8p杂合性缺失与膀胱肿瘤的关系

肿瘤遗传学和分子生物学研究表明,癌症的发生是由癌基因的激活及抑癌基因失活的结果,而抑癌基因的失活可能在其中起着更为关键的作用。抑癌基因(tumor suppressor gene)是能够抑制细胞的恶性转化,对正常细胞的增殖起负性调节的基因。抑癌基因的失活常常表现为一个等位基因丢失(     

P73表达在人类肿瘤中的意义

原癌基因（proto-oncogene）的激活和/或抑癌基因（tumor suppressor gene）的缺失和灭活是恶性肿瘤发生、发展的分子生物学基础.P53基因是迄今为止发现的与人类肿瘤相关性最高的抑癌基因,其第一个被发现的家族成员P73基因作为候选的抑癌基因受到学者们的广泛关注.本文对P73基因在人类肿瘤中的表达及意义作一综述.     

抗癌基因的功能

抗癌基因是一类参与细胞生长发育、增殖分化,抑制胞非正常增殖的调控基因,它的缺失或失活与肿瘤发生密切有关。近年对它的研究取得了较大进展。此文较详细地介绍抗癌基因的生物学功能。抗癌基因(anti-oncogene)或称肿瘤抑制基因(tumor suppressor gene)是一类参与细胞生长发育、增殖分化的调控基因。它表达或加强表达时,能抑制由活化或过渡表达的癌基因造成的细胞表型恶性转化;当它缺失或失活时,又可导致细胞恶性转化而发生肿瘤。近年来对它的研究     

Polymorphism analyses of hepatitis B virus X gene in hepatocellular carcinoma patients from southern China

Chronic hepatitis B virus(HBV)infection is one of the major causes of hepatocellularcarcinoma(HCC),and the HBV X(HBx)gene plays a critical role in the molecular pathogenesis ofHBV-related HCC.We have investigated whether there are particular HBx gene mutations associated withHCC in patients from southern China.The HBx gene was examined in 51 paraffin-embedded tumor tissuesamples from patients with HCC and 25 serum samples from the HBV carrier by nested polymerase chainreaction(PCR),single-stranded conformational polymorphism and heteroduplex analysis.The HBx geneswith potentially important mutations from tumor tissue samples were cloned,sequenced and aligned withthe published HBx gene sequence.HBV genotypes in tumor tissue samples were analyzed by nested PCR.Analyses of HBx gene polymorphism showed that 31.3% of HBx gene fragments in tumor tissue sampleshad a special pattern.A common deletion at nt 382-400 of the HBx gene accompanied by 29 point mutationswas detected in four randomly selected tumor tissue samples with this pattern which caused a frame-shiftin the HBx open reading frame with a new stop codon at nt 1818,resulting in an HBx polypeptide chaintruncated at the C end in these cases.Among the four randomly selected samples,three were HBV genotypeB,and one was not detected by our present assay.In another tumor tissue sample,amplification of thefull-length HBx gene yielded a shorter fragment.Sequencing of this fragment revealed a 264 bp deletionbetween nt 1577 and 1840 of the HBV gene.These results suggest that HBx gene mutation occurs frequentlyin HCC samples,and the deletion at nt 382-400 of the HBx gene might play a role in carcinogenesis of HCCin southern China.     

8p杂合性缺失与膀胱肿瘤的关系

肿瘤遗传学和分子生物学研究表明,癌症的发生是由癌基因的激活及抑癌基因失活的结果,而抑癌基因的失活可能在其中起着更为关键的作用。抑癌基因（tumor suppressor gene）是能够抑制细胞的恶性转化,对正常细胞的增殖起负性调节的基因。抑癌基因的失活常常表现为一个等位基因丢失（allelic loss）和另一个存留等位基因（retained allele）突变。其中,等位基因丢失就是由肿瘤中常见的染色体区域或节段缺失所致,它同时还会伴有抑癌基因座位相邻区域的杂合性缺失（loss of heterozygosity,LOH）。IDH是指肿瘤基因中特定染色体上某种DNA多态标记的等位基因片段由同一患正常组织基因组的两种变成一种,即等位基因型由杂合子变成纯合子。IDH是肿瘤细胞中染色体缺失的表现。     

伪狂犬病毒立即早期基因5’端特异性反义RNA对病毒增殖的影响

伪狂犬病毒(Pseudorabies virus,PRV)属疱疹病毒科α-疱疹病毒亚科,基因组为线状双链DNA,长约150kb,至少可编码70～100种蛋白质。根据伪狂犬病毒感染细胞后DNA转录、表达时间的先后可将PRV基因分为立即早期基因(Immediateearly gene),早期基因(Early gene)和晚期基因(Late gene),这三类基因依此以级联方式调节。     

伪狂犬病毒立即早期基因5''''端特异性反义RNA对病毒增殖的影响

伪狂犬病毒(Pseudorabies virus,PRV)属疱疹病毒科α-疱疹病毒亚科,基因组为线状双链DNA,长约150kb,至少可编码70～100种蛋白质.根据伪狂犬病毒感染细胞后DNA转录、表达时间的先后可将PRV基因分为立即早期基因(Immediateearly gene),早期基因(Early gene)和晚期基因(Late gene),这三类基因依此以级联方式调节[1].第一个被转录的基因是立即早期基因,它的转录即使在细胞蛋白质合成被放线菌酮(Cycloheximide)抑制的情况下也能进行.     

宫颈癌p16基因甲基化及表达的研究

为了探讨p16基因甲基化及异常表达在宫颈癌中的意义,分别采用甲基化特异性PCR（MSP）方法检测不同病理类型和临床分期的60例宫颈癌组织中p16基因启动子区域5´CpG岛甲基化状态;采用PCR方法检测p16基因外显子1（E1)和外显子2(E2)纯合缺失情况;采用免疫组化的方法分析p16蛋白的表达缺失和减弱情况。结果显示正常对照组织及癌旁p16基因无甲基化,且无E1和E2缺失和p16蛋白表达异常。60例宫颈癌标本的甲基化率为21.67%（13/60）;p16 基因缺失率为15.00%（9/60）;p16蛋白表达下降或无表达为51.67%（31/60）。可见p16基因蛋白的阳性表达率随着临床分期升高呈明显下降趋势。结果提示p16基因失活在宫颈癌中多见且与病理分级密切相关。p16 基因甲基化在宫颈癌发生中起着一定作用。Abstract： To detect hypermethylation and aberrant expression of the p16 gene in cervical carcinoma (CC), methylation-specific PCR (MSP) was used to determine the methylation status of 5´CpG islands of the p16 gene, loss or decrease of p16 expression was analyzed by immunohistochemistry (IHC), and homozygous deletion of exon 1 (E1) and/or exon 2 (E2) was determined by PCR. in 60 cases of CC at different pathological grades and clinical stages. The results showed absence of methylation and presence of normal expression of the p16 gene in the control and adjacent tissues of CC. Hypermethylation, loss or decrease of expression and deletion of the p16 gene were detected in 21.67%(13/60), 51.67%(31/60) and 15.00%(9/60) of the tumor tissues, respectively. The rate of p16 expression markedly reduced with the increase of clinical stages. Our data suggested that inactivation of the p16 gene was a frequent event and positively correlated with pathological grades in CC, and that methylation of the p16 gene was an important event in carcinogenesis of CC.     

Hippo信号通路核心组分lats1:一种新的肿瘤分子标记和潜在治疗靶点

大肿瘤抑制基因1(large tumor suppressor gene 1,lats1)是hippo信号通路中的关键组分之一,通过下调靶基因yap抑制肿瘤的发生和发展。研究发现,lats1在多种肿瘤组织中表达下调或缺失,被认为是一个抑癌基因。因此,lats1很可能成为一个新的恶性肿瘤分子标记和治疗靶点,该文就lats1在该领域的研究进展作一综述。     

医学分子遗传学 第一讲人体基因组的结构解剖

一个细胞的全部遗传信息都编码在长长的线状 DNA分子上，构成一个基因组（Genome)。在DNA分 子上排列着各种不同的基因，基因携带着产生所有蛋 白质的遗传信息。在人体基因组内，有些基因是一个个 单独分布的，在基因与基因之间隔着较长的非编码区 域，这些DNA称为间隔DNA (spacer DNA)。有些 基因则紧密排列在一起，形成基因簇(gene clusters), 或称为基因复合体（gene complexes).     

两次有关抗癌基因的国际会议简介

抗癌基因,或称肿瘤抑制基因、隐性癌基因(anti-oncogenes, tumor suppressor Eenes, recessive oncogenes),是一类发生隐性突变时能导致肿瘤发生的基因。对它们的研究开始于八十年代中期。由于抗癌基因的失活是多阶段癌变中的重要事件,抗癌基因的鉴定分离及其机能的阐明将为癌、特别是中晚期癌的治疗开发出新的强力手段。 1988年,国际上召开了多次有关抗癌基因的国际会议。本文摘要介绍其中两次:《肿瘤抑     

人类癌基因

<正> 细胞癌基因结构与功能的发现是近年来肿瘤研究的重大突破。目前,它已成为对癌变本质研究中的重要方面,引起广泛的重视。迄今为止,已有十余种人的癌基因从不同组织与胚层(结肠癌、肺癌、胰腺癌、胆囊癌、胱膀癌、纤维肉瘤、胚胎性横纹肌肉瘤等),不同来源(实体瘤、细胞株)的人体肿瘤细胞中检出。 癌基因(oncogene,或致癌基因、致肿瘤基因)是以原癌基因(proto-oncogene)的形     

肺癌发生过程分子生物学机制的研究进展

肺癌已成为人类癌症死亡的主要原因之一。综述近年来在肺癌发生发展过程中起重要作用且研究较为成熟的癌基因、抑癌基因及一些肺癌相关蛋白,它们包括细胞周期素D1(Cyclin D1)及抑癌基因p16、肺癌转移相关蛋白、谷胱甘肽-S-转移酶(GSTs)、癌基因Bcl-2、ras基因、恶性肿瘤特异性生长因子(TSGF)、绒毛膜促性腺激素(HCG)、粘蛋白、8-羟基-脱氧鸟苷(8-OH-dG)、具有磷酸酯酶活性的抑癌基因-PTEN、组织多肽特异性抗原(TPS),通过介绍这些生物大分子在肺癌组织中上调或下调机制,以期为肺癌的早期检测和治疗提供标志物。     

妊娠小鼠子宫内膜LIF基因表达的研究

本文对妊娠第4天(Ⅰ组)、第7天(Ⅱ组)、第10天(Ⅲ组)的小鼠(各20只)子宫内膜LIF基因表达进行了研究。Ⅰ组20只小鼠子宫内膜全部存在LIF基因的表达、Ⅱ组有5只小鼠表达、Ⅲ组仅有1只小鼠表达。文中对不同孕期LIF基因的表达程度与胚胎着床的关系进行了讨论。 Abstract:Leukemia inhibitory factor(LIF)is a glycoprotein with multiple activities and is essential for blastocyst implantation in mouse.We have examined LIF gene expression in mice endometrium on day 4(group Ⅰ),day 7(group Ⅱ),day 10(group Ⅲ)of pregnancy.In group Ⅰ all had LIF gene expression,5 mice had LIF gene expression in group Ⅱ,only one mouse had LIF gene expression in group Ⅲ.We discussed the relation between level of LIF gene expression and embryonic implantation.     

多位点序列和比较基因组学分析对盐单胞菌科菌株JSM 104105的系统发育学研究

【目的】为了精准地判定产铁载体嗜盐新菌株JSM 104105在盐单胞菌科(Halomonadaceae)中的系统发育地位。【方法】采用基于16SrRNA基因、DNA促旋酶B亚基基因(DNAgyraseB subunit gene, gyrB)和核糖核酸聚合酶σ因子RpoD基因(RNA polymerase sigma factor RpoD gene,rpoD)序列的多位点序列分析方法(multilocus sequence analysis, MLSA),对菌株JSM 104105的系统发育地位进行初步分析;采用比较基因组学分析(comparative genomics analysis),分析该菌株与其系统发育关系密切的典型菌株之间的GC含量、平均核苷酸一致性(average nucleotide identity,ANI)和数字DNA-DNA杂交值(digital DNA-DNA hybridization, dDDH),并进行基因组系统发育学分析(phylogenomic analysis),更准确地判定菌株JSM 104105在盐单胞菌科中的系统发育地位。【结果】MLSA分析...     

利用CLSM检测GFP基因在家蚕的瞬时表达

将绿色荧光蛋白(GFP)基因导入农蚕蛹(G0)的睾丸,利用激光共聚焦扫描显微镜(CLSM)系统检测,得到GFP基因在家蚕刚孵出未进食的幼虫(蚁蚕)(G1)瞬时表达的荧光图像。 Abstract:Plasmid DNA containing the GFP(Green Fluorescent Protein)reporter gene was injected into the testis of silkworm(Bombyx mori L.)pupa(G0),we observe the fluorescence imaging of expression of GFP gene in silkworm newly-hatched larvae(G1)examined by Confocal Laser Scanning Microscope.     

小鼠受精抗原1基因与人类同源基因的关系

参照已报道小鼠受精抗原1（FA1）基因序列设计引物,运用PCR和PCR产物克隆测序等方法,对人受精抗原1（FA1）基因进行了克隆,并对两者进行了比较,结果显示:（1）已报道的小鼠FA1基因序列在其可读框内可能存在两处错误。（2）人OTK27基因可能与小鼠FA1基因同源,即OTK27基因就是人hFA1基因,或FA1基因就是小鼠otk27基因。 Abstract:The cloning of human fertilization antigen 1 gene（FA1） ,the supposed counterpart gene of mouse fertilization antigen 1 gene (FA1),was performed using the PCR and PCR products cloned sequencing methods.The result shows that there might be two mistakes in the mouse FA1 gene open reading frame (ORF),and human OTK27 gene and mouse FA1 gene might be homogeneous genes in the two species.     

基因捕捉及其在植物基因分离和功能基因组学上的应用

基因捕捉是一种报告基因的随机整合技术。基因捕捉系统已成为分离基因、鉴定基因功能的重要手段。基因捕捉(gene traps)包括增强子捕捉(enhancer trap)、启动子捕捉(promoter trap)和基因捕捉(gene trap),通称为基因捕捉(gcne traps)。在增强子捕捉中,报告基因与一个基本启动子融合,这个启动子不能使报告基因表达,但可被临近的增强子激活。在启动子捕捉和基因捕捉中,报告基因的启动子被去除,融合基因只有以正确的方向插入到转录单元内才能表达。对基因捕捉系统的结构特征、构建方法、应用范围、研究现状和应用前景等作了系统论述,并对有关问题进行了讨论。     

Low-volume jet injection for efficient nonviral in vivo gene transfer

The transfer of naked deoxyribonucleic acid (DNA) represents an alternative to viral and liposomal gene transfer technologies for gene therapy applications. Various procedures are employed to deliver naked DNA into the desired cells or tissues in vitro and in vivo, such as by simple needle injection, particle bombardment, in vivo electroporation or jet injection. Among the various nonviral gene delivery technologies jet injection is gaining increasing acceptance because it allows gene transfer into different tissues with deeper penetration of the applied naked DNA. The versatile hand-held Swiss jet injector uses pressurized air to force small volumes of 3 to 10 μL of naked DNA into targeted tissues. The β-galactosidase (LacZ) reporter gene construct and tumor necrosis factor α gene-expressing vectors were successfully jet injected at a pressure of 3.0 bar into xenotransplanted human tumor models of colon carcinoma. Qualitative and quantitative expression analysis of jet injected tumor tissues revealed the efficient expression of these genes in the tumors. Using this Swiss jet-injector prototype repeated jet injections of low volumes (3–10 μL) into one target tissue can easily be performed. The key parameters of in vivo jet injection such as jet injection volume, pressure, jet penetration into the tumor tissue, DNA stability have been defined for optimized nonviral gene therapy. These studies demonstrate the applicability of the jet injection technology for the efficient and simultaneous in vivo gene transfer of two different plasmid DNAs into tumors. It can be employed for nonviral gene therapy of cancer using minimal amounts of naked DNA.