SNP功能活性研究方法进展

SNP位点是目前基因多态性研究的主要内容,包括检测分型和功能活性研究两个层次,已经建立了高度自动化和高通量的SNP检测分型技术.本文系统介绍了在性状功能、蛋白质表达、mRNA转录、基因组结构功能等不同层次上进行SNP功能活性研究的方法,并对相关研究结果进行分析,通过对各种研究方法及结果的比较,对SNP位点功能活性研究的前景进行了展望.     

节木代料香菇子实体蛋白质的营养评价

对不同节木代料香菇子实体蛋白质的营养价值进行了研究。结果表明 ,2种节木代料香菇子实体蛋白质的必需氨基酸含量与木屑代料香菇子实体蛋白质的必需氨基酸含量没有明显差异 ,且前者蛋白质的氨基酸系数分均高于后者 ,这说明节木代料香菇子实体蛋白质具有较高的营养价值。     

作物节木代料香菇与纯木屑代料香菇蛋白质营养比较研究

采用国际通用的蛋白质营养评价方法,对2种作物节木代料和纯木屑代料(CK)香菇子实体蛋白质的营养价值进行了比较研究。结果表明,2种作物节木代料香菇子实体蛋白质的NI指标低于纯木屑代料香菇,而CS、AAS、EAAI、BV、SRCAA等指标均高于纯木屑代料香菇。结论:作物节木代料香菇子实体和纯木屑代料香菇子实体蛋白质均具有较高营养价值,且二者之间无显著差异。     

XA21和PI-D2激酶蛋白质在酿酒酵母中的表达及其自我磷酸化研究

白叶枯病和稻瘟病是最主要的水稻病害。Xa21是水稻白叶枯病抗性基因,Pi-d2是稻瘟病抗性基因,二者都编码类受体激酶蛋白质。在前期研究中,曾系统地研究了细菌中表达XA21激酶蛋白质的生化活性。在此实验中利用真核表达系统酿酒酵母对Xa21和Pi-d2编码的蛋白激酶进行了表达、纯化及自我磷酸化活性分析,为进一步的生化分析、蛋白质-蛋白质相互作用研究、底物筛选等奠定了基础。     

外源茉莉酸甲酯诱导对香菇多糖代谢及关键酶基因表达的影响

香菇多糖是重要的生物活性成分,其药用价值高,茉莉酸甲酯有助于提高食用菌多糖含量,但关于其对香菇多糖合成的影响尚不清楚。本研究以香菇新808为实验材料,对不同浓度茉莉酸甲酯（MeJA）诱导下香菇菌丝生物量和生长速率、香菇多糖代谢关键酶活性及基因相对表达量、香菇多糖含量进行比较分析。结果表明：10μmol/L的茉莉酸甲酯可显著促进香菇菌丝生长并提高菌丝体生物量,分别是对照的1.14倍、1.2倍;与香菇多糖代谢相关的UDP-葡萄糖焦磷酸化酶（UGPase）、葡萄糖磷酸异构酶（PGI）、α-葡萄糖磷酸变位酶（α-PGM）活性增加,为对照组的1.58、1.13、3.21倍;其基因相对表达量较对照组也显著上调,为对照组的5.73、1.4、1.77倍;香菇多糖合成量显著增加,为对照组1.58倍。10μmol/L的MeJA处理后,香菇多糖代谢关键酶活性及基因相对表达量与多糖含量间存在显著的正相关关系,表明添加适宜浓度的茉莉酸甲酯会影响香菇菌丝的生长及多糖合成。     

美洲大蠊新基因Parcxpwxxq01的分析及功能预测

为进一步研究已发现的美洲大蠊新基因Parcxpwxxq01,我们采用BLASTp,ORF Finder,ProtScale,ScanProsite和Tmpred Server等软件或数据库进行相似性比较、开放读码框预测和编码蛋白质的功能等生物信息学方法对该序列进行特征分析和功能预测,以获得该基因及其编码的蛋白质的更多功能提示。结果发现得到的Parcxpwxxq01序列是该基因的全长序列,该基因编码的蛋白质是一碱性跨膜蛋白,该蛋白质可能为美洲大蠊的药用有效成分,有进一步研究的价值。     

细胞蛋白质相互作用的结构基础

随着人类基因组计划的进行 ,大量基因被发现和定位 ,基因的功能问题将成为今后研究的热点。大多数基因的最终产物是相应的蛋白质 ,因此要认识基因的功能 ,必然要研究基因所表达的蛋白质。蛋白质的功能往往体现在与其他蛋白质及 /或核酸的相互作用之中。细胞各种重要的生理过程 ,包括信号的转导 ,细胞对外界环境及内环境变化的反应等 ,都是以蛋白质间相互作用为纽带 ,并形成网络。所以 ,近年来 ,蛋白质间相互作用的研究逐渐得到重视。蛋白质分子的结构域有很多种 ,但是现在明确作为为介导蛋白质 蛋白质间相互作用的结构域并不多 ,这里取已明…     

功能RNA分子的构建、表达及其在基因功能鉴定中的应用

人工构建的siRNAs、aptazymes、maxizymes以及intramers等功能RNA分子,可以在mRNA或蛋白质水平上调控基因的功能.功能RNA分子可在活体内或转基因模式动、植物中抑制目标基因的表达,使目标基因和蛋白质功能丧失,进而引起表型变异.胞内表达的活性RNAs可作为有效的研究工具应用于基因及其编码蛋白的功能鉴定,并在药物开发和人类疾病治疗上有潜在的应用前景.     

基因的推理设计与改造—体外分子进化的捷径

体外分子进化是改造基因、获得新的功能蛋白质重要手段之一,已经取得了令人瞩目的成就。推理设计是利用序列和结构的比较信息创造新的基因和蛋白质,是研究改造蛋白质功能的有效方法。文章着重介绍了基因推理设计在基因体外分子进化中的应用,从简单实用的基因密码偏爱设计,结合多个不同性状相关功能基因信息的基因推理设计,关键功能区域的简并引物设计,位点直接蛋白质重组4个方面进行描述,并综述了该方法近年来的应用。     

香菇C91-3转录本Unigene 24277基因克隆表达及其生物学活性的研究

通过对香菇C_91-3转录本Unigene 24277基因的生物信息学分析,克隆表达含RCC1结构域的Unigene 24277基因,并研究其抗肿瘤活性。从香菇C_91-3菌丝体中提取总RNA,反转录合成cDNA,并利用Rapid Amplification of cDNA Ends（RACE）技术获得基因全长。NCBI数据库分析提示其含有RCC1结构域。PCR扩增RCC1结构域,将其克隆产物与pET-32a（+）载体连接,热转化至E.coil Rosetta-gami（DE3）中诱导表达,纯化、复性后,通过MTT法研究其抗肿瘤活性。结果显示原核表达载体构建成功,重组蛋白成功诱导表达,并初步证明了重组蛋白具有抑制肿瘤细胞增殖活性的功能,为后续抗肿瘤机制的探究奠定了基础。     

New molecular tumor markers for endometrial cancer

Although the International Federation of Gynecology and Obstetrics officially changed the classification system of endometrial cancer from a clinically staged to a surgically staged disease in 1988, optimal management of patients with endometrial cancer is still controversial. Gynecologists happen to experience that patients with tumors that are identical in grade and stage often have significantly different clinical outcomes or responses to therapy. In order to identify an objective biological factor correlating with tumor aggressiveness, many tumor markers have been investigated. So far, CA125 is one of the most reliable tumor marker for adenocarcinoma of the uterus and frequently used in a clinical setting. Recently, with the advent of molecular biological techniques, many genes and regions of the genome related to endometrial cancer have been identified. We undertook a genome-wide screening to detect genetic changes by comparative genomic hybridization (CGH) in primary endometrioid cancers, since CGH analysis provides comprehensive information concerning relative chromosomal losses and gains in tumors by a single hybridization. In this paper, the usefulness of serum tumor markers and the new promising molecular tumor markers for endometrial cancer are discussed.     

基因组学与表观遗传学在肿瘤标志物研究中的应用

肿瘤标志物是一类能反映肿瘤存在与生长状态的生化物质,它们在肿瘤的早期筛查、辅助诊断、预后判断、疗效评价、复发和转移监测中具有重要意义. 随着细胞与分子生物学领域的发展,人类基因组计划大量研究成果的涌现,人们对肿瘤的发生和发展机理有了越来越清楚的认识,肿瘤标志物的研究也得到了极大的拓展与更新,特别是基因组学和表观遗传学的进展大大促进了新型肿瘤标志物的发现. 文章就肿瘤标志物发展历程,常用肿瘤标志物的种类和临床应用进行介绍,分析了现有肿瘤标志物的局限性,重点阐述了新型肿瘤标志物,如多种表观遗传学标志物及循环核酸的研究及应用. 同时,对肿瘤标志物的研究前景提出了一些观点.     

癌组织中的遗传不稳定性的RAPD分析(简报)

肿瘤仍然是导致人类死亡的重要原因,由于缺乏深刻了解癌症的发生机制,尽管在过去25年中肿瘤的诊断和治疗都取得很大的进展,但肿瘤病人的存活率并没有显著的提高。目前有很多癌基因和抑癌基因如P16、P53、P73、ras、DCC和RB等     

癌组织中的遗传不稳定性的RAPD分析（简报）

In five kinds of tumors, total 128 specimens were analyzed by RAPD (random amplified polymorphic DNA) PCR with nine 10-base arbitrary primers for detecting instabilities of DNA and chromosome and screening new molecular markers coupled to putative or unknown oncogenes and/or tumor suppressor genes. Bands representing instabilities have been recovered and purified from agarose and cloned into pCAPs vector, and further labeled by DIG as probes for analysis of Southern blot, Northern blot and Sequencing. Results revealed that sample 5 and 3 of the gastric cancers showed the highest genomic changes and the average detectability in five sorts of cancers was up to at least 40% (42.2%-49.4%), and that there were significant differences in the ability of each primer to detect genomic instability, which ranged from 27% to 68%. Despite the highest detectability of genetic instability (68%) in tumor tissues, primer 2 could produce stable profiles of DNA bands in normal tissue genome with good reproducibility. On the contrary, primer 8 was of the lowest one (27%). Band B of single copy found to be allelic losses in gastric and colon cancers according to RFLP analysis was of a novel sequence and registered by Gen-Bank (Accession Number AF151005). Therefore the genetic instabilities often concentrated on some special locuses of chromosome e.g. repetitive sequences etc. and coupled to carcinogenesis. It was impossible or difficult to get great achievements for cancer treatments with the procedure of gene therapy only to one oncogene or one tumor suppressor gene because the extensive DNA variations occurred during the progression of tumor. RAPD assay connected with other techniques was a good tool for the detection of genomic instabilities and direct screening of some new molecular markers related to tumor suppressor genes or oncogenes.     

Prowling wolves in sheep's clothing: the search for tumor stem cells

The importance of a subset of cells which have 'stem like' characteristics and are capable of tumor initiation has been reported for a range of tumors. Isolation of these tumor-initiating cells (TICs) has largely been based on differential cell surface protein expression. However, there is still much debate on the functional significance of these markers in initiating tumors, as many properties of tumor initiation are modified by cell-cell interactions. In particular, the relationship between TICs and their microenvironment is poorly understood but has therapeutic implications, as the microenvironment can maintain tumor cells in a prolonged period of quiescence. However, a major limitation in advancing our understanding of the crosstalk between TICs and their microenvironment is the lack of sensitive techniques which allow the in vivo tracking and monitoring of TICs. Application of new in vivo cellular and molecular imaging technologies holds much promise in uncovering the mysteries of TIC behavior at the three-dimensional level. This review will describe recent advances in our understanding of the TIC concept and how the application of in vivo imaging techniques can advance our understanding of the biological fate of TICs. A supplementary resource guide describing TICs from different malignancies is also presented.     

噬菌体抗体库技术在肿瘤抗体药物研究中的进展及应用

目的:综述噬菌体抗体库技术的研究进展,介绍该技术的原理,构建,筛选和应用,为抗肿瘤抗体药物研发提供参考。方法:采用文献综述的方法,筛选近5年来噬菌体抗体库技术试验论文,对噬菌体抗体库技术的原理,构建,筛选和应用进行总结。结果:噬菌体抗体库主要分为免疫抗体库和非免疫抗体库两大类;噬菌体抗体库筛选技术包括亲和筛选、细胞筛选和生物体内筛选三种;噬菌体抗体库技术主要应用于肿瘤标志物的识别和肿瘤诊断,抗肿瘤抗体药物的筛选和制备。结论:噬菌体抗体库技术方便、快速、高效,可以在体外环境下培养,这些特点决定了其在肿瘤标志物的发现和肿瘤抗体药物研发中的广泛应用。目前噬菌体抗体库技术还存在一定缺陷,但技术的不断发展和革新必然使噬菌体抗体库技术成为研制抗体药物的新思路,极大促进了肿瘤抗体药物的研发。     

Characterization of supernumerary rings and giant marker chromosomes in well-differentiated lipomatous tumors by a combination of G-banding,CGH, M-FISH,and chromosome- and locus-specific FISH

Supernumerary ring chromosomes and/or giant marker chromosomes are often seen in soft-tissue tumors of low-grade or borderline malignancy, such as well-differentiated liposarcomas or atypical lipomas. Classic cytogenetic banding techniques have proved insufficient to identify the genomic composition and structure of such rings and markers, but fluorescent in situ hybridization (FISH) studies have shown that they consist mainly of amplified material from chromosome 12, more specifically from bands 12q13-->q15. We have used the new FISH-based screening techniques comparative genomic hybridization (CGH) and multicolor-FISH (M-FISH) in combination with G-banding and analysis by chromosome- and locus-specific fluorescent in situ probes to examine in detail the karyotypic characteristics of 22 lipomatous tumors, most of them classified histologically as well-differentiated liposarcomas, selected because they had been shown to harbor rings and/or marker chromosomes. M-FISH, in contrast to G- banding, was found to be informative with regard to the chromosomal origin of the rings and other markers present, whereas CGH and hybridizations with locus-specific probes helped identify which subchromosomal regions were involved. We found that chromosome bands 12q15-->q21 were always gained, with 12q15-->q21 being amplified (i.e., a green-to-red ratio >2 by CGH) in 14 of 22 tumors. In three tumors, two distinct but close amplicons in 12q could be identified, corresponding to bands 12q13-->q15 and 12q21. The genomic segment 1q21-->q23 was gained in 12 cases, reaching the level of amplification in seven. Bands 6q24 and 7p15, whose pathogenetic involvement in liposarcomas has not been reported previously, were gained in three cases each. In addition, the rings and giant markers often contained interspersed sequences from several other chromosomes that did not give an equally clear impression of being nonrandomly involved.     

Thirty-one new RFLP systems detected by twenty-four DNA markers on human chromosome 10.

Thirty-one new RFLP systems corresponding to 24 loci have been identified from a chromosome 10-specific cosmid library. Twelve of the markers on the proximal long arm (cen-q11.2) of this chromosome, including four RFLP systems for the RET locus, will be especially useful in efforts to identify the gene responsible for multiple endocrine neoplasia type 2A (MEN2A). The new panel of markers also may contribute to fine-scale mapping of tumor suppressor genes associated with glioblastoma multiforme or renal cell carcinoma, because allelic deletions in these tumors have implied the presence of a tumor suppressor gene(s) on chromosome 10.     

用于肿瘤治疗的免疫检查点抑制剂相关预测生物标志物的研究进展

恶性肿瘤是严重威胁人类健康和社会发展的疾病。传统的肿瘤治疗方法如手术、放疗、化疗和靶向治疗等不能完全满足临床治疗的需求,新兴的免疫治疗成为了肿瘤治疗领域的研究热点。免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)作为一种肿瘤免疫治疗方法,已获批用于治疗多种肿瘤,如肺癌、肝癌、胃癌和结直肠癌等。然而,ICIs在临床使用过程中,只有少数患者会出现持久反应,一些患者还会出现耐药和不良反应。因此,预测生物标志物的鉴定和开发对提高ICIs的治疗效果至关重要。肿瘤ICIs预测生物标志物主要包括肿瘤生物标志物、肿瘤微环境生物标志物、循环相关生物标志物、宿主环境生物标志物以及组合生物标志物等,对患者筛查、个体化治疗和预后评估具有重要意义。本文就肿瘤ICIs治疗预测生物标志物的前沿进展作一综述。     

Towards developing biomarkers for glioblastoma multiforme: a proteomics view

Glioblastoma multiforme (GBM) is one of the most aggressive and lethal forms of the primary brain tumors. With predominance of tumor heterogeneity and emergence of new subtypes, new approaches are needed to develop tissue-based markers for tumor typing or circulatory markers to serve as blood-based assays. Multi-omics data integration for GBM tissues would offer new insights on the molecular view of GBM pathogenesis useful to identify biomarker panels. On the other hand, mapping differentially expressed tissue proteins for their secretory potential through bioinformatics analysis or analysis of the tumor cell secretome or tumor exosomes would enhance our understanding of the tumor microenvironment and prospects for targeting circulatory biomarkers. In this review, the authors first present potential biomarker candidates for GBM that have been reported and then focus on plausible pipelines for multi-omic data integration to identify additional, high-confidence molecular panels for clinical applications in GBM.