BACKGROUND Colorectal cancer (CRC) is the third most prevalent malignancy and has the fourth highest global cancer mortality rate. Early diagnosis and prompt medical attention can improve quality of life and the progn...BACKGROUND Colorectal cancer (CRC) is the third most prevalent malignancy and has the fourth highest global cancer mortality rate. Early diagnosis and prompt medical attention can improve quality of life and the prognosis of CRC patients. Accumulating evidence reveals that long non-coding RNAs (lncRNAs) function as oncogenes or anti-oncogenes, as well as biomarkers in various cancers. AIM To investigate the levels and molecular mechanism of the lncRNA maternally expressed gene 3 (MEG3) in CRC. METHODS The levels of lncRNA MEG3 in CRC tissue, serum and cell line samples were explored via qRT-PCR. The relationship between MEG3 levels and clinicopathological features in CRC was investigated. The diagnostic and prognostic values of serum MEG3 levels were analyzed with ROC curves and KaplanMeier survival curves, respectively. RESULTS Significant decreased levels of MEG3 existed in CRC tissue, cell lines and serum. CRC patients with down-regulated serum MEG3 levels had larger tumor sizes, and advanced clinical stages. The sensitivity and specificity of serum MEG3 levels in CRC detection was 0.667 and 0.875, respectively. Tumor size, T stages, and serum MEG3 levels are indie factors that produce an effect on CRC patients' prognosis. KaplanMeier survival curves suggested that CRC patients with high levels of MEG3 had a remarkably better overall survival rate. CONCLUSION LncRNA MEG3 is down-regulated in CRC, and regulates cell functions by targeting adenosine deaminase’s effect on RNA 1 in CRC.展开更多
既往研究发现,SMAD特异性E3泛素蛋白连接酶1(SMAD specific E3 ubiquitin protein ligase 1,SMURF1)通过其E3泛素连接酶活性介导自噬进程,然而SMURF1的泛素化底物蛋白质仍有待进一步挖掘。本文利用免疫共沉淀(Co-IP)联合蛋白质谱分析捕...既往研究发现,SMAD特异性E3泛素蛋白连接酶1(SMAD specific E3 ubiquitin protein ligase 1,SMURF1)通过其E3泛素连接酶活性介导自噬进程,然而SMURF1的泛素化底物蛋白质仍有待进一步挖掘。本文利用免疫共沉淀(Co-IP)联合蛋白质谱分析捕获并鉴定THP-1细胞中SMURF1的相互作用蛋白质集合物,发现在THP-1细胞中SMURF1可与222种蛋白质物理性结合,RNA腺苷脱氨酶1(adenosine deaminase acting on RNA 1,ADAR1)具有较高的肽段结合分数。构建SMURF1过表达载体并转染到HEK-293T细胞中,Co-IP和Western印迹检测验证外源性SMURF1与内源性ADAR1存在相互作用。qRT-PCR和Western印迹检测结果显示,在HEK-293T细胞中过表达SMURF1后ADAR 1 mRNA水平差异无统计学意义、蛋白质水平明显降低(P<0.05)。用放线菌酮(CHX)分别处理正常和过表达SMURF1的HEK-293T细胞,Western印迹检测显示,过表达SMURF1后ADAR1的半衰期缩短(P<0.05)。进一步在HEK-293T细胞中共转染泛素(Ub)过表达载体和SMURF1过表达载体,通过Co-IP和Western印迹检测结果证实,过表达SMURF1后ADAR1的多聚泛素化水平显著增加(P<0.05)。在蛋白酶体抑制剂(MG132)作用后,Western印迹检测结果表明,蛋白酶体降解途径受抑制后SMURF1对ADAR1的负调控作用减弱(P<0.05)。本研究表明,SMURF1可以与ADAR1相互作用,催化ADAR1的多聚泛素化修饰并介导其蛋白酶体途径降解,为探索SMURF1通过影响ADAR1蛋白质稳定性而具备的多种生物学功能提供理论基础。展开更多
目的探究乙肝病毒(hepatitis B virus,HBV)感染对肝细胞癌(hepatocellular carcinoma,HCC)患者肝脏正常组织和癌组织中腺嘌呤转变为次黄嘌呤(adenine to inosine,A-to-I)RNA编辑活性的影响。方法从基因表达数据库(gene expression omnib...目的探究乙肝病毒(hepatitis B virus,HBV)感染对肝细胞癌(hepatocellular carcinoma,HCC)患者肝脏正常组织和癌组织中腺嘌呤转变为次黄嘌呤(adenine to inosine,A-to-I)RNA编辑活性的影响。方法从基因表达数据库(gene expression omnibus,GEO)收集28套成对正常组织和癌组织的转录组数据,分为HBV阴性正常组织(HBV-N)组、HBV阴性癌组织(HBV-T)组、HBV阳性正常组织(HBV+N)组和HBV阳性癌组织(HBV+T)组。用SPRINT软件进行位点鉴定后,从催化酶表达水平、位点编辑水平和位点所在基因的基因本体论(gene ontology,GO)富集通路层面进行分析。结果在正常组织和癌组织中均发现HBV感染时腺苷酸脱氨酶1(adenosine deaminases acting on RNA 1,ADAR1)表达水平更高。癌组织中HBV阳性样本的A-to-I RNA编辑水平上升,正常组织中则无此现象。两类组织中HBV阳性样本编辑基因显著富集在细胞增殖、基因调控相关信号通路。结论HBV感染上调ADAR1的表达,从而改变宿主编辑事件活性,这对HCC的发生发展可能有促进作用。展开更多
We conducted genome sequence analysis to examine the presence/absence of two types of Z-DNA binding domains in various organisms. We examined 68 organisms from archaea, 914 organisms from bacteria, and 199 organisms f...We conducted genome sequence analysis to examine the presence/absence of two types of Z-DNA binding domains in various organisms. We examined 68 organisms from archaea, 914 organisms from bacteria, and 199 organisms from eukaryotes. RecA protein from Escherichia coli has a Z-DNA binding domain and this protein promotes homologous recombination. All the organisms examined had this domain. This result indicated that this domain is essential for all the organisms. RNA editing enzyme, adenosine deaminase from human has another type of Z-DNA binding domain. This domain was observed in some organisms of archaea, bacteria, and eukaryotes. The presence/absence of Z-DNA binding domain in adenosine deaminase indicated that gain and loss of this domain had occurred in the process of evolution. The implication of presence and absence of this domain is discussed in this study.展开更多
A-to-I RNA editing, the important event of gene modification, which takes place at post-transcriptional level, was firstly reported in 1991. The molecular mechanism of A-to-I RNA editing involves site-selective deamin...A-to-I RNA editing, the important event of gene modification, which takes place at post-transcriptional level, was firstly reported in 1991. The molecular mechanism of A-to-I RNA editing involves site-selective deamination of adenosine to inosine in pre-mRNA, which leads to altering translation codons and splicing in nuclear transcripts, thereby functionally distinct proteins can be produced from a single gene. The mammalian editing enzymes ADARs (adenosine deaminases acting on RNA) are widely expressed in brain and other tissues, however, up to date their sub-strates are mainly found in the central nervous system. It has recently been noticed that imperfect editing of these RNA substrates play critical roles in corresponding diseases, indi-cating that A-to-I RNA editing may be quite important in physiological or pathophysiological processes. Finding more new substrates of ADARs, especially in peripheral tissues, and performing functional research on new genes will be helpful to elucidate the biological significance of A-to-I RNA editing.展开更多
文摘BACKGROUND Colorectal cancer (CRC) is the third most prevalent malignancy and has the fourth highest global cancer mortality rate. Early diagnosis and prompt medical attention can improve quality of life and the prognosis of CRC patients. Accumulating evidence reveals that long non-coding RNAs (lncRNAs) function as oncogenes or anti-oncogenes, as well as biomarkers in various cancers. AIM To investigate the levels and molecular mechanism of the lncRNA maternally expressed gene 3 (MEG3) in CRC. METHODS The levels of lncRNA MEG3 in CRC tissue, serum and cell line samples were explored via qRT-PCR. The relationship between MEG3 levels and clinicopathological features in CRC was investigated. The diagnostic and prognostic values of serum MEG3 levels were analyzed with ROC curves and KaplanMeier survival curves, respectively. RESULTS Significant decreased levels of MEG3 existed in CRC tissue, cell lines and serum. CRC patients with down-regulated serum MEG3 levels had larger tumor sizes, and advanced clinical stages. The sensitivity and specificity of serum MEG3 levels in CRC detection was 0.667 and 0.875, respectively. Tumor size, T stages, and serum MEG3 levels are indie factors that produce an effect on CRC patients' prognosis. KaplanMeier survival curves suggested that CRC patients with high levels of MEG3 had a remarkably better overall survival rate. CONCLUSION LncRNA MEG3 is down-regulated in CRC, and regulates cell functions by targeting adenosine deaminase’s effect on RNA 1 in CRC.
文摘既往研究发现,SMAD特异性E3泛素蛋白连接酶1(SMAD specific E3 ubiquitin protein ligase 1,SMURF1)通过其E3泛素连接酶活性介导自噬进程,然而SMURF1的泛素化底物蛋白质仍有待进一步挖掘。本文利用免疫共沉淀(Co-IP)联合蛋白质谱分析捕获并鉴定THP-1细胞中SMURF1的相互作用蛋白质集合物,发现在THP-1细胞中SMURF1可与222种蛋白质物理性结合,RNA腺苷脱氨酶1(adenosine deaminase acting on RNA 1,ADAR1)具有较高的肽段结合分数。构建SMURF1过表达载体并转染到HEK-293T细胞中,Co-IP和Western印迹检测验证外源性SMURF1与内源性ADAR1存在相互作用。qRT-PCR和Western印迹检测结果显示,在HEK-293T细胞中过表达SMURF1后ADAR 1 mRNA水平差异无统计学意义、蛋白质水平明显降低(P<0.05)。用放线菌酮(CHX)分别处理正常和过表达SMURF1的HEK-293T细胞,Western印迹检测显示,过表达SMURF1后ADAR1的半衰期缩短(P<0.05)。进一步在HEK-293T细胞中共转染泛素(Ub)过表达载体和SMURF1过表达载体,通过Co-IP和Western印迹检测结果证实,过表达SMURF1后ADAR1的多聚泛素化水平显著增加(P<0.05)。在蛋白酶体抑制剂(MG132)作用后,Western印迹检测结果表明,蛋白酶体降解途径受抑制后SMURF1对ADAR1的负调控作用减弱(P<0.05)。本研究表明,SMURF1可以与ADAR1相互作用,催化ADAR1的多聚泛素化修饰并介导其蛋白酶体途径降解,为探索SMURF1通过影响ADAR1蛋白质稳定性而具备的多种生物学功能提供理论基础。
文摘目的探究乙肝病毒(hepatitis B virus,HBV)感染对肝细胞癌(hepatocellular carcinoma,HCC)患者肝脏正常组织和癌组织中腺嘌呤转变为次黄嘌呤(adenine to inosine,A-to-I)RNA编辑活性的影响。方法从基因表达数据库(gene expression omnibus,GEO)收集28套成对正常组织和癌组织的转录组数据,分为HBV阴性正常组织(HBV-N)组、HBV阴性癌组织(HBV-T)组、HBV阳性正常组织(HBV+N)组和HBV阳性癌组织(HBV+T)组。用SPRINT软件进行位点鉴定后,从催化酶表达水平、位点编辑水平和位点所在基因的基因本体论(gene ontology,GO)富集通路层面进行分析。结果在正常组织和癌组织中均发现HBV感染时腺苷酸脱氨酶1(adenosine deaminases acting on RNA 1,ADAR1)表达水平更高。癌组织中HBV阳性样本的A-to-I RNA编辑水平上升,正常组织中则无此现象。两类组织中HBV阳性样本编辑基因显著富集在细胞增殖、基因调控相关信号通路。结论HBV感染上调ADAR1的表达,从而改变宿主编辑事件活性,这对HCC的发生发展可能有促进作用。
文摘We conducted genome sequence analysis to examine the presence/absence of two types of Z-DNA binding domains in various organisms. We examined 68 organisms from archaea, 914 organisms from bacteria, and 199 organisms from eukaryotes. RecA protein from Escherichia coli has a Z-DNA binding domain and this protein promotes homologous recombination. All the organisms examined had this domain. This result indicated that this domain is essential for all the organisms. RNA editing enzyme, adenosine deaminase from human has another type of Z-DNA binding domain. This domain was observed in some organisms of archaea, bacteria, and eukaryotes. The presence/absence of Z-DNA binding domain in adenosine deaminase indicated that gain and loss of this domain had occurred in the process of evolution. The implication of presence and absence of this domain is discussed in this study.
文摘A-to-I RNA editing, the important event of gene modification, which takes place at post-transcriptional level, was firstly reported in 1991. The molecular mechanism of A-to-I RNA editing involves site-selective deamination of adenosine to inosine in pre-mRNA, which leads to altering translation codons and splicing in nuclear transcripts, thereby functionally distinct proteins can be produced from a single gene. The mammalian editing enzymes ADARs (adenosine deaminases acting on RNA) are widely expressed in brain and other tissues, however, up to date their sub-strates are mainly found in the central nervous system. It has recently been noticed that imperfect editing of these RNA substrates play critical roles in corresponding diseases, indi-cating that A-to-I RNA editing may be quite important in physiological or pathophysiological processes. Finding more new substrates of ADARs, especially in peripheral tissues, and performing functional research on new genes will be helpful to elucidate the biological significance of A-to-I RNA editing.
