本文从遗传基因方面对药物转化过程中酶作用的影响予以简述,以对临床合理用药提供参考。1 药物转化酶的分布类型及特性转化酶对机体中的一切代谢反应过程都有催化作用。按其催化作用的特性可分为:氧化还原酶、转移酶、水解酶、合成酶、...本文从遗传基因方面对药物转化过程中酶作用的影响予以简述,以对临床合理用药提供参考。1 药物转化酶的分布类型及特性转化酶对机体中的一切代谢反应过程都有催化作用。按其催化作用的特性可分为:氧化还原酶、转移酶、水解酶、合成酶、裂解酶、异构酶等等。能催化药物进行转化的酶系主要有三种。(1)血浆和细胞浆中的可溶部分及线粒体中酶系主要有胺氧化酶、酰胺酶、磷酸酶、脂环族芳香化酶、醛氧化酶、胆碱酯酶、醇脱氢酶、黄嘌呤氧化酶、酯酶、S—氧化酶、N—氧化物还原酶、丙酸辅酶 A 羟化酶等。(2)肝药酶系多为非特异性,可对各种不同药物进行生物转化。主要有多功能的氧化酶系统、多种结合酶、还原酶及酯酶。但多功能氧化酶在功能上对底物常有一定的选择性。展开更多
AIM: To study the inhibitory effects of siRNAs targeting different hTERT sequences and to screen the effective siRNA sequence.METHODS: Five double-stranded siRNAs targeting coding and non-coding regions of hTERT gene ...AIM: To study the inhibitory effects of siRNAs targeting different hTERT sequences and to screen the effective siRNA sequence.METHODS: Five double-stranded siRNAs targeting coding and non-coding regions of hTERT gene were designed and synthesized by T7 transcription system in vitro. siRNA4sequence was screened by full length gene targeting technique and the rest of the siRNA sequences were selected randomly. After being purified by ethanol precipitation, the siRNAs were transfected to the human hepatocellular carcinoma cell (HepG2) by Lipofectamine 2000TM. At 48-72 h after siRNAs transfection, MTT assay,RT-PCR and Western-blot were applied to evaluate the effects of siRNAs on cell growth, mRNA and protein expression level of hTERT gene, respectively.RESULTS: Compared to the control cells, the cells treated with the five double-stranded siRNAs exhibited different degrees of inhibition of cell proliferation in a dose-dependent manner. siRNA2 and siRNA4, exhibited obvious effects of inhibiting hTERT mRNA and protein expression in HepG2cells.CONCLUSION: siRNAs targeting different hTERT sequences have significantly various inhibitory effects on hTERT gene expression. The siRNA sequence screened by full length gene targeting technique has comparable inhibitory effect with the rest siRNA sequences screened by random selection, suggesting that siRNAs and antisense oligonucleic acids may have the same effective target sites. Compared with chemical synthesis method,synthesizing double-stranded siRNA by T7 transcription system in vitro is a rapid, simple, and inexpensive method suitable for screening high-effect siRNA targeting site for specific gene.展开更多
文摘本文从遗传基因方面对药物转化过程中酶作用的影响予以简述,以对临床合理用药提供参考。1 药物转化酶的分布类型及特性转化酶对机体中的一切代谢反应过程都有催化作用。按其催化作用的特性可分为:氧化还原酶、转移酶、水解酶、合成酶、裂解酶、异构酶等等。能催化药物进行转化的酶系主要有三种。(1)血浆和细胞浆中的可溶部分及线粒体中酶系主要有胺氧化酶、酰胺酶、磷酸酶、脂环族芳香化酶、醛氧化酶、胆碱酯酶、醇脱氢酶、黄嘌呤氧化酶、酯酶、S—氧化酶、N—氧化物还原酶、丙酸辅酶 A 羟化酶等。(2)肝药酶系多为非特异性,可对各种不同药物进行生物转化。主要有多功能的氧化酶系统、多种结合酶、还原酶及酯酶。但多功能氧化酶在功能上对底物常有一定的选择性。
基金Supported by the National Natural Science Foundation of China, No. 30371662
文摘AIM: To study the inhibitory effects of siRNAs targeting different hTERT sequences and to screen the effective siRNA sequence.METHODS: Five double-stranded siRNAs targeting coding and non-coding regions of hTERT gene were designed and synthesized by T7 transcription system in vitro. siRNA4sequence was screened by full length gene targeting technique and the rest of the siRNA sequences were selected randomly. After being purified by ethanol precipitation, the siRNAs were transfected to the human hepatocellular carcinoma cell (HepG2) by Lipofectamine 2000TM. At 48-72 h after siRNAs transfection, MTT assay,RT-PCR and Western-blot were applied to evaluate the effects of siRNAs on cell growth, mRNA and protein expression level of hTERT gene, respectively.RESULTS: Compared to the control cells, the cells treated with the five double-stranded siRNAs exhibited different degrees of inhibition of cell proliferation in a dose-dependent manner. siRNA2 and siRNA4, exhibited obvious effects of inhibiting hTERT mRNA and protein expression in HepG2cells.CONCLUSION: siRNAs targeting different hTERT sequences have significantly various inhibitory effects on hTERT gene expression. The siRNA sequence screened by full length gene targeting technique has comparable inhibitory effect with the rest siRNA sequences screened by random selection, suggesting that siRNAs and antisense oligonucleic acids may have the same effective target sites. Compared with chemical synthesis method,synthesizing double-stranded siRNA by T7 transcription system in vitro is a rapid, simple, and inexpensive method suitable for screening high-effect siRNA targeting site for specific gene.
