RESUMEN
In the yeast Saccharomyces cerevisiae, the yeast episomal plasmid (YEp), containing a partial sequence from a natural 2-µm plasmid, has been frequently used to induce high levels of gene expression. In this study, we used Japanese sake yeast natural cir0 strain as a host for constructing an entire 2-µm plasmid with an expression construct using the three-fragment gap-repair method without Escherichia coli manipulation. The 2-µm plasmid contains two long inverted repeats, which is problematic for the amplification by polymerase chain reaction. Therefore, we amplified it by dividing into two fragments, each containing a single repeat together with an overlapping sequence for homologous recombination. TDH3 promoter-driven yEmRFP (TDH3p-yEmRFP) and the URA3 were used as a reporter gene and a selection marker, respectively, and inserted at the 3' end of the RAF1 gene on the 2-µm plasmid. The three fragments were combined and used for the transformation of sake yeast cir0 ura3- strain. The resulting transformant colonies showed a red or purple coloration, which was significantly stronger than that of the cells transformed with YEp-TDH3p-yEmRFP. The 2-µm transformants were cultured in YPD medium and observed by fluorescence microscopy. Almost all cells showed strong fluorescence, suggesting that the plasmid was preserved during nonselective culture conditions. The constructed plasmid maintained a high copy state similar to that of the natural 2-µm plasmid, and the red fluorescent protein expression was 54 fold compared with the chromosomal integrant. This vector is named YHp, the Yeast Hyper expression plasmid.
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Genes Fúngicos , Técnicas de Amplificación de Ácido Nucleico , Plásmidos/genética , Saccharomyces cerevisiae/genética , Clonación Molecular , ADN de Hongos/genética , Alimentos Fermentados/microbiología , Expresión Génica , Proteínas Luminiscentes/genética , Recombinación Genética , Proteína Fluorescente RojaRESUMEN
AIMS: Codrituzumab (GC33) is a recombinant, humanized mAb that binds to glypican-3 (GPC3), an oncofetal protein highly expressed in hepatocellular carcinoma (HCC). This investigation aimed to identify clinically relevant factors that may affect the overall survival (OS) in HCC patients treated with codrituzumab and to quantitatively annotate their effects. METHODS: Codrituzumab exposure was estimated by a population pharmacokinetics model with a nonlinear elimination pathway. Analysis of OS was performed using a time-to-event model in 181 patients with advanced HCC. The model was tested with the addition of various covariates, including levels of immune biomarkers, such as CD16 (measured in terms of molecules of equivalent soluble fluorophore; CD16MESF ) and CD4, codrituzumab exposure and potential prognostic biomarkers of HCC such as baseline tumour size and soluble GPC3. RESULTS: The time-to-event model estimated a prolonged OS (>3 months) in patients with codrituzumab exposure of ≥230 µg ml-1 and high CD16MESF level (>5.26 × 105 MESF at least). The Weibull model was selected as the base hazard model. The baseline tumour size was included in the hazard model as a parameter independent of the drug effect. A logistic model was applied to explain the effects of drug exposure and CD16MESF level. CONCLUSIONS: The final model indicates that adequate drug exposure plus a favourable immune environment are associated with prolonged OS. This quantitative model should be further validated with emerging data so as to guide study design in future clinical trials.
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Anticuerpos Monoclonales Humanizados/uso terapéutico , Antígenos CD4/sangre , Carcinoma Hepatocelular/tratamiento farmacológico , Glipicanos/sangre , Neoplasias Hepáticas/tratamiento farmacológico , Receptores de IgG/sangre , Anticuerpos Monoclonales Humanizados/sangre , Anticuerpos Monoclonales Humanizados/farmacocinética , Biomarcadores de Tumor/sangre , Carcinoma Hepatocelular/sangre , Carcinoma Hepatocelular/mortalidad , Método Doble Ciego , Humanos , Modelos de Riesgos Proporcionales , Análisis de SupervivenciaRESUMEN
BACKGROUND: Although nucleos(t)ide analog (NA) therapy effectively reduces the hepatitis B virus (HBV) DNA load in the serum of patients with chronic hepatitis B, it does not completely reduce the incidence of hepatocellular carcinoma (HCC). METHODS AND RESULTS: A total of 109 patients who had chronic hepatitis B and were receiving NA therapy were analyzed. Multivariate Cox regression analysis showed that age (>60 years had a hazard ratio [HR] of 2.66), FIB-4 index (an index of >2.1 had a HR of 2.57), and the presence of HBV core-related antigen (HBcrAg; HR, 3.53) during treatment were significantly associated with the development of HCC. The amount of HBV DNA and pregenomic RNA in liver were significantly higher in 16 HBcrAg-positive patients, compared with 12 HBcrAg-negative patients, suggesting active HBV replication in HBcrAg-positive livers. Hepatic gene expression profiling showed that HBV-promoting transcriptional factors, including HNF4α, PPARα, and LRH1, were upregulated in HBcrAg-positive livers. HepAD38 cells overexpressing LRH1 increased HBV replication, characterized by higher HBV DNA and pregenomic RNA levels, during long-term exposure to entecavir. Conversely, overexpression of precore/core in HepG2 cells increased levels of these transcriptional factors. Metformin efficiently repressed HBV replication in primary human hepatocytes. CONCLUSIONS: Modulating HBV transcriptional factors by metformin in combination with NA therapy would potentiate anti-HBV activity and reduce the incidence of HCC in HBcrAg-positive patients.
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Antivirales/uso terapéutico , Carcinoma Hepatocelular/virología , Antígenos del Núcleo de la Hepatitis B/sangre , Hepatitis B Crónica/complicaciones , Neoplasias Hepáticas/virología , Adulto , Anciano , Línea Celular Tumoral , Femenino , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/fisiología , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/virología , Humanos , Hipoglucemiantes/farmacología , Hígado/virología , Cirrosis Hepática/patología , Masculino , Metformina/farmacología , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Transcriptoma , Replicación Viral/efectos de los fármacosRESUMEN
Differentially regulated microRNA (miRNA) are associated with hepatic fibrosis; however, their potential usefulness for blocking hepatic fibrosis has not been exploited fully. We examined the expression of miRNA in the liver of a transgenic mouse model in which platelet-derived growth factor C (PDGF-C) is overexpressed (Pdgf-c Tg), resulting in hepatic fibrosis and steatosis and the eventual development of hepatocellular carcinoma (HCC). Robust induction of miR-214 correlated with fibrogenesis in the liver of Pdgf-c Tg mice, atherogenic high-fat diet-induced NASH mice, and patients with chronic hepatitis B or C. Pdgf-c Tg mice were injected with locked nucleic acid (LNA)-antimiR-214 via the tail vein using Invivofectamine 2.0 and the degree of hepatic fibrosis and tumor incidence were evaluated. Pdgf-c Tg mice treated with LNA-antimiR-214 showed a marked reduction in fibrosis and tumor incidence compared with saline or LNA-miR-control-injected control mice. In vitro, LNA-antimiR-214 significantly ameliorated TGF-ß1-induced pro-fibrotic gene expression in Lx-2 cells. MiR-214 targets a negative regulator of EGFR signaling, Mig-6. Mimic-miR-214 decreased the expression of Mig-6 and increased the levels of EGF-mediated p-EGFR (Y1173 and Y845) and p-Met (Tyr1234/1235) in Huh-7 cells. Conversely, LNA-antimiR-214 repressed the expression of these genes. In conclusion, miR-214 appears to participate in the development of hepatic fibrosis by modulating the EGFR and TGF-ß signaling pathways. LNA-antimiR-214 is a potential therapy for the prevention of hepatic fibrosis.
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Cirrosis Hepática/genética , Neoplasias Hepáticas/genética , Linfocinas/genética , Ratones Transgénicos/genética , MicroARNs/genética , Factor de Crecimiento Derivado de Plaquetas/genética , Animales , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Línea Celular , Línea Celular Tumoral , Factor de Crecimiento Epidérmico/genética , Receptores ErbB/genética , Expresión Génica/genética , Células HEK293 , Células Hep G2 , Humanos , Incidencia , Hígado/patología , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Oligonucleótidos/genética , Proteínas Proto-Oncogénicas c-met/genética , Transducción de Señal/genética , Factor de Crecimiento Transformador beta1/genéticaRESUMEN
UNLABELLED: Pretreatment up-regulation of hepatic interferon (IFN)-stimulated genes (ISGs) has a stronger association with the treatment-resistant interleukin (IL)28B minor genotype (MI; TG/GG at rs8099917) than with the treatment-sensitive IL28B major genotype (MA; TT at rs8099917). We compared the expression of ISGs in the liver and blood of 146 patients with chronic hepatitis C who received pegylated IFN and ribavirin combination therapy. Gene expression profiles in the liver and blood of 85 patients were analyzed using an Affymetrix GeneChip (Affymetrix, Santa Clara, CA). ISG expression was correlated between the liver and blood of the MA patients, whereas no correlation was observed in the MI patients. This loss of correlation was the result of the impaired infiltration of immune cells into the liver lobules of MI patients, as demonstrated by regional gene expression analysis in liver lobules and portal areas using laser capture microdissection and immunohistochemical staining. Despite having lower levels of immune cells, hepatic ISGs were up-regulated in the liver of MI patients and they were found to be regulated by multiple factors, namely, IL28A/B, IFN-λ4, and wingless-related MMTV integration site 5A (WNT5A). Interestingly, WNT5A induced the expression of ISGs, but also increased hepatitis C virus replication by inducing the expression of the stress granule protein, GTPase-activating protein (SH3 domain)-binding protein 1 (G3BP1), in the Huh-7 cell line. In the liver, the expression of WNT5A and its receptor, frizzled family receptor 5, was significantly correlated with G3BP1. CONCLUSIONS: Immune cells were lost and induced the expression of other inflammatory mediators, such as WNT5A, in the liver of IL28B minor genotype patients. This might be related to the high level of hepatic ISG expression in these patients and the treatment-resistant phenotype of the IL28B minor genotype.
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Farmacorresistencia Viral/genética , Hepacivirus/inmunología , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/genética , Interferón-alfa/farmacología , Interleucinas/genética , Polietilenglicoles/farmacología , Adulto , Anciano , Antivirales/farmacología , Regulación hacia Abajo/inmunología , Farmacorresistencia Viral/inmunología , Femenino , Receptores Frizzled/inmunología , Receptores Frizzled/metabolismo , Genotipo , Hepacivirus/crecimiento & desarrollo , Hepatitis C Crónica/inmunología , Humanos , Interferón alfa-2 , Interferón-alfa/genética , Interferón-alfa/inmunología , Interferón beta/genética , Interferón beta/inmunología , Interferones , Interleucinas/inmunología , Hígado/citología , Hígado/efectos de los fármacos , Hígado/inmunología , Masculino , Persona de Mediana Edad , Proteínas Proto-Oncogénicas/inmunología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Recombinantes/farmacología , Transducción de Señal/inmunología , Regulación hacia Arriba/inmunología , Proteínas Wnt/inmunología , Proteínas Wnt/metabolismo , Proteína Wnt-5aRESUMEN
BACKGROUND: Targeting of cellular proteins to the extracellular environment is directed by a secretory signal sequence located at the N-terminus of a secretory protein. These signal sequences usually contain an N-terminal basic amino acid followed by a stretch containing hydrophobic residues, although no consensus signal sequence has been identified. In this study, simple modeling of signal sequences was attempted using Gaussia princeps secretory luciferase (GLuc) in the yeast Kluyveromyces marxianus, which allowed comprehensive recombinant gene construction to substitute synthetic signal sequences. RESULTS: Mutational analysis of the GLuc signal sequence revealed that the GLuc hydrophobic peptide length was lower limit for effective secretion and that the N-terminal basic residue was indispensable. Deletion of the 16th Glu caused enhanced levels of secreted protein, suggesting that this hydrophilic residue defined the boundary of a hydrophobic peptide stretch. Consequently, we redesigned this domain as a repeat of a single hydrophobic amino acid between the N-terminal Lys and C-terminal Glu. Stretches consisting of Phe, Leu, Ile, or Met were effective for secretion but the number of residues affected secretory activity. A stretch containing sixteen consecutive methionine residues (M16) showed the highest activity; the M16 sequence was therefore utilized for the secretory production of human leukemia inhibitory factor protein in yeast, resulting in enhanced secreted protein yield. CONCLUSIONS: We present a new concept for the provision of secretory signal sequence ability in the yeast K. marxianus, determined by the number of residues of a single hydrophobic residue located between N-terminal basic and C-terminal acidic amino acid boundaries.
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Proteínas de Artrópodos/genética , Copépodos/genética , Kluyveromyces/genética , Luciferasas/genética , Señales de Clasificación de Proteína/genética , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Aminoácidos/química , Aminoácidos/genética , Aminoácidos/metabolismo , Animales , Proteínas de Artrópodos/química , Proteínas de Artrópodos/metabolismo , Western Blotting , Copépodos/enzimología , Expresión Génica , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Kluyveromyces/metabolismo , Factor Inhibidor de Leucemia/genética , Factor Inhibidor de Leucemia/metabolismo , Luciferasas/química , Luciferasas/metabolismo , Datos de Secuencia Molecular , Mutación , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Proteínas Recombinantes/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de AminoácidoRESUMEN
Many fusion genes, which are the result of chromosomal translocation and work as an oncogene, have been recently identified, but their mode of actions is still unclear. Here, we performed a yeast mutant screening for oncogenes of Ewing's sarcoma to easily identify essential regions responsible for fusion protein functions using a yeast genetic system. Three kinds of oncogenes including EWS/FLI1, EWS/ERG, and EWS/E1AF exhibited growth inhibition in yeast. In this screening, we identified 13 single amino acid substitution mutants which could suppress growth inhibition by oncogenes. All of the point mutation positions of the EWS/ETS family proteins were located within the ETS domain, which is responsible for the interaction with a specific DNA motif. Eight-mutated residues within the ETS domain matched to 13 completely conserved amino acid residues in the human ETS domains. Moreover, mutants also showed reduced transcriptional activities on the DKK2 promoter, which is upregulated by the EWS/ETS family, compared to that of the wild type. These results suggest that the ETS domain in the EWS/ETS family proteins may be a primary target for growth inhibition of Ewing's sarcoma and that this yeast screening system can be applied for the functional screening of the oncogenes.
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Proteínas E1A de Adenovirus/genética , Pruebas Genéticas/métodos , Proteínas Mutantes/genética , Proteína Proto-Oncogénica c-fli-1/genética , Proteínas Proto-Oncogénicas/genética , Sarcoma de Ewing/genética , Transactivadores/genética , Proteínas E1A de Adenovirus/metabolismo , Sustitución de Aminoácidos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Proteínas Mutantes/metabolismo , Regiones Promotoras Genéticas , Unión Proteica , Estructura Terciaria de Proteína , Proteína Proto-Oncogénica c-fli-1/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-ets , Transactivadores/metabolismo , Regulador Transcripcional ERG , Levaduras/genéticaRESUMEN
AIMS/HYPOTHESIS: The cholesterol absorption inhibitor ezetimibe has been shown to ameliorate non-alcoholic fatty liver disease (NAFLD) pathology in a single-armed clinical study and in experimental animal models. In this study, we investigated the efficacy of ezetimibe on NAFLD pathology in an open-label randomised controlled clinical trial. METHODS: We had planned to enrol 80 patients in the trial, as we had estimated that, with this sample size, the study would have 90% power. The study intervention and enrolment were discontinued because of the higher proportion of adverse events (significant elevation in HbA(1c)) in the ezetimibe group than in the control group. Thirty-two patients with NAFLD were enrolled and randomised (allocation by computer program). Ezetimibe (10 mg/day) was given to 17 patients with NAFLD for 6 months. The primary endpoint was change in serum aminotransferase level. Secondary outcomes were change in liver histology (12 control and 16 ezetimibe patients), insulin sensitivity including a hyperinsulinaemic-euglycaemic clamp study (ten control and 13 ezetimibe patients) and hepatic fatty acid composition (six control and nine ezetimibe patients). Hepatic gene expression profiling was completed in 15 patients using an Affymetrix gene chip. Patients and the physician in charge knew to which group the patient had been allocated, but people carrying out measurements or examinations were blinded to group. RESULTS: Serum total cholesterol was significantly decreased in the ezetimibe group. The fibrosis stage and ballooning score were also significantly improved with ezetimibe treatment. However, ezetimibe treatment significantly increased HbA1c and was associated with a significant increase in hepatic long-chain fatty acids. Hepatic gene expression analysis showed coordinate downregulation of genes involved in skeletal muscle development and cell adhesion molecules in the ezetimibe treatment group, suggesting a suppression of stellate cell development into myofibroblasts. Genes involved in the L-carnitine pathway were coordinately downregulated by ezetimibe treatment and those in the steroid metabolism pathway upregulated, suggestive of impaired oxidation of long-chain fatty acids. CONCLUSIONS/INTERPRETATION: Ezetimibe improved hepatic fibrosis but increased hepatic long-chain fatty acids and HbA1c in patients with NAFLD. These findings shed light on previously unrecognised actions of ezetimibe that should be examined further in future studies. TRIAL REGISTRATION: University Hospital Medical Information Network (UMIN) Clinical Trials Registry UMIN000005250. FUNDING: The study was funded by grants-in-aid from the Ministry of Education, Culture, Sports, Science and Technology, Japan, and research grants from MSD.
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Anticolesterolemiantes/uso terapéutico , Azetidinas/uso terapéutico , Glucosa/metabolismo , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Anciano , Área Bajo la Curva , Biopsia , Carnitina/metabolismo , Colesterol/química , Ezetimiba , Ácidos Grasos/metabolismo , Femenino , Fibrosis , Perfilación de la Expresión Génica , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Hemoglobina Glucada/metabolismo , Humanos , Insulina/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Miofibroblastos/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Transducción de Señal , Transaminasas/sangre , Resultado del TratamientoRESUMEN
The cloning of DNA fragments into vectors or host genomes has traditionally been performed using Escherichia coli with restriction enzymes and DNA ligase or homologous recombination-based reactions. We report here a novel DNA cloning method that does not require DNA end processing or homologous recombination, but that ensures highly accurate cloning. The method exploits the efficient non-homologous end-joining (NHEJ) activity of the yeast Kluyveromyces marxianus and consists of a novel functional marker selection system. First, to demonstrate the applicability of NHEJ to DNA cloning, a C-terminal-truncated non-functional ura3 selection marker and the truncated region were PCR-amplified separately, mixed and directly used for the transformation. URA3(+) transformants appeared on the selection plates, indicating that the two DNA fragments were correctly joined by NHEJ to generate a functional URA3 gene that had inserted into the yeast chromosome. To develop the cloning system, the shortest URA3 C-terminal encoding sequence that could restore the function of a truncated non-functional ura3 was determined by deletion analysis, and was included in the primers to amplify target DNAs for cloning. Transformation with PCR-amplified target DNAs and C-terminal truncated ura3 produced numerous transformant colonies, in which a functional URA3 gene was generated and was integrated into the chromosome with the target DNAs. Several K. marxianus circular plasmids with different selection markers were also developed for NHEJ-based cloning and recombinant DNA construction. The one-step DNA cloning method developed here is a relatively simple and reliable procedure among the DNA cloning systems developed to date.
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Clonación Molecular/métodos , Kluyveromyces/genética , Recombinación Genética , Selección Genética , Transformación Genética , Plásmidos , Proteínas de Saccharomyces cerevisiae/genéticaRESUMEN
In this study, we developed the drug-drug interaction (DDI) method as a new assessment technique of intestinal availability (F(G), the fraction of drug transferred from the intestinal enterocytes into the liver, escaping from intestinal metabolism) based on the clearance theory. This method evaluates F(G) from changes caused by DDIs in the area under the blood concentration-time curve and in the elimination half-life of victim drugs. Application of the DDI method to data from the literature revealed that the mean and S.D. of F(G) values for 20 substrate drugs of CYP3A was 0.56 ± 0.29, whereas that for 8 substrate drugs of CYP2C9, CYP2C19, and CYP2D6 was 0.86 ± 0.11. These results were consistent with the fact that intestinal metabolism is mediated predominantly by CYP3A. The DDI method showed reasonable correlations with the conventional i.v./p.o. method and the grape fruit juice (GFJ) method (coefficients of determination of 0.41 and 0.81, respectively). The i.v./p.o. method was more susceptible to fluctuations in the hepatic blood flow rate compared with the DDI and GFJ methods. The DDI method evaluates F(G) separating from the absorption ratio (F(A)) although it requires approximation of F(A). Since preciseness of approximation of F(A) does not greatly affect the evaluation of F(G) by the DDI method, we proposed a reasonable approximation method of F(A) for the evaluation of F(G) in the DDI method. The DDI method would be applicable to a broad range of situations in which various DDI data are utilizable.
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Sistema Enzimático del Citocromo P-450/metabolismo , Interacciones Farmacológicas , Absorción Intestinal , Modelos Biológicos , Preparaciones Farmacéuticas/metabolismo , HumanosRESUMEN
BACKGROUND & AIMS: Gene expression profiling of hepatocellular carcinoma (HCC) and background liver has been studied extensively; however, the relationship between the gene expression profiles of different lesions has not been assessed. METHODS: We examined the expression profiles of 34 HCC specimens (17 hepatitis B virus [HBV]-related and 17 hepatitis C virus [HCV]-related) and 71 non-tumor liver specimens (36 chronic hepatitis B [CH-B] and 35 chronic hepatitis C [CH-C]) using an in-house cDNA microarray consisting of liver-predominant genes. Graphical Gaussian modeling (GGM) was applied to elucidate the interactions of gene clusters among the HCC and non-tumor lesions. RESULTS: In CH-B-related HCC, the expression of vascular endothelial growth factor-family signaling and regulation of T cell differentiation, apoptosis, and survival, as well as development-related genes was up-regulated. In CH-C-related HCC, the expression of ectodermal development and cell proliferation, wnt receptor signaling, cell adhesion, and defense response genes was also up-regulated. Many of the metabolism-related genes were down-regulated in both CH-B- and CH-C-related HCC. GGM analysis of the HCC and non-tumor lesions revealed that DNA damage response genes were associated with AP1 signaling in non-tumor lesions, which mediates the expression of many genes in CH-B-related HCC. In contrast, signal transducer and activator of transcription 1 and phosphatase and tensin homolog were associated with early growth response protein 1 signaling in non-tumor lesions, which potentially promotes angiogenesis, fibrogenesis, and tumorigenesis in CH-C-related HCC. CONCLUSIONS: Gene expression profiling of HCC and non-tumor lesions revealed the predisposing changes of gene expression in HCC. This approach has potential for the early diagnosis and possible prevention of HCC.
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Carcinoma Hepatocelular/genética , Perfilación de la Expresión Génica , Hepatitis B/complicaciones , Hepatitis C/complicaciones , Neoplasias Hepáticas/genética , Modelos Genéticos , Adulto , Anciano , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/virología , Adhesión Celular/genética , Daño del ADN/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/virología , Masculino , Persona de Mediana Edad , Distribución Normal , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/metabolismo , Transcripción Genética , Factores de Crecimiento Endotelial Vascular/genética , Factores de Crecimiento Endotelial Vascular/metabolismo , Vía de Señalización Wnt/genéticaRESUMEN
pET vectors allow inducible expression of recombinant proteins in Escherichia coli. In this system, isopropyl ß-d-1-thiogalactopyranoside (IPTG) drives lacUV5 promoter to produce T7 RNA polymerase, simultaneously releasing the suppression of T7lac promoter. T7 RNA polymerase then strongly transcribes the target gene. A lac repressor encoded by lacI in the vector represses the promoters. Despite stringent repression and inducible expression achieved with the pET system, unexpected leaky expression can occur without IPTG induction. Here, by evaluating leaky expression in recombinant cells cultured in various Luria-Bertani (LB) media, prepared using yeast extract and peptone from different suppliers, as well as in five commercial premix-LB media, we confirmed the presence of unknown lac inducers in LB. To explore these inducers, we examined E. coli growth in media comprising yeast extract or peptone. At 4% concentration, five commercial yeast extract and six peptone samples individually allowed E. coli growth equivalent to that in LB medium. We determined the luciferase activity of the luxCDABE operon in the pET vector under these conditions. The presence of different concentrations of inducers was detected in both the yeast extract and peptone. Furthermore, we blended yeast extract and peptone with low or high concentrations of lac inducers. The low-expression blend, used as a basal medium before IPTG addition, allowed leak-free, tightly controlled expression. The high-expression blend was used for constitutive high-expression and pET induction with the basal medium, in lieu of IPTG. These blended media can be used for well-controlled inducible and constitutive expression using the pET system.
RESUMEN
BACKGROUND AND PURPOSE: Fraction metabolized (fm ) and fraction transported (ft ) are important for understanding drug-drug interactions (DDIs) in drug discovery and development. However, current in vitro systems cannot accurately estimate in vivo fm due to inability to reflect the ft by efflux transporters (ft,efflux ). This study demonstrates how CYP3A-mediated DDI for CYP3A/P-gp substrates can be predicted using Hu-PXB mice as human liver chimeric mice. EXPERIMENTAL APPROACH: For estimating human in vitro fm by CYP3A enzyme (fm,CYP3A,in vitro ), six drugs, including CYP3A/P-gp substrates (alprazolam, cyclosporine, docetaxel, midazolam, prednisolone, and theophylline) and human hepatocytes were incubated with or without ketoconazole as a CYP3A inhibitor. We calculated fm,CYP3A,in vitro based on hepatic intrinsic clearance. To estimate human in vivo fm,CYP3A (fm,CYP3A,in vivo ), we collected information on clinical DDI caused by ketoconazole for these six drugs. We calculated fm,CYP3A,in vivo using the change of total clearance (CLtotal ). For evaluating the human DDI predictability, the six drugs were administered intravenously to Hu-PXB and SCID mice with or without ketoconazole. We calculated the change of CLtotal caused by ketoconazole. We compared the CLtotal change in humans with that in Hu-PXB and SCID mice. KEY RESULTS: The fm,CYP3A,in vitro was overestimated compared to the fm,CYP3A,in vivo . Hu-PXB mice showed much better correlation in the change of CLtotal with humans (R2 = 0.95) compared to SCID mice (R2 = 0.0058). CONCLUSIONS AND IMPLICATIONS: CYP3A-mediated DDI can be predicted by correctly estimating human fm,CYP3A,in vivo using Hu-PXB mice. These mice could be useful predicting hepatic fm and ft,efflux .
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Citocromo P-450 CYP3A , Cetoconazol , Humanos , Ratones , Animales , Citocromo P-450 CYP3A/metabolismo , Cetoconazol/metabolismo , Ratones SCID , Hígado/metabolismo , Interacciones FarmacológicasRESUMEN
Recombinant DNAs are traditionally constructed using Escherichia coli plasmids. In the yeast Saccharomyces cerevisiae, chromosomal gene targeting is a common technique, implying that the yeast homologous recombination system could be applied for recombinant DNA construction. In an attempt to use a S. cerevisiae chromosome for recombinant DNA construction, we selected the single ura3Δ0 locus as a gene targeting site. By selecting this single locus, repeated recombination using the surrounding URA3 sequences can be performed. The recombination system described here has several advantages over the conventional plasmid system, as it provides a method to confirm the selection of correct recombinants because transformation of the same locus replaces the pre-existing selection marker, resulting in the loss of the marker in successful recombinations. In addition, the constructed strains can serve as both PCR templates and hosts for preparing subsequent recombinant strains. Using this method, several yeast strains that contained selection markers, promoters, terminators and target genes at the ura3Δ0 locus were successfully generated. The system described here can potentially be applied for the construction of any recombinant DNA without the requirement for manipulations in E. coli. Interestingly, we unexpectedly found that several G/C-rich sequences used for fusion PCR lowered gene expression when located adjacent to the start codon.
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ADN Recombinante/genética , Marcación de Gen/métodos , Recombinación Homóloga , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Regulación Fúngica de la Expresión Génica , Sitios Genéticos , Reacción en Cadena de la Polimerasa , Regiones Promotoras GenéticasRESUMEN
The isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. For the development of these genetic methods in the thermotolerant fermentative yeast Kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. To identify the mutated genes, linear DNA fragments of nutrient biosynthetic pathway genes were amplified from Saccharomyces cerevisiae chromosomal DNA and used to directly transform the K. marxianus auxotrophic mutants by random integration into chromosomes through non-homologous end joining (NHEJ). The appearance of transformant colonies indicated that the specific S. cerevisiae gene complemented the K. marxianus mutant. Using this interspecific complementation approach with linear PCR-amplified DNA, we identified auxotrophic mutations of ADE2, ADE5,7, ADE6, HIS2, HIS3, HIS4, HIS5, HIS6, HIS7, LYS1, LYS2, LYS4, LYS9, LEU1, LEU2, MET2, MET6, MET17, TRP3, TRP4 and TRP5 without the labour-intensive requirement of plasmid construction. Mating, sporulation and tetrad analysis techniques for K. marxianus were also established. With the identified auxotrophic mutant strains and S. cerevisiae genes as selective markers, NHEJ-mediated integrative transformation with PCR-amplified DNA is an attractive system for facilitating genetic analyses in the yeast K. marxianus.
Asunto(s)
ADN de Hongos/genética , Kluyveromyces/genética , Saccharomyces cerevisiae/genética , Prueba de Complementación Genética , Kluyveromyces/citología , Mutación , Plásmidos/genética , Recombinación Genética , Saccharomyces cerevisiae/citología , Transformación Genética , TransgenesRESUMEN
BACKGROUND: The acyclic retinoid, peretinoin, has been shown to be effective for suppressing hepatocellular carcinoma (HCC) recurrence after definitive treatment in a small-scale randomized clinical trial. However, little has been documented about the mechanism by which peretinoin exerts its inhibitory effects against recurrent HCC in humans in vivo. METHODS: Twelve hepatitis C virus-positive patients whose HCC had been eradicated through curative resection or ablation underwent liver biopsy at baseline and week 8 of treatment with either a daily dose of 300 or 600 mg peretinoin. RNA isolated from biopsy samples was subjected to gene expression profile analysis. RESULTS: Peretinoin treatment elevated the expression levels of IGFBP6, RBP1, PRB4, CEBPA, G0S2, TGM2, GPRC5A, CYP26B1, and many other retinoid target genes. Elevated expression was also observed for interferon-, Wnt-, and tumor suppressor-related genes. By contrast, decreased expression levels were found for mTOR- and tumor progression-related genes. Interestingly, gene expression profiles for week 8 of peretinoin treatment could be classified into two groups of recurrence and non-recurrence with a prediction accuracy rate of 79.6% (P<0.05). In the liver of patients with non-recurrence, expression of PDGFC and other angiogenesis genes, cancer stem cell marker genes, and genes related to tumor progression was down-regulated, while expression of genes related to hepatocyte differentiation, tumor suppression genes, and other genes related to apoptosis induction was up-regulated. CONCLUSIONS: Gene expression profiling at week 8 of peretinoin treatment could successfully predict HCC recurrence within 2 years. This study is the first to show the effect of peretinoin in suppressing HCC recurrence in vivo based on gene expression profiles and provides a molecular basis for understanding the efficacy of peretinoin.
Asunto(s)
Antineoplásicos/farmacología , Carcinoma Hepatocelular/genética , Expresión Génica/efectos de los fármacos , Neoplasias Hepáticas/genética , Recurrencia Local de Neoplasia/genética , Retinoides/farmacología , Anciano , Análisis de Varianza , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/complicaciones , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/cirugía , Femenino , Perfilación de la Expresión Génica , Hepatitis C Crónica/complicaciones , Humanos , Neoplasias Hepáticas/complicaciones , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/prevención & control , Análisis de Secuencia por Matrices de Oligonucleótidos , Retinoides/uso terapéuticoRESUMEN
Drugs affecting cellular morphological changes leading to tumor cell migration and invasion are desirable for cancer therapy. In the present study, we screened for small-molecule compounds that affect the cellular morphology of both unicellular yeast and mammalian HEK293 cells to identify drug candidates. The yeast formin protein Bni1 and Src homology 3 (SH3)-pleckstrin homology (PH) domain protein Boi1, which are required for proper morphogenesis, cause growth defects when overexpressed in yeast. Using this system, we screened a chemical library consisting of ï½8000 compounds to identify drug candidates that suppress these growth defects. None of the screened compounds induced morphological changes in vegetatively growing yeast cells, but several compounds had inhibitory effects on pheromone-induced projection formation and actin localization, suggesting that these compounds affected a specific stage of morphogenesis. Five of the compounds also induced morphological changes in mammalian HEK293 cells. Among the identified compounds, BTB03156, 2-[(4-chlorophenyl)sulfonyl]-1-methyl-3,5-dinitrobenzene, and BTB02467, 1-[(4-chlorophenyl)sulfonyl]-2-nitro-4-(trifluoromethyl)benzene, although they have similar structures, displayed differing effects on the yeast growth defects caused by latrunculin A, an actin polymerization inhibitor. The chemical library compounds identified using this in vivo screening approach are simple, cell-permeable molecules, and therefore may be useful in the development of therapeutic drugs for cancer metastasis and other actin-related diseases.
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Actinas/metabolismo , Citoesqueleto/metabolismo , Proteínas de Microfilamentos/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Actinas/química , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Citoesqueleto/efectos de los fármacos , Células HEK293 , Humanos , Proteínas de Microfilamentos/química , Morfogénesis/efectos de los fármacos , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMEN
Ossifying fibromas are bone-related benign neoplasms that are characterized by well-demarcated lesions composed of fibrocellular tissue and mineralized material with varying appearances. Although small lesions are asymptomatic, they may cause enlargement of the affected jaw and rarely require reconstructive or restorative treatments for aesthetic and functional problems. In this study, we report a 35-year-old woman who underwent multidisciplinary treatment for a large ossifying fibroma of the mandible. A segmental mandibular resection was performed, and immediate reconstruction was performed using iliac bone and great auricular nerve grafts. After consolidation of the grafted bone, oral rehabilitation was fulfilled using osseointegrated implants and a fixed prosthesis. There was no evidence of recurrence ten years after the resection of the tumor. The range of mouth opening and motion of the temporomandibular joint provided a functional mandible. The neurosensory examination revealed the recovery of sensibility of the mental region and pulpal sensitivity of the teeth. The prosthesis was stable, and no clinical or radiographic signs of implant failure were observed. Our results demonstrate that the proper combination of reconstructive and restorative treatments could result in appropriate aesthetic and functional outcomes for a period of ten years.
Asunto(s)
Trasplante Óseo , Implantación Dental Endoósea , Pabellón Auricular/inervación , Fibroma Osificante/rehabilitación , Fibroma Osificante/cirugía , Mandíbula/cirugía , Neoplasias Mandibulares/rehabilitación , Neoplasias Mandibulares/cirugía , Reconstrucción Mandibular/métodos , Rehabilitación Bucal/métodos , Transferencia de Nervios , Adulto , Femenino , Fibroma Osificante/patología , Estudios de Seguimiento , Humanos , Ilion/cirugía , Ilion/trasplante , Mandíbula/diagnóstico por imagen , Neoplasias Mandibulares/patología , Oseointegración , CintigrafíaRESUMEN
BACKGROUND: Mechanistic static pharmacokinetic (MSPK) models are simple, have fewer data requirements, and have broader applicability; however, they cannot use in vitro information and cannot distinguish the contributions of multiple cytochrome P450 (CYP) isoenzymes and the hepatic and intestinal first-pass effects appropriately. We aimed to establish a new MSPK analysis framework for the comprehensive prediction of drug interactions (DIs) to overcome these disadvantages. METHODS: Drug interactions that occurred by inhibiting CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A in the liver and CYP3A in the intestine were simultaneously analyzed for 59 substrates and 35 inhibitors. As in vivo information, the observed changes in the area under the concentration-time curve (AUC) and elimination half-life (t1/2), hepatic availability, and urinary excretion ratio were used. As in vitro information, the fraction metabolized (fm) and the inhibition constant (Ki) were used. The contribution ratio (CR) and inhibition ratio (IR) for multiple clearance pathways and hypothetical volume (VHyp) were inferred using the Markov Chain Monte Carlo (MCMC) method. RESULT: Using in vivo information from 239 combinations and in vitro 172 fm and 344 Ki values, changes in AUC, and t1/2 were estimated for all 2065 combinations, wherein the AUC was estimated to be more than doubled for 602 combinations. Intake-dependent selective intestinal CYP3A inhibition by grapefruit juice has been suggested. By separating the intestinal contributions, DIs after intravenous dosing were also appropriately inferred. CONCLUSION: This framework would be a powerful tool for the reasonable management of various DIs based on all available in vitro and in vivo information.
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Citocromo P-450 CYP3A , Isoenzimas , Humanos , Citocromo P-450 CYP3A/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Interacciones FarmacológicasRESUMEN
BACKGROUND & AIMS: Patients with advanced chronic hepatitis C (CH-C) often are malnourished, but the effects of malnutrition on interferon (IFN) signaling and response to treatment have not been determined. We assessed the importance of the nutritional state of the liver on IFN signaling and treatment response. METHODS: We studied data from 168 patients with CH-C who were treated with the combination of pegylated-IFN and ribavirin. Plasma concentrations of amino acids were measured by mass spectrometry. Liver gene expression profiles were obtained from 91 patients. Huh-7 cells were used to evaluate the IFN signaling pathway, mammalian target of rapamycin complex 1 (mTORC1), and forkhead box O (FoxO). Antiviral signaling induced by branched-chain amino acids (BCAAs) was determined using the in vitro hepatitis C virus replication system. RESULTS: Multivariate logistic regression analysis showed that Fischer's ratio was associated significantly with nonresponders, independent of interleukin-28B polymorphisms or the histologic stage of the liver. Fischer's ratio was correlated inversely with the expression of BCAA transaminase 1, and was affected by hepatic mTORC1 signaling. IFN stimulation was impaired substantially in Huh-7 cells grown in medium that was low in amino acid concentration, through repressed mTORC1 signaling, and increased Socs3 expression, which was regulated by Foxo3a. BCAA could restore impaired IFN signaling and inhibit hepatitis C virus replication under conditions of malnutrition. CONCLUSIONS: Malnutrition impaired IFN signaling by inhibiting mTORC1 and activating Socs3 signaling through Foxo3a. Increasing BCAAs to up-regulate IFN signaling might be used as a new therapeutic approach for patients with advanced CH-C.