目的结合生物信息学分析方法对线粒体翻译起始因子(MTIF2)基因的甲基化特征进行分析,并探讨其与肝细胞癌发生发展的关系。方法应用MethSurv、EWAS Data Hub软件对MTIF2甲基化样本进行标准化分析和聚类分析,内容包括生存曲线分析、甲基...目的结合生物信息学分析方法对线粒体翻译起始因子(MTIF2)基因的甲基化特征进行分析,并探讨其与肝细胞癌发生发展的关系。方法应用MethSurv、EWAS Data Hub软件对MTIF2甲基化样本进行标准化分析和聚类分析,内容包括生存曲线分析、甲基化特征分析、肿瘤信号通路相关性及泛癌数据库比对分析。计量资料两组间比较采用成组t检验;多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。使用Cox比例风险模型基于患者CpG部位的甲基化水平执行单变量和多变量生存分析。通过Kaplan-Meier图标识较低和较高甲基化患者组之间的生存差异。Log-likelihood ratio法用于组间生存差异分析。结果MTIF2甲基化整体聚类表明在种族、人种、BMI、年龄等特征间MTIF2基因甲基化水平没有明显差异。Kaplan-Meier生存曲线分析发现,MTIF2基因N-Shore高甲基化的患者预后明显好于低甲基化患者(HR=0.492,P<0.001),而CpG island和S-Shore甲基化的高低与生存率无明显差异(P值均>0.05)。基于不同年龄、性别、BMI、人种、种族、临床分期绘制MTIF2基因甲基化谱发现,随年龄增长会降低MTIF2基因N-Shore和CpG island的甲基化水平,白种人的MTIF2基因N-Shore的甲基化水平明显低于亚洲人(P<0.05),临床分期Ⅳ期患者MTIF2基因N-Shore和CpG island的甲基化水平明显低于Ⅰ/Ⅱ期患者(P值均<0.05)。临床验证试验表明,Ⅲ/Ⅳ期肝细胞癌患者MTIF2甲基化水平明显低于Ⅰ/Ⅱ期患者(P<0.05),且低于健康人群(P<0.05)。结论MTIF2基因N-Shore低甲基化是肝细胞癌发生发展的危险因素。展开更多
Leukoencephalopathy with vanishing white matter(VWM) is one of the most prevalent inherited white matter disorders in childhood,and it′s the only known hereditary human disease due to the direct defects in protein sy...Leukoencephalopathy with vanishing white matter(VWM) is one of the most prevalent inherited white matter disorders in childhood,and it′s the only known hereditary human disease due to the direct defects in protein synthesis process,with the gene defects in EIF2B1-5,encoding the five subunits of eukaryotic translation initiation factor(eIF2B α,β,γ,δ and ε) respectively.eIF2B is essential for the protein translation initiation process,and its action is realized via eukaryotic translation initiation factor2(eIF2).Phosphorylation of eIF2α and eIF2Bε is an important way to regulate eIF2B function,and thus play a key role in control of the protein translation level under physiological condition.Mutant eIF2B results in functional defects and decrease of the overall protein translation in cells,but in increase the translation of proteins with multiple upstream open reading frames,such as activating transcription factor 4(AFT4),which leads to the susceptibility to un-folded protein response under stress,and the following apoptosis.The exact pathogenic mechanisms of VWM are far from well understood.It′s suggested that level of AFT4 in cells with eIF2B mutations is higher than in wild type cells under physiological condition,which makes the mutant cells more susceptible to endoplasmic reticulum(ER) stress and unfolded protein response(UPR).Under stress,the defect eIF2B leads to a vicious cycle of UPR activation,which may underlie the neurological aggravation in VWM patients after minor stress,a specific cli-nical feature of VWM.Elucidating the pathogenesis of VWM will be helpful to further understand the protein translation process in eukaryotic cells,and provide a clue for possible therapeutic targets and treatment strategies in the future.Abstract:SUMM ARY Leukoencephalopathy with vanishing white matter(VWM) is one of the most prevalent in-herited white matter d isorders in childhood,and i′ts the only known hered itary human d isease due to the d irect defects in protein synthesis process,with the gene defects inEIF2B1-5,encod ing the five sub-units of eukaryotic translation initiation factor(eIF2Bα,β,γ,δandε) respectively.eIF2B is essential for the protein translation initiation process,and its action is realized via eukaryotic translation initiation factor2(eIF2).Phosphorylation of eIF2αand eIF2Bεis an important way to regulate eIF2B function,and thus play a key role in control of the protein translation level under physiological cond ition.Mutant eIF2B results in functional defects and decrease of the overall protein translation in cells,but in increase the translation of proteins with multiple upstream open read ing frames,such as activating transcription factor 4(AFT4),which leads to the susceptibility to un-folded protein response under stress,and the following apoptosis.The exact pathogenic mechanisms ofVWM are far from well understood.I′ts sugges-ted that level ofAFT4 in cells with eIF2B mutations is higher than in wild type cells under physiological cond ition,which makes the mutant cellsmore susceptible to endoplasm ic reticulum(ER) stress and un-folded protein response(UPR).Under stress,the defect eIF2B leads to a vicious cycle ofUPR activa-tion,which may underlie the neurological aggravation in VWM patients afterm inor stress,a specific cli-nical feature ofVWM.E lucidating the pathogenesis ofVWM will be helpful to further understand the pro-tein translation process in eukaryotic cells,and provide a clue for possible therapeutic targets and treat-ment strategies in the future.展开更多
文摘Leukoencephalopathy with vanishing white matter(VWM) is one of the most prevalent inherited white matter disorders in childhood,and it′s the only known hereditary human disease due to the direct defects in protein synthesis process,with the gene defects in EIF2B1-5,encoding the five subunits of eukaryotic translation initiation factor(eIF2B α,β,γ,δ and ε) respectively.eIF2B is essential for the protein translation initiation process,and its action is realized via eukaryotic translation initiation factor2(eIF2).Phosphorylation of eIF2α and eIF2Bε is an important way to regulate eIF2B function,and thus play a key role in control of the protein translation level under physiological condition.Mutant eIF2B results in functional defects and decrease of the overall protein translation in cells,but in increase the translation of proteins with multiple upstream open reading frames,such as activating transcription factor 4(AFT4),which leads to the susceptibility to un-folded protein response under stress,and the following apoptosis.The exact pathogenic mechanisms of VWM are far from well understood.It′s suggested that level of AFT4 in cells with eIF2B mutations is higher than in wild type cells under physiological condition,which makes the mutant cells more susceptible to endoplasmic reticulum(ER) stress and unfolded protein response(UPR).Under stress,the defect eIF2B leads to a vicious cycle of UPR activation,which may underlie the neurological aggravation in VWM patients after minor stress,a specific cli-nical feature of VWM.Elucidating the pathogenesis of VWM will be helpful to further understand the protein translation process in eukaryotic cells,and provide a clue for possible therapeutic targets and treatment strategies in the future.Abstract:SUMM ARY Leukoencephalopathy with vanishing white matter(VWM) is one of the most prevalent in-herited white matter d isorders in childhood,and i′ts the only known hered itary human d isease due to the d irect defects in protein synthesis process,with the gene defects inEIF2B1-5,encod ing the five sub-units of eukaryotic translation initiation factor(eIF2Bα,β,γ,δandε) respectively.eIF2B is essential for the protein translation initiation process,and its action is realized via eukaryotic translation initiation factor2(eIF2).Phosphorylation of eIF2αand eIF2Bεis an important way to regulate eIF2B function,and thus play a key role in control of the protein translation level under physiological cond ition.Mutant eIF2B results in functional defects and decrease of the overall protein translation in cells,but in increase the translation of proteins with multiple upstream open read ing frames,such as activating transcription factor 4(AFT4),which leads to the susceptibility to un-folded protein response under stress,and the following apoptosis.The exact pathogenic mechanisms ofVWM are far from well understood.I′ts sugges-ted that level ofAFT4 in cells with eIF2B mutations is higher than in wild type cells under physiological cond ition,which makes the mutant cellsmore susceptible to endoplasm ic reticulum(ER) stress and un-folded protein response(UPR).Under stress,the defect eIF2B leads to a vicious cycle ofUPR activa-tion,which may underlie the neurological aggravation in VWM patients afterm inor stress,a specific cli-nical feature ofVWM.E lucidating the pathogenesis ofVWM will be helpful to further understand the pro-tein translation process in eukaryotic cells,and provide a clue for possible therapeutic targets and treat-ment strategies in the future.
