protein to facilitate DNA repair following DNA gamma-irradiation. Contrary to the HAT-associated activity, MSL1-dependent DNA-repair activity is almost completely dependent on 53BP1 expression. The picture that has emerged from our findings is that 53BP1 could be a scaffold that gets the HAT MSL1-dependent DNA-repair activity to the sites of DNA damage. Finally, we also found that, although p8 expression is transiently activated after gamma-irradiation, it is eventually submitted to sustained down-regulation, presumably to allow development of MSL1-associated DNA-repair activity. We conclude that interaction of MSL1 with 53BP1 brings MSL1-dependent HAT activity to the vicinity of damaged DNA. MSL1-dependent HAT activity, which is negatively regulated by the stress protein p8, induces chromatin remodeling and relaxation allowing access to DNA of the repair machinery.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/fisiologia , Raios gama , Proteínas de Neoplasias/fisiologia , Linhagem Celular , Proliferação de Células , Ensaio de Unidades Formadoras de Colônias , Expressão Gênica/genética , Expressão Gênica/efeitos da radiação , Células HeLa , Histona Acetiltransferases/genética , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Humanos , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Ligação Proteica/fisiologia , RNA Interferente Pequeno/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Ressonância de Plasmônio de Superfície , Transfecção , Proteína 1 de Ligação à Proteína Supressora de Tumor p53 , Técnicas do Sistema de Duplo-Híbrido
5.
Pancreatology ; 9(6): 738-54, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20090395

RESUMO

The current 5-year survival rate of pancreatic cancer is about 3% and the median survival less than 6 months because the chemotherapy and radiation therapy presently available provide only marginal benefit. Clearly, pancreatic cancer requires new therapeutic concepts. Recently, the kinase inhibitors imatinib and gefitinib, developed to treat chronic myelogenous leukaemia and breast cancer, respectively, gave very good results. Kinases are deregulated in many diseases, including cancer. Given that phosphorylation controls cell survival signalling, strategies targeting kinases should obviously improve cancer treatment. The purpose of this review is to summarize the present knowledge on kinases potentially usable as therapeutic targets in the treatment of pancreatic cancer. All clinical trials using available kinase inhibitors in monotherapy or in combination with chemotherapeutic drugs failed to improve survival of patients with pancreatic cancer. To detect kinases relevant to this disease, we undertook a systematic screening of the human kinome to define a 'survival kinase' catalogue for pancreatic cells. We selected 56 kinases that are potential therapeutic targets in pancreatic cancer. Preclinical studies using combined inhibition of PAK7, MAP3K7 and CK2 survival kinases in vitro and in vivo showed a cumulative effect on apoptosis induction. We also observed that these three kinases are rather specific of pancreatic cancer cells. In conclusion, if kinase inhibitors presently available are unfortunately not efficient for treating pancreatic cancer, recent data suggest that inhibitors of other kinases, involved more specifically in pancreatic cancer development, might, in the future, become interesting therapeutic targets.


Assuntos
Neoplasias Pancreáticas/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Ensaios Clínicos como Assunto , Feminino , Humanos , Masculino , Neoplasias Pancreáticas/enzimologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores
6.
Pancreatology ; 9(1-2): 66-72, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19077456

RESUMO

MicroRNAs (miRNAs) are small non-coding RNAs 19-24 nucleotides in length that regulate gene expression of target genes by translational repression. They regulate crucial processes such as development, proliferation, apoptosis, stress response and differentiation. Recent reports support a role for miRNAs in the initiation and progression of human malignancies; in particular, aberrant expression of miRNAs can contribute to carcinogenesis by promoting the expression of proto-oncogenes or by inhibiting the expression of tumor suppressor genes. Large high-throughput studies in patients revealed that miRNA profiling allows classifying tumors with high accuracy and predicting their outcome. In this review, we summarize recent knowledge about miRNA expression in pancreatic ductal adenocarcinoma, their possible molecular implications, and finally, we discuss the possible repercussion of these findings in terms of diagnosis and treatment of this disease.


Assuntos
Adenocarcinoma/genética , MicroRNAs/metabolismo , Neoplasias Pancreáticas/genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/terapia , Humanos , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia
7.
Pancreatology ; 9(3): 267-72, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19407481

RESUMO

BACKGROUND: Genomic alterations present in pancreatic adenocarcinoma have been described only partially. In addition, the relations between these alterations and the aggressiveness of the phenotype remain unknown. METHODS: Genomic DNA and total RNA from 5 pancreatic cell lines, of which 2 have an aggressive phenotype and are gemcitabine-resistant (Mia-Paca2 and Panc-1), and 3 less aggressive and gemcitabine-sensitive (Capan-1, Capan-2 and BxPC3), have been purified. DNA abnormalities have been analyzed using an ultra-high-resolution CGH array and mRNA expression was studied with an Affymetrix GeneChip expression array. RESULTS: We identified 573 amplified and 30 deleted genes common to all 5 cell lines. Some of them have already been described, whereas other genes, implicated in signal transduction, apoptosis, cell cycle or cell migration, are described for the first time as being related to this cancer. Comparison of genomic abnormalities between the 2 most aggressive and the 3 less aggressive cell lines led to the identification of 368 genes specifically amplified in the aggressive cell lines. However, no specific gene deletion seems to be associated with the aggressive phenotype. CONCLUSION: Using a high-resolution approach, we could precisely describe the genomic alterations associated with pancreatic adenocarcinoma and determine those associated with an aggressive phenotype.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Hibridização Genômica Comparativa/métodos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Adenocarcinoma/mortalidade , Linhagem Celular Tumoral , Mapeamento Cromossômico , Cromossomos Humanos/genética , Cromossomos Humanos X , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Resistência a Medicamentos , Variação Genética , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pancreáticas/mortalidade , Fenótipo , RNA Mensageiro/genética , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Sensibilidade e Especificidade , Taxa de Sobrevida , Gencitabina
8.
FASEB J ; 20(12): 1982-91, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17012250

RESUMO

Except for gemcitabine, chemotherapeutic agents are ineffective with pancreatic adenocarcinoma because this cancer is resistant to apoptosis induction. Involvement of specific kinases in such resistance is likely. We developed a systematic strategy to screen the human kinome and select kinases whose inhibition in pancreatic cancer cells can increase 1) spontaneous apoptosis or 2) gemcitabine-induced apoptosis. The pancreatic adenocarcinoma cell line MiaPaCa-2 was transfected with 645 pairs of siRNAs directed to all human kinases. The same experiment was conducted in cells treated with 150 microM gemcitabine. Apoptosis was measured after 2 days and the results were normalized for cell viability. A panel of 56 kinases whose inhibition increased spontaneous apoptosis by at least 50% was established. Ten of them gave similar results on Panc1 and BxPC3 pancreatic adenocarcinoma cell lines. A panel of 83 kinases whose inhibition increased gemcitabine-induced apoptosis by 50% or more was also established. Twelve kinases appeared in both panels. A cumulative increase in apoptosis was observed when inhibiting simultaneously several kinases. Such a systematic approach allowed characterization of all kinases involved in pancreatic cancer cell survival and resistance to gemcitabine. Inhibitors of these kinases, used alone or in combination, might improve the treatment of pancreatic adenocarcinoma.


Assuntos
Apoptose , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Fosfotransferases/antagonistas & inibidores , Antimetabólitos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular , Desoxicitidina/farmacologia , Inibidores Enzimáticos/farmacologia , Genoma Humano , Humanos , Fosfotransferases/farmacologia , RNA Interferente Pequeno/farmacologia , Gencitabina
9.
Intensive Care Med ; 33(9): 1633-6, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17497124

RESUMO

OBJECTIVE: To assess morphological alterations of the pancreas by contrast-enhanced computed tomography (cCT) and subclinical cellular damage of the pancreas by measuring pancreatitis-associated protein (PAP) in critically ill patients without prior pancreatic disorder who presented with raised serum lipase levels. DESIGN: Prospective, observational study SETTING: Mixed surgical/neurosurgical intensive care unit of a German university hospital. PATIENTS: One hundred and thirty consecutive critically ill patients without prior damage or disease of the pancreas and an expected length of stay of more than 5 days. INTERVENTIONS: Daily serum lipase measurements and daily serum PAP measurements. Contrast-enhanced upper abdominal cCT study in patients with triple increase of serum lipase. MEASUREMENTS AND RESULTS: Thirty-eight patients showed raised serum lipase levels and qualified for the cCT scan study. In 20 patients cCT scans were performed. Morphological alterations of the pancreas were found in 7 out these 20 patients while serum PAP levels were raised in all patients. CONCLUSION: Hyperlipasemia is a common finding in critically ill patients without prior pancreatic disorder. While elevated serum PAP levels indicate pancreatic cellular stress morphological alterations of the pancreas are rare and of little clinical importance.


Assuntos
Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/sangue , Lectinas Tipo C/sangue , Lipase/sangue , Pancreatite/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Meios de Contraste , Estado Terminal , Feminino , Humanos , Unidades de Terapia Intensiva , Iopamidol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Pâncreas/diagnóstico por imagem , Pancreatite/sangue , Proteínas Associadas a Pancreatite , Estudos Prospectivos
10.
Clin Cancer Res ; 12(1): 235-41, 2006 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16397047

RESUMO

Gemcitabine is the only available chemotherapeutic treatment of pancreatic cancers. It is, however, moderately effective, showing a tumor response rate of only 12%. The aim of this work was to identify new pathways involved in the resistance of pancreatic cancer cells to gemcitabine, in the hope of developing new adjuvant strategies to enhance its therapeutic efficacy. Comparison of gene expression patterns of five human pancreatic cancer cell lines showing different degrees of resistance to gemcitabine revealed specific overexpression of several genes in the most resistant. One of them encoded the antiapoptotic p8 protein. We found that (a) knocking down p8 expression in gemcitabine-resistant cells promoted cell death and increased caspase-3 activity; (b) forced overexpression of p8 in gemcitabine-sensitive cells increased their resistance to gemcitabine-induced apoptosis; and (c) gemcitabine down-regulated p8 mRNA expression. These results suggest that, in pancreatic cancer cells, a large part of gemcitabine-induced apoptosis results from the inhibition of the constitutive antiapoptotic activity of p8. Hence, targeting the p8-associated pathway could be a new adjuvant therapy improving the response of patients with pancreatic cancer to gemcitabine treatment.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Desoxicitidina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/metabolismo , Apoptose/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/efeitos dos fármacos , Linhagem Celular Tumoral , Desoxicitidina/farmacologia , Citometria de Fluxo , Expressão Gênica , Humanos , Proteínas de Neoplasias/efeitos dos fármacos , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pancreáticas/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Gencitabina
11.
Oncoimmunology ; 7(1): e1372080, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29296524

RESUMO

Vγ9Vδ2 T cells are anti-tumor immune effectors of growing interest in cancer including Pancreatic Ductal Adenocarcinoma (PDAC), an especially aggressive cancer characterized by a hypoxic and nutrient-starved immunosuppressive microenvironment. Since Butyrophilin 3 A (BTN3A) isoforms are critical activating molecules of Vγ9Vδ2 T cells, we set out to study BTN3A expression under both basal and stress conditions in PDAC primary tumors, and in novel patient-derived xenograft and PDAC-derived cell lines. BTN3A2 was shown to be the most abundant isoform in PDAC and was stress-regulated. Vγ9Vδ2 T cells cytolytic functions against PDAC required BTN3A and this activity was strongly enhanced by the agonist anti-BTN3A 20.1 mAb even under conditions of hypoxia. In PDAC primary tumors, we established that BTN3A expression and high plasma levels of soluble BTN3A were strongly associated with a decreased survival. These findings may have important implications in the design of new immunotherapeutic strategies that target BTN3A for treating PDAC.

12.
Oncogene ; 24(55): 8093-104, 2005 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-16044147

RESUMO

TP53INP1 is an alternatively spliced gene encoding two nuclear protein isoforms (TP53INP1alpha and TP53INP1beta), whose transcription is activated by p53. When overexpressed, both isoforms induce cell cycle arrest in G1 and enhance p53-mediated apoptosis. TP53INP1s also interact with the p53 gene and regulate p53 transcriptional activity. We report here that TP53INP1 expression is induced during experimental acute pancreatitis in p53-/- mice and in cisplatin-treated p53-/- mouse embryo fibroblasts (MEFs). We demonstrate that ectopic expression of p73, a p53 homologue, leads to TP53INP1 induction in p53-deficient cells. In turn, TP53INP1s alters the transactivation capacity of p73 on several p53-target genes, including TP53INP1 itself, demonstrating a functional association between p73 and TP53INP1s. Also, when overexpressed in p53-deficient cells, TP53INP1s inhibit cell growth and promote cell death as assessed by cell cycle analysis and colony formation assays. Finally, we show that TP53INP1s potentiate the capacity of p73 to inhibit cell growth, that effect being prevented when the p53 mutant R175H is expressed or when p73 expression is blocked by a siRNA. These results suggest that TP53INP1s are functionally associated with p73 to regulate cell cycle progression and apoptosis, independently from p53.


Assuntos
Proteínas de Transporte/genética , Ciclo Celular/fisiologia , Morte Celular/fisiologia , Cisplatino/farmacologia , Proteínas de Ligação a DNA/genética , Proteínas de Choque Térmico/genética , Proteínas Nucleares/genética , Transcrição Gênica , Doença Aguda , Processamento Alternativo , Animais , Apoptose , Proteínas Reguladoras de Apoptose , Sequência de Bases , Linhagem Celular Tumoral , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Regulação da Expressão Gênica , Genes Supressores de Tumor , Humanos , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Pancreatite/genética , Regiões Promotoras Genéticas , Proteína Tumoral p73 , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor
13.
Biochim Biophys Acta ; 1723(1-3): 8-18, 2005 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-15715980

RESUMO

PSP/Lithostathine/PTP/regI, PAP/p23/HIP, reg1L, regIV and "similar to PAP" are the members of a multifunctional family of secreted proteins containing a C-type lectin-like domain linked to a short N-terminal peptide. The expression of this group of proteins is controlled by complex mechanisms, some members being constitutively expressed in certain tissues while, in others, they require activation by several factors. These members have several apparently unrelated biological effects, depending on the member studied and the target cell. These proteins may act as mitogenic, antiapoptotic or anti-inflammatory factors, can regulate cellular adhesion, promote bacterial aggregation, inhibit CaCO3 crystal growth or increase resistance to antitumoral agents. The presence of specific receptors for these proteins is suggested because biological effects were observed after the addition of purified protein to culture media or after systemic administration to animals, whereas other biological effects could be explained by their biochemical capacity to form homo or heteromers or to form insoluble fibrils at physiological pH.


Assuntos
Proteínas de Ligação ao Cálcio/química , Proteínas do Tecido Nervoso/química , Sequência de Aminoácidos , Animais , Proteínas de Ligação ao Cálcio/análise , Proteínas de Ligação ao Cálcio/fisiologia , Humanos , Litostatina , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/análise , Proteínas do Tecido Nervoso/fisiologia , Transdução de Sinais
14.
Oncogene ; 21(11): 1685-94, 2002 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-11896600

RESUMO

p8 is a stress-induced DNA-binding protein, biochemically related to the architectural chromatin binding HMG protein family and whose function is presently unknown. We obtained fibroblast from mice lacking p8 and found that p8 is involved in cell growth regulation and in apoptosis. p8(-/-) mouse embryonic fibroblasts (MEFs) grow more rapidly than p8(+/+) MEFs. This might be explained by the higher intracellular level and activity of the Cdk2 and Cdk4 observed in p8(-/-) MEFs, which in turn may result, at least in part, from the concomitant decrease observed in the amount of cyclin-dependent kinase inhibitor p27. We also report that p8 mRNA expression is strongly activated in fibroblasts after cell growth arrest induced by serum deprivation or confluence. As expected, MEFs expressing p8 arrest their growth more rapidly after serum deprivation than MEFs lacking p8, which strongly suggests that p8 over-expression is implicated in cell growth arrest. On the other hand, p8(+/+) MEFs are more sensitive than p8(-/-) MEFs to the apoptosis induced by adriamycin treatment. p53 might be involved, as p8 expression increases its intracellular amount and trans-activation capacity. Finally, demonstration that p53 is a negative trans-activator of p8 suggests the presence of a complex autoregulatory loop. In conclusion, p8 is a cell growth inhibitor that facilitates apoptosis induced in fibroblasts by DNA damage.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Ligação a DNA/fisiologia , Doxorrubicina/farmacologia , Substâncias de Crescimento/fisiologia , Proteínas de Neoplasias , Animais , Ciclo Celular , Divisão Celular , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Dano ao DNA , Proteínas de Ligação a DNA/genética , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Substâncias de Crescimento/genética , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/análise , Proteína Supressora de Tumor p53/fisiologia
15.
Mol Cancer ; 4(1): 4, 2005 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-15651998

RESUMO

BACKGROUND: In cancer, cellular transformation is followed by tumour development. Knowledge on the mechanisms of transformation, involving activation of proto-oncogenes and inactivation of tumour-suppressor genes has considerably improved whereas tumour development remains poorly understood. An interesting way of gaining information on tumour progression mechanisms would be to identify genes whose expression is altered during tumour formation. We used the Affymetrix-based DNA microarray technology to analyze gene expression profiles of tumours derived from rasV12/E1A-transformed mouse embryo fibroblasts in order to identify the genes that could be involved in tumour development. RESULTS: Among the 12,000 genes analyzed in this study, only 489 showed altered expression during tumour development, 213 being up-regulated and 276 down-regulated. The genes differentially expressed are involved in a variety of cellular functions, including control of transcription, regulation of mRNA maturation and processing, regulation of protein translation, activation of interferon-induced genes, intracellular signalling, apoptosis, cell growth, angiogenesis, cytoskeleton, cell-to-cell interaction, extracellular matrix formation, metabolism and production of secretory factors. CONCLUSIONS: Some of the genes identified in this work, whose expression is altered upon rasV12/E1A transformation of MEFs, could be new cancer therapeutic targets.


Assuntos
Transformação Celular Neoplásica/genética , Genes Neoplásicos , Neoplasias Experimentais/genética , Proteínas E1A de Adenovirus/metabolismo , Animais , Apoptose , Linhagem Celular Transformada , Proliferação de Células , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Embrião de Mamíferos/citologia , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Masculino , Camundongos , Camundongos Nus , Neoplasias Experimentais/metabolismo , Proteína Oncogênica p21(ras)/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Transdução de Sinais , Transcrição Gênica
16.
Eur J Cell Biol ; 81(5): 294-301, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12067065

RESUMO

The mouse stress-induced protein (SIP) mRNA is activated in the pancreas with acute pancreatitis and in several cell lines in response to various stress agents. The SIP gene is alternatively spliced, generating two proteins (SIP'8 and SIP27). Both proteins, located mainly in the nucleus, promote cell death when overexpressed in vitro. We show that induction by stress agents of the expression of SIP18 and SIP27 mRNAs, observed in human- and mouse-derived cell lines, is absent from cells with deleted, mutated or inactive p53, suggesting that regulation of SIP gene expression is dependent on p53. That hypothesis is consistent with the presence of a functional p53-response element within the promoter region of the mouse SIP gene and confirmed by the induction of SIP mRNA expression in mouse embryo fibroblasts upon activation of a p53-dependent pathway by transfection with rasV12 or rasV12/E1A. In conclusion, SIP being a proapoptotic gene induced through p53 activation could be a stress-induced gene with antitumour properties.


Assuntos
Proteínas de Transporte/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Sequência de Aminoácidos , Animais , Antineoplásicos/metabolismo , Proteínas Reguladoras de Apoptose , Proteínas de Transporte/genética , Transformação Celular Neoplásica , Células Cultivadas , Clonagem Molecular , Doxorrubicina/metabolismo , Fibroblastos/citologia , Fibroblastos/fisiologia , Genes Reporter , Proteínas de Choque Térmico/genética , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Alinhamento de Sequência , Distribuição Tecidual , Transcrição Gênica , Proteína Supressora de Tumor p53/genética , Proteínas ras/genética , Proteínas ras/metabolismo
17.
Mol Cancer ; 2: 19, 2003 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-12685932

RESUMO

BACKGROUND: Ras is an area of intensive biochemical and genetic studies and characterizing downstream components that relay ras-induced signals is clearly important. We used a systematic approach, based on DNA microarray technology to establish a first catalog of genes whose expression is altered by ras and, as such, potentially involved in the regulation of cell growth and transformation. RESULTS: We used DNA microarrays to analyze gene expression profiles of rasV12/E1A-transformed mouse embryonic fibroblasts. Among the approximately 12,000 genes and ESTs analyzed, 815 showed altered expression in rasV12/E1A-transformed fibroblasts, compared to control fibroblasts, of which 203 corresponded to ESTs. Among known genes, 202 were up-regulated and 410 were down-regulated. About one half of genes encoding transcription factors, signaling proteins, membrane proteins, channels or apoptosis-related proteins was up-regulated whereas the other half was down-regulated. Interestingly, most of the genes encoding structural proteins, secretory proteins, receptors, extracellular matrix components, and cytosolic proteins were down-regulated whereas genes encoding DNA-associated proteins (involved in DNA replication and reparation) and cell growth-related proteins were up-regulated. These data may explain, at least in part, the behavior of transformed cells in that down-regulation of structural proteins, extracellular matrix components, secretory proteins and receptors is consistent with reversion of the phenotype of transformed cells towards a less differentiated phenotype, and up-regulation of cell growth-related proteins and DNA-associated proteins is consistent with their accelerated growth. Yet, we also found very unexpected results. For example, proteases and inhibitors of proteases as well as all 8 angiogenic factors present on the array were down-regulated in transformed fibroblasts although they are generally up-regulated in cancers. This observation suggests that, in human cancers, proteases, protease inhibitors and angiogenic factors could be regulated through a mechanism disconnected from ras activation. CONCLUSIONS: This study established a first catalog of genes whose expression is altered upon fibroblast transformation by rasV12/E1A. This catalog is representative of the genome but not exhaustive, because only one third of expressed genes was examined. In addition, contribution to ras signaling of post-transcriptional and post-translational modifications was not addressed. Yet, the information gathered should be quite useful to future investigations on the molecular mechanisms of oncogenic transformation.


Assuntos
Proteínas E1A de Adenovirus/metabolismo , Transformação Celular Neoplásica/genética , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Proteína Oncogênica p21(ras)/metabolismo , Proteínas E1A de Adenovirus/genética , Animais , Linhagem Celular Transformada , Regulação para Baixo , Etiquetas de Sequências Expressas , Regulação Neoplásica da Expressão Gênica , Camundongos , Proteína Oncogênica p21(ras)/genética , Regulação para Cima
18.
BMC Gastroenterol ; 3: 25, 2003 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-12959645

RESUMO

BACKGROUND: p8 is a DNA-binding protein induced in many tissues in response to LPS treatment. Hence, p8 could be a mediator of LPS-associated effects or, on the contrary, p8 expression may be part of the protective mechanism of the tissues in response to LPS. Finally, p8 expression in response to LPS could also be a simple epiphenomenon. METHODS: To investigate the role of p8 in vivo, we generated p8-deficient mice by gene targeting. Because p8 is a stress protein, we analyzed the response of p8-/- mice to a systemic stress induced by LPS injection. Liver was chosen as model organ to monitor alterations in gene expression. RESULTS: LPS resulted in higher serum TNF-alpha concentration and higher mortality rate in p8-deficient mice than in wild-type. Also, liver and pancreas, but not lung, from p8-/- mice showed increased amounts of MPO and HPO. To gain insight into the molecular bases of such susceptibility, we used high density DNA microarrays consisting of ~6000 genes and ESTs to compare gene regulation in response to LPS in p8+/+ and p8-/- livers. In wild-type, 105 genes and 73 ESTs were up-regulated and 232 genes and 138 ESTs down-regulated. By contrast, 212 genes and 125 ESTs were found up-regulated and 90 genes and 85 ESTs down regulated in p8-/- mice. Among them, only 93 (51 induced and 42 repressed) corresponded to the wild-type pattern, demonstrating that p8 deficiency hinders the normal response to LPS, which may account for the increased sensitivity of p8-/-mice to the endotoxin. CONCLUSIONS: The large number of genes showing abnormal regulation after LPS suggests that p8 is an important regulatory factor involved in many cellular defence pathways.


Assuntos
Proteínas de Ligação a DNA/genética , Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Fígado/efeitos dos fármacos , Proteínas de Neoplasias , Animais , Proteínas de Ligação a DNA/metabolismo , Expressão Gênica/genética , Proteína HMGB1/metabolismo , Peróxido de Hidrogênio/metabolismo , Fígado/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Peroxidase/metabolismo , Estresse Fisiológico/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
19.
Gastroenterol Clin Biol ; 26(1): 23-8, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11938036

RESUMO

BACKGROUND AND AIMS: Pancreatitis-associated protein (PAP) is a pancreatic stress protein also expressed in the ileum but not in the colon. Its serum concentration is increased in patients with small bowel inflammation due to untreated celiac disease. We searched to determine whether PAP could be a serum marker for ileal location of active Crohn's disease (CD). METHODS: A multicenter prospective study was conducted, including 54 healthy controls and 124 patients with CD of whom 38 had quiescent ileal or ileocolonic disease (group A), 45 had active ileal or ileocolonic disease (group B), 18 had quiescent colon-only CD (group C), and 28 had active colonic disease (group D). Active disease was defined by a Crohn's disease activity index > 150 and serum C-reactive protein (CRP) > 10 mg/mL. Location of lesions was assessed by endoscopy. PAP was assayed in serum, the upper threshold for normal values being 50 ng/mL. RESULTS: In group B, 27 patients (60%) had elevated serum PAP, compared to one in group A (2.5%), one in group C (5.3%), three in group D (10.7%) and none in the control group (P<0.01). By contrast, serum levels of C-reactive protein did not differ between patients with active CD and either ileal location (group B) or pure colonic location (group D) (38 +/-10.5 vs 41.6 +/- 6.4 mg/mL, NS). Within group B, serum PAP concentration was correlated with none of the epidemiological, clinical or biological data available. Increased serum level of PAP diagnosed ileal location in active CD with a sensitivity of 60%, a specificity of 94%, a positive predictive value of 84% and a negative predictive value of 81%. CONCLUSION: Elevated serum PAP (> 50 ng/mL ) is significantly associated with disease activity and ileal location


Assuntos
Proteínas de Fase Aguda/análise , Antígenos de Neoplasias , Biomarcadores Tumorais , Biomarcadores/sangue , Doença de Crohn/sangue , Íleo/patologia , Lectinas Tipo C , Adolescente , Adulto , Doença de Crohn/epidemiologia , Doença de Crohn/patologia , Feminino , Humanos , Masculino , Proteínas Associadas a Pancreatite , Estudos Prospectivos , Valores de Referência , Sensibilidade e Especificidade
20.
Gastroenterol Clin Biol ; 27(10): 895-900, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14631304

RESUMO

BACKGROUND AND AIM: Recent clinical data suggest that pancreatitis could be an extraintestinal manifestation of inflammatory bowel disease. However, no experimental data support such a clinical relationship. The aim of this study was to investigate the presence of pancreatic damages in mice with TNBS-induced colitis. METHODS: Colitis was induced in Balb/C mice by intrarectal instillation of TNBS. Control mice received either intrarectal instillation of NaCl saline solution or 50% ethanol. Presence of colitis was assessed by macroscopic and microscopic examination, extent of mucosal damage being evaluated by the scoring systems of Wallace and Ameho in 8 mice with TNBS-induced colitis and in 4 controls. Pancreatic samples from the same mice underwent morphological examination after standard coloration. Intrapancreatic expression of the pancreatitis-associated protein (PAP), a marker of pancreatic inflammation, was monitored by automated immunohistochemistry using specific antibodies. In addition, quantification of TNFalpha mRNA by competitive PCR and semi-quantification of PAP, IL-10 and IL-1B mRNAs were performed on pancreas in 10 mice with TNBS-induced colitis and in 10 control mice. RESULTS: All mice treated with TNBS and none of the controls had colitis. Macroscopic and microscopic examination of the pancreas of the 4 control mice was normal, whereas in 5 out of the 8 TNBS-treated mice histological changes were observed, with inflammatory infiltrate and fibrin aggregates at the periphery of the gland. PAP immunohistochemistry was negative in all control mice and positive in all mice with TNBS-induced colitis, with a patchy distribution of staining. PAP immunolocalized to the cytoplasm of acinar cells, duct cells and islets of Langherans being negative. PAP and IL-1B mRNA levels in the pancreas were significantly increased but the increase in TNFalpha mRNA level did not reach statistical significance (P=0.06). IL-10 mRNA levels did not show any significant modification. CONCLUSION: PAP overexpression in pancreas demonstrates that inflammatory stress early occurs in the mouse pancreas during the course of TNBS-induced colitis. The concomitant pancreatic overexpression of IL-1B and, to a lesser extent, of TNFalpha, two proinflammatory cytokines also associated with the intestinal lesions of colitis, supported a pancreatic inflammatory mechanism mediated by cytokines.


Assuntos
Colite/patologia , Pâncreas/patologia , Animais , Colite/induzido quimicamente , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Associadas a Pancreatite , Ácido Trinitrobenzenossulfônico/administração & dosagem
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