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1.
Cell Immunol ; 286(1-2): 22-30, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24287273

RESUMO

Helicobacter pylori encoded CagA is presently the only known virulence factor that is injected into gastric epithelial cells where it destroys apical junctional complexes and induces dedifferentiation of gastric epithelial cells, leading to H. pylori-related gastric carcinogensis. However, little is known about the molecular mechanisms by which CagA mediates these changes. Caudal-related homeobox 2 (Cdx2) is an intestine-specific transcription factor highly expressed in multistage tissues of dysplasia and cancer. One specific target of Cdx2, Claudin-2, is involved in the regulation of tight junction (TJ) permeability. In this study, our findings showed that the activity of Cdx2 binding to Cdx binding sites of CdxA (GTTTATG) and CdxB (TTTTAGG) of probes corresponding to claudin-2 flanking region increased in AGS cells, infected with CagA positive wild-type strain of H. pylori, compared to CagA negative isogenic mutant-type strain. Moreover, Cdx2 upregulated claudin-2 expression at transcriptional level and translational level. In the meantime, we found that TJs of AGS cells, infected with CagA positive wild-type strain of H. pylori, compared to CagA negative isogenic mutant-type strain, were more severely destroyed, leading to wider cell gap, interference of contact, scattering and highly elevated migration of cells. Herein, this study is firstly demonstrated that H. pylori-encoded CagA disrupts TJs and induces invasiveness of AGS gastric carcinoma cells via Cdx2-dependent targeting of Claudin-2. This provides a new mechanism whereby CagA induced dedifferentiation of AGS cells, leading to malignant behavior of biology.


Assuntos
Adenocarcinoma/microbiologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Claudina-2/genética , Helicobacter pylori/genética , Proteínas de Homeodomínio/genética , Neoplasias Gástricas/microbiologia , Junções Íntimas/microbiologia , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Fator de Transcrição CDX2 , Desdiferenciação Celular , Linhagem Celular Tumoral , Claudina-2/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Regulação da Expressão Gênica , Helicobacter pylori/crescimento & desenvolvimento , Helicobacter pylori/patogenicidade , Proteínas de Homeodomínio/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Invasividade Neoplásica , Ligação Proteica , Transdução de Sinais , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Junções Íntimas/metabolismo , Junções Íntimas/patologia
2.
Int J Cancer ; 125(3): 688-97, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19358264

RESUMO

XAF1 (XIAP-associated factor 1) is a novel XIAP binding protein that can antagonize XIAP and sensitize cells to other cell death triggers. Our previous results have shown that aberrant hypermethylation of the CpG sites in XAF1 promoter is strongly associated with lower expression of XAF1 in gastric cancers. In our study, we investigated the effect of restoration of XAF1 expression on growth of gastric cancers. We found that the restoration of XAF1 expression suppressed anchorage-dependent and -independent growth and increased sensitivity to TRAIL and drug-induced apoptosis. Stable cell clones expressing XAF1 exhibited delayed tumor initiation in nude mice. Restoration of XAF1 expression mediated by adenovirus vector greatly increased apoptosis in gastric cancer cell lines in a time- and dose-dependent manner and sensitized cancer cells to TRAIL and drugs-induced apoptosis. Adeno-XAF1 transduction induced cell cycle G2/M arrest and upregulated the expression of p21 and downregulated the expression of cyclin B1 and cdc2. Notably, adeno-XAF1 treatment significantly inhibited tumor growth, strongly enhanced the antitumor activity of TRAIL in a gastric cancer xenograft model in vivo, and significantly prolonged the survival time of animals bearing tumor xenografts. Complete eradication of established tumors was achieved on combined treatment with adeno-XAF1 and TRAIL. Our results document that the restoration of XAF1 inhibits gastric tumorigenesis and tumor growth and that XAF1 is a promising candidate for cancer gene therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Terapia Genética/métodos , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/farmacologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/terapia , Proteínas Adaptadoras de Transdução de Sinal , Adenoviridae , Animais , Apoptose , Proteínas Reguladoras de Apoptose , Western Blotting , Ciclo Celular/genética , Linhagem Celular Tumoral , Ciclina B/metabolismo , Ciclina B1 , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Regulação para Baixo , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica , Vetores Genéticos , Humanos , Marcação In Situ das Extremidades Cortadas , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Neoplasias/uso terapêutico , Plasmídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/fisiopatologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Fatores de Tempo , Transdução Genética , Transfecção , Transplante Heterólogo , Regulação para Cima
3.
J Gastroenterol ; 43(9): 679-86, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18807129

RESUMO

BACKGROUND: This multicenter retrospective study investigated the management and outcome of patients with peptic ulcer/erosion-related aspirin and clopidogrel (A + C) cotherapy. METHODS: From January 2002 to September 2006, patients with endoscopically proven peptic ulcers/erosions after receiving A + C cotherapy were analyzed. RESULTS: This group consisted of 106 patients (age, 69.3 +/- 11.7 years). Ulcers/erosions developed in 27 patients during hospitalization for cardiac events and in 79 patients after hospital discharge. Of 27 patients hospitalized for acute cardiac events, gastrointestinal (GI) bleeding and dyspepsia occurred in 24 and three, respectively. The most common lesion was gastric ulcer. Of 79 discharged patients, GI bleeding and dyspepsia occurred in 64 and 15, respectively. The most common bleeding and dyspeptic lesions were gastric ulcer and gastritis, respectively. Overall, 17 patients underwent endoscopic hemostasis all successfully. A + C cotherapy was continued in 57 patients for a median (interquartile range) of 3.0 (6.2) months. Most were coprescribed a proton pump inhibitor (PPI) (53, 93%). No recurrent GI bleeding was observed. CONCLUSIONS: After A + C cotherapy, gastric ulcer or gastritis were the most common endoscopic lesions. The combination of a PPI and endoscopic treatment for ulcer bleeding was highly successful. After patient stabilization, continuation of A + C cotherapy with a PPI appears to be safe.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Aspirina/efeitos adversos , Úlcera Péptica/induzido quimicamente , Ticlopidina/análogos & derivados , Idoso , Anti-Inflamatórios não Esteroides/administração & dosagem , Aspirina/administração & dosagem , Clopidogrel , Doença das Coronárias/terapia , Feminino , Hemorragia Gastrointestinal/terapia , Hemostase Endoscópica , Hospitalização , Humanos , Masculino , Úlcera Péptica/complicações , Úlcera Péptica/terapia , Inibidores da Agregação Plaquetária/uso terapêutico , Stents , Ticlopidina/administração & dosagem , Ticlopidina/efeitos adversos
4.
Antivir Ther ; 12(8): 1295-303, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18240869

RESUMO

BACKGROUND: Long-term effects of lamivudine treatment on chronic hepatitis B patients without advanced disease remain unknown. Our aim was to investigate the effects of long-term lamivudine treatment and lamivudine-resistant virus (YMDD) on the development of cirrhosis and hepatocellular carcinoma (HCC) in asymptomatic patients without advanced disease. METHODS: One hundred and forty-two hepatitis B e antigen (HBeAg)-positive patients (median age: 33.9 years) on long-term lamivudine (median treatment duration: 89.9 months) and 124 HBeAg-positive controls (median age: 33.4 years) were prospectively followed up. Patients were monitored for the development of cirrhosis and HCC, liver biochemistry, hepatitis B virus (HBV) DNA levels, HBeAg seroconversion and hepatitis flares. YMDD mutations (YMDD-MT) were determined annually. RESULTS: Lamivudine-treated patients had a significantly lower cumulative rate of development of cirrhosis and/or HCC compared with controls (P = 0.005). YMDD-MT occurred in 76.3% of patients after 8 years of lamivudine treatment. When compared with controls and patients with YMDD-MT, patients without YMDD-MT had the greatest reduction of HBV DNA and bilirubin levels, slowest decline of albumin level, highest rate of HBeAg seroconversion and lowest risk of hepatitis flare. Patients with YMDD-MT still had a lower risk for developing cirrhosis and/or HCC (P = 0.024) and a greater HBV DNA reduction (P = 0.001) in comparison with controls. Patients with YMDD-MT and controls had a similar chance of hepatitis flares and hepatic decompensation. CONCLUSIONS: Long-term lamivudine treatment was associated with a reduced chance of developing cirrhosis and HCC in patients without advanced disease. Although YMDD-MT reduced the benefits from lamivudine therapy, the outcome of these patients was still better than untreated patients.


Assuntos
Hepatite B Crônica/tratamento farmacológico , Lamivudina/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Adulto , Carcinoma Hepatocelular/etiologia , Progressão da Doença , Farmacorresistência Viral , Feminino , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/complicações , Humanos , Lamivudina/farmacologia , Cirrose Hepática/etiologia , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento
5.
Cancer Invest ; 25(8): 750-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18058473

RESUMO

The interactions of cigarette smoking with COX-2 on colitis and colitis-associated adenoma formation were studied. Mice were induced with colitis and exposed to cigarette smoke (CS) and/or SC236 (a COX-2 inhibitor). Results indicated that CS did not alter acute colonic inflammation. Addition of SC236 abolished the induction of proliferation and oxidative damage by colitis. Chronic SC236 treatment abolished the promoting effect of CS on colonic adenoma formation, via suppression of COX-2- and VEGF-mediated proliferation and angiogenesis, and reversed bcl-2-mediated inhibition of apoptosis by CS. To conclude, COX-2 inhibitor could be an implication on cancer prevention in smokers with chronic colitis.


Assuntos
Adenoma/etiologia , Colite Ulcerativa/complicações , Neoplasias do Colo/etiologia , Ciclo-Oxigenase 2/fisiologia , Pirazóis/uso terapêutico , Fumar/efeitos adversos , Sulfonamidas/uso terapêutico , Adenoma/prevenção & controle , Animais , Apoptose , Proliferação de Células , Neoplasias do Colo/prevenção & controle , Sulfato de Dextrana , Masculino , Camundongos , Camundongos Endogâmicos BALB C
6.
Antivir Ther ; 11(6): 779-86, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17310822

RESUMO

BACKGROUND: Comprehensive study on viral factors predicting treatment responsiveness to lamivudine is lacking. AIMS: To define the significance of various viral factors and changes of viral population with lamivudine treatment. PATIENTS AND METHODS: Hepatitis B virus (HBV) DNA levels at baseline, week 24, 52 and year 3 were measured in 80 patients on continuous lamivudine therapy for 3 years. Genotypes, core promoter/precore mutations, YMDD mutations, polymorphic sequence of polymerase gene (rt91 I/L, rt256S/C) were determined at baseline, week 12, 24 and 52. YMDD mutations were also determined at year 3. RESULTS: High alanine aminotransferase levels and presence of core promoter/ precore mutations at baseline were associated with higher chance of achieving HBV DNA <1,000 copies/ml (good response) and higher rate of hepatitis Be antigen (HBeAg) seroconversion at week 52. Achieving HBV DNA levels <1,000 copies/mi at week 24 as well as baseline core promoter/precore mutations were associated with higher chance of achieving good response, higher rate of HBeAg seroconversion and lower rate of YMDD mutations at year 3. Lamivudine reversed core promoter mutations to wild type in 25% of patients. All 5 patients with rt256C had poor HBV DNA response, persistent HBeAg and YMDD mutations by year 3. There was no difference in treatment response between patients with genotype B and C. CONCLUSIONS: Achieving HBV DNA levels <1,000 copies/ml at 24 week is the best target for short- and long-term treatment efficacy. Core promoter and precore mutations were associated with better treatment outcome, and rt256C polymorphism in the polymerase gene with poor response.


Assuntos
Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Lamivudina/uso terapêutico , Mutação , Inibidores da Transcriptase Reversa/uso terapêutico , Carga Viral , Adolescente , Adulto , Alanina Transaminase/sangue , Antivirais/uso terapêutico , DNA Viral/sangue , DNA Polimerase Dirigida por DNA/genética , Feminino , Antígenos do Núcleo do Vírus da Hepatite B/genética , Vírus da Hepatite B/enzimologia , Vírus da Hepatite B/genética , Hepatite B Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Precursores de Proteínas/genética , Fatores de Tempo , Resultado do Tratamento
7.
Cancer Lett ; 241(2): 268-74, 2006 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-16337741

RESUMO

The c-Jun NH(2)-terminal kinase (JNK) is activated in several tumor cell lines. The aim of this study was to determine the effects of SP-600125, a specific JNK inhibitor, on the viability, apoptosis, cell cycle distribution of gastrointestinal cancer cells, and the potential anti-tumor mechanisms. Three gastric cancer cell lines, AGS, BCG-823 and MKN-45, and three colorectal cancer cell lines, SW1116, COLO205 and HT-29, were used. Cells were treated with SP-600125, and cell viability, apoptosis and cell cycle distribution, caspase-3 activity, expression of JNK and apoptosis related proteins were detected. SP-600125 inhibited cell proliferation by 10-80% for the different cell lines, and increased apoptosis by 1.5-4.5 folds for COLO205, BCG-823, MKN-45, AGS cells. Caspase-8 and caspase-3 were involved in the induction of apoptosis. SP-600125 caused G2/M cell cycle arrest and elevation of cyclin B1 and p27(kip). The differential response in cells to SP-600125 was associated with the basal level of phosphorylated JNK2. It is concluded that SP-600125 inhibits proliferation, induces apoptosis and causes cell cycle arrest in gastrointestinal cancer cells, indicating that JNK inhibitors have an anti-tumor effect and are potential therapeutic agents for cancers.


Assuntos
Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Fase G2/efeitos dos fármacos , Neoplasias Gastrointestinais/tratamento farmacológico , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Caspases/metabolismo , Proliferação de Células/efeitos dos fármacos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas
8.
Inflamm Bowel Dis ; 12(5): 369-73, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16670525

RESUMO

Ulcerative colitis (UC) is characterized by chronic intestinal inflammation as a result of an exaggerated T cell response. Cytotoxic T lymphocyte associated antigen-4 (CTLA-4), expressed mainly in activated T cells, inhibits T cell activation and proliferation by combining B7 through competing CD28 and maintains immune homeostasis. Polymorphisms of the CTLA-4 gene are known to be associated with several autoimmune diseases. The aim of this study was to investigate the association between the CTLA-4 gene microsatellite polymorphism and UC in Chinese patients. Unrelated 100 Chinese patients with UC and 140 healthy controls were studied. The (AT) repeats in the 3' untranslated region of exon 4 of the CTLA-4 gene were amplified by allele-specific polymerase chain reaction (PCR). The amplified products were electrophoresed on a 12% polyacrylamide gel, followed by silver staining. Twenty alleles were found in Chinese patients and healthy controls. The 122-bp allele was increased in UC compared with healthy controls (9.5% vs 0.7%, P = 0.0001/Pc = 0.002, OR = 14.591, 95%CI 3.357-63.420). The frequency of the longer alleles (>or=118 bp) of UC was higher than that in healthy controls (26% vs 4%, P = 0.0001/Pc = 0.0002, OR = 7.644, 95%CI 3.950-14.792), but was not associated with location and severity of the disease. Furthermore, the longer alleles were not associated with haplotypes of C-318T/A+49G of the CTLA-4 gene in Chinese patients with UC. The longer alleles of the CTLA-4 gene microsatellite polymorphism were strongly associated with UC in Chinese patients.


Assuntos
Antígenos de Diferenciação/genética , Colite Ulcerativa/genética , Predisposição Genética para Doença , Repetições de Microssatélites/genética , Adolescente , Adulto , Idoso , Antígenos CD , Povo Asiático , Antígeno CTLA-4 , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético
9.
Cancer Res ; 64(16): 5787-94, 2004 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15313921

RESUMO

Protein kinase C (PKC) family, which functions through serine/threonine kinase activity, is involved in signal transduction pathways necessary for cell proliferation, differentiation, and apoptosis. Its critical role in neoplastic transformation and tumor invasion renders PKC a potential target for anticancer therapy. In this study, we investigated the effect of targeting individual PKCs on gastric carcinogenesis. We established gastric cancer cell lines stably expressing antisense PKCalpha, PKCbeta1, and PKCbeta2 cDNA. These stable transfectants were characterized by cell morphology, cell growth, apoptosis, and tumorigenicity in vitro and in vivo. PKCalpha-AS and PKCbeta1-AS transfectants showed a different morphology with flattened, long processes and decreased nuclear:cytoplasmic ratio compared with the control cells. Cell growth was markedly inhibited in PKCalpha-AS and PKCbeta1-AS transfectants. PKCalpha-AS and PKCbeta1-AS cells were more responsive to mitomycin C- or 5-fluorouracil-induced apoptosis. However, antisense targeting of PKCbeta2 did not have any significant effect on cell morphology, cell growth, or apoptosis. Furthermore, antisense inhibition of PKCalpha and PKCbeta1 markedly suppressed colony-forming efficiency in soft agar and in nude mice xenografts. Inhibition of PKCalpha or PKCbeta1 significantly suppressed transcriptional and DNA binding activity of activator protein in gastric cancer cells, suggesting that PKCalpha or PKCbeta1 exerts their effects on cell growth through regulation of activator protein activity. These data provide evidence that targeting PKCalpha and PKCbeta1 by antisense method is a promising therapy for gastric cancer.


Assuntos
DNA Antissenso/administração & dosagem , Proteína Quinase C/antagonistas & inibidores , Neoplasias Gástricas/terapia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Adesão Celular/genética , Divisão Celular/genética , Linhagem Celular Tumoral , DNA Antissenso/genética , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína Quinase C/genética , Proteína Quinase C beta , Proteína Quinase C-alfa , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Fator de Transcrição AP-1/antagonistas & inibidores , Transfecção , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Cancer Res ; 63(22): 7724-32, 2003 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-14633697

RESUMO

Survivin plays an important role in cancer development. We aim to show here that suppression of survivin expression or function by antisense and dominant-negative (DN) mutant can inhibit gastric cancer carcinogenesis and angiogenesis in vivo. Plasmid constructs expressing survivin antisense and DN mutant replacing the cysteine residue at amino acid 84 with alanine (Cys84Ala) were prepared and introduced into BCG-823 and MKN-45 gastric cancer cells to establish stable transfectants. We showed that both antisense and DN mutant stable transfectants exhibited abnormal morphology, with decreased cell growth and increased rate of spontaneous apoptosis and mitotic catastrophe. Furthermore, in nude mice xenografts, these cells exhibited decreased de novo gastric tumor formation and reduced development of angiogenesis. Results from these studies strongly suggest that survivin is a promising target for gastric cancer treatment.


Assuntos
Adenocarcinoma/terapia , DNA Antissenso/genética , Proteínas Associadas aos Microtúbulos/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/genética , Neovascularização Patológica/terapia , Neoplasias Gástricas/terapia , Adenocarcinoma/irrigação sanguínea , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Apoptose/genética , Divisão Celular/genética , Linhagem Celular Tumoral , Feminino , Humanos , Proteínas Inibidoras de Apoptose , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas de Neoplasias , Neovascularização Patológica/genética , Neoplasias Gástricas/irrigação sanguínea , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Survivina , Transfecção , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Oncogene ; 22(8): 1189-97, 2003 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-12606945

RESUMO

Selective cyclooxygenase-2 (COX-2) inhibitors are promising anti-inflammatory drugs with potential antitumor activities. The nuclear factor-kappa B (NF-kappaB) family of proteins is important transcriptional regulators of genes involved in immunity, inflammation, and carcinogenesis. In the present study, we investigated whether and by which molecular mechanism the selective COX-2 inhibitors inhibit NF-kappaB activation in gastric cancer. The effects of SC236 and its derivative, but devoid of COX-2 enzyme inhibition activity on NF-kappaB signaling, were evaluated using electromobility shift, transfection, and reporter gene assay. The translocation of RelA/p65 was investigated using Western blotting and immunocytochemistry. We showed that SC236 suppressed NF-kappaB-mediated gene transcription and binding activity in gastric cancer. This effect occurred through a mechanism independent of cyclooxygenase activity and prostaglandin synthesis. Furthermore, unlike aspirin, SC236 affected neither the phosphorylation, degradation, nor expression of IkappaB-alpha, suggesting that the effects of SC236 are independent of IKK activity and IkappaB-alpha gene transcription. Instead, SC236 worked directly through suppressing nuclear translocation of RelA/p65. It is possible that SC236 directly targets proteins that facilitate the nuclear translocation of NF-kappaB. Our study suggests an important molecular mechanism by which COX-2 inhibitors reduce inflammation and suppress carcinogenesis in gastrointestinal tract.


Assuntos
Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Anticarcinógenos/farmacologia , Neoplasias do Colo/patologia , Inibidores de Ciclo-Oxigenase/farmacologia , Isoenzimas/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Proteínas de Neoplasias/antagonistas & inibidores , Pirazóis/farmacologia , Neoplasias Gástricas/patologia , Sulfonamidas/farmacologia , Aspirina/farmacologia , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , DNA de Neoplasias/metabolismo , Ativação Enzimática/efeitos dos fármacos , Humanos , Quinase I-kappa B , Proteínas I-kappa B/genética , Proteínas I-kappa B/metabolismo , Proteínas de Membrana , Inibidor de NF-kappaB alfa , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases , Ligação Proteica/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Fator de Transcrição RelA , Transcrição Gênica/efeitos dos fármacos , Transfecção , Fator de Necrose Tumoral alfa/farmacologia
12.
Oncogene ; 21(39): 6113-22, 2002 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-12203123

RESUMO

Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of gastrointestinal cancers. Recently, a similar protective effect has been demonstrated by the specific cyclo-oxygenase-2 (COX-2) inhibitors. However, the exact mechanism that accounts for the anti-proliferative effect of specific COX-2 inhibitors is still not fully understood, and it is still controversial whether these protective effects are predominantly mediated through the inhibition of COX-2 activity and prostaglandin synthesis. Identification of molecular targets regulated by COX-2 inhibitors could lead to a better understanding of their pro-apoptotic and anti-neoplastic activities. In the present study, we investigated the effect and the possible molecular target of a COX-2-specific inhibitor SC-236 on gastric cancer. We showed that SC-236 induced apoptosis in gastric cancer cells. However, this effect was not dependent on COX-2 inhibition. SC-236 down-regulated the protein expression and kinase activity of PKC-beta(1), increased the expression of PKCdelta and PKCeta, but did not alter the expression of other PKC isoforms in AGS cells. Moreover, exogenous prostaglandins or PGE(2) receptor antagonists could not reverse the inhibition effect on PKCbeta(1) by SC-236, which suggested that this effect occurred through a mechanism independent of cyclo-oxygenase activity and prostaglandin synthesis. Overexpression of PKCbeta(1) attenuated the apoptotic response of AGS cells to SC-236 and was associated with overexpression of p21(waf1/cip1). Inhibition of PKCbeta(1)-mediated overexpression of p21(waf1/cip1) partially reduced the anti-apoptotic effect of PKCbeta(1). The down-regulation of PKCbeta(1) provides an explanation for COX-independent apoptotic effects of specific COX-2 inhibitor in cultured gastric cancer cells. We also suggest that PKCbeta(1) act as survival mediator in gastric cancer, and its down-regulation by COX-2 inhibitor SC-236 may provide new target for future treatment of gastric cancer.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase/farmacologia , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Pirazóis/farmacologia , Neoplasias Gástricas/enzimologia , Sulfonamidas/farmacologia , Western Blotting , Proteínas de Ciclo Celular/metabolismo , Inibidor de Quinase Dependente de Ciclina p21 , Inibidor de Quinase Dependente de Ciclina p27 , Ciclinas/genética , Ciclinas/metabolismo , DNA Antissenso/farmacologia , Regulação para Baixo , Genes myc/fisiologia , Humanos , Isoenzimas/antagonistas & inibidores , Prostaglandinas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C beta , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores de Prostaglandina E/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Transfecção , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/enzimologia , Células Tumorais Cultivadas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína X Associada a bcl-2
13.
J Clin Oncol ; 21(12): 2288-93, 2003 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-12805328

RESUMO

PURPOSE: To evaluate whether pretherapeutic serum soluble E-cadherin is an independent factor predicting long-term survival in gastric cancer. Gastric cancer remains the second leading cause of cancer-related deaths in the world, but a satisfactory tumor marker is currently unavailable for gastric cancer. Soluble E-cadherin has recently been found to have prognostic value in gastric cancer. PATIENTS AND METHODS: One hundred sixteen patients with histologically proven gastric adenocarcinoma were included in the trial. Pretherapeutic serum was collected, and soluble E-cadherin was assayed using a commercially available enzyme-linked immunosorbent assay kit. The patients were followed up prospectively at the outpatient clinic. RESULTS: There were 75 men and 41 women, with a mean (+/- SD) age of 66 +/- 14 years. Forty-eight percent of tumors were located in the gastric antrum. The median survival time was 11 months. The mean pretherapeutic value of soluble E-cadherin was 9,159 ng/mL (range, 6,002 to 10,025 ng/mL), and the mean pretherapeutic level of carcinoembryonic antigen was 11 ng/mL (range, 0.3 to 4,895 ng/mL). On multivariate analysis, soluble E-cadherin is an independent factor predicting long-term survival. Ninety percent of patients with a serum level of E-cadherin greater than 10,000 ng/mL had a survival time of less than 3 years (P =.009). CONCLUSION: Soluble E-cadherin is a potentially valuable pretherapeutic prognostic factor in patients with gastric cancer.


Assuntos
Adenocarcinoma/sangue , Biomarcadores Tumorais/sangue , Caderinas/sangue , Neoplasias Gástricas/sangue , Adenocarcinoma/diagnóstico , Adulto , Idoso , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodos , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estatísticas não Paramétricas , Neoplasias Gástricas/diagnóstico , Taxa de Sobrevida
14.
World J Gastroenterol ; 11(18): 2726-32, 2005 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-15884111

RESUMO

AIM: It is controversial whether patients with non-ulcer dyspepsia (NUD) respond differently to Helicobacter pylori (H pylori) eradication treatment than those with peptic ulcer disease (PUD). To review the evidence for any difference in H pylori eradication rates between PUD and NUD patients. METHODS: A literature search for full articles and meeting abstracts to July 2004 was conducted. We included studies evaluating the efficacy of a proton pump inhibitor (P) or ranitidine bismuth citrate (RBC) plus two antibiotics of clarithromycin (C), amoxicillin (A), metronidazole (M), or P-based quadruple therapies for eradicating the infection. RESULTS: Twenty-two studies met the criteria. No significant difference in eradication rates was found between PUD and NUD patients when treated with 7-d RBCCA, 10-d PCA or P-based quadruple therapies. When the 7-d PCA was used, the pooled H pylori eradication rate was 82.1% (431/525) and 72.6% (448/617) for PUD and NUD patients, respectively, yielding a RR of 1.15 (95%CI 1.01-1.29). However, the statistically significant difference was seen only in meeting abstracts, but not in full publications. CONCLUSION: There is no convincing evidence to suggest that NUD patients respond to H pylori eradication treatments differently from those with PUD, although a trend exists with the 7-d PCA therapy.


Assuntos
Quimioterapia Combinada , Dispepsia/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori , Úlcera Péptica/microbiologia , Ranitidina/análogos & derivados , Antibacterianos , Antiulcerosos/uso terapêutico , Bismuto/uso terapêutico , Quimioterapia Combinada/uso terapêutico , Humanos , Inibidores da Bomba de Prótons , Ranitidina/uso terapêutico , Resultado do Tratamento
15.
World J Gastroenterol ; 11(26): 4067-77, 2005 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-15996033

RESUMO

AIM: To systematically evaluate the efficacy of H(2)-receptor antagonists (H(2)RAs) and proton pump inhibitors in healing erosive esophagitis (EE). METHODS: A meta-analysis was performed. A literature search was conducted in PubMed, Medline, Embase, and Cochrane databases to include randomized controlled head-to-head comparative trials evaluating the efficacy of H(2)RAs or proton pump inhibitors in healing EE. Relative risk (RR) and 95% confidence interval (CI) were calculated under a random-effects model. RESULTS: RRs of cumulative healing rates for each comparison at 8 wk were: high dose vs standard dose H(2)RAs, 1.17 (95%CI, 1.02-1.33); standard dose proton pump inhibitors vs standard dose H(2)RAs, 1.59 (95%CI, 1.44-1.75); standard dose other proton pump inhibitors vs standard dose omeprazole, 1.06 (95%CI, 0.98-1.06). Proton pump inhibitors produced consistently greater healing rates than H(2)RAs of all doses across all grades of esophagitis, including patients refractory to H(2)RAs. Healing rates achieved with standard dose omeprazole were similar to those with other proton pump inhibitors in all grades of esophagitis. CONCLUSION: H(2)RAs are less effective for treating patients with erosive esophagitis, especially in those with severe forms of esophagitis. Standard dose proton pump inhibitors are significantly more effective than H(2)RAs in healing esophagitis of all grades. Proton pump inhibitors given at the recommended dose are equally effective for healing esophagitis.


Assuntos
Esofagite/tratamento farmacológico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Inibidores da Bomba de Prótons , Humanos , Omeprazol/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Cicatrização/efeitos dos fármacos
16.
World J Gastroenterol ; 11(13): 1946-50, 2005 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-15800984

RESUMO

AIM: Helicobacter pylori (H pylori) is associated with increased gastric inflammatory and epithelial expression of macrophage migration inhibitory factor (MIF) and gastric epithelial cell proliferation. This study aimed at determining whether H pylori directly stimulates release of MIF in monocytes, whether the cag pathogenicity island (PAI) is involved for this function, and whether MIF stimulated by H pylori increases gastric epithelial cell proliferation in vitro. METHODS: A cytotoxic wild-type H pylori strain (TN2), its three isogenic mutants (TN2Deltacag, TN2DeltacagA and TN2DeltacagE) were co-cultured with cells of a human monocyte cell line, THP-1, for 24 h at different organism/cell ratios. MIF in the supernatants was measured by an ELISA. Cells of a human gastric cancer cell line, MKN45, were then co-cultured with the supernatants, with and without monoclonal anti-MIF antibody for 24 h. The cells were further incubated for 12 h after addition of 3H-thymidine, and the levels of incorporation of 3H-thymidine were measured with a liquid scintillation counter. RESULTS: The wild-type strain and the isogenic mutants, TN2DeltacagA and TN2 DeltacagE, increased MIF release at organism/cell ratios of 200/1 and 400/1, but not at the ratios of 50/1 and 100/1. However, the mutant TN2delta cag did not increase the release of MIF at any of the four ratios. 3H-thymidine readings for MKN-45 cells were significantly increased with supernatants derived from the wild-type strain and the mutants TN2DeltacagA and TN2DeltacagE, but not from the mutant TN2Deltacag. Moreover, in the presence of monoclonal anti-MIF antibody, the stimulatory effects of the wild-type strain on cell proliferation disappeared. CONCLUSION: H pylori stimulates MIF release in monocytes, likely through its cag PAI, but not related to cagA or cagE. H pylori-stimulated monocyte culture supernatant increases gastric cell proliferation, which is blocked by anti-MIF antibody, suggesting that MIF plays an important role in H pylori-induced gastric epithelial cell proliferation.


Assuntos
Infecções por Helicobacter/patologia , Helicobacter pylori , Fatores Inibidores da Migração de Macrófagos/metabolismo , Monócitos/microbiologia , Estômago/microbiologia , Anticorpos Monoclonais/farmacologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Divisão Celular/fisiologia , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Helicobacter pylori/genética , Humanos , Técnicas In Vitro , Fatores Inibidores da Migração de Macrófagos/imunologia , Monócitos/citologia , Mutação , Estômago/patologia
17.
Clin Infect Dis ; 37(4): 593-7, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-12905145

RESUMO

Hepatitis B virus (HBV) genotypes and precore and core promoter mutations were determined in 318 patients with HBV. Patients infected with HBV genotype B had a higher median alanine aminotransferase level and bilirubin level and a lower median albumin level during exacerbations of disease, compared with patients infected with HBV genotype C (all P<.001). By logistic regression analysis, HBV genotype B infection (P=.014) and low albumin levels (P=.006) were independently associated with a higher risk of hepatic decompensation during severe exacerbations of disease. Patients infected with genotype B had a significantly higher mortality due to hepatic decompensation than did patients with genotype C (70% vs. 27.8%; P=.05).


Assuntos
Vírus da Hepatite B/genética , Hepatite B Crônica/metabolismo , Adolescente , Adulto , Idoso , Alanina Transaminase/metabolismo , Albuminas/metabolismo , Bilirrubina/metabolismo , Feminino , Genótipo , Vírus da Hepatite B/classificação , Humanos , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas
18.
Clin Infect Dis ; 36(8): 979-84, 2003 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-12684909

RESUMO

Forty-seven patients with severe hepatitis B exacerbation were compared with patients who had mild exacerbation (n=96) or no exacerbation (n=96). Seventeen patients (36.2%) died or underwent liver transplantation. Preexisting cirrhosis and a prothrombin time (PT) of >30 s were associated with adverse outcome in 60.9% and 87.5% of patients, respectively. The rate of adverse outcome increased to 92.3% when albumin levels of < or =35 g/L and bilirubin levels of >200 microM were present. Other factors associated with adverse outcomes included peak bilirubin level, peak PT, time to reach peak PT, and the presence of encephalopathy and/or ascites. There was no difference in the frequency of precore mutations in patients with severe or mild exacerbation or without exacerbation. A significantly lower prevalence of core promoter mutants was found in patients with severe exacerbation (50%), compared with those who had mild exacerbation (81.3%; P=.004). Patients with severe exacerbation of hepatitis B with poor prognostic factors should be considered for early liver transplantation.


Assuntos
Vírus da Hepatite B/genética , Hepatite B Crônica/diagnóstico , Adolescente , Adulto , Idoso , Ascite , Biomarcadores , DNA Viral/metabolismo , Feminino , Fibrose/etiologia , Encefalopatia Hepática , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/imunologia , Hepatite B Crônica/fisiopatologia , Humanos , Lamivudina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Regiões Promotoras Genéticas , Testes Sorológicos
19.
Clin Infect Dis ; 37(7): 882-9, 2003 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-13130398

RESUMO

The aim of this study was to investigate the effect of metronidazole resistance (MtzR) and clarithromycin resistance (ClaR) on the eradication rate for omeprazole, clarithromycin, and metronidazole triple-therapy regimen and on the development of posttherapy drug resistance in a region of high rates of MtzR. One hundred ninety-six Helicobacter pylori isolates were recovered from patients with duodenal ulcer, gastric ulcer, or nonulcer dyspepsia during upper endoscopy. The prevalences of MtzR, ClaR, and dual resistance were 37.8%, 13.8%, and 8.7%, respectively. The intention-to-treat eradication rates for metronidazole-susceptible (87.2% vs. 67.6%; P=.001) and clarithromycin-susceptible (86.4% vs. 40.7%; P<.001) strains were significantly higher than the rates for resistant strains. Multiple logistic regression analysis implicated younger age (<40 years old), MtzR, ClaR, and the diagnosis of nonulcer dyspepsia as independent factors that predicted treatment failure. The rates of posttreatment MtzR, ClaR, and dual resistance were 88%, 88%, and 75%, respectively. MtxR and ClaR significantly affected the success of eradication therapy. Posttreatment rates of resistance were high and were related to the presence of pretreatment antibiotic resistance.


Assuntos
Antibacterianos/farmacologia , Claritromicina/farmacologia , Helicobacter pylori/efeitos dos fármacos , Metronidazol/farmacologia , Adulto , Fatores Etários , Idoso , Antibacterianos/uso terapêutico , Antiulcerosos/farmacologia , Antiulcerosos/uso terapêutico , Claritromicina/uso terapêutico , Farmacorresistência Bacteriana , Feminino , Infecções por Helicobacter/tratamento farmacológico , Humanos , Masculino , Metronidazol/uso terapêutico , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Omeprazol/farmacologia
20.
Psychosom Med ; 65(3): 443-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12764218

RESUMO

OBJECTIVE: This study sought to explore some psychosocial factors that distinguished individuals with noncardiac chest pain (NCCP) from those without NCCP, and whether these psychosocial factors were associated with anxiety and depression that are co-morbid factors of NCCP. METHODS: A matched case-control design was adopted to compare differences in psychosocial factors among a target group of patients with NCCP (N = 70), a pain control group of patients with rheumatism (N = 70), and a community control group of healthy individuals (N = 70). RESULTS: Compared with subjects from the two control groups, NCCP patients tended to monitor more, use more problem-focused coping, display a coping pattern with a poorer strategy-situation fit, and receive less emotional support in times of stress. Moreover, monitoring perceptual style and problem-focused coping were associated with higher levels of anxiety and depression. Coping pattern with a strategy-situation fit and emotional support were related to lower levels of anxiety and depression. CONCLUSIONS: The present new findings suggest that monitoring perceptual style and inflexible coping style are risk factors that enhance one's vulnerability to NCCP. Emotional support may be a resource factor that reduces one's susceptibility to NCCP.


Assuntos
Adaptação Psicológica , Dor no Peito/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ansiedade/epidemiologia , Estudos de Casos e Controles , Dor no Peito/etiologia , Angiografia Coronária , Depressão/epidemiologia , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Reumáticas/complicações , Índice de Gravidade de Doença , Método Simples-Cego , Apoio Social , Fatores Socioeconômicos , Estresse Psicológico/psicologia
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