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1.
J Surg Oncol ; 102(7): 856-62, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20818602

RESUMO

INTRODUCTION: The purpose of the present study was to detect the presence of BASC-like stem cell-related indicators, such as clara cell secretory protein (CCSP), Octamer-4 (OCT4) and Bmi-1, and evaluate their implications in the prognosis of patients with lung adenocarcinoma. METHODS: Specimens of 134 cases of lung adenocarcinoma were collected after radical surgery from January 1999 to June 2004. RESULTS: One hundred and twenty-six cases showed cells that were positive for CCSP, 99 cases positive for OCT4, 91 cases simultaneous expression of CCSP and OCT4 and 74 cases positive for Bmi-1. Bmi-1 was significantly higher in patients at stage III compared to patients at stages I and II. The pattern of survival curves showed that Bmi-1 was a significant prognostic factor of poor overall survival in lung adenocarcinoma patients (P = 0.0000), and the patients with OCT4(+) expression showed a greater increase in mortality than OCT4(-) patients (P = 0.0103). The results of univariate and multivariate Cox analysis revealed that the pathological stages of tumor node metastases (P = 0.037), OCT4 (P = 0.046) and Bmi-1 expression (P = 0.001) were independent prognostic factors. CONCLUSIONS: OCT4 and Bmi-1 may be good biomarkers to predict the prognosis of patients with completely resected lung adenocarcinoma.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Uteroglobina/metabolismo , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Complexo Repressor Polycomb 1 , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto Jovem
2.
Jpn J Clin Oncol ; 40(7): 670-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20382636

RESUMO

OBJECTIVE: The purpose of this study was to evaluate the value of vascular endothelial growth factor-A and E-cadherin expression as well as other confirmed prognostic factors in predicting the clinical outcome after definitive surgery of pathologic stage I non-small cell lung cancer. METHODS: One hundred and eighty-five consecutive and non-selected patients who underwent definitive surgery for stage I non-small cell lung cancer in our institute were included in this study. Formalin-fixed paraffin-embedded specimens were stained for vascular endothelial growth factor-A and E-cadherin and the correlation between the staining, its clinicopathological parameters and its prognostic power were analyzed statistically. RESULTS: Of the 185 patients studied, 92 cases (49.7%) were strongly positive for vascular endothelial growth factor-A. Vascular endothelial growth factor-A expression was only related to visceral pleural involvement (P < 0.001). A total of 95 carcinomas (51.4%) were E-cadherin-negative tumors. E-cadherin expression correlated with histology (P < 0.001), tumor size (P = 0.001) and visceral pleural involvement (P < 0.001). In univariate analysis by log-rank test, gender, tumor size, lymphovascular invasion, visceral pleural involvement, vascular endothelial growth factor-A expression and E-cadherin expression were significant prognostic factors (P = 0.003, 0.042, 0.026, 0.035, 0.008 and 0.006, respectively). In multivariate analysis, gender, vascular endothelial growth factor-A and E-cadherin expression maintained its independent prognostic influence on overall survival (P = 0.013, <0.001 and 0.036, respectively). CONCLUSIONS: Expression of vascular endothelial growth factor-A is related to visceral pleural involvement, and E-cadherin expression correlates with histology, tumor size and visceral pleural involvement. Multivariate analysis confirmed gender, vascular endothelial growth factor-A and E-cadherin expression were significant predictive factors for overall survival in completely resected pathologic stage I non-small cell lung cancer.


Assuntos
Caderinas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Neoplasias Pulmonares/diagnóstico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico
3.
Zhonghua Jie He He Hu Xi Za Zhi ; 33(4): 284-8, 2010 Apr.
Artigo em Zh | MEDLINE | ID: mdl-20646461

RESUMO

OBJECTIVE: To study the effects and possible mechanisms of the protein kinase C (PKC) inhibitor chelerythrine chloride (CH), combined with cisplatin (DDP) on human non-small cell lung cancer. METHODS: The effect of CH, DDP and the combination on proliferation and apoptosis of human lung cancer cell line A549 were evaluated by MTT assay and flow cytometry respectively. The inhibitory effects of CH and DDP on neoplasia were verified on subcutaneous implanted tumor of nude mice. Implanted tumor models were constructed in nude mice using human lung adenocarcinoma cell line A549. Twenty-four BALB/c nude mice with implanted tumors were divided into 4 groups randomly: group CH, group DDP, group CH + DDP, and normal saline group (group NS), each with 5 mice. CH, DDP or NS were intraperitoneally injected into nude mice for 3 weeks (DDP or NS was injected once a week, CH was injected twice a week). RESULTS: CH inhibited A549 cell proliferation in a concentration-dependent pattern. When CH and DDP were combined, the inhibitory effect was enhanced in a synergistic or additive pattern. Both CH and DDP significantly increased the apoptosis of A549 cells, and this action was remarkably increased when DDP was combined with CH. CH and DDP inhibited the growth of subcutaneous implanted tumor in nude mice and the inhibitory rate of group CH + DDP (80.5%) was significantly higher than that of group CH (72.4%) or group DDP (64.3%) (t = 11.34, P < 0.01). CONCLUSION: CH combined with DDP shows significantly synergistic anti-tumor effects on non-small cell lung cancer cell line A549 and subcutaneous implanted tumor in nude mice, possibly by enhancement of growth inhibition and apoptosis induction on tumor cells.


Assuntos
Apoptose/efeitos dos fármacos , Benzofenantridinas/farmacologia , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Benzofenantridinas/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral/efeitos dos fármacos , Cisplatino/uso terapêutico , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína Quinase C/antagonistas & inibidores , Inibidores de Proteínas Quinases/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Zhonghua Jie He He Hu Xi Za Zhi ; 33(10): 738-41, 2010 Oct.
Artigo em Zh | MEDLINE | ID: mdl-21176503

RESUMO

OBJECTIVE: To evaluate the diagnostic yield and the safety of endobronchial ultrasound-guided transbronchial needle biopsy (EBUS-TBNA) in mediastinal and hilar lymph nodes and lung tumors. METHODS: EBUS-TBNA was performed in 70 patients with thoracic masses or mediastinal-hilar lymphoadenopathy proved by CT scan. RESULTS: From July 2009 to January 2010, 70 patients were included in the study. EBUS-guided TBNA was performed to obtain samples from mediastinal and hilar lymph nodes (120 stations) and lung tumors (11 masses). In 46 cases of newly diagnosed lung cancer, 44 were confirmed by EBUS-TBNA without on site cytology assistance, with 2 false negative cases. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBUS-TBNA in the diagnosis of lung cancer were 96%, 100%, 100%, 92% and 97% respectively. Non-caseous granuloma formed by epithelioid cells was found in EBUS-TBNA histological specimen from 5 out of 10 patients with clinically diagnosed sarcoidosis. TBNA cytological smear showed acid-fast bacilli and histology of the lymph node demonstrated coagulatory necrosis from 1 out of 4 tuberculous cases. The procedure was uneventful, and there were no complications. CONCLUSION: EBUS-TBNA is an effective and safe method for the diagnosis of bronchogenic carcinoma and unknown mediastinal-hilar lymphadenopathy.


Assuntos
Biópsia por Agulha Fina/métodos , Endossonografia/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Pulmonares/patologia , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Adulto Jovem
5.
Zhonghua Zhong Liu Za Zhi ; 29(3): 186-8, 2007 Mar.
Artigo em Zh | MEDLINE | ID: mdl-17649633

RESUMO

OBJECTIVE: To study the effects of two specific cyclooxygenase inhibitors (SCI), rofecoxib and celecoxib, combined with chemotherapeutic drugs 5-Fu, DDP and VP-16 on gastric cancer cell line BGC-823, and to evaluate whether specific cyclooxygenase inhibitors can be used as a synergetic agent in chemotherapy. METHODS: The gastric cancer cell line BGC-823 cells were incubated for 48 hours with rofecoxib and celecoxib, 5-Fu, DDP and VP-16 (concentration gradient of 5-Fu, DDP and VP-16:1 microg/ml, 10 microg/ml and 100 microg/ml), or in combination, respectively. MTT working solution was added to each culture and calculated the survival rates of gastric cancer cells. Median-effect principle and Professor Jin's evaluation methods were applied to detect the interaction between the specific cyclooxygenase inhibitors and chemotherapeutic agents. RESULTS: The inhibition rates of gastric cancer cells were 42.63% +/- 1.26% and 50.67% +/- 2.35% by treatment with 0.1 micromol/L rofecoxib and 50 micromol/L celecoxib, respectively. The inhibition rates of gastric cancer cells by treatment with 5-Fu, DDP and VP-16 at different concentrations (1 microg/ml, 10 microg/ml and 100 microg/ml) were 39.75% +/- 3.14%, 49.96% +/- 2.08%, 87.93% +/- 3.66%; 48.28% +/- 2.08%, 59.46% +/- 1.69%, 88.23% +/- 4.81%; and 29.23% +/- 3.27%, 49.34% +/- 3.75%, 79.24% +/- 2.44%, respectively. However, the inhibition rates showed a synergetic role while combined the two SCI (0.1 micromol/L rofecoxib and 50 micromol/L celecoxib) with chemotherapeutic agent at different concentrations (P <0.05). CONCLUSION: Both rofecoxib and celecoxib have an ability to suppress gastric cancer cells in vitro, and the synergetic role becomes evident when rofecoxib and celecoxib are combined with chemotherapeutic agents at different concentrations, which indicate that the two specific cyclooxygenase inhibitors may be used as a chemotherapeutic sensitizer.


Assuntos
Antineoplásicos/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Lactonas/farmacologia , Pirazóis/farmacologia , Neoplasias Gástricas/patologia , Sulfonamidas/farmacologia , Sulfonas/farmacologia , Adenocarcinoma/patologia , Antimetabólitos Antineoplásicos/farmacologia , Celecoxib , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Inibidores de Ciclo-Oxigenase 2/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Etoposídeo/farmacologia , Fluoruracila/farmacologia , Humanos
6.
J Cancer Res Clin Oncol ; 132(2): 92-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16261346

RESUMO

PURPOSE: A comparative proteomic approach was used to identify and analyze proteins related to metastasis of hepatocellular carcinoma (HCC). METHODS: Proteins extracted from 12 HCC tissue specimens (six with metastases and six without) were separated by two-dimensional gel electrophoresis (2-DE). The protein spots exhibiting statistical alternations between the two groups through computerized image analysis were then identified by mass spectrometry. In addition immunohistochemistry (IHC), Western blotting and RT-PCR were performed to verify the expression of certain candidate proteins. RESULTS: 16 proteins including HSP27, S100A11, CK18 were annotated by mass spectrometry, relevant to chaperone function, cell mobility, cytoskeletal architecture, respectively. Most were previously unconnected with metastasis of HCC. Of these HSP27 was found overexpressed consistently in 2-DE patterns of all metastatic HCC tissues compared with nonmetastatic ones. IHC and Western blotting of HCC tissues confirmed this difference while RT-PCR did not. CONCLUSION: There are various proteins joined together in HCC metastasis. The overexpression of HSP27 may serve as a biomarker for early detection and therapeutic targets unique to the metastatic phenotype of HCC.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/química , Proteínas de Choque Térmico/análise , Neoplasias Hepáticas/química , Proteínas de Neoplasias/análise , Actinas/análise , Western Blotting , Eletroforese em Gel Bidimensional , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP27 , Humanos , Imuno-Histoquímica , Espectrometria de Massas , Chaperonas Moleculares , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regulação para Cima
7.
Zhonghua Gan Zang Bing Za Zhi ; 13(5): 331-4, 2005 May.
Artigo em Zh | MEDLINE | ID: mdl-15918964

RESUMO

OBJECTIVE: A comparative proteomic approach was used to identify and analyze proteins relevant to metastasis of hepatocellular carcinoma (HCC). METHODS: Proteins extracted from 12 liver tumor tissue specimens (6 with metastases and 6 without) were separated by two-dimensional gel electrophoresis (2-DE). Comparative analyses of 2-DE protein patterns between the two groups were done using computerized image analysis. Selected proteins exhibiting statistically significant alternations were identified by mass spectrometry. Immunohistochemistry, Western blotting and RT-PCR were performed to examine the expressions of the candidate proteins. RESULTS: 16 proteins including HSP27, S100A11, CK18 were identified using mass spectrometry, which were related to cell mobility, signal transduction, and energy metabolism respectively. Of these, HSP27 was found to be uniquely over-expressed in 2-DE maps of all metastatic HCCs when compared to the non-metastatic HCC tissues. Immunohistochemistry and Western blotting of HCC tissues confirmed this difference while RT-PCR did not. CONCLUSION: There are different proteins working together that affect the metastasis of HCCs. The overexpression of HSP27 may serve as a biomarker for early detection and therapeutic targets to the metastatic phenotype of HCC. The role of HSP27 in HCC metastasis warrants further investigation.


Assuntos
Carcinoma Hepatocelular/química , Proteínas de Choque Térmico/análise , Neoplasias Hepáticas/química , Proteínas de Neoplasias/análise , Carcinoma Hepatocelular/patologia , Eletroforese em Gel Bidimensional , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP27 , Humanos , Neoplasias Hepáticas/patologia , Espectrometria de Massas , Chaperonas Moleculares , Proteoma/análise , Proteínas S100/análise
8.
Zhonghua Jie He He Hu Xi Za Zhi ; 27(8): 542-5, 2004 Aug.
Artigo em Zh | MEDLINE | ID: mdl-15388004

RESUMO

OBJECTIVE: To clarify whether functionally competent dendritic cells (DC) can be generated from malignant pleural effusion in patients with lung cancer. METHODS: Malignant effusion-associated monocytes were separated by adherence from malignant effusion-associated mononuclear cells and cultured in medium with granulocyte macrophage colony-stimulating factor (GM-CSF) plus interleukin 4 (IL-4). TNF-alpha was added for the last 24 h before culture termination. Cultured DC were identified by (1) using microscopy, scanning electron microscopy, and immunocytochemistry for the morphological features; (2) phenotypic markers; and (3) functional characteristics including a high stimulatory capacity to activate proliferation of lymphocyte in an allogeneic mixed leukocyte reaction and the ability to produce high levels of IFN-gamma. RESULTS: Cultured DC had the typical morphological features. The phenotype of DCs generated from effusion showed higher expression of CD(86) (84.6 +/- 6.1)%, HLA-DR (81.1 +/- 13.0)%, CD(40) (42.0 +/- 21.7)%, CD(1a) (20.0 +/- 9.5)% and lower expression of CD(14) (4.8 +/- 3.5)% than the control group. There was a significant difference in the stimulatory activity in allogeneic lymphocyte proliferation and the ability to produce high levels of IFN-gamma between DC derived from the malignant effusion and the control group. CONCLUSION: These findings suggest that DC can be generated from malignant pleural effusion, which might be a useful source of DC for immunotherapy.


Assuntos
Células Dendríticas/imunologia , Neoplasias Pulmonares/complicações , Macrófagos/fisiologia , Derrame Pleural Maligno/patologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/fisiologia , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Interleucina-4/farmacologia , Neoplasias Pulmonares/patologia , Macrófagos/imunologia , Monócitos/imunologia , Monócitos/fisiologia , Fator de Necrose Tumoral alfa/farmacologia
9.
Med Oncol ; 29(2): 663-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21556932

RESUMO

The purpose of this study was to investigate GPC3 gene expression in lung squamous cell carcinoma tissue and its correlation with clinical and tumor characteristics. Using RT-PCR, the presence of GPC3 gene expression was detected in cancer tissue and adjacent normal tissue in 66 cases of lung squamous cell carcinoma and positive rates were calculated. Using Western blot, changes in GPC3 protein expression were detected in lung squamous cell carcinoma and adjacent normal tissues. The percentage of tissue samples expressing GPC3 mRNA was significantly higher in lung squamous cell carcinoma than in adjacent normal tissue (P < 0.05). This percentage was also significantly higher for cases with lymph node metastasis than for those without lymph node metastasis (P < 0.05). Further, the percentage of samples expressing GPC3 mRNA was higher with lowering degrees of tumor differentiation (P < 0.05). Rates of GPC3 expression were, however, independent of patient gender, age, and tumor size (P > 0.05). The expression of GPC3 protein in lung squamous cell carcinoma was significantly higher than that in adjacent normal tissues (P < 0.05). The expression in cases with lymph node metastasis was significantly higher than in those without lymph node metastasis (P < 0.05), and GPC3 protein expression increased with lowering degrees of tumor differentiation (P < 0.05). Further investigation is warranted for the association of initiation, development, invasion, and metastasis of disease.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Glipicanas/genética , Neoplasias Pulmonares/genética , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Feminino , Seguimentos , Glipicanas/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
PLoS One ; 7(3): e34457, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22461913

RESUMO

PURPOSE: Lung cancer is the leading cause of cancer death worldwide, but techniques for effective early diagnosis are still lacking. Proteomics technology has been applied extensively to the study of the proteins involved in carcinogenesis. In this paper, a classification method was developed based on principal components of surface-enhanced laser desorption/ionization (SELDI) spectral data. This method was applied to SELDI spectral data from 71 lung adenocarcinoma patients and 24 healthy individuals. Unlike other peak-selection-based methods, this method takes each spectrum as a unity. The aim of this paper was to demonstrate that this unity-based classification method is more robust and powerful as a method of diagnosis than peak-selection-based methods. RESULTS: The results showed that this classification method, which is based on principal components, has outstanding performance with respect to distinguishing lung adenocarcinoma patients from normal individuals. Through leaving-one-out, 19-fold, 5-fold and 2-fold cross-validation studies, we found that this classification method based on principal components completely outperforms peak-selection-based methods, such as decision tree, classification and regression tree, support vector machine, and linear discriminant analysis. CONCLUSIONS AND CLINICAL RELEVANCE: The classification method based on principal components of SELDI spectral data is a robust and powerful means of diagnosing lung adenocarcinoma. We assert that the high efficiency of this classification method renders it feasible for large-scale clinical use.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Pulmonares/metabolismo , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Adenocarcinoma/classificação , Adenocarcinoma/diagnóstico , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Modelos Logísticos , Neoplasias Pulmonares/classificação , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Reprodutibilidade dos Testes
11.
J Dig Dis ; 12(5): 393-400, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21955433

RESUMO

OBJECTIVE: To evaluate the immunomodulation of inducible co-stimulator (ICOS) in cytokine-induced killer (CIK) cells against cholangiocarcinoma. METHODS: CIK cells were generated from normal peripheral blood mononuclear cells. Methyl thiazolyl tetrazolium assay was performed to assess proliferation of CIK-ICOS and controlled CIK cells; ELISA was used to analyze the expression of cytokines. Reverse transcription-polymerase chain reaction and immunohistochemistry were performed to evaluate the expression of ICOS ligand (ICOSL) in CIK cells and human cholangiocarcinoma cell line QBC939 cells. The cytotoxicity of CIK cells was determined either by lactate dehydrogenase-releasing assay in vivo or alteration of tumor size prior to and after the treatment of CIK cells in vivo. RESULTS: CIK-ICOS cells proliferated more and expressed higher secretion a level of interferon-γ than the controlled CIK. These cells exhibited higher cytotoxicity against cholangiocarcinoma cell lines at all efficacy: toxicity (E:T) ratios tested than the controlled CIK cells. More importantly, the anti-ICOSL antibody was able to attenuate the elevated cytotoxicity mediated by ICOS overexpression. When injected into cholangiocarcinoma xenografts in severe combined immunodeficiency mice, CIK-ICOS cells survived better than the controlled CIK cells around xenografts and significantly reduced the growth rate of cholangiocarcinoma, with least volume increase and more severe necrosis of the xenografts than controlled mice treated with saline, CIK or CIK-enhanced green fluorescent protein. CONCLUSION: ICOS can enhance the cytotoxic effect of CIK cells against cholangiocarcinoma both in vitro and in vivo. This effect is mediated by ICOS-augmented cytokine secretion and cell proliferation, and in part through ICOS-ICOSL interaction.


Assuntos
Neoplasias dos Ductos Biliares/terapia , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/terapia , Células Matadoras Induzidas por Citocinas/imunologia , Ligante Coestimulador de Linfócitos T Induzíveis/fisiologia , Proteína Coestimuladora de Linfócitos T Induzíveis/fisiologia , Animais , Neoplasias dos Ductos Biliares/imunologia , Linhagem Celular Tumoral , Colangiocarcinoma/imunologia , Humanos , Camundongos
12.
J Biol Chem ; 279(44): 46253-62, 2004 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-15319423

RESUMO

A rare form of human ACAT1 mRNA, containing the optional long 5'-untranslated region, is produced as a 4.3-kelonucleotide chimeric mRNA through a novel interchromosomal trans-splicing of two discontinuous RNAs transcribed from chromosomes 1 and 7. To investigate its function, we express the chimeric ACAT1 mRNA in Chinese hamster ovary cells and show that it can produce a larger ACAT1 protein, with an apparent molecular mass of 56 kDa on SDS-PAGE, in addition to the normal, 50-kDa ACAT1 protein, which is produced from the ACAT1 mRNAs without the optional long 5'-untranslated repeat. To produce the 56-kDa ACAT1, acat1 sequences located at both chromosomes 7 and 1 are required. The 56-kDa ACAT1 can be recognized by specific antibodies prepared against the predicted additional amino acid sequence located upstream of the N-terminal of the ACAT1(ORF). The translation initiation codon for the 56-kDa protein is GGC, which encodes for glycine, as deduced by mutation analysis and mass spectrometry. Similar to the 50-kDa protein, when expressed alone, the 56-kDa ACAT1 is located in the endoplasmic reticulum and is enzymatically active. The 56-kDa ACAT1 is present in native human cells, including human monocyte-derived macrophages. Our current results show that the function of the chimeric ACAT1 mRNA is to increase the ACAT enzyme diversity by producing a novel isoenzyme. To our knowledge, our result provides the first mammalian example that a trans-spliced mRNA produces a functional protein.


Assuntos
Cromossomos Humanos Par 1 , Cromossomos Humanos Par 7 , Isoenzimas/genética , Esterol O-Aciltransferase/genética , Sequência de Aminoácidos , Retículo Endoplasmático/enzimologia , Éxons , Humanos , Isoenzimas/química , Macrófagos/enzimologia , Dados de Sequência Molecular , Peso Molecular , Biossíntese de Proteínas , Esterol O-Aciltransferase/química
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