睾丸特异性基因TSF22在小鼠中的表达研究

目的 筛选与精子发生相关的基因。方法 将4、9、18、35、54日龄和6月龄小鼠睾丸组织cDNA探针与Affymetrix全基因组芯片进行杂交，筛选出差异表达的基因。利用网络信息资源对该基因进行生物学信息分析。RT-PCR分析该基因在小鼠睾丸不同发育阶段及小鼠不同组织中的表达。结果 芯片结果分析筛选出一个差异表达杂交点（GenBank登录号：NM_199034），生物信息学分析发现该基因全长1597bp，含有570bp的完整ORF，编码190个氨基酸、分子量为22．106kDa的蛋白质，我们将其命名为TSF22。RT-PCR分析表明TSF22基因特异性表达于睾丸组织及18日龄小鼠睾丸中。结论 TSF22基因的表达与小鼠精子发生的过程一致，可能在精子发生中起重要作用。     

Decreased gene expression of steroid 5 alpha-reductase 2 in human prostate cancer: implications for finasteride therapy of prostate carcinoma

BACKGROUND: Steroid 5alpha-reductase 2 (SRD5A2) catalyzes the conversion of testosterone to the more potent androgen, DHT, in the prostate. The therapeutic influence of SRD5A2 inhibitor finasteride on prostate cancer is currently unknown. The direction and extent of changes in SRD5A2 expression in disease tissues is a relevant issue in this regard. METHODS: The expression differences of SRD5A2 in tissues representative of normal, benign, and malignant growth in the human prostate were examined in parallel by comparative analysis of relevant microarray gene expression data. Semiquantitative RT-PCR was used to further verify the gene expression differences of SRD5A2. RESULTS: Consistently decreased expression of SRD5A2 was observed in 25 prostate cancer samples when compared to 25 matched normal samples and nine BPH samples. Expression differences among these samples for six other genes were presented in parallel as indicators of the direction and extent of expression changes. These additional genes include SRD5A1, Hepsin (overexpressed in prostate cancer), AMACR (overexpressed in prostate cancer), Keratin 8 (epithelial marker), smooth muscle actin (stromal marker), Nell2 (overexpressed in BPH). Semiquantitative RT-PCR verified the expression differences for SRD5A2 in six normal, six BPH, and six prostate cancer samples. CONCLUSIONS: Results from this study, combined with those from previous studies, indicate an association of prostate cancer with reduced 5alpha-reductase enzymatic activity as a result of remarkably decreased expression of the SRD5A2 gene. The implications of this study for finasteride therapy of prostate cancer are discussed.     

黏蛋白在膀胱癌中的研究进展

膀胱癌是泌尿系统最常见的恶性肿瘤.近年来分子生物技术的发展及新肿瘤标志物的发现,为膀胱癌的早期诊断提供了物质基础.本文就黏蛋白( Mucins,MUC)及同种型MUC/Y基因在膀胱癌中的研究作一综述,采用RT- PCR法检测黏蛋白,对膀胱肿瘤早期诊断及预后判断具有潜在的临床应用价值.通过膀胱镜活检取得膀胱组织,检测其组...     

Statistical Issues in the Design and Analysis of Gene Expression Microarray Studies of Animal Models

Appropriate statistical design and analysis of gene expression microarray studies is critical in order to draw valid and useful conclusions from expression profiling studies of animal models. In this paper, several aspects of study design are discussed, including the number of animals that need to be studied to ensure sufficiently powered studies, usefulness of replication and pooling, and allocation of samples to arrays. Data preprocessing methods for both cDNA dual-label spotted arrays and Affymetrix-style oligonucleotide arrays are reviewed. High-level analysis strategies are briefly discussed for each of the types of study aims, namely class comparison, class discovery, and class prediction. For class comparison, methods are discussed for identifying genes differentially expressed between classes while guarding against unacceptably high numbers of false positive findings. Various clustering methods are discussed for class discovery aims. Class prediction methods are briefly reviewed, and reference is made to the importance of proper validation of predictors.     

DNA microarrays in otolaryngology-head and neck surgery.

OBJECTIVES: Our goal was to review the technologies underlying DNA microarrays and to explore their use in otolaryngology-head and neck surgery. STUDY DESIGN: The current literature relating to microarray technology and methodology is reviewed, specifically the use of DNA microarrays to characterize gene expression. Bioinformatics involves computational and statistical methods to extract, organize, and analyze the huge amounts of data produced by microarray experiments. The means by which these techniques are being applied to otolaryngology-head and neck surgery are outlined. RESULTS: Microarray technologies are having a substantial impact on biomedical research, including many areas relevant to otolaryngology-head and neck surgery. CONCLUSIONS: DNA microarrays allow for the simultaneous investigation of thousands of individual genes in a single experiment. In the coming years, the application of these technologies to clinical medicine should allow for unprecedented methods of diagnosis and treatment. SIGNIFICANCE: These highly parallel experimental techniques promise to revolutionize gene discovery, disease characterization, and drug development.     

DOC-1基因的原核表达载体构建及其重组蛋白的表达纯化

目的：克隆DOC-1基因、构建原核表达载体并纯化出其重组蛋白。方法：从人胎脑组织中提取总RNA，经逆转录一聚合酶链式反应（RT—PCR）扩增DOC-1的CDS序列，再通过基因重组技术将该基因片段依次克隆到pMO18-T和pGEX-4T-1载体中，构建融合表达载体pGEX-4T-1-DOC-1，经酶切、测序鉴定后，用该重组质粒转化E．coliBL21，用IPTG诱导表达，Glutathlone Sepharose 4B柱亲和层析纯化重组蛋白。结果：电泳证实RT-PCR扩增产物与预期目的基因DOC-1长度一致，测序结果与GenBank公布的DOC-1基因序列完全一致，IPTG诱导后经SDS—PAGE电泳分析表明，在相对分子质量38000左右出现新的蛋白表达条带，经亲和层析柱纯化后得到高纯度的GST-p12重组蛋白。结论：成功构建了pGEX-4T-1-DOC-1原核表达载体，表达并纯化出GST-p12重组蛋白，为进一步研究p12^DOC-1蛋白打下了实验基础。     

Risk of Type 1 Diabetes Progression in Islet Autoantibody-Positive Children Can Be Further Stratified Using Expression Patterns of Multiple Genes Implicated in Peripheral Blood Lymphocyte Activation and Function

There is tremendous scientific and clinical value to further improving the predictive power of autoantibodies because autoantibody-positive (AbP) children have heterogeneous rates of progression to clinical diabetes. This study explored the potential of gene expression profiles as biomarkers for risk stratification among 104 AbP subjects from the Diabetes Autoimmunity Study in the Young (DAISY) using a discovery data set based on microarray and a validation data set based on real-time RT-PCR. The microarray data identified 454 candidate genes with expression levels associated with various type 1 diabetes (T1D) progression rates. RT-PCR analyses of the top-27 candidate genes confirmed 5 genes (BACH2, IGLL3, EIF3A, CDC20, and TXNDC5) associated with differential progression and implicated in lymphocyte activation and function. Multivariate analyses of these five genes in the discovery and validation data sets identified and confirmed four multigene models (BI, ICE, BICE, and BITE, with each letter representing a gene) that consistently stratify high- and low-risk subsets of AbP subjects with hazard ratios >6 (P < 0.01). The results suggest that these genes may be involved in T1D pathogenesis and potentially serve as excellent gene expression biomarkers to predict the risk of progression to clinical diabetes for AbP subjects.     

Designer genes: Filling the gap in transplantation

Accelerated evolution of the field of functional genomics has been greatly facilitated by high-throughput microarray-based gene function studies, relating to the parallel and serial expression measurements of genomes. Microarray experimentation is being applied for the study of basic research questions, drug target discovery, pharmacology, toxicogenomics, target selectivity, disease biomarker determination, development of prognostic tests, and disease subclass determination. This article will review the current applications of microarray technology in the field of organ transplantation and discuss the potential impact of this technology on transplantation medicine.     

Loss of imprinting and loss of heterozygosity on 11p15.5 in head and neck squamous cell carcinomas

BACKGROUND: IGF2 and H19 are reciprocal imprinted genes with paternal and maternal monoallelic expression, respectively. This is interesting, because IGF2 is known as a growth factor, and H19 encodes a RNA with putative tumor suppressor action. Furthermore, IGF2 and H19 are linked genes located on chromosome 11p15.5, a common site of loss of heterozygosity in human cancers. METHODS: We performed an allelic-typing assay using a PCR-RFLP-based method for identification of heterozygous informative cases in head and neck squamous cell carcinomas. Tumoral total RNA was extracted from each of the heterozygotes and further studied by RT-PCR analysis. RESULTS: We detected the expression of the IGF2 gene in 10 of 10 informative cases. Two cases exhibited LOI of the IGF2 gene as evidenced by biallelic expression, and in another case, LOH was coupled with monoallelic expression of this growth factor. LOI for the H19 gene was observed in 1 of 14 informative samples analyzed. In this case, we also detected parallel monoallelic expression of the IGF2 gene. Down-regulation of the H19 gene was observed in 10 of 14 cases. CONCLUSION: These findings support the hypothesis that H19 may be a tumor suppressor gene involved in head and neck carcinogenesis. Furthermore, our data showed that genetic and epigenetic changes at 11p15.5 could lead to abnormal expression of imprinted genes in HNSCC.     

HBx基因大鼠卵圆细胞株的建立及鉴定

目的 构建带增强型绿色荧光蛋白(EGFP)的真核表达质粒pEGF-HBx,建市稳定、高效表达乙型肝炎病毒x基因(HBx)的大鼠卵圆细胞株,以便进一步研究HBx基因和卵圆细胞在肝癌发牛过程中的作用和机制.方法 用PCR方法从质粒pcDNA3.1-HBx中扩增含Kpn Ⅰ和Hind Ⅲ酶切位点的HBx基因序列.对增强型绿色荧光蛋白质粒(pEGFP-NI)及扩增的HBx目的 基因片段进行双酶切,纯化后用连接酶连接得到重组体pEGFP-HBx,将其转化大肠杆菌DHSα,抗生素筛选培养得到阳性克降,提取质粒后用双酶切和基因测序进行鉴定.通过脂质体介导将质粒pEGFP-HBx转染到大鼠卵圆细胞株(LE/6)中,经G418筛选,尤限传代后得到稳定表达EGFP-HBx融合蛋白的细胞株.分别采用RT-PCR和免疫细胞化学技术检测细胞株中HBx基凶的表达情况.结果 双酶切及基因测序结果均显示构建的pEGFP-HBx质粒中含有完整的HBx基因片段.将得到的抗性细胞株培养传代20次后仍表达强的荧光;RT-PCR及免疫细胞化学检测均发现HBx基因在抗性细胞(LE/6)中得到了稳定转录和翻译.结论 已成功构建带HBx基因的真核表达质粒pEGFP-HBx,获得了稳定、高效表达EGFP-HBx融合蛋白的大鼠卵圆细胞株,为进一步研究HBx基凶和卵圆细胞在肝癌发生过程中的作用和机制奠定了实验基础.     

Mechanisms of Disease: biomarkers and molecular targets from microarray gene expression studies in prostate cancer

Molecular biomarkers can serve as useful diagnostic markers, as prognostic markers for predicting clinical behavior, or as targets for new therapeutic strategies. Application of expression microarray technology, which allows the expression of all or most of the genes in the human genome to be analyzed simultaneously, has dramatically enhanced the discovery of prostate cancer biomarkers. The diagnostic markers identified include AMACR (alpha-methylacyl CoA racemase), a protein that has already been translated into clinical use as an aid in distinguishing prostate cancer from benign disease. Individual genes, such as the polycomb gene EZH2 whose expression indicates poor survival, have been identified. The power of microarray technology is that it has allowed the identification of gene signatures (each composed of multiple genes) that might provide improved prediction of clinical outcomes in human prostate cancer. The development of a new method for analyzing expression microarray data, called COPA, has led to the discovery of TMPRSS2-ERG gene fusion involvement in the development of prostate cancer, while expression analysis of castration-resistant prostate cancer has suggested the use of novel therapeutic approaches for advanced disease. Despite these successes, there are limitations in the application of microarray technology to prostate cancer; for example, unlike with other cancers, this approach has failed to provide a consistent unsupervised classification of the disease. Overcoming the reasons for these failures represents a major challenge for future research endeavors.     

Keloid scarring: understanding the genetic basis, advances, and prospects

Keloid disease is a fibroproliferative dermal tumor with an unknown etiology that occurs after a skin injury in genetically susceptible individuals. Increased familial aggregation, a higher prevalence in certain races, parallelism in identical twins, and alteration in gene expression all favor a remarkable genetic contribution to keloid pathology. It seems that the environment triggers the disease in genetically susceptible individuals. Several genes have been implicated in the etiology of keloid disease, but no single gene mutation has thus far been found to be responsible. Therefore, a combination of methods such as association, gene-gene interaction, epigenetics, linkage, gene expression, and protein analysis should be applied to determine keloid etiology.     

Inflammatorische Reaktion bei abriebinduzierter und infektiöser Lockerung von Hüft- und Knieendoprothesen

BACKGROUND: A previous cDNA-microarray analysis described constantly differentially expressed genes in wear particle induced and infectious SLIM (synovial-like interface membrane). This study aims to validate the cDNA microarray data in order to approve differences of the gene expression profiles of RNA and proteins. METHODS: Tissue from 16 wear particle induced and 20 infectious periprosthetic membranes were analyzed by RT-PCR and immunohistology with regard to the expression of inflammatoric associated genes. RESULTS: RT-PCR showed the genes cd9, cd11b, cd18, cd52 as well as pdgfrbeta in interface membranes. In the wear particle induced membrane the immunohistochemical analysis showed a significantly weaker gene expression of PDGFRbeta, whereas the differential overexpression of CD9, CD11b and CD52 was confirmed. For CD18, there was no difference in expression between wear induced and infectious periprosthetic tissue. CONCLUSION: Different pathomechanisms, which are reflected by different gene expression profiles, might produce different types of periprosthetic membranes. By RT-PCR and immunohistochemical analysis the micro array data of the genes cd9, cd11b, cd52 and pdgfrbeta could be validated. Identifying the gene products of cd9, cd11b and cd52 in blood or tissue may help to differentiate between wear induced and infectious loosening.