RESUMO
BACKGROUND: Modifications of erythrocyte membrane fatty acid (FA) contents may affect cellular function or transmembrane receptors. One cross-sectional study has shown that kidney transplant (KTP) recipients have lower erythrocyte membrane oleic acid content than dialysis patients do. Therefore, we prospectively tested whether erythrocyte membrane contents of FA including oleic acid change after KTP. METHODS: We recruited 23 KTP recipients (September 2011 through May 2014). Blood samples were obtained immediately before KTP and 6 months after. Erythrocyte membrane FA contents were measured by gas chromatography. RESULTS: Mean age of the enrolled KTP recipients was 45.3 ± 10.9 years, and men represented 66.7% of the cases. ABO-incompatible KTPs constituted 14.3% and cadaver donors 42.9% of the cases. Steroids, mycophenolate mofetil, and tacrolimus were used as immunosuppressive treatment. There was no significant difference in dietary consumption between time points before and 6 months after KTP. Total cholesterol and low-density lipoprotein cholesterol levels were significantly higher at 6 months after KTP as compared with baseline. Erythrocyte membrane contents of polyunsaturated FA, ω-3 FA, ω-6 FA, and the ω-3 index were significantly higher, but erythrocyte membrane contents of total saturated FAs, total monounsaturated FAs, including oleic acid, total trans-FA, palmitoleic acid, and the ω-6-to-ω-3 ratio were significantly lower at 6 months after KTP. CONCLUSIONS: Erythrocyte membrane FA contents significantly changed toward a more favorable cardiovascular profile after KTP. These changes in erythrocyte membrane FA contents may be related to improved renal function because of the absence of significant dietary changes.
Assuntos
Membrana Eritrocítica/metabolismo , Ácidos Graxos/sangue , Transplante de Rim , Adulto , Cromatografia Gasosa , Estudos Transversais , Membrana Eritrocítica/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Human epidermal growth factor receptor 2 (HER2)-directed treatment using trastuzumab has shown clinical benefit in HER2-positive gastric cancer. Clinical trials using lapatinib in HER2-positive gastric cancer are also currently underway. As with other molecularly targeted agents, the emergence of acquired resistance to HER2-directed treatment is an imminent therapeutic problem for HER2-positive gastric cancer. In order to investigate the mechanisms of acquired resistance to HER2-directed treatment in gastric cancer, we generated lapatinib-resistant gastric cancer cell lines (SNU216 LR) in vitro by chronic exposure of a HER2-positive gastric cancer cell line (SNU216) to lapatinib. The resultant SNU216 LR cells were also resistant to gefitinib, cetuximab, trastuzumab, afatinib and dacomitinib. Interestingly, SNU216 LR cells displayed an epithelial-mesenchymal transition (EMT) phenotype and maintained the activation of MET, HER3, Stat3, Akt and mitogen-activated protein kinase signaling in the presence of lapatinib. Using gene expression arrays, we identified the upregulation of a variety of EMT-related genes and extracellular matrix molecules, such as Testican-1, in SNU216 LR cells. We showed that the inhibition of Testican-1 by small interfering RNA decreased Testican-1-induced, MET-dependent, downstream signaling, and restored sensitivity to lapatinib in these cells. Furthermore, treatment with XAV939 selectively inhibited ß-catenin-mediated transcription and Testican-1-induced EMT signaling, leading to G1 arrest. Taken together, these data support the potential role of EMT in acquired resistance to HER2-directed treatment in HER2-positive gastric cancer, and provide insights into strategies for preventing and/or overcoming this resistance in patients.
Assuntos
Transição Epitelial-Mesenquimal/genética , Proteoglicanas/genética , Quinazolinas/farmacologia , Receptor ErbB-2/genética , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fase G1/efeitos dos fármacos , Fase G1/genética , Humanos , Lapatinib , Proteoglicanas/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptor ErbB-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , beta Catenina/genética , beta Catenina/metabolismoRESUMO
Gene fusion is involved in the development of various types of malignancies. Recent advances in sequencing technology have facilitated identification of gene fusions and have stimulated the research of this field in cancer. In the present study, we performed next-generation transcriptome sequencing in order to discover novel gene fusions in gastric cancer. A total of 282 fusion transcript candidates were detected from 12 gastric cancer cell lines by bioinformatic filtering. Among the candidates, we have validated 19 fusion transcripts, which are 7 inter-chromosomal and 12 intra-chromosomal fusions. A novel DUS4L-BCAP29 fusion transcript was found in 2 out of 12 cell lines and 10 out of 13 gastric cancer tissues. Knockdown of DUS4L-BCAP29 transcript using siRNA inhibited cell proliferation. Soft agar assay further confirmed that this novel fusion transcript has tumorigenic potential. We also identified that microRNA-coding gene PVT1, which is amplified in double minute chromosomes in SNU-16 cells, is recurrently involved in gene fusion. PVT1 produced six different fusion transcripts involving four different genes as fusion partners. Our findings provide better insight into transcriptional and genetic alterations of gastric cancer: namely, the tumorigenic effects of transcriptional read-through and a candidate region for genetic instability.
Assuntos
Fusão Gênica , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Proteínas de Membrana/genética , Oxirredutases/genética , RNA Longo não Codificante/genética , Reprodutibilidade dos Testes , Neoplasias Gástricas/genéticaRESUMO
Although the pathogenesis of Streptococcus oralis may be different from that of other viridans group streptococci, S. oralis shares a high degree of DNA sequence similarity with these streptococci. As a result, discrimination of S. oralis from its close relatives has long been considered difficult. This study was conducted to find specific genes that allow for the in vitro identification of S. oralis, but not other oral commensals. Four hundred ninety S. oralis clones obtained by suppressive subtractive hybridization were used for Southern hybridization, and positive clones were sequenced. Of 5 S. oralis-specific clones, newly designed primer sets based on the glucosyltransferase regulatory gene amplified genomic DNA only from S. oralis strains, but not from any of the other 125 strains tested. Our findings may be useful for the future development of efficient diagnostic tools for the rapid identification and differentiation of S. oralis from other oral streptococci strains.
Assuntos
Proteínas de Bactérias/análise , Marcadores Genéticos/genética , Streptococcus oralis/classificação , Transativadores/análise , Proteínas de Bactérias/genética , Southern Blotting , Células Clonais , Primers do DNA , DNA Bacteriano/análise , Enterococcus/classificação , Enterococcus/genética , Genoma Bacteriano/genética , Cocos Gram-Positivos/classificação , Cocos Gram-Positivos/genética , Humanos , Lactococcus/classificação , Lactococcus/genética , Análise de Sequência de DNA/métodos , Streptococcus/classificação , Streptococcus/genética , Streptococcus mitis/classificação , Streptococcus mitis/genética , Streptococcus oralis/genética , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/genética , Transativadores/genéticaRESUMO
Mounting evidence indicates that alterations of AKT signalling play important roles in cancer development. An earlier study discovered an oncogenic AKT1 gene mutation (AKT1 E17K) in breast, colorectal and ovarian cancers. The aim of this study was to see whether the AKT1 E17K mutation is common in breast, colorectal, lung, gastric and hepatocellular carcinomas and acute leukaemias. We analysed the presence of the AKT1 E17K mutation in 731 cancer tissues by a single-strand conformation polymorphism assay. In addition, we analysed the corresponding sequences of AKT1 E17K in AKT2 and AKT3 genes. Overall, we detected the four AKT1 E17K mutations in the breast cancers (4/93; 4.3%), but none in other cancers. There was no AKT2 or AKT3 mutation in the cancers. This study demonstrated that the AKT1 E17K mutation occurs in breast cancers at a low frequency, and that it is rare in other common cancers, including colorectal, lung, gastric and hepatocellular carcinomas and acute leukaemias. Despite the confirmed oncogenic function of the AKT1 E17K, the rare incidences of the mutation suggest that it may not play a crucial role in the development of the most common types of human cancers.
Assuntos
Leucemia/genética , Mutação , Neoplasias/genética , Proteínas Proto-Oncogênicas c-akt/genética , Doença Aguda , Adenocarcinoma/genética , Adulto , Idoso , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/genética , Carcinoma Hepatocelular/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Colorretais/genética , Análise Mutacional de DNA , Feminino , Ácido Glutâmico , Humanos , Neoplasias Hepáticas/genética , Neoplasias Pulmonares/genética , Lisina , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Neoplasias Gástricas/genéticaAssuntos
Adenocarcinoma/genética , Neoplasias da Mama/genética , Carcinoma Ductal/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias do Colo/genética , Neoplasias Pulmonares/genética , Fator 1 de Ligação ao Facilitador Linfoide/genética , Neoplasias Gástricas/genética , Proteínas Wnt/genética , Análise Mutacional de DNA , Humanos , Polimorfismo Conformacional de Fita Simples , beta Catenina/metabolismoRESUMO
BACKGROUND: Mounting evidence indicates that alteration of apoptosis is involved in the mechanisms of cancer development. PUMA, a pro-apoptotic member of Bcl-2 family, mediates p53-dependent and -independent apoptosis. AIM: The aim of this study was to explore whether alteration of PUMA protein expression is a characteristic of human gastric carcinomas. PATIENTS AND METHODS: We analysed expression of PUMA protein in 60 gastric adenocarcinomas by immunohistochemistry. Also, we examined PUMA gene mutation in the same tissues by a single-strand conformation polymorphism. RESULTS: PUMA protein expression was detected in 44 cases (73%) of the 60 gastric carcinomas, whereas it was not detected in normal gastric mucosal epithelial cells. The mutational analysis revealed no PUMA mutation in the gastric carcinomas. CONCLUSIONS: Our data suggest that PUMA mutation is not a direct target of inactivation in gastric tumourigenesis. Also, increased expression of PUMA in malignant gastric epithelial cells compared with normal mucosal epithelial cells suggested that PUMA expression may play a role in gastric tumourigenesis.
Assuntos
Adenocarcinoma/genética , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Neoplasias Gástricas/genética , Análise Mutacional de DNA , Humanos , Imuno-Histoquímica , Polimorfismo Conformacional de Fita Simples , Análise Serial de Proteínas , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: It has become clear that, together with proliferation, deregulation of apoptosis plays a pivotal role in tumourigenesis. BAD is a pro-apoptotic Bcl-2 family protein and regulates the intrinsic apoptosis pathway. Phosphorylation of BAD inhibits the apoptosis function of BAD. AIMS: To investigate whether alteration of the phospho-BAD protein and somatic mutation of BAD gene are characteristics of human hepatocellular carcinoma. PATIENTS AND METHODS: We analysed the expression of phospho-BAD in 20 hepatocellular carcinomas by immunohistochemistry. Also, we analysed the BAD gene for the detection of somatic mutations by a single-strand conformation polymorphism assay in 69 hepatocellular carcinomas. RESULTS: Phospho-BAD expression in the non-tumour hepatocytes was seen in all of the hepatocellular carcinomas, while the expression in the cancer cells was observed in 15% (3 of the 20) of the hepatocellular carcinomas. There was no somatic mutation of BAD Bcl-2 homology 3 (BH3) domain in the 69 hepatocellular carcinomas. CONCLUSIONS: The data showed that loss of phospho-BAD expression, but not BAD gene mutation, is a feature of hepatocellular carcinomas. The decreased expression of phospho-BAD in the hepatocellular carcinoma cells compared to the non-tumour hepatocytes suggests that loss of phospho-BAD expression may play a role in hepatocellular tumourigenesis.