EB病毒潜伏膜蛋白LMP1疫苗的预测及验证

目的 采用生物信息学方法分析EB病毒潜伏膜蛋白LMP1,为疫苗的研发提供理论依据。方法 在NCBI数据库中获取LMP1蛋白的基因组序列和氨基酸序列,采用生物信息学分析工具ProtParam、SOPMA、SWISS MODEL、SignalP、TMHMM、Cell-PLoc 2.0、NetNGly、NetPhos-3.1、Conserved domains、IEDB、BLAST、Immunomedicine Group、UniProt预测LMP1蛋白的理化性质,二、三级结构,信号肽和跨膜区域,亚细胞定位,糖基化位点和磷酸化位点,保守结构域,B、T细胞表位,同源性,抗原决定簇以及相互作用蛋白。构建重组质粒LMP1-pMV261以及重组卡介苗,并通过检测LMP1分子及蛋白表达水平探究构建疫苗的基本条件。结果 LMP1蛋白分子式为C₁₉₀₁H₂₈₇₇N₄₉₃O₅₆₂S₁₁,氨基酸数为386,相对分子质量为41.98238×10³,原子总数为5 844。LMP1蛋白...     

胰腺癌患者P^16基因第二外显子缺失与突变的研究

用银染聚合物酶链反应（ＰＣＲ）及单链构象多态（ＳＳＣＰ）技术检测了３０例胰腺癌患者的Ｐ＾１６基因。结果８例存在Ｐ＾１６基因纯合性缺失，２例突变，变异频率为３０％，Ｐ＾１３基因变异与胰腺癌组织学分级无关，与病理分期密切相关，提示Ｐ＾１６基因变异是胰腺癌发生发展中的频发事件，可用以评估胰腺癌预后。     

MHC区域LMP和TAP基因与1型糖尿病的关系

1型糖尿病是一种慢性自身免疫性疾病 ,主要是通过 T淋巴细胞介导的免疫损伤造成胰岛细胞进行性破坏。目前认为该病的发生与遗传背景关系极为密切 ,其中 MHC- 类区域的基因型是决定 1型糖尿病易感性的最重要因素。近年来在 MHC- 类区域发现了某些基因所编码产生的蛋白参与 T淋巴细胞的活化和增殖 ,在其中起关键性作用的是 :蛋白酶体相关基因(又称低分子量多肽基因 ,low- molecular polypeptide,L MP)及抗原处理相关转运体基因 (transporter associate with antigenprocessing,TAP)。一、简介L MP是于 1982年 Monaco[1 ] 在分析鼠 MH…     

KAI1基因在胰腺癌中的突变分析

目的探讨KAI1基因在胰腺癌中的突变情况.方法对17例伴有淋巴结转移的原发性胰腺癌(Ⅲ期),7例无淋巴结转移的原发性胰腺癌(2例Ⅰ期,5例Ⅱ期)和9例正常胰腺组织标本进行KAI1基因突变分析.结果24例胰腺癌标本中,7例证实有KAI1点突变.这种突变出现在886位核苷酸上,导致从A到G的转变,缬氨酸置换异亮氨酸,且有突变的癌标本均属于晚期有转移的胰腺癌(Ⅲ期).结论上述结果提示KAI1基因突变使KAI1 mRNA水平降低可能是胰腺癌转移的主要因素之一.     

鼻咽癌组织中EB病毒LMP1与hsa-miR-19b表达及其相关性分析

目的观察鼻咽癌（NPC）组织中EB病毒潜伏膜蛋白1（LMP1）和hsa—miR-19b表达变化及其与NPC临床病理特征的关系。方法采用免疫组化技术检测46例NPC放疗前活检标本中LMP1的表达情况,用实时定量PCR检测hsa-miR-19b表达情况。分析二者表达相关性及其与NPC临床病理特征的关系。结果NPC组织中LMP1阳性表达率为60．95％,hsa-miR-19b阳性表达量为68．27±69．00;LMP1、hsa-miR-19b表达均与NPC分期和淋巴结转移有关。LMP1表达与hsa—miR-19b表达呈正相关（r=0．390,P=0．007）。结论LMP1可能调控hsa-miR-19b的表达,两者的表达呈正相关关系。LMP1、hsa-miR-19b的高表达与NPC分期和转移有关。     

中国人群线粒体基因C3394T及A12026G突变与2型糖尿病相关性的Meta分析

目的 研究中国人群线粒体基因C3394T及A12026G突变与T2DM相关性。方法检索中国知网、万方、维普、Pubmed数据库,对2001-2013年中国人群线粒体基因C3394T、A12026G突变与T2DM相关性的随机对照试验（RCTs）文献进行检索。经质量评价和资料提取后,对符合质量标准的RCTs进行Meta分析。结果 共纳入11个RCTs。7个RCTs结果显示,C3394T突变合并OR（95% CI）为7.48（3.17-17.76）,4个RCTs结果显示,A12026G突变合并OR（95% CI）为1.88（1.14-3.11）。 结论 中国人群线粒体基因C3394T及A12026G突变与T2DM有相关性,且是其发病的危险因素之一。     

GSTM1基因多态性与中国汉族人群肺癌易感性的Meta分析

目的 探索谷胱甘肽硫转移酶M1(GSTM1)基因多态性与中国汉族人群肺癌发生的相关性.方法 检索2011年8月之前GSTM1基因多态性与肺癌相关性的相关文献,根据纳入、排除标准选择符合要求的文献,整理GSTM1功能型基因型、缺失型基因型频数或频率,采用Mantel-Haenszel固定效应模型分析合并OR值,并用漏斗图和Egger线性回归分析评估文献的发表偏倚.结果 GSTM1(-)基因型携带者发生肺癌的风险是GSTM1(+)基因型携带者的1.64倍(95％CI:1.43～1.87),有统计学意义(Z=7.19,P＜0.01);发表偏倚的漏斗图对称,Egger线性回归分析回归截距为-0.422(95％CI:-3.011～2.167),无发表偏倚(P=0.734).结论 GSTM1基因是肺癌发生的易感基因,其中GSTM1缺失型基因型是中国汉族人群发生肺癌的风险因子.     

维生素D受体基因多态性与1型糖尿病易感性的Meta分析

目的探讨维生素D受体(VDR)基因多态性与T1DM易感性的关系。方法通过检索PubMed、Web of Science、WanFang等数据库获得相关文献,计算相关基因位点的OR值和95%CI。结果共纳入文献28条。分析结果发现,BsmI和ApaI多态性是亚洲T1DM人群的易感基因[B vs b:OR(95%CI)=1.53(1.06~2.20),P=0.024;AAvs aa:OR(95%CI)=1.60(1.06~2.40),P=0.023]。结论 BsmI和ApaI多态性可能是亚洲T1DM人群的易感基因。     

幽门螺杆菌感染与1型糖尿病的相关性Meta分析

目的:通过Meta分析探讨幽门螺杆菌(Helicobacter pylori,H.pylori)感染与1型糖尿病(type 1 diabetes mellitus).是否具有相关性.方法:从PubMed、Embase、Cochrane Library、万方、维普资讯和中国知网等在线数据库检索自建库至2015-11发表的有关H.pylori感染与1型糖尿病关系的文献.由2名研究人员独立提取资料并评价纳入文献的质量,采用Revman5.3软件进行Meta分析,计算合并OR值及其95%CI.结果:纳入11篇参考文献,总样本量2982人,其中病例组1085例,对照组1897例,数据表现为异质性.与对照组比较,H.pylori感染增加1型糖尿病的发生风险(OR=1.68,95%CI:1.09-2.59).回归分析显示检测方法和地区分布与研究结论无关.发表偏倚和敏感性分析证实上述Meta分析结果是稳定和可靠的.结论:H.pylori感染与1型糖尿病的发生存在相关性.     

Meta-analysis of association between GSTM1 gene polymorphism and cervical cancer

ObjectiveTo investigate association between glutathione S-transferases (GSTs) and cervical cancer.MethodsPublished literature from PubMed, EMBASE, and other databases were retrieved. All studies evaluating the association between GSTM1/GSTT1 polymorphisms and cervical were included. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using fixed- or random-effects model.ResultsA total of 15 case-control studies were included in the meta-analysis of GSTM1 genotypes (1 825 cases and 2 104 controls). The overall result showed that the association between GSTM1 null genotype and risk for cervical cancer was statistically significant (OR=1.53, 95%CI=1.18–2.00). Great heterogeneity was found between studies. Subgroup analysises were performed based on smoking and ethnicity. Our results showed that smokers with null GSTM1 genotype had higher risk of cervical cancer (OR=1.56, 95%CI=1.01–2.41). For the ethnicity stratification, significant increased risk of null GSTM1 genotype was found in Chinese and Indian population, but no increased risk in other population.ConclusionsThis meta-analysis provides strong evidence that the GSTM1 null genotype is associated with the development of cervical cancer, and especially in Chinese and Indian population, and smoking shows a modification on the association between GSTM1 null genotype and cervical cancer.     

LMP2/LMP7基因编码区多态性及单倍体型与胃癌易感无相关性

目的:探讨中国汉族人群中肿瘤抗原递呈的限速基因LMP2/LMP7单核苷酸多态性与胃癌的遗传易感性关联.方法:提取145例胃癌患者及152例健康献血员外周血基因组DNA,用PCR-RFLP方法检测两组人群中LMP2-codon60/LMP7-codon145两个多态性位点的基因型;并采用PHASE1.0软件构建这两个多态性位点的个体单倍体型,以非条件Logistic回归校正混杂因素,并进行多态性与胃癌患者风险关联的统计学分析.结果:PCR-RFLP检测结果显示:LMP2-codon60与LMP7-codon145处的多态性在中国人群中普遍存在,LMP2/LMP7多态性位点的各自的等位基因频率分布符合Hardy-Weinberg平衡定律;最后的统计分析表明:在145例胃癌患者与152例健康对照人群中LMP2/LMP7两个多态性位点的基因型频率、以及所构建的4个单倍体型频率均没有统计学差异(P值均大于0.05).结论:在中国汉族人群中,LMP2/LMP7基因编码区两个位点的多态性以及单倍体型与胃癌易感无相关性.     

LMP2/LMP7基因多态性与乙型肝炎病毒感染结局的关系

目的:探讨低相对分子质量蛋白酶体(LMP)基因单核苷酸多态性(SNP)与HBV感染结局之间的关联.方法:提取287例HBV持续感染者(包括无症状HBV携带者、慢性乙型肝炎及乙型肝炎后肝硬化患者)及278例健康对照外周血基因组DNA,用PCR-RFLP方法分析LMP2/LMP7基因Codon60/Codon145两个多态性位点的基因型.结果:LMP7基因多态性位点在健康对照与无症状HBV携带者之间的差异有统计学意义(P＜0.05),与携带Gln/Gln基因型者比较,携带Gln/Lys基因型者乙型肝炎患病风险增加3.35倍(95%CI:2.02-5.58),携带Lys/Lys基因型者乙型肝炎患病风险增加3.46倍(95%CI:1.41-8.48),携带至少1个Lys等位基因者(即Gln/Lys和Lys/Lys基因型)乙型肝炎患病风险增加3.37倍(95%CI:2.06-5.52);LMP7基因多态性位点在健康对照与进展性肝炎(包括慢性乙型肝炎和肝硬化)患者之间的差异有统计学意义(P＜0.05),与携带Gln/Gln基因型者比较,携带Gln/Lys基因型者乙型肝炎患病风险增加2.22倍(95%CI:1.48-3.32),携带Lys/Lys基因型者乙型肝炎患病风险增加4.33倍(95%CI:2.15-8.73),携带至少1个Lys等位基因者(即Gln/Lys和Lys/Lys基因型)乙型肝炎患病风险增加2.49倍(95%CI:1.69-3.65);LMP2/LMP7基因多态性位点在无症状HBV携带者与进展性肝炎患者间的差异无统计学意义(p>0.05).结论:LMP7基因可能是无症状HBV携带和进展性肝炎的易感基因:LMP基因多态性与HBV感染的结局可能无明显相关性.     

C4A gene deletion: association with Graves' disease

The association of HLA class I and class II antigens, particularly HLA-B8,DR3, with a variety of autoimmune diseases has been well documented. The C4A*Q0 (non-expressed C4A) allele which is in linkage disequilibrium with HLA-B8,DR3 has also been reported to be associated with systemic lupus erythematosus, insulin-dependent diabetes mellitus and Graves' disease. However, the number of studies has been limited by the requirement of family data for the assignment of the C4A*Q0 allele based on C4 protein typing. Recently, with the availability of a C4 cDNA probe, a C4A gene deletion associated with HLA-B8,DR3 has been reported in normal individuals. We have tried to resolve the problem of assigning the C4A*Q0 allele by using both phenotypic and genotypic approaches and have determined the significance of the C4A*Q0 allele in 80 unrelated patients with Graves' disease and in 50 normal control subjects. Our results demonstrate a strong association of the C4A*Q0 allele with Graves' disease (56 versus 26%; P less than 0.002, relative risk = 3.7) and in particular in association with HLA-B8 and/or DR3 (92 versus 70.6%; P less than 0.04) when compared with normal controls. All the C4A*Q0 alleles that were associated with HLA-B8 and/or DR3 were due to a C4A gene deletion. Of the C4A*Q0 alleles, in Graves' disease, 94% (compared with 82% in the control group) could be detected by C4 DNA analysis using either TaqI or EcoRI restriction endonucleases. It is suggested that a combination of C4 protein typing with C4 DNA analysis is the best approach for the determination of the C4A*Q0 allele in unrelated individuals without access to family data.     

Inverse association between cyclin D1 overexpression and retinoblastoma gene mutation in thyroid carcinomas

Cyclin D1 plays a key role in the regulation of the G1/S transition through the cell cycle. Deregulation of cyclin D1, most often leading to overexpression of the gene, has been reported in many tumor types. It has been suggested that cyclin D1 overexpression could be an alternative mechanism for pRb inactivation. We have previously found Rb gene mutations in 55% of malignant thyroid tumors. In the present study, we examined the cyclin D1 gene expression and amplification in 24 tumor samples (two of them are benign goiters) randomly selected from the same series of thyroid tumors, to see whether cyclin D1 over-expression is present in those specimens without Rb gene mutations. We found a four- to fivefold increase in cyclin D1 expression in 7 of 22 thyroid carcinomas as compared with that in benign nodular goiters. Six of them were found in carcinomas without Rb gene mutations. Among the remaining 15 thyroid carcinoma samples, 11 were found previously to have Rb gene mutations. The association between increased cyclin D1 expression and absence of Rb mutation is statistically significant (p < 0.05). We found no evidence of the cyclin D1 gene amplification or rearrangement to account for such an increase in cyclin D1 expression. We conclude that cyclin D1 overexpression may be relevant to thyroid carcinogenesis. Two mechanisms may be involved in the inactivation of pRb: one is through Rb gene mutations, and the other is by cyclin D1 overexpression.     

中国大陆新发现丙型肝炎病毒3'非编码区终止密码子变异

目的获得全长中国大陆1b型丙型肝炎病毒(HCV)3'非编码区(3'UTR)cDNA,并分析一级结构的变异,为进一步研究其在HCV复制、翻译中的调控机制和开发新的抗HCV药物奠定基础.方法利用逆转录套式聚合酶链反应(RT-PCR)限制性内切酶长度多态性分析(RFLP)初步筛选出1例1b型HCV感染者,采用半套式RT-PCR法扩增出约400bp的cDNA片段,克隆测序.结果获得的全长1b型HCV 3'端序列,由高变区、Poly(u)区、Poly(u/c)区及98碱基区4部分组成;首次发现终止密码子突变由TGA突变为TGG,可导致NS5B的翻译不能及时终止.结论半套式RT-PCR法可有效获得病毒基因组的全长末端序列;首次报道终止密码子突变导致NS5B区延长,3'UTR缩短.该发现对了解HCV的复制和翻译机制可能有一定的理论和实践意义.     

Meta-analysis of association of insertion/deletion polymorphism of angiotensin I-converting enzyme gene with diabetic nephropathy and retinopathy

Summary An insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene has repeatedly been shown to be associated with ischaemic heart disease, but the association of this genetic marker with diabetic microangiopathy is controversial. To assess the association of the genotypes with the development of diabetic nephropathy or retinopathy, we performed a meta-analysis of data from the literature, using Mantel-Haenszel method followed by the Breslow-Day test for assessing homogeneity among data. In a total of 4773 diabetic patients from 18 studies with (n = 2495) and without (n = 2278) renal complications, the D allele was significantly associated with diabetic nephropathy (p < 0.0001) in a dominant model (summary odds ratio 1.32, 95 % confidence interval: 1.15 to 1.51). There was no significant evidence against homogeneity of the odds ratios (χ ² = 18.9, 20 df; p = 0.53). The association was significant both in non-insulin-dependent (p < 0.005) and in insulin-dependent diabetes mellitus (p < 0.05). Likewise, in a total of 2010 diabetic patients with (n = 1008) and without (n = 1002) retinopathy, there was no association of the I/D polymorphism with diabetic retinopathy. These data suggest that the ACE I/D polymorphism affects the risk for diabetic nephropathy, but not for diabetic retinopathy. [Diabetologia (1998) 41: 47–53] Received: 30 April 1997 and in revised form: 31 July 1997     

Hepatocyte-specific deletion of DDB1 induces liver regeneration and tumorigenesis

Etiologic risk factors for hepatocellular carcinoma can be involved in the transformation process by directly targeting intracellular signaling pathways or by indirectly stimulating chronic cycles of hepatocyte destruction and regeneration. However, the contribution of these two routes to hepatocarcinogenesis has not been determined, partly because of the difficulty in distinguishing damaged and regenerated hepatocytes. Here we report that induced deletion of the damaged DNA binding protein 1 (DDB1) abrogates the self-renewing capacity of hepatocytes, resulting in compensatory proliferation of DDB1-expressing hepatocytes. Constitutive stimulation of this regeneration process leads to development of hepatocellular carcinoma, which surprisingly contains no disruption of the DDB1 gene, indicating a cell-nonautonomous role of DDB1 inactivation in tumor initiation. Our results suggest that viruses and hepatoxins may cause liver tumors by simply driving hepatocyte turnover without directly targeting cancer cells.     

RNA secondary structure and squence conservation in C1 region of human immunodeficiency virus type 1 env gene

We have analyzed amino acid, nucleotide sequence, and RNA secondary structure variability in the env gene of human immunodeficiency virus type (HIV-1). In applying algorithms for computing optimal RNA-folding patterns to a nonredundant data set of 178 env nucleotide sequences, we found a conserved RNA stem-loop structure in the first conserved (C1) region of the env gene. This detailed examination also revealed the known secondary structure conservation of the Rev-responsive element (RRE). This finding is also supported by a higher third position conservation of the translatable reading frame along these subregions. The typical folding of the C1 region consists of two isolated stem-loop structures. These highly conserved structures are likely to have a biological function. This assumption is supported by the conservation of the third position along the coding region of these structures. The third position retains a conservation level above what would be statistically expected.