Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 6: 21211, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26887806

RESUMO

Endocrine and exocrine pancreas tissues are both derived from the posterior foregut endoderm, however, the interdependence of these two cell types during their formation is not well understood. In this study, we generated mutant mice, in which the exocrine tissue is hypoplastic, in order to reveal a possible requirement for exocrine pancreas tissue in endocrine development and/or function. Since previous studies showed an indispensable role for Pdx1 in pancreas organogenesis, we used Elastase-Cre-mediated recombination to inactivate Pdx1 in the pancreatic exocrine lineage during embryonic stages. Along with exocrine defects, including impaired acinar cell maturation, the mutant mice exhibited substantial endocrine defects, including disturbed tip/trunk patterning of the developing ductal structure, a reduced number of Ngn3-expressing endocrine precursors, and ultimately fewer ß cells. Notably, postnatal expansion of the endocrine cell content was extremely poor, and the mutant mice exhibited impaired glucose homeostasis. These findings suggest the existence of an unknown but essential factor(s) in the adjacent exocrine tissue that regulates proper formation of endocrine precursors and the expansion and function of endocrine tissues during embryonic and postnatal stages.


Assuntos
Diabetes Mellitus/metabolismo , Células Secretoras de Insulina/metabolismo , Integrases , Pâncreas Exócrino/metabolismo , Elastase Pancreática , Transativadores/deficiência , Animais , Diabetes Mellitus/embriologia , Diabetes Mellitus/genética , Proteínas de Homeodomínio , Camundongos , Camundongos Knockout , Pâncreas Exócrino/embriologia
2.
Int J Clin Oncol ; 21(1): 118-25, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26123314

RESUMO

BACKGROUND: We aimed to construct a prognostic model to predict survival in patients with advanced pancreatic cancer (APC) receiving palliative chemotherapy using readily available pretreatment factors. METHODS: The model was constructed using data from 306 consecutive patients with APC who received palliative chemotherapy between January 2006 and March 2013. The predictive accuracy of the model was assessed using a concordance index (c-index) and calibration curves. RESULTS: Among the 12 potential prognostic factors investigated, multivariate analysis identified the following six independent negative prognostic factors-performance status (PS), the presence of distant metastatic disease, the status of initially unresectable disease, carcinoembryonic antigen (CEA) level, carbohydrate antigen 19-9 (CA19-9) level, and neutrophil-lymphocyte ratio (NLR). A prognostic index (PI) based on the coefficients of these factors was constructed as follows-PI = 2 (if PS 2-3) + 1 (if distant metastatic disease) + 1 (if initially unresectable disease) + 1 (if CEA level ≥5.0 ng/ml) + 1 (if CA 19-9 level ≥1,000 U/ml) + 2 (if NLR ≥5). The patients were classified into three prognostic groups-favorable (PI 0-1, n = 73), intermediate (PI 2-3, n = 145), and poor (PI 4-8, n = 88). The median overall survival times for each prognostic group were 16.5, 12.3, and 6.2 months, respectively (P < 0.001). Bootstrapping verified the good fitness of this model for predicting 1-year survival, and the c-index was 0.658. CONCLUSIONS: This simple prognostic model could help clinicians to estimate survival in patients with APC who receive palliative chemotherapy.


Assuntos
Antineoplásicos/uso terapêutico , Modelos Teóricos , Cuidados Paliativos , Neoplasias Pancreáticas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno CA-19-9/sangue , Antígeno Carcinoembrionário/sangue , Feminino , Nível de Saúde , Humanos , Contagem de Linfócitos , Linfócitos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Metástase Neoplásica , Neutrófilos , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Valor Preditivo dos Testes , Prognóstico , Taxa de Sobrevida
3.
JOP ; 15(6): 622-5, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25435584

RESUMO

CONTEXT: Pancreatic neuroendocrine tumor (P-NET) is a rare and slow-growing tumor. Unfortunately, there is no clear consensus on the role and timing of surgery for primary tumor and liver metastases, although current reports refer to liver surgery including LT for unresectable liver metastases. CASE REPORT: A thirty-nine-year-old man was diagnosed with nonfunctioning pancreatic neuroendocrine tumor (P-NET) in the pancreatic head, with multiple liver metastases. The tumor was 2.5 cm in diameter and he was asymptomatic. Small but multiple metastases were detected in the liver, and no extrahepatic metastases were observed. We initially intended to control the liver metastases before resection of the primary tumor. To begin with, transarterial chemoembolization (TACE) and transcatheter arterial infusion (TAI) were repeated. Thereafter, systemic chemotherapy and biotherapy were introduced according to follow-up assessments. Unfortunately, imaging assessment at about 10 months later revealed that liver metastases were partially enlarged, although some were successfully treated. Therefore, these therapies were switched to other regimens, and TACE/TAI, systemic chemotherapies and biotherapies were repeated. Although liver metastases seemed to be stable for a while, the primary tumor was enlarged even after therapy. At 3.5 years after initial diagnosis, the primary tumor became symptomatic (pain and jaundice). Liver metastases enlarged and massive swelling of the para-aortic lymph nodes was observed. Thereafter, palliative therapy was the main course of action. He died at 4.3 years after initial diagnosis. CONCLUSION: Our young patient could have been a candidate for initial surgery for primary tumor and might have had a chance of subsequent liver transplantation for unresectable metastases. Surgeons still face questions in deciding the best surgical scenario in patients with P-NET with liver metastases.

4.
Clin Nucl Med ; 39(4): e277-80, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23676658

RESUMO

We report a 74-year-old man with intraductal tubulopapillary neoplasm (ITPN), a rare primary intraductal neoplasm of the pancreas. Focal intense uptake of 18F-FDG was seen on the initial PET, corresponding to a pancreatic mass. Although the patient had no treatment, the uptake was mild to moderate on a second PET performed about 1 month later. The tumor was resected, with the final diagnosis of ITPN with an associated invasive carcinoma. Clinicians should be aware that decreased uptake of FDG during the follow-up period without treatment can occur even in malignant tumors.


Assuntos
Fluordesoxiglucose F18/metabolismo , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/metabolismo , Idoso , Transporte Biológico , Humanos , Masculino , Neoplasias Pancreáticas/cirurgia , Tomografia por Emissão de Pósitrons
5.
Pancreas ; 43(1): 7-14, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24212241

RESUMO

OBJECTIVES: SRY (sex determining region Y) box 9 (SOX9) plays a key role in the embryologic development, differentiation, and maintenance of organs in the pancreas as well as progression of several kinds of tumors. The aim of the present study was to evaluate the expression and potential role of SOX9 in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. METHODS: The authors selected 27 pathological tissues from 19 IPMN cases to assess the expression of SOX9 by means of immunohistochemistry and analyzed the expression pattern of SOX9 with 78 lesions obtained from these tissues stained by SOX9. RESULTS: SOX9 was expressed in the normal pancreas, IPMN, and pancreatic ductal adenocarcinoma. SOX9-positive cells were confined to the lower portions of the papillary structures of IPMN. However, SOX9 was expressed in the entire epithelium once the neoplasms advanced to high-grade dysplasia and invasive carcinoma. The expression pattern of SOX9 was similar to that of CD44 in the normal pancreas and IPMN. Double staining of SOX9 and CD44 detected colocalization of SOX9 and CD44 in IPMN. CONCLUSIONS: Changes in the SOX9 expression pattern may be involved in the mechanisms of the malignant progression of IPMN.


Assuntos
Adenocarcinoma Mucinoso/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Papilar/metabolismo , Neoplasias Pancreáticas/metabolismo , Fatores de Transcrição SOX9/biossíntese , Adenocarcinoma Mucinoso/patologia , Idoso , Carcinoma Ductal Pancreático/patologia , Carcinoma Papilar/patologia , Feminino , Humanos , Receptores de Hialuronatos/biossíntese , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia
6.
Pathol Int ; 63(9): 469-75, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24200159

RESUMO

The combination of exocrine and neuroendocrine neoplasms is rarely found in the pancreas. These combined lesions vary from a clonal tumor with mixed differentiation to the incidental co-existence of two or more independent tumors, but the differential diagnosis is sometimes difficult. Here we report a case of multiple endocrine neoplasia type 1 (MEN1) with extensive ductal and neuroendocrine neoplastic changes. These two types of tumors admixed markedly in some parts, which made it difficult to determine the pathological diagnosis based on histological findings. Cytogenetic analysis showed that loss of heterozygosity (LOH) of the MEN1 locus exists in neuroendocrine but not in exocrine neoplasms, indicating that independent mechanisms of tumorigenesis may occur in these two types of tumors. This case shows the usefulness of cytogenetic analysis for the diagnosis of combined tumors of the pancreas. Extensive exocrine neoplastic change, including pancreatic intraepithelial neoplasia (PanIN) in virtually all pancreatic ducts and a focus of intraductal papillary mucinous neoplasm (IPMN) with focal invasion, was a distinguishing feature of the present case. The possible association of ductal tumorigenesis and a MEN1 background is discussed.


Assuntos
Carcinoma in Situ/patologia , Carcinoma Neuroendócrino/patologia , Perda de Heterozigosidade/genética , Neoplasia Endócrina Múltipla Tipo 1/patologia , Neoplasias Primárias Múltiplas/patologia , Neoplasias Pancreáticas/patologia , Idoso , Carcinoma in Situ/genética , Carcinoma Neuroendócrino/genética , Análise Citogenética/métodos , Feminino , Humanos , Neoplasia Endócrina Múltipla Tipo 1/genética , Mutação/genética , Neoplasias Primárias Múltiplas/genética , Pâncreas Exócrino/patologia , Ductos Pancreáticos/patologia , Neoplasias Pancreáticas/genética
7.
Cancer Chemother Pharmacol ; 71(6): 1521-30, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23543271

RESUMO

BACKGROUND: A growing number of preclinical studies have demonstrated that curcumin could be a promising anticancer drug; however, poor bioavailability has been the major obstacle for its clinical application. To overcome this problem, we developed a new form of curcumin (Theracurmin) and reported high plasma curcumin levels could be safely achieved after a single administration of Theracurmin in healthy volunteers. In this study, we aimed to evaluate the safety of repetitive administration of Theracurmin in cancer patients. METHODS: Pancreatic or biliary tract cancer patients who failed standard chemotherapy were eligible for this study. Based on our previous pharmacokinetic study, we selected Theracurmin containing 200 mg of curcumin (Level 1) as a starting dose, and the dose was safely escalated to Level 2, which contained 400 mg of curcumin. Theracurmin was orally administered every day with standard gemcitabine-based chemotherapy. In addition to safety and pharmacokinetics data, NF-κB activity, cytokine levels, efficacy, and quality-of-life score were evaluated. RESULTS: Ten patients were assigned to level 1 and six were to level 2. Peak plasma curcumin levels (median) after Theracurmin administration were 324 ng/mL (range, 47-1,029 ng/mL) at Level 1 and 440 ng/mL (range, 179-1,380 ng/mL) at Level 2. No unexpected adverse events were observed and 3 patients safely continued Theracurmin administration for >9 months. CONCLUSIONS: Repetitive systemic exposure to high concentrations of curcumin achieved by Theracurmin did not increase the incidence of adverse events in cancer patients receiving gemcitabine-based chemotherapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Neoplasias do Sistema Biliar/tratamento farmacológico , Curcumina/efeitos adversos , Curcumina/farmacocinética , Neoplasias Pancreáticas/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/química , Neoplasias do Sistema Biliar/metabolismo , Neoplasias do Sistema Biliar/mortalidade , Disponibilidade Biológica , Curcumina/administração & dosagem , Curcumina/química , Citocinas/antagonistas & inibidores , Citocinas/imunologia , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Esquema de Medicação , Composição de Medicamentos , Estabilidade de Medicamentos , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , NF-kappa B/antagonistas & inibidores , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/mortalidade , Qualidade de Vida , Solubilidade
8.
Surg Today ; 43(10): 1180-4, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23188387

RESUMO

Living donor liver transplantation (LDLT) for Budd-Chiari syndrome (BCS) presents a unique challenge as it does not involve replacement of the hepatic inferior vena cava (IVC). We report a case of successful LDLT in a patient with BCS associated with occlusion of the hepatic veins as well as the IVC. A 34-year-old woman with a history of two open pericardial procedures had decompensated liver failure and portal hypertension. Venography showed complete obstruction of the hepatic IVC and well-developed collateral vessels. We performed LDLT via sternotomy and laparotomy, with an end-to-end anastomosis between the left hepatic vein of the donor and the patient's suprahepatic vena cava in the pericardium. The patient recovered uneventfully and has been doing well for 5 years. LDLT without caval replacement for BCS in a patient with hepatic IVC obstruction is feasible if the patient has good functional collaterals before liver transplantation.


Assuntos
Síndrome de Budd-Chiari/cirurgia , Transplante de Fígado/métodos , Fígado/irrigação sanguínea , Doadores Vivos , Pericárdio/cirurgia , Veia Cava Inferior/cirurgia , Adulto , Anastomose Cirúrgica/métodos , Feminino , Veias Hepáticas/cirurgia , Humanos , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/métodos
9.
Nihon Geka Gakkai Zasshi ; 113(5): 451-5, 2012 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-23061368

RESUMO

Beta cell replacement by islet transplantation is a promising clinical therapy for patients with type 1 diabetes because it satisfies safety issues and offers reliability in controlling blood glucose levels. One remaining problem is that it requires islets from two to three donor pancreases to achieve insulin independence, thus aggravating the donor shortage. Islet regeneration in vivo and generation of beta cells ex vivo followed by transplantation represent attractive therapeutic methods to restore the beta cell mass. Recent studies have suggested a number of postnatal pancreatic epithelial cells as candidate sources for future beta cell replacement therapy. Beta cells can reenter the cell cycle after a brief quiescent stage, suggesting the potential for engineering for expansion. The mechanisms of alpha cell-to-beta cell transdifferentiation can also be utilized to increase the beta cell population. Pancreatic ductal cells can proliferate and differentiate into regenerated beta cells. Pancreatic acinar cells are also observed to transdifferentiate into endocrinal cells, although infrequently under in vivo conditions. After a few more series of careful studies performed on human cells, the ultimate goal of translation to the clinic appears to be just around the corner. Islet cell transplantation will become a welcome new form of cell-regeneration therapy.


Assuntos
Engenharia Celular/métodos , Diabetes Mellitus Tipo 1/terapia , Células Secretoras de Insulina/transplante , Animais , Humanos
10.
Nat Genet ; 43(1): 34-41, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21113154

RESUMO

The liver and exocrine pancreas share a common structure, with functioning units (hepatic plates and pancreatic acini) connected to the ductal tree. Here we show that Sox9 is expressed throughout the biliary and pancreatic ductal epithelia, which are connected to the intestinal stem-cell zone. Cre-based lineage tracing showed that adult intestinal cells, hepatocytes and pancreatic acinar cells are supplied physiologically from Sox9-expressing progenitors. Combination of lineage analysis and hepatic injury experiments showed involvement of Sox9-positive precursors in liver regeneration. Embryonic pancreatic Sox9-expressing cells differentiate into all types of mature cells, but their capacity for endocrine differentiation diminishes shortly after birth, when endocrine cells detach from the epithelial lining of the ducts and form the islets of Langerhans. We observed a developmental switch in the hepatic progenitor cell type from Sox9-negative to Sox9-positive progenitors as the biliary tree develops. These results suggest interdependence between the structure and homeostasis of endodermal organs, with Sox9 expression being linked to progenitor status.


Assuntos
Mucosa Intestinal/metabolismo , Fígado/metabolismo , Pâncreas/metabolismo , Fatores de Transcrição SOX9/metabolismo , Células-Tronco/metabolismo , Animais , Diferenciação Celular , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Intestinos/citologia , Fígado/citologia , Camundongos , Camundongos Knockout , Pâncreas/citologia , Fatores de Transcrição SOX9/genética , Células-Tronco/citologia
11.
Diabetes ; 57(9): 2421-31, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18591390

RESUMO

OBJECTIVE: Most pancreatic endocrine cells derive from Ptf1a-expressing progenitor cells. In humans, nonsense mutations in Ptf1a have recently been identified as a cause of permanent neonatal diabetes associated with pancreatic agenesis. The death of Ptf1a-null mice soon after birth has not allowed further insight into the pathogenesis of the disease; it is therefore unclear how much pancreatic endocrine function is dependent on Ptf1a in mammals. This study aims to investigate gene-dosage effects of Ptf1a on pancreas development and function in mice. RESEARCH DESIGN AND METHODS: Combining hypomorphic and null alleles of Ptf1a and Cre-mediated lineage tracing, we followed the cell fate of reduced Ptf1a-expressing progenitors and analyzed pancreas development and function in mice. RESULTS: Reduced Ptf1a dosage resulted in pancreatic hypoplasia and glucose intolerance with insufficient insulin secretion in a dosage-dependent manner. In hypomorphic mutant mice, pancreatic bud size was small and substantial proportions of pancreatic progenitors were misspecified to the common bile duct and duodenal cells. Growth with branching morphogenesis and subsequent exocrine cytodifferentiation was reduced and delayed. Total beta-cell number was decreased, proportion of non-beta islet cells was increased, and alpha-cells were abnormally intermingled with beta-cells. Interestingly, Pdx1 expression was decreased in early pancreatic progenitors but elevated to normal level at the mid-to-late stages of pancreatogenesis. CONCLUSIONS-The dosage of Ptf1a is crucial for pancreas specification, growth, total beta-cell number, islet morphogenesis, and endocrine function. Some neonatal diabetes may be caused by mutation or single nucleotide polymorphisms in the Ptf1a gene that reduce gene expression levels.


Assuntos
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Dosagem de Genes , Regulação da Expressão Gênica no Desenvolvimento , Ilhotas Pancreáticas/anormalidades , Fatores de Transcrição/genética , Animais , Tamanho Corporal , Divisão Celular/fisiologia , Duodeno/citologia , Intolerância à Glucose/genética , Intolerância à Glucose/patologia , Proteínas de Homeodomínio/genética , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/patologia , Ilhotas Pancreáticas/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Pâncreas Exócrino/anormalidades , Pâncreas Exócrino/patologia , Pâncreas Exócrino/fisiologia , Células-Tronco/citologia , Transativadores/genética
12.
PLoS One ; 3(5): e2261, 2008 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-18493308

RESUMO

While Blood vessel epicardial substance (Bves) confers adhesive properties, the molecular mechanism of regulating this activity is unknown. No predicted functional motifs in this highly conserved integral membrane protein, other than the transmembrane domain, have been identified. Here, we report for the first time that Bves interacts with itself through an intracellular interaction domain that is essential for its intercellular adhesion activity. Glutathione-S-transferase (GST) pull-down and SPOTs analyses mapped this domain to amino acids 268-274 in the intracellular C-terminus. Site-directed mutagenesis revealed that lysines 272 and 273 are essential for homodimerization and cell adhesion. Human corneal cells transfected with wild-type Bves trafficked the protein to the cell surface, assembled junction complexes and formed epithelial sheets. In contrast, cells expressing Bves mutated at these positions did not form continuous epithelial sheets or maintain junctional proteins such as ZO-1 and E-cadherin at the membrane. A dramatic reduction in transepithelial electrical resistance was also observed indicating a functional loss of tight junctions. Importantly, expression of mutated Bves in epithelial cells promoted the transformation of cells from an epithelial to a mesenchymal phenotype. This study is the first to demonstrate the essential nature of any domain within Bves for maintenance of epithelial phenotype and function.


Assuntos
Vasos Sanguíneos/fisiologia , Proteínas de Membrana/fisiologia , Animais , Células COS , Moléculas de Adesão Celular , Chlorocebus aethiops , Córnea/irrigação sanguínea , Glutationa Transferase/química , Glutationa Transferase/genética , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas Musculares , Mutagênese Sítio-Dirigida
13.
Dev Dyn ; 236(11): 2973-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17948313

RESUMO

Mesothelia comprise the epithelial covering of coelomic organs and line the cavities in which they are housed. Mesothelia contribute to the vasculature of the heart and the intestinal tract by developmental processes of epithelial-mesenchymal transition (EMT), migration, and differentiation into endothelial cells, vascular smooth muscle cells, and pericytes. Here, we establish a novel in vitro system to analyze the differentiative potential of mesothelia. Using explants from serosal mesothelium (the mesothelial covering of the gut), we demonstrate that much of the developmental program observed in embryonic mesothelia is retained in the adult structure. Namely, processes of epithelial spreading, EMT, and differentiation into smooth muscle cells from these cells are observed. Interestingly, we were unable to stimulate endothelial cell differentiation using serum or various signaling factors. Taken together, these data reveal that differentiated serosal cells retain vasculogenic potential and provide a generalizable model for future studies on the developmental and differentiative capacity of the mesothelial cell type.


Assuntos
Diferenciação Celular , Células Epiteliais/citologia , Músculo Liso Vascular/citologia , Membrana Serosa/citologia , Actinas/metabolismo , Animais , Becaplermina , Vasos Sanguíneos , Células Cultivadas , Desmina/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Epitélio/fisiologia , Fatores de Crescimento de Fibroblastos/metabolismo , Queratinas/metabolismo , Camundongos , Músculo Liso Vascular/metabolismo , Miosinas/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Proto-Oncogênicas c-sis , Membrana Serosa/fisiologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Proteínas WT1/metabolismo
14.
Surgery ; 136(3): 686-92, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15349119

RESUMO

BACKGROUND: Vascular endothelial growth factor (VEGF), a dominant angiogenic factor in gastric cancer, is upregulated by cytokines in the tumor microenvironment. Interleukin-1beta (IL-1beta), a proinflammatory cytokine, has been shown to be proangiogenic in vivo, despite its not demonstrating angiogenic activity in vitro. We hypothesized that IL-1beta regulates VEGF expression in human gastric cancer cells and investigated the mechanism by which this occurs. METHODS: We treated the TMK-1 human gastric cancer cell line with IL-1beta for 1 to 24 hours, and then analyzed VEGF mRNA expression by Northern blotting and signaling intermediates by Western blotting. Signaling inhibitors were used to identify the dominant pathways involved in IL-1beta induction of VEGF. VEGF promoter-luciferase constructs and transcription blockers were used to investigate the transcriptional regulation of VEGF by IL-1beta. RESULTS: Treating TMK-1 cells with IL-1beta increased VEGF mRNA levels and activated extracellular signal-regulated kinases 1 and 2 (Erk 1/2) and p38, but not Akt. Inhibitors of the Erk and p38 pathways blocked IL-1beta induction of VEGF mRNA. Treating TMK-1 cells with IL-1beta also increased VEGF promoter activity. VEGF transcriptional activity was found to depend on a 120-bp region just proximal to the transcription start site. CONCLUSIONS: In human gastric cancer cells, IL-1beta induced VEGF through Erk- and p38-dependent pathways; this induction of VEGF was transcriptionally regulated.


Assuntos
Interleucina-1/fisiologia , Neoplasias Gástricas/fisiopatologia , Fatores de Crescimento do Endotélio Vascular/biossíntese , Linhagem Celular Tumoral , Regulação da Expressão Gênica/genética , Humanos , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Transdução de Sinais/fisiologia , Transcrição Gênica/genética , Proteínas Quinases p38 Ativadas por Mitógeno
15.
Cancer Res ; 63(12): 3370-7, 2003 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-12810673

RESUMO

Angiopoietin (Ang)-1 and -2 are critical regulators of embryonic and postnatal neovascularization. Ang-1 activates the endothelial cell-specific tyrosine kinase receptor Tie-2, which in turn leads to enhanced endothelial cell survival and stabilization. The effects of Ang-1 on tumor angiogenesis remain controversial; although we have previously demonstrated that Ang-1 overexpression in colon cancer cells leads to a decrease in s.c. tumor growth, others have shown that Ang-1 may be proangiogenic. Few studies have addressed the role of the Angs in tumors growing in the organ of metastatic growth. We hypothesized that overexpression of Ang-1 may inhibit the growth of colon cancers growing in the liver by inhibition of angiogenesis. We also wanted to investigate the mechanisms by which Ang-1 affects angiogenesis in vivo. Human colon cancer cells (HT29) were stably transfected with an Ang-1 construct or an empty vector (pcDNA) and injected directly into the livers of nude mice. After 37 days, livers were harvested and weighed, and tumor sizes were measured. In an additional experiment, to validate the paracrine effect of Ang-1, various mixtures of control cells and Ang-1-transfected cells were injected into livers, and tumor growth was assessed. Direct effects of recombinant Ang-1 on angiogenesis were studied with an in vivo Gelfoam angiogenesis assay. The impact of Ang-1 on vascular permeability was investigated using an intradermal Miles assay with conditioned media from transfected cells. Liver weights (P < 0.05), tumor volumes (P < 0.05), vessel counts (P < 0.01), and tumor cell proliferation (P < 0.01) in the Ang-1 group were significantly lower than those in the control (pcDNA) group. Tumor vessels in the Ang-1 group developed a significantly higher degree of pericyte coverage (P < 0.02) than vessels in pcDNA tumors. In the cell mixture experiment, even as few as a 1:10 mixture of Ang-1-transfected cells/control cells resulted in a significant reduction of hepatic tumor volumes (P < 0.04). In the angiogenesis assay, vessel counts in Gelfoam implants were significantly decreased by the addition of Ang-1 (P < 0.01). Finally, conditioned medium from Ang-1-transfected cells decreased vascular permeability more than that from control cells (P < 0.05). Our results suggest that Ang-1 is an important regulator of angiogenesis and vascular permeability and that this effect may be secondary to increasing periendothelial support and vessel stabilization. Thus, Ang-1 could potentially serve as an antineoplastic or anti-permeability agent for patients with metastatic colorectal cancer.


Assuntos
Indutores da Angiogênese/fisiologia , Permeabilidade Capilar/fisiologia , Neoplasias do Colo/patologia , Terapia Genética , Neoplasias Hepáticas Experimentais/secundário , Glicoproteínas de Membrana/fisiologia , Neovascularização Patológica/terapia , Indutores da Angiogênese/genética , Indutores da Angiogênese/uso terapêutico , Angiopoietina-1 , Animais , Técnicas de Cocultura , Meios de Cultivo Condicionados/farmacologia , Humanos , Neoplasias Hepáticas Experimentais/irrigação sanguínea , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Comunicação Parácrina , Pericitos/patologia , Fosforilação , Processamento de Proteína Pós-Traducional , Receptores Proteína Tirosina Quinases/metabolismo , Receptor TIE-2 , Proteínas Recombinantes de Fusão/fisiologia , Transfecção , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/transplante , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Nucl Med Biol ; 30(1): 1-9, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12493537

RESUMO

The association of the alpha(v)beta(3) integrin with tumor metastasis and tumor related angiogenesis has been suggested. Therefore, by imaging the alpha(v)beta(3) receptor with PET, information concerning the tumor status could be obtained. Cyclic peptides including the RGD sequence, were radiolabeled by direct electrophilic fluorination with [(18)F]AcOF. In tumor-bearing mice, the labeled peptides accumulated at the tumor with a high tumor to blood ratio. These findings suggest that an assessment of tumor characteristics may be obtained by using these (18)F-labeled peptides.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Adenocarcinoma/metabolismo , Radioisótopos de Flúor/farmacocinética , Integrina alfaVbeta3/metabolismo , Acetatos/administração & dosagem , Acetatos/síntese química , Acetatos/farmacocinética , Animais , Dorso/diagnóstico por imagem , Neoplasias do Colo/diagnóstico por imagem , Neoplasias do Colo/metabolismo , Ésteres/administração & dosagem , Ésteres/síntese química , Ésteres/farmacocinética , Radioisótopos de Flúor/administração & dosagem , Radioisótopos de Flúor/química , Humanos , Injeções Intravenosas , Integrina alfaVbeta3/administração & dosagem , Integrina alfaVbeta3/química , Marcação por Isótopo/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Especificidade de Órgãos , Oxirredução , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/farmacocinética , Sensibilidade e Especificidade , Distribuição Tecidual , Tomografia Computadorizada de Emissão/métodos
17.
Pancreas ; 25(2): e30-5, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12142752

RESUMO

INTRODUCTION: Overexpression of integrin alphaVbeta3 had been demonstrated in various tumors. Studies have suggested that elevated levels of integrin alphaVbeta3 in melanoma cells are deeply involved in the mechanism of increased melanoma invasiveness. AIMS: To examine the expression of integrin alphaVbeta3 in pancreatic carcinoma and to evaluate the correlation between integrin expression accompanied by MMP-2 activation and clinicopathologic factors. METHODOLOGY: Integrin alphaVbeta3 specific antibody LM-609 was used for immunochemical analysis, and intracellular localization was determined in human pancreatic cancer cell lines cultured on vitronectin coating. Fifty pancreatic adenocarcinomas analyzed immunohistochemically and 26 frozen samples were analyzed gelatin-zymographically. RESULTS: Two of three pancreatic cancer cell lines demonstrated integrin alphaVbeta3 immunofluorescence with a membranous pattern, and 29 of 50 pancreatic carcinomas showed positive immunostaining of tumor cells. There was no significant correlation between integrin alphaVbeta3 expression and tumor size, tumor grade, or peripancreatic invasion. However, primary tumors with lymph node metastasis featured significantly higher expression of integrin alphaVbeta3 than those without node metastasis. Tumors with high integrin alphaVbeta3 expression showed significantly higher MMP-2 activation ratios than did tumors with low expression. CONCLUSION: Expression analysis in pancreatic cancer tissue demonstrated involvement of alphaVbeta3 integrin in lymph node metastasis rather than peripancreatic invasion. MMP-2 activation is linked, at least in part, to the expression of integrin alphaVbeta3 of pancreatic cancer cells.


Assuntos
Neoplasias Pancreáticas/patologia , Receptores de Vitronectina/biossíntese , Idoso , Ativação Enzimática , Feminino , Humanos , Imuno-Histoquímica , Metástase Linfática , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Pessoa de Meia-Idade , Neoplasias Pancreáticas/metabolismo , Análise de Sobrevida , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...