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1.
Br J Surg ; 106(12): 1602-1610, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31573086

RESUMEN

BACKGROUND: A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent. METHODS: This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events. RESULTS: Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed. CONCLUSION: EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).


ANTECEDENTES: Se ha descrito que un lavado peritoneal extenso intraoperatorio (extensive intraoperative peritoneal lavage, EIPL) proporciona un beneficio en la supervivencia en pacientes con cáncer gástrico con citología peritoneal positiva. La hipótesis de este estudio era que el EIPL podría disminuir la recidiva peritoneal en pacientes con cáncer gástrico avanzado sometidos a cirugía con intención curativa. MÉTODOS: Ensayo clínico fase 3, abierto, multicéntrico y aleatorizado para evaluar los efectos de un lavado peritoneal extenso intraoperatorio (EIPL) frente a tratamiento estándar tras gastrectomía curativa por cáncer gástrico ≥T3 resecable. La variable de resultado primaria fue la supervivencia libre de enfermedad (disease-free survival, DFS), y las variables de resultado secundarias fueron la supervivencia global (overall survival, OS), la supervivencia libre de recidiva peritoneal y la incidencia de efectos adversos. RESULTADOS: Entre julio de 2011 y enero de 2014, se reclutaron 314 pacientes de 15 instituciones y se analizaron los datos de 295 pacientes (145 en el grupo con EIPL y 150 en el grupo sin EIPL). La DFS a los 3 años fue 63,9% (i.c. del 95% 55,5-71,2) en el grupo con EIPL y 59,7% (i.c. del 95% 51,3-67,1) en el grupo control (cociente de riesgos instantáneos, hazard ratio, HR 0,81 (i.c. del 95% 0,57-1,16), P = 0,249). La OS a los 3 años fue 75,0% (i.c. del 95% 67,1-81,3) en el grupo con EIPL y 73,7% (i.c. del 95% 65,9-80,1) en el grupo control (HR 0,91 i.c. del 95% 0,60-1,37), P = 0,634). No se observaron diferencias estadísticamente significativas entre los dos grupos en la supervivencia libre de recidiva peritoneal (P = 0,676, HR 0,92 (i.c. del 95% 0,62-1,36). No se observaron complicaciones intraoperatorias relacionadas con EIPL. CONCLUSIÓN: El EIPL no mejoró la supervivencia o la recidiva peritoneal en pacientes sometidos a gastrectomía por cáncer gástrico avanzado.


Asunto(s)
Adenocarcinoma/cirugía , Gastrectomía , Cuidados Intraoperatorios , Lavado Peritoneal , Neoplasias Gástricas/cirugía , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/mortalidad , Adenocarcinoma/secundario , Anciano , Quimioterapia Adyuvante , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Peritoneales/secundario , Recurrencia , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/patología
2.
Oncogene ; 34(13): 1679-87, 2015 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-24747971

RESUMEN

Small cell lung carcinoma (SCLC) often features the upregulation of the Sonic hedgehog (Shh) pathway leading to activation of Gli transcription factors. SCLC cells secrete bombesin (BBS)-like neuropeptides that act as autocrine growth factors. Here, we show that SCLC tumor samples feature co-expression of Shh and BBS-cognate receptor (gastrin-releasing peptide receptor (GRPR)). We also demonstrate that BBS activates Gli in SCLC cells, which is crucial for BBS-mediated SCLC proliferation, because cyclopamine, an inhibitor of the Shh pathway, hampered the BBS-mediated effects. BBS binding to GRPR stimulated Gli through its downstream Gαq and Gα12/13 GTPases, and consistently, other Gαq and Gα13 coupled receptors (such as muscarinic receptor, m1, and thrombin receptor, PAR-1) and constitutively active GαqQL and Gα12/13QL mutants stimulated Gli. By using cells null for Gαq and Gα12/13, we demonstrate that these G proteins are strictly necessary for Gli activation by BBS. Moreover, by using constitutively active Rho small G-protein (Rho QL) as well as its inhibitor, C3 toxin, we show that Rho mediates G-protein-coupled receptor (GPCR)-, Gαq- and Gα12/13-dependent Gli stimulation. At the molecular level, BBS caused a significant increase in Shh gene transcription and protein secretion that was dependent on BBS-induced GPCR/Gαq-12/13/Rho mediated activation of nuclear factor κB (NFκB), which can stimulate a NF-κB response element in the Shh gene promoter. Our data identify a novel molecular network acting in SCLC linking autocrine BBS and Shh circuitries and suggest Shh inhibitors as novel therapeutic strategies against this aggressive cancer type.


Asunto(s)
Proteínas Hedgehog/fisiología , Neoplasias Pulmonares/patología , Receptores de Bombesina/fisiología , Transducción de Señal/fisiología , Carcinoma Pulmonar de Células Pequeñas/patología , Animales , Bombesina/farmacología , Ácidos Borónicos/farmacología , Bortezomib , Cisplatino/farmacología , Subunidades alfa de la Proteína de Unión al GTP G12-G13/fisiología , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/fisiología , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Ratones , Células 3T3 NIH , Proteínas Oncogénicas/fisiología , Pirazinas/farmacología , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Transactivadores/fisiología , Proteína con Dedos de Zinc GLI1
3.
Endosc Ultrasound ; 3(Suppl 1): S4-5, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26425529

RESUMEN

INTRODUCTION: We report a case of low-risk stomach gastrointestinal stromal tumor (GIST) which has been under a long-term observation, obtaining from this experience knowledge useful in determining the treatment formula for this disease. RESULTS: During the observation for 6 years, no such change as ulcer formation was observed in the appearance of the tumor. The measurement of tumor diameter, however, showed gradual growth of maximum tumor diameter from 2.7 to 5.0 cm. When the changes in the diameter of tumor during this period is plotted, taking the timeon the horizontal axis and the tumor diameter on the vertical axis, the growth of the tumor can be approximated with a secondary function, making it possible to estimate the developmental period of the GIST concerned from the approximated secondary function. Thus, the developmental period in this case was estimated to go back 19 years before the time when it was discovered for the 1(st) time. Further, it was considered that the coefficient of the secondary function represents the rate of tumor growth, and that comparison with this coefficient contributed to the evaluation of malignancy stage of the GIST concerned. CONCLUSION: The growth curve predicting the growth of tumor could be depicted by measuring the diameter of the tumor in GIST twice or more at an interval of 6-12 months with EUS, and it was thought that this was utilizable for determining treatment formula for GISTs.

4.
Endosc Ultrasound ; 3(Suppl 1): S7, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26425534

RESUMEN

Aberrant pancreas is used to describe ectopic pancreatic tissue lying outside its normal location with no anatomic or vascular connection to the pancreas proper. Patients with aberrant pancreas are usually asymptomatic, so aberrant pancreas are typically discovered incidentally during endoscopy, surgery, or autopsy. This time, we report a case of gastric aberrant pancreas bleeding was repeated and endoscopic hemostasis was difficult. A 22-year-old man was admitted to a hospital with a complaint of epigastric pain and melena. Upper gastrointestinal endoscopy and endoscopic ultrasonography (EUS) revealed a submucosal tumor with a bleeding ulcer at the anterior wall of the antrum in the stomach, and diagnosed it as an aberrant pancreas. It was hard to stop bleeding by in total 7 times endoscopic hemostasis and anemia was gradually progressed, so partial gastrectomy was performed. This gastric tumor measured 40 mm × 30 mm × 20 mm and had a severe ulcerative change. The pathological diagnosis was aberrant pancreas with Langerhans islet, acinous cells and excretory duct. (Heinrich type) Until December 2013 in Japan, 13 cases of gastric aberrant pancreas with bleeding have been reported and in these, a surgery was done in 11 cases. In gastric aberrant pancreas cases with ulcer formation like this case, endoscopic hemostasis is expected to be difficult, and surgery is necessary. Hence, early accurate diagnosis by EUS is a very important to decide better treatment plan.

5.
Clin Lab Haematol ; 28(4): 262-6, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16898967

RESUMEN

This is a case report of granulocytic sarcoma occurring as a nasal lesion prior to the onset of acute myelogenous leukaemia (AML). To understand this case in more detail, we used 40,000 human cDNA microarray to identify the gene expression patterns of nonleukaemic stage bone marrow (BM), AML stage BM and AML stage peripheral blood cells and subsequently define the molecular basis of this disease progression. Of significance, we have tracked the expression profile of BM samples during the course of nonleukaemic to leukaemic progression, and identified a number of genes that may account for the growth potential of leukaemia cells and indicate poor prognosis of this case.


Asunto(s)
Regulación Leucémica de la Expresión Génica/genética , Leucemia Mieloide Aguda/genética , Neoplasias Nasales/genética , Sarcoma Mieloide/genética , Anciano de 80 o más Años , Progresión de la Enfermedad , Regulación hacia Abajo/genética , Resultado Fatal , Femenino , Humanos , Leucemia Mieloide Aguda/patología , Neoplasias Nasales/patología , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Sarcoma Mieloide/patología , Regulación hacia Arriba/genética
6.
Int J Oncol ; 19(5): 971-6, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11604996

RESUMEN

Mutations of the Kristen ras (K-ras) gene have been implicated in the pathogenesis of human lung cancer, especially adenocarcinoma, and have been proposed to be a prognostic factor. The K-ras mutation in codon 12 is detectable even in cell-free fluids by using the enriched polymerase chain reaction (PCR) technique. On the other hand, based on experimental results, the rho A mutation in codon 14 is also proposed to be oncogenic as observed in the K-ras mutation. Malignant pleural effusion is a common complication of lung cancer. We studied the point mutation of K-ras codon 12 and rho A codon 14 using enriched PCR in specimens of pleural effusion. Forty patients with pleural effusion were enrolled in this study. The causes of pleural effusion were non-small cell lung cancer (18 cases), small cell lung cancer (6 cases), malignant mesothelioma (2 cases), metastatic lung tumor (5 cases), thymoma (1 case), malignant lymphoma (1 case), and pleuritis tuberculosa (7 cases). The K-ras mutation was detected in 4 of 14 cases with adenocarcinoma, 1 of 3 cases with squamous cell carcinoma, 1 of 1 case with large cell carcinoma, and 1 of 5 cases with metastatic lung tumor, respectively. The rho A mutation was not detected in any pleural effusion examined in this study. Our study demonstrates the usefullness of pleural effusion as a clinical specimen for a search of point mutation of oncogenes. The K-ras codon 12 mutation is readily detected in pleural effusion, and the demonstration of this mutation has potentially important implications for the diagnosis of malignant pleural effusion.


Asunto(s)
Genes ras/genética , Derrame Pleural Maligno/genética , Mutación Puntual , Proteína de Unión al GTP rhoA/genética , Adulto , Anciano , Carcinoma de Células Pequeñas/genética , Codón/genética , Cartilla de ADN , ADN de Neoplasias/análisis , Femenino , Humanos , Neoplasias Pulmonares/genética , Linfoma/genética , Masculino , Mesotelioma/genética , Persona de Mediana Edad , Derrame Pleural Maligno/diagnóstico , Reacción en Cadena de la Polimerasa , Pronóstico , Timoma/genética , Tuberculosis/genética
7.
Int J Oncol ; 19(5): 1035-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11605006

RESUMEN

Retinoblastoma (RB) protein and antibody against RB protein in sera from 45 lung cancer patients and 30 healthy volunteers were examined using bacterially synthesized glutathione S-transferase (GST) RB fusion protein and immunoblot analysis. RB protein was not detected in sera from any individuals with lung cancer or in any healthy volunteers. Sera from 6 patients, including 4 with non-small cell carcinoma and 2 with small cell carcinoma, reacted to a GST-RB fusion protein but not with a GST protein. Sera from 30 normal volunteers reacted to neither GST-RB fusion protein nor GST protein. The backgrounds such as age, gender, performance status, histology, stage, smoking history, and prior treatment were not significantly different between the patients with and without anti-RB antibodies. This is the first report describing the presence of anti-RB antibody in patients with malignant tumors. Further studies are needed to establish clinical significance for anti-RB antibody.


Asunto(s)
Autoanticuerpos/sangre , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Células Pequeñas/inmunología , Neoplasias Pulmonares/inmunología , Proteína de Retinoblastoma/inmunología , Adulto , Anciano , Cartilla de ADN/química , Femenino , Glutatión Transferasa/genética , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Proteínas Recombinantes de Fusión/inmunología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
8.
J Pediatr Surg ; 36(11): 1675-8, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11685700

RESUMEN

PURPOSE: Thyroid receptor alpha-1 (TR-alpha1) and thyroid receptor beta-1 (TR-beta1) are thought to be essential for the fetal and postnatal development of the lung. The authors investigated gene level expression of TR-alpha1 and TR-beta1 in the lung of nitrofen-induced congenital diaphragmatic hernia (CDH) using reverse transcription polymerase chain reaction (RT-PCR). METHODS: CDH was induced in pregnant rats after administration of 100 mg nitrofen on day 9.5 of gestation. Cesarean section was performed on day 21 of gestation. The fetuses were divided into 3 groups: normal controls (n = 16), nitrofen-induced CDH (n = 16), and nitrofen-treated without CDH (n = 16). mRNA was extracted from the left lung in each group. RT-PCR was performed to evaluate mRNA expressions of TR-alpha1 and TR-beta1. Levels of mRNA were expressed as a ratio of the band density divided by that of beta-actin, a house-keeping gene. RESULTS: TR-alpha1 mRNA expression was decreased significantly in CDH lung (1.618 +/- 0.148) compared with controls (2.658 +/- 0.251; P <.01) and nitrofen-treated without CDH lung (2.232 +/- 0.193; (P <.05). TR-beta1 mRNA expression also was significantly decreased in CDH lung (2.223 +/- 0.270) compared with controls (3.569 +/- 0.262; P <.01) and nitrofen-treated without CDH lung (3.235 +/- 0.299; P <.05). CONCLUSION: These data suggest that the downregulation of thyroid hormone signaling pathway through altered expression of TR-alpha1 and TR-beta1 during lung morphogenesis may be a contributory factor in the pathogenesis of pulmonary hypoplasia in nitrofen-induced CDH.


Asunto(s)
Expresión Génica , Hernia Diafragmática/metabolismo , Pulmón/anomalías , Pulmón/metabolismo , ARN Mensajero/metabolismo , Receptores de Hormona Tiroidea/metabolismo , Animales , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Femenino , Herbicidas , Hernia Diafragmática/inducido químicamente , Hernia Diafragmática/genética , Pulmón/embriología , Morfogénesis , Éteres Fenílicos , Embarazo , Ratas , Ratas Sprague-Dawley , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores de Hormona Tiroidea/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
9.
Plant Cell Physiol ; 42(8): 849-56, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11522911

RESUMEN

The Lhcb gene family in green plants encodes several light-harvesting Chl a/b-binding (LHC) proteins that collect and transfer light energy to the reaction centers of PSII. We comprehensively characterized the Lhcb gene family in the unicellular green alga, Chlamydomonas reinhardtii, using the expressed sequence tag (EST) databases. A total of 699 among over 15,000 ESTs related to the Lhcb genes were assigned to eight, including four new, genes that we isolated and sequenced here. A sequence comparison revealed that six of the Lhcb genes from C. reinhardtii correspond to the major LHC (LHCII) proteins from higher plants, and that the other two genes (Lhcb4 and Lhcb5) correspond to the minor LHC proteins (CP29 and CP26). No ESTs corresponding to another minor LHC protein (CP24) were found. The six LHCII proteins in C. reinhardtii cannot be assigned to any of the three types proposed for higher plants (Lhcb1-Lhcb3), but were classified as follows: Type I is encoded by LhcII-1.1, LhcII-1.2 and LhcII-1.3, and Types II, III and IV are encoded by LhcII-2, LhcII-3 and LhcII-4, respectively. These findings suggest that the ancestral LHC protein diverged into LHCII, CP29 and CP26 before, and that LHCII diverged into multiple types after the phylogenetic separation of green algae and higher plants.


Asunto(s)
Proteínas Algáceas/genética , Chlamydomonas reinhardtii/genética , Complejos de Proteína Captadores de Luz , Proteínas del Complejo del Centro de Reacción Fotosintética/genética , Complejo de Proteína del Fotosistema II , Proteínas de Plantas/genética , Proteínas Algáceas/química , Proteínas Algáceas/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Evolución Biológica , Chlamydomonas reinhardtii/metabolismo , Clorofila/metabolismo , Clorofila A , Proteínas de Unión a Clorofila , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Etiquetas de Secuencia Expresada , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , Datos de Secuencia Molecular , Familia de Multigenes , Filogenia , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Mensajero/efectos de la radiación , Homología de Secuencia de Aminoácido
10.
Respir Physiol ; 127(2-3): 105-11, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11504583

RESUMEN

Positive-pressure mechanical ventilation can injure the lung, causing edema and alveolar inflammation in a complication termed ventilator-induced lung injury (VILI). Cytokines such as interleukin-8 (IL-8) reportedly are important in this inflammatory response. On the other hand, hepatocyte growth factor (HGF) promotes regeneration of the lung, and delays pulmonary fibrosis. We postulated that cyclic stretch upregulates production and release of both of mediators. Human alveolar epithelial cells (A549) cultured on a silicoelastic membrane were tested for mRNA expression and release of IL-8 and HGF after cyclic stretch in vitro. Stretch induced mRNA expression and release of these mediators. The signaling pathway from cyclic stretch to release of IL-8 and HGF appeared to involve protein kinase C in the signal transduction pathway.


Asunto(s)
Células Epiteliales/enzimología , Factor de Crecimiento de Hepatocito/genética , Interleucina-8/genética , Proteína Quinasa C/metabolismo , Alveolos Pulmonares/citología , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Células Epiteliales/citología , Expresión Génica/fisiología , Humanos , Péptidos/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Edema Pulmonar/metabolismo , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/fisiología , Estrés Mecánico
11.
Pediatr Surg Int ; 17(4): 284-7, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11409163

RESUMEN

Newborns with congenital diaphragmatic hernia (CDH) still have high mortality. Recently, a possible role of cardiac maldevelopment has been suggested. Human and experimental studies have demonstrated that heart weight is significantly reduced in the presence of CDH. Recent studies have suggested an important role for insulin-like growth factor-I (IGF-I) in the regulation of cardiac growth, structure, and function. Administration of IGF-I to normal rats has been shown to cause cardiac hypertrophy. Epidermal growth factor (EGF) plays an important role in cardiac differentiation and development. The aim of this study was to determine the gene-level expression of IGF-I and EGF in the hearts of rats with nitrofen-induced CDH using the reverse-transcription polymerase chain reaction technique (RT-PCR). CDH was induced in pregnant rats following administration of 100 mg nitrofen on day 9.5 of gestation (term 22 days). In control animals, the same dose of olive oil was given without nitrofen. Cesarean section was performed on day 21 of gestation. The fetuses were divided into three groups: normal controls (n = 8), nitrofen without CDH (n = 8), and nitrofen-induced CDH (n = 8). Total RNA was extracted from the hearts in each group and measured. mRNA was extracted from total RNA. RT-PCR was performed to evaluate mRNA expressions of IGF-I and EGF. Levels of mRNA were expressed as a ratio of band density divided by that of beta-actin, a housekeeping gene known to be expressed at a constant level. IGF-I mRNA expression was significantly decreased in CDH hearts (0.177 +/- 0.109) compared to controls (0.393 +/- 0.138) (P < 0.01) and nitrofen hearts without CDH (0.321 +/- 0.088) (P < 0.05). EGF mRNA expression was significantly decreased in CDH hearts (0.218 +/- 0.118) compared to controls (0.534 +/- 0.196) (P < 0.01) and nitrofen hearts without CDH (0.383 +/- 0.136) (P < 0.05). Decreased cardiac gene expression of IGF-I and EGF in the hypoplastic heart suggests that cardiac hypoplasia in nitrofen-induced rat CDH may be due to reduced synthesis of IGF-I and EGF by myocytes in the developing heart.


Asunto(s)
Regulación hacia Abajo/genética , Factor de Crecimiento Epidérmico/genética , Enfermedades Fetales/inducido químicamente , Enfermedades Fetales/genética , Expresión Génica/fisiología , Corazón/fisiopatología , Hernia Diafragmática/inducido químicamente , Hernia Diafragmática/genética , Síndrome del Corazón Izquierdo Hipoplásico/genética , Factor I del Crecimiento Similar a la Insulina/genética , Plaguicidas/efectos adversos , Éteres Fenílicos/efectos adversos , ARN Mensajero/genética , Animales , Modelos Animales de Enfermedad , Femenino , Hernias Diafragmáticas Congénitas , Síndrome del Corazón Izquierdo Hipoplásico/fisiopatología , Embarazo , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
12.
J Biol Chem ; 275(34): 26441-8, 2000 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-10840034

RESUMEN

The Ras guanine-nucleotide exchange factor Ras-GRF/Cdc25(Mn) harbors a complex array of structural motifs that include a Dbl-homology (DH) domain, usually found in proteins that interact functionally with the Rho family GTPases, and the role of which is not yet fully understood. Here, we present evidence that Ras-GRF requires its DH domain to translocate to the membrane, to stimulate exchange on Ras, and to activate mitogen-activated protein kinase (MAPK). In an unprecedented fashion, we have found that these processes are regulated by the Rho family GTPase Cdc42. We show that GDP- but not GTP-bound Cdc42 prevents Ras-GRF recruitment to the membrane and activation of Ras/MAPK, although no direct association of Ras-GRF with Cdc42 was detected. We also demonstrate that catalyzing GDP/GTP exchange on Cdc42 facilitates Ras-GRF-induced MAPK activation. Moreover, we show that the potentiating effect of ionomycin on Ras-GRF-mediated MAPK stimulation is also regulated by Cdc42. These results provide the first evidence for the involvement of a Rho family G protein in the control of the activity of a Ras exchange factor.


Asunto(s)
Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteína de Unión al GTP cdc42/fisiología , ras-GRF1/metabolismo , Células 3T3 , Animales , Células COS , Membrana Celular/metabolismo , Activación Enzimática , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Ionomicina/farmacología , Ionóforos/farmacología , Ratones , Relación Estructura-Actividad
13.
Biochem Biophys Res Commun ; 272(3): 717-20, 2000 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-10860821

RESUMEN

Cells organize diverse types of specialized adhesion sites upon attachment to extracellular matrix (ECM) components. One of the physiological roles of such cell-ECM interactions is to initiate and regulate adhesion-mediated signal transduction responses. The association of cells with fibronectin fibrils has been shown to regulate the JNK and p38 signaling pathways. We tested whether tensin, a cytoskeletal component localized to both focal contacts and fibronectin-associated fibrillar adhesions, can induce these signaling pathways. We found that tensin overexpression resulted in activation of both the c-Jun amino-terminal kinase (JNK) and p38 pathways. Tensin-mediated JNK activation was independent of the activities of the small GTP binding proteins Rac and Cdc42, but did depend on SEK, a kinase involved in the JNK pathway. We suggest that tensin may directly activate the JNK and p38 pathways, acting downstream or independent of the activities of the small GTP binding proteins Rac and Cdc42.


Asunto(s)
MAP Quinasa Quinasa 4 , Sistema de Señalización de MAP Quinasas , Proteínas de Microfilamentos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Línea Celular , Activación Enzimática , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Genes Dominantes/genética , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , MAP Quinasa Quinasa 6 , Proteínas de Microfilamentos/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/genética , Modelos Biológicos , Mutación/genética , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Tensinas , Transfección , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos , Proteínas de Unión al GTP rac/genética , Proteínas de Unión al GTP rac/metabolismo
15.
No To Shinkei ; 51(9): 799-803, 1999 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-10511958

RESUMEN

We report a 30-year-old man with acute disseminated encephalomyelitis (ADEM) accompanying Mycoplasma pneumoniae (M. pneumoniae) infection. He was admitted to our hospital because of headache, disturbed behavior, and unconsciousness following an upper respiratory tract infection on December 19, 1996. On admission, he was febrile (37.3 degrees C) and showed hypersomnia and neck stiffness. There were scattered rhonchi in both lungs. Cerebrospinal fluid (CSF) contained 19 white cells; the protein was 20 mg/dl and glucose 71 mg/dl (blood glucose 170 mg/dl); no organisms were seen or cultured. Cranial MRI showed multiple T 2-weighted hyperintense in the periventricular region of the cerebral white matter. M. pneumoniae antibody titer in serum was remarkably elevated. ADEM related to M. pneumoniae was suspected. Although intravenous methylprednisolone, piperacillin and clindamycin were administered, there was no subsequent improvement in the symptoms. Further MRI scan revealed extension of the inflammatory lesion. He had both pneumonia and he required mechanical ventilation. Since the end of the critical period, he has been in an akinetic mutism. We conclude that M. pneumoniae has to be considered as a possible cause of ADEM with severe respiratory symptoms.


Asunto(s)
Encefalomielitis Aguda Diseminada/etiología , Neumonía por Mycoplasma/complicaciones , Adulto , Encefalomielitis Aguda Diseminada/diagnóstico , Humanos , Masculino , Pronóstico
17.
Oncogene ; 17(8): 991-8, 1998 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-9747878

RESUMEN

The small GTP-binding Rho proteins control a variety of biological activities, including organization of the actin cytoskeleton, regulation of gene expression and cellular transformation. In contrast, Ras proteins do not induce actin stress fibers, but potently transform cells which exhibit a morphology clearly distinct from that caused by activated forms of Rho. To investigate whether nuclear signaling and oncogenic potential of Rho are a consequence of its profound effect on cytoskeletal organization, we replaced each amino acid in the Rho effector loop with those of Ras, or replaced conserved residues with others known to result in differential signaling capability when introduced into Ras and Rac1. These Rho mutants did not gain the ability to induce the MAPK, JNK or p38 pathways but, surprisingly, all Rho effector loop mutants still continued to induce actin stress fiber formation. However, three of these Rho mutants, with substitutions of leucine-39, glutamic acid-39, or cysteine-42, lost the ability to stimulate gene transcription via the serum response factor (SRF) and failed to induce neoplastic transformation. Thus, these results indicate that cytoskeletal changes are not sufficient to induce the transformed phenotype, and that Rho-effector molecules regulating the actin cytostructure are distinct from those signaling to the nucleus and subverting normal growth control.


Asunto(s)
Transformación Celular Neoplásica/metabolismo , Citoesqueleto/metabolismo , Proteínas de Unión al GTP/genética , Proteínas de Unión al GTP/metabolismo , Proteínas Quinasas Activadas por Mitógenos , Mutagénesis , Señales de Localización Nuclear/genética , Células 3T3 , Secuencia de Aminoácidos , Animales , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Línea Celular , Transformación Celular Neoplásica/genética , Citoesqueleto/fisiología , Perros , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Proteínas de Unión al GTP/fisiología , Proteínas Quinasas JNK Activadas por Mitógenos , Riñón , Ratones , Ratones Desnudos , Datos de Secuencia Molecular , Señales de Localización Nuclear/fisiología , Estructura Terciaria de Proteína , Transfección , Proteínas Quinasas p38 Activadas por Mitógenos , Proteínas de Unión al GTP rac , Proteínas ras/genética , Proteínas ras/metabolismo
18.
Rinsho Shinkeigaku ; 38(1): 32-7, 1998 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-9597907

RESUMEN

A 62-year-old woman with pulmonary tuberculosis was admitted to our hospital. She was completely neurologically free at admission and her CSF was normal. Brain MRI with Gd-DTPA enhancement demonstrated two mass lesions with ring-enhancement in the left temporal lobe and the right frontal lobe. The left temporal lesion had a bright central core with hypointense periphery on T2 weighted image. Extended hyperintense area was observed around this lesions, which represented brain edema. On T1 weighted image, the central core was demonstrated hypointense and its periphery was isointense. After starting antituberculous therapy, MRI revealed paradoxical expansion of left temporal lesion and neurological symptoms worsened temporarily, but, eventually the intracranial lesions diminished in size and disappeared, and the symptoms improved. So we diagnosed her as having intracranial tuberculoma. By long-term following up with MRI, we observed that the central core of the left temporal tuberculoma had changed gradually to hypointense on T2 weighted image and hyperintense on T1 weighted image respectively. We thought that the change of the central core on MRI represented organization of caseated necrosis.


Asunto(s)
Encéfalo/patología , Imagen por Resonancia Magnética , Tuberculoma Intracraneal/diagnóstico , Antituberculosos/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Isoniazida/administración & dosificación , Persona de Mediana Edad , Necrosis , Rifampin/administración & dosificación , Estreptomicina/administración & dosificación , Factores de Tiempo , Tuberculoma Intracraneal/tratamiento farmacológico
20.
Rinsho Shinkeigaku ; 38(12): 1054-8, 1998 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-10349348

RESUMEN

A 39-year-old female, who had splenectomy for idiopathic thrombocytopenic purpura (ITP) in 1988, was admitted to our hospital with high fever, headache, and loss of consciousness on November 29,1997. Neck stiffness and Kernig's sign were present. Examination of cerebrospinal fluid showed pleocytosis up to 506 cells/mm3 with 89% of polymorphonuclear cells and elevated protein to 1,135 mg/dl, and absence of glucose, Streptococcus pneumoniae phagocytosis was detected in the fluid. We diagnosed her as having pneumococcal meningitis as overwhelming postsplenectomy infection (OPSI) syndrome. After administration of dexamethasone (8 mg/day), cefotaxime (4 g/day), and ampicillin (6 g/day), she survived without any complications. Splenectomized patients have been recognized as immunocompromized hosts, and carry high morbidity and mortality risk from fulminant bacterial infections. Therefore, emergency treatment is important to reduce high mortality in such infections. We present an adult case of OPSI syndrome which occurred as pneumococcal meningitis, and we would like to emphasize the importance of prompt use of corticosteroids and high dose of sensitive antibiotics before DIC may occur during the course of illness.


Asunto(s)
Meningitis Neumocócica/tratamiento farmacológico , Complicaciones Posoperatorias/tratamiento farmacológico , Esplenectomía , Adulto , Ampicilina/administración & dosificación , Antiinflamatorios/administración & dosificación , Cefotaxima/administración & dosificación , Cefalosporinas/administración & dosificación , Dexametasona/administración & dosificación , Quimioterapia Combinada/administración & dosificación , Femenino , Humanos , Huésped Inmunocomprometido , Penicilinas/administración & dosificación , Púrpura Trombocitopénica Idiopática/cirugía , Resultado del Tratamiento
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