RESUMO
Warfarin is a commonly prescribed anticoagulant drug for the prevention of thromboembolic disorders. We investigated the contribution of genetic variations of four genes and clinical factors to warfarin dose requirement and provided a warfarin-dosing algorithm based on genetic and clinical variables in Korean patients. We recruited 564 Korean patients on stable anticoagulation. Single nucleotide polymorphisms (SNPs) for the VKORC1, CYP2C9, CYP4F2 and GGCX were analyzed. Using multiple regression analysis, we developed a model to predict the warfarin requirement. The SNPs of VKORC1, CYP2C9, CYP4F2 and GGCX showed significant correlation with warfarin dose. Patients with the 3730AA genotype received significantly higher doses of warfarin than those with the 3730GG (P=0.0001). For CYP2C9, the highest maintenance dose was observed in the patients with wild-type genotype compared with the variant allele carriers (P<0.0001). The multiple regression model including age, gender, body surface area (BSA), international normalized ratio (INR) and four genetic polymorphisms accounted for 35% of total variations in warfarin dose (R(2)=0.3499; P<0.0001). This study shows that age, gender, BSA, INR and VKORC1, CYP2C9 and CYP4F2 polymorphism affect warfarin dose requirements in Koreans. Translation of this knowledge into clinical guidelines for warfarin prescription may contribute to improve the efficacy and safety of warfarin treatment for Korean patients.
Assuntos
Algoritmos , Anticoagulantes/administração & dosagem , Povo Asiático/genética , Modelos Biológicos , Farmacogenética/métodos , Varfarina/administração & dosagem , Fatores Etários , Idoso , Análise de Variância , Hidrocarboneto de Aril Hidroxilases/genética , Tamanho Corporal , Citocromo P-450 CYP2C9 , Sistema Enzimático do Citocromo P-450/genética , Família 4 do Citocromo P450 , Relação Dose-Resposta a Droga , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Oxigenases de Função Mista/genética , Polimorfismo de Nucleotídeo Único/genética , Análise de Regressão , Fatores Sexuais , Vitamina K Epóxido RedutasesRESUMO
An extracellular enzyme (RMEBE) possessing alpha- (1-->4)-(1-->6)-transferring activity was purified to homogeneity from Rhodothermus marinus by combination of ammonium sulfate precipitation, Q-Sepharose ion-exchange, and Superdex- 200 gel filtration chromatographies, and preparative native polyacrylamide gel electrophoresis. The purified enzyme had an optimum pH of 6.0 and was highly thermostable with a maximal activity at 80 degrees . Its half-life was determined to be 73.7 and 16.7 min at 80 and 85 degrees , respectively. The enzyme was also halophilic and highly halotolerant up to about 2 M NaCl, with a maximal activity at 0.5M. The substrate specificity of RMEBE suggested that it possesses partial characteristics of both glucan branching enzyme and neopullulanase. RMEBE clearly produced branched glucans from amylose, with partial alpha-(1-->4)-hydrolysis of amylose and starch. At the same time, it hydrolyzed pullulan partly to panose, and exhibited alpha-(1-->4)-(1-->6)-transferase activity for small maltooligosaccharides, producing disproportionated alpha-(1-->6)-branched maltooligosaccharides. The enzyme preferred maltopentaose and maltohexaose to smaller maltooligosaccharides for production of longer branched products. Thus, the results suggest that RMEBE might be applied for production of branched oligosaccharides from small maltodextrins at high temperature or even at high salinity.
Assuntos
Amilases/química , Amilases/isolamento & purificação , Espaço Extracelular/enzimologia , Rhodothermus/enzimologia , Água do Mar/microbiologia , Amilases/genética , Amilases/metabolismo , Amilopectina , Amilose/metabolismo , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Peso Molecular , Oligossacarídeos/metabolismo , Amido/metabolismo , Especificidade por Substrato , Temperatura , Transferases/química , Transferases/genética , Transferases/isolamento & purificação , Transferases/metabolismoRESUMO
Studies on non-small cell lung cancer (NSCLC) patients with KRAS or BRAF mutations are urgently needed to improve clinical outcomes. We evaluated the cytotoxicities of paclitaxel and sorafenib alone and in combination in NSCLC cell lines with KRAS or BRAF mutations and investigated the mechanism of the interaction between the drugs. We found synergistic antitumor efficacy with paclitaxel followed by sorafenib in in vitro and in vivo models of NSCLC. And, we determined that downregulation of the phosphorylated ERK and Rb, and Mcl-1 plays a critical role in the synergistic activity of the drugs. Further clinical trials are needed to verify the antitumor efficacy of this combination.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas ras/genética , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Benzenossulfonatos/administração & dosagem , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação , Proteína de Sequência 1 de Leucemia de Células Mieloides , Niacinamida/análogos & derivados , Paclitaxel/administração & dosagem , Compostos de Fenilureia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Piridinas/administração & dosagem , Proteína do Retinoblastoma/genética , Transdução de Sinais/efeitos dos fármacos , Sorafenibe , Proteína Supressora de Tumor p53/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: The aim of this study is to investigate the effect of genetic variations and the expression of the reduced folate carrier (RFC) and dihydrofolate reductase (DHFR) on the drug sensitivity to methotrexate (MTX) in different cancer cell lines. MATERIALS AND METHODS: We examined the six human cancer cell lines (MCF-7, AGS, A549, NCI-H23, HCT-116 and Saos-2). The cytotoxicity of MTX was measured by sulforhodamine B (SRB) assay. The expressions of the DHFR and RFC were evaluated by real-time PCR and western blotting. Four single nucleotide polymorphisms (SNPs) of the DHFR and two SNPs of the RFC were genotyped. RESULTS: The IC50s of MTX was in an extensively broad range from 6.05±0.81 nM to>1,000 nM in the cell lines. The Saos-2 (>1,000 nM) and MCF-7 (114.31±5.34 nM) cells were most resistant to MTX; in contrast, the AGS and HCT-116 cells were highly sensitive to MTX with an IC(50) of 6.05±0.81 nM and 13.56±3.76 nM, respectively. A reciprocal change of the RFC and DHFR mRNA expression was found between the MTX-sensitive AGS and MTX-resistant Saos-2 cells. There was no significant difference in the expression levels of RFC protein in both the AGS and Saos-2 cells, whereas DHFR protein was more increased in the MTX-resistant Saos-2 cells treated with MTX. The genotype of the MTX-sensitive AGS cells were mutant variants of the DHFR; in contrast, the Saos-2 cells had the wild-type of the DHFR. CONCLUSION: In conclusion, this study showed that inverse change of the RFC and DHFR mRNA and protein expression was associated with RFC and DHFR polymorphisms and it is postulated that this phenomenon might play an important role in sensitivity of certain cancers to MTX.