目的:研究拓扑异构酶(TOPO)Ⅱα启动子调控因子(SP1、ATF-2、SP3、NF-YA、NF-M、P53、CMYB、C-JUN、ICBP90)组蛋白甲基化修饰在苯中毒致造血毒性中的作用。方法:25例临床慢性苯中毒患者骨髓单个核细胞为病例组,25例正常人骨髓单个核细...目的:研究拓扑异构酶(TOPO)Ⅱα启动子调控因子(SP1、ATF-2、SP3、NF-YA、NF-M、P53、CMYB、C-JUN、ICBP90)组蛋白甲基化修饰在苯中毒致造血毒性中的作用。方法:25例临床慢性苯中毒患者骨髓单个核细胞为病例组,25例正常人骨髓单个核细胞为对照组,染色质免疫沉淀分析(Ch IP)技术探讨TOPOⅡα启动子各调控因子组蛋白甲基化水平的变化,RT-PCR法测定TOPO Ⅱα启动子各调控因子m RNA表达水平的改变。结果:1与对照组比较,病例组TOPO Ⅱα启动子调控因子NF-M、C-JUN组蛋白H3K4甲基化水平下降,差异有统计学意义(P<0.05),SP1、ATF-2、SP3、NF-YA、P53、C-MYB、ICBP90组蛋白H3K4甲基化水平无明显改变(P>0.05);SP1、NF-M组蛋白H3K9甲基化水平升高,差异有统计学意义(P<0.05或P<0.01),而ATF-2、SP3、NF-YA、P53、C-MYB、C-JUN、ICBP90组蛋白H3K9甲基化水平无明显改变(P>0.05)。2与对照组比较,病例组TOPO Ⅱα启动子调控因子SP1、NF-YA、C-MYB、NF-M及C-JUN m RNA表达水平降低,差异有统计学意义(P<0.05或P<0.01),ATF-2、ICBP90 m RNA表达水平不变(P>0.05),SP3、P53 m RNA表达水平则升高(P<0.05或P<0.01)。结论:1慢性苯中毒TOPO Ⅱα启动子调控因子组蛋白化学修饰水平的改变伴随着调控因子m RNA水平的变化。2TOPO Ⅱα启动子调控因子组蛋白甲基化修饰在苯中毒所致的造血毒性中发挥一定的作用。展开更多
Human X-box binding protein 1 （XBP1）, an important transcription factor, participates in many signal transduction processes. To further investigate the biological function of XBP1, sequences of XBP1 promoter and its...Human X-box binding protein 1 （XBP1）, an important transcription factor, participates in many signal transduction processes. To further investigate the biological function of XBP1, sequences of XBP1 promoter and its two deletion mutants were first determined using bioinformatic analysis. The report vectors containing XBP1 promoter and its deletion mutants were then constructed, namely, p1-XBPlp, p2-XBPlp, and p3-XBPlp. Each reporter vector was separately transfected into HepG2, L02, K562, SMMC-7721, HSF, and Lipocyte lto Cell line using FuGENE 6 transfection reagents. The activity of chloramphenicol acetyltransferase （CAT） in each group of transfected cells was detected by ELISA assay, which in turn reflects the transcription activity of the XBP1 gene promoter. The activity involving p3-XBPlp was the highest in HepG2, which was 12.4-fold of that of pCAT3-Basic. The activities of p3-XBPlp in K562 and SMMC-7721 were the second and the third highest, which were 10.9-fold and 10.0-fold of that of the pCAT3-Basic, respectively. The CAT activity in L02 was lower than that in the above-mentioned abnormal cell, and no reporter activity was detected in HSF and Ito Cell. The XBP1 transcription and expression in K562, HepG2 and SMMC-7721 were found to be higher than that in L02, HSF and Ito cells, based on the results of real-time RT-PCR and Western blot. The XBP1 transcription and expression in L02, HSF was lower, whereas that in Ito cells was totally lacking. The result was similar to that of CAT-ELISA. Therefore, the XBP1 gene promoter can drive its downstream gene expression and its activity is cell line-dependent. The core sequence of XBP1 promoter was found between -227bp and 66bp sequence. This sequence was closely associated with the transcriptional activity of XBP1 promoter.展开更多
AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined...AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.展开更多
文摘目的:研究拓扑异构酶(TOPO)Ⅱα启动子调控因子(SP1、ATF-2、SP3、NF-YA、NF-M、P53、CMYB、C-JUN、ICBP90)组蛋白甲基化修饰在苯中毒致造血毒性中的作用。方法:25例临床慢性苯中毒患者骨髓单个核细胞为病例组,25例正常人骨髓单个核细胞为对照组,染色质免疫沉淀分析(Ch IP)技术探讨TOPOⅡα启动子各调控因子组蛋白甲基化水平的变化,RT-PCR法测定TOPO Ⅱα启动子各调控因子m RNA表达水平的改变。结果:1与对照组比较,病例组TOPO Ⅱα启动子调控因子NF-M、C-JUN组蛋白H3K4甲基化水平下降,差异有统计学意义(P<0.05),SP1、ATF-2、SP3、NF-YA、P53、C-MYB、ICBP90组蛋白H3K4甲基化水平无明显改变(P>0.05);SP1、NF-M组蛋白H3K9甲基化水平升高,差异有统计学意义(P<0.05或P<0.01),而ATF-2、SP3、NF-YA、P53、C-MYB、C-JUN、ICBP90组蛋白H3K9甲基化水平无明显改变(P>0.05)。2与对照组比较,病例组TOPO Ⅱα启动子调控因子SP1、NF-YA、C-MYB、NF-M及C-JUN m RNA表达水平降低,差异有统计学意义(P<0.05或P<0.01),ATF-2、ICBP90 m RNA表达水平不变(P>0.05),SP3、P53 m RNA表达水平则升高(P<0.05或P<0.01)。结论:1慢性苯中毒TOPO Ⅱα启动子调控因子组蛋白化学修饰水平的改变伴随着调控因子m RNA水平的变化。2TOPO Ⅱα启动子调控因子组蛋白甲基化修饰在苯中毒所致的造血毒性中发挥一定的作用。
基金This work was supported by the Research Foundation of Chongqing Education Committee (No. KJ070314)Innovation Foundation of Chongqing Medical University (No. CX200526)Research Foundation for Advanced Talents of Chongqing Medical Univer-sity (No. QD200316).
文摘Human X-box binding protein 1 （XBP1）, an important transcription factor, participates in many signal transduction processes. To further investigate the biological function of XBP1, sequences of XBP1 promoter and its two deletion mutants were first determined using bioinformatic analysis. The report vectors containing XBP1 promoter and its deletion mutants were then constructed, namely, p1-XBPlp, p2-XBPlp, and p3-XBPlp. Each reporter vector was separately transfected into HepG2, L02, K562, SMMC-7721, HSF, and Lipocyte lto Cell line using FuGENE 6 transfection reagents. The activity of chloramphenicol acetyltransferase （CAT） in each group of transfected cells was detected by ELISA assay, which in turn reflects the transcription activity of the XBP1 gene promoter. The activity involving p3-XBPlp was the highest in HepG2, which was 12.4-fold of that of pCAT3-Basic. The activities of p3-XBPlp in K562 and SMMC-7721 were the second and the third highest, which were 10.9-fold and 10.0-fold of that of the pCAT3-Basic, respectively. The CAT activity in L02 was lower than that in the above-mentioned abnormal cell, and no reporter activity was detected in HSF and Ito Cell. The XBP1 transcription and expression in K562, HepG2 and SMMC-7721 were found to be higher than that in L02, HSF and Ito cells, based on the results of real-time RT-PCR and Western blot. The XBP1 transcription and expression in L02, HSF was lower, whereas that in Ito cells was totally lacking. The result was similar to that of CAT-ELISA. Therefore, the XBP1 gene promoter can drive its downstream gene expression and its activity is cell line-dependent. The core sequence of XBP1 promoter was found between -227bp and 66bp sequence. This sequence was closely associated with the transcriptional activity of XBP1 promoter.
基金Supported by National Natural Science Foundation of China,No. 81071998Hubei Natural Science Foundation,No.2008CDB159Specialized Research Fund for the Doctoral Program of Higher Education,No. 20070487114
文摘AIM:To investigate the reciprocal modulation between microRNA(miRNA) and DNA methylation via exploring the correlation between miR-373 and methyl-CpGbinding domain protein(MBD)2.METHODS:MiR-373 expression was examined using the TaqMan miRNA assay.Methylation of miR-373 was investigated using methylation-specific polymerase chain reaction,and recruitment of methyl binding proteins was studied using the chromatin immunoprecipitation assay.Mutation analysis was conducted using the QuikChange Site-Directed Mutagenesis kit.The activity of miR-373 gene promoter constructs and targeting at MBD2-three prime untranslated region(3'UTR) by miR-373 were evaluated by a dual-luciferase reporter gene assay.RESULTS:In hilar cholangiocarcinoma,miR-373 decreased and was closely associated with poor cell differentiation,advanced clinical stage,and shorter survival.The promoter-associated CpG island of miR-373 gene was hypermethylated and inhibited expression of miR-373.MBD2 was up-regulated and enriched at the promoter-associated CpG island of miR-373.Methylation-mediated suppression of miR-373 required MBD2 enrichment at the promoter-associated CpG island,and miR-373 negatively regulated MBD2 expression through targeting the 3'UTR.CONCLUSION:MiR-373 behaves as a direct transcriptional target and negative regulator of MBD2 activity through a feedback loop of CpG island methylation.
