AIM:To determine the expression levels of three metabolic enzymes of fluoropyrimidines:thymidylate synthase (TS),thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in seven human gastrointestinal c...AIM:To determine the expression levels of three metabolic enzymes of fluoropyrimidines:thymidylate synthase (TS),thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in seven human gastrointestinal cancer cell lines,and to compare the enzyme levels with the sensitivity to 5-fluorouracil (5-FU) and 5-fluoro-2′-deoxyuridine (FdUrd).METHODS:TS,TP and DPD mRNA levels were assessed by semi-quantitative RT-PCR,TP and DPD protein contents were measured by ELISA. Fifty percent inhibitory concentrations of growth (IC50),representing the sensitivity to drugs,were determined by MTT assay.RESULTS:IC50 values ranged from 1.28 to 12.26μM for 5-FU,and from 5.02 to 24.21μM for FdUrd,respectively.Cell lines with lower DPD mRNA and protein levels tended to be more sensitive to 5-FU (P<0.05), but neither TS nor TP correlated with 5-FU IC50 (P>0.05).Only TS mRNA level was sharply related with FdUrd sensitivity (P<0.05),but TP and DPD were not (P>0.05).A correlation was found between mRNA and protein levels of DPD (P<0.05),but not TP (P<0.05).CONCLUSION:DPD and TS enzyme levels may be useful indicators in predicting the antitumor activity of 5-FU or FdUrd,respectively.展开更多
目的研究慢性丙型病毒性肝炎患者外周血单核细胞(PBMC)中2’,5’寡腺苷酸合成酶(2’,5’-Oligoadenylate synthetase,2-5AS)的表达及其传导与转录激活因子(Signal transducer and activator of transcription,Stat)Stat1和Stat2等的水...目的研究慢性丙型病毒性肝炎患者外周血单核细胞(PBMC)中2’,5’寡腺苷酸合成酶(2’,5’-Oligoadenylate synthetase,2-5AS)的表达及其传导与转录激活因子(Signal transducer and activator of transcription,Stat)Stat1和Stat2等的水平相关性分析。方法选择60例慢性丙肝患者,抽取外周血分离PBMC。首先测定每份标本的2-5AS活性。然后将所有丙肝患者的PBMC标本按按编号单双数分为对照组和实验组,进行体外培养。其中,对照组PBMC不添加干扰素α(interferon alpha,IFN-α),而实验组PBMC添加1000IU/ml IFN-α。体外培养大约24小时后,测定PBMC中2-5AS活性、Stat1和Stat2等的表达量。结果和对照组相比,实验组PBMC的2-5AS活性明显升高(P<0.05)。实验组PBMC中,在2-5AS活性增高的同时,Stat1和Stat2等表达量也呈现明显增多的趋势(P<0.05)。结论基础的2-5AS活性与加入IFNα刺激培养后Stat1的改变幅度呈负相关(P<0.05);2-5AS基础水平和IFNα刺激后的Stat2表达的变化没有相关性(P>0.05)。展开更多
文摘AIM:To determine the expression levels of three metabolic enzymes of fluoropyrimidines:thymidylate synthase (TS),thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) in seven human gastrointestinal cancer cell lines,and to compare the enzyme levels with the sensitivity to 5-fluorouracil (5-FU) and 5-fluoro-2′-deoxyuridine (FdUrd).METHODS:TS,TP and DPD mRNA levels were assessed by semi-quantitative RT-PCR,TP and DPD protein contents were measured by ELISA. Fifty percent inhibitory concentrations of growth (IC50),representing the sensitivity to drugs,were determined by MTT assay.RESULTS:IC50 values ranged from 1.28 to 12.26μM for 5-FU,and from 5.02 to 24.21μM for FdUrd,respectively.Cell lines with lower DPD mRNA and protein levels tended to be more sensitive to 5-FU (P<0.05), but neither TS nor TP correlated with 5-FU IC50 (P>0.05).Only TS mRNA level was sharply related with FdUrd sensitivity (P<0.05),but TP and DPD were not (P>0.05).A correlation was found between mRNA and protein levels of DPD (P<0.05),but not TP (P<0.05).CONCLUSION:DPD and TS enzyme levels may be useful indicators in predicting the antitumor activity of 5-FU or FdUrd,respectively.
文摘目的研究慢性丙型病毒性肝炎患者外周血单核细胞(PBMC)中2’,5’寡腺苷酸合成酶(2’,5’-Oligoadenylate synthetase,2-5AS)的表达及其传导与转录激活因子(Signal transducer and activator of transcription,Stat)Stat1和Stat2等的水平相关性分析。方法选择60例慢性丙肝患者,抽取外周血分离PBMC。首先测定每份标本的2-5AS活性。然后将所有丙肝患者的PBMC标本按按编号单双数分为对照组和实验组,进行体外培养。其中,对照组PBMC不添加干扰素α(interferon alpha,IFN-α),而实验组PBMC添加1000IU/ml IFN-α。体外培养大约24小时后,测定PBMC中2-5AS活性、Stat1和Stat2等的表达量。结果和对照组相比,实验组PBMC的2-5AS活性明显升高(P<0.05)。实验组PBMC中,在2-5AS活性增高的同时,Stat1和Stat2等表达量也呈现明显增多的趋势(P<0.05)。结论基础的2-5AS活性与加入IFNα刺激培养后Stat1的改变幅度呈负相关(P<0.05);2-5AS基础水平和IFNα刺激后的Stat2表达的变化没有相关性(P>0.05)。