Comparative proteome analysis of breast cancer and adjacent normal breast tissues in human

Two-dimensional polyacrylamide gel assisted laser desorption/ionization electrophoresis （2D-PAGE） and matrixtandem time-of-flight mass spectrometry （MALDI-TOF/TOF-MS）, incorporated with online database searching, were performed to investigate differential proteins of breast cancer and adjacent normal breast tissues. Considering that serum albumin is abundantly presented in normal control samples, 15 differential spots detected in 11 out of 12 （91.7%） breast cancer samples were identified by online SIENA-2DPAGE database searching and MALDI-TOF/TOF-MS analysis. The results indicate that pathological changes of breast cancer are concerned with augmentation of substance metabolism, promotion of proteolytic activity, decline of activity of some inhibitors of enzymes, and so on. Some important proteins involved in the pathological process of breast cancer with changed expression may be useful biomarkers, such as alpha-l-antitrypsin, EF- 1-beta, cathepsin D, TCTP, SMT3A, RPS12, and PSMA1, among which SMT3A, RPSl2, and PSMA1 were first reported for breast cancer in this study.     

Toward a high resolution 2-DE profile of the normal human liver proteome using ultra-zoom gels

The human liver is the largest organ in the body and has many important physiological functions. A global analysis of human liver proteins is essential for a better understanding of the molecular basis of the normal functions of the liver and of its diseases. As part of the Human Liver Proteome Project (HLPP), the goal of the present study was to visualize and detect as many proteins as possible in normal human livers using two-dimensional gel electrophoresis (2-DE). We have constructed a reference map of the proteins of human normal liver that can be used for the comprehensive analysis of the human liver proteome and other related research. To improve the resolution and enhance the detection of low abundance proteins, we developed and optimized narrow pH range ultra-zoom 2-DE gels. High resolution patterns of human liver in pH gradients 4.5–5.5, 5–6, 5.5–6.7, 6–9 and 6–11 are presented. To improve the poor resolution in the alkaline pH range of 2-DE gels, we optimized the isoelectric focusing protocol by including sample application using cup loading at the anode and incorporating 1.2% hydroxyethyl disulfide, 15% 2-propanol and 5% glycerol in the rehydration buffer. Using the optimized protocol, we obtained reproducibly better resolution in both analytical and preparative 2-DE gels. Compared with the 2386 and 1878 protein spots resolved in the wide range 3–10 and 4–7 pH gradients respectively, we obtained 5481 protein spots from the multiple (overlapping) narrow pH range ultra-zoom gels in the range of pH 4.5–9. The visualized reference map of normal human liver proteins presented in this paper will be valuable for comparative proteomic research of the liver proteome.     

Comparative Proteome Analysis of Human Temporal Cortex Lobes by Two-Dimensional Electrophoresis and Identification of Selected Common Proteins

Human brain proteins were isolated from left and right temporal cortex lobes at the age of 73, 23, 84 years and separated by two-dimensional gel electrophoresis (2-DE). 2-DE was carried out with an immobilized pH gradient strip in the first dimension and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. Over 800 polypeptide spots were resolved with a silver-staining protocol by computerized 2-D gel analsis. Seven of the polypeptide spots were evidently distinguishable between human left and right temporal lobes. Four of the polypeptide spots were larger and three were smaller in human right temporal lobe. One of these three protein spots that have descendent expression in human right temporal lobe was identified as carbonyl reductase (NADPH) 1 by MALDI-TOF MS. Thirty-three common spots were identified by ESI-MS/MALDI-TOF MS/Edman sequencing and a protein database search. These identified proteins include some important enzymes and regulating proteins.     

蛋白质组研究的现状与展望

蛋白质组是后基因组时代出现的一个新兴研究领域。蛋白质组的研究主要是先通过双向凝胶电泳等方法分离蛋白质,然后用质谱等技术进行鉴定。它是后基因组重要的研究方向之一,具有巨大的商业应用前景,将会推动整个生命科学的发展。蛋白质组研究取得了很大进展,已经成为生物技术中的一个重要领域。     

Comparative proteome analysis of thalamus in MK-801-treated rats

Two-dimensional gel-electrophoresis in combination with mass spectrometry is a powerful approach to compare protein expression in brain tissues. Using this proteomic approach, and based on the hypothesis that schizophrenia involves hypoglutamergic brain function, alterations in protein levels in the thalamus of rats treated with the N-methyl-D-aspartate (NMDA) receptor antagonist [+]-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]-cycloheptene-5,10-iminehydrogenmaleate (MK-801), as compared to saline-treated animals, were assessed in an unbiased fashion. The rats were divided into two groups; group 1 (short-term treated) and group 2 (long-term treated). In group 1, the levels of seven proteins were increased and four proteins reduced. In group 2, the levels of six proteins were reduced. Several of the altered proteins (heat shock proteins 60 and 72, albumin, dihydropyrimidinase related protein-2, aldolase c, and malate dehydrogenase) have previously been connected to schizophrenia. Alterations of other proteins (dihydrolipoamide acetyltransferase component of pyruvate dehydrogenase complex E2, guanine deaminase, alpha-enolase, aconitase, ATP-synthase and alpha-internexin), have not, to the best of our knowledge, earlier been implicated in schizophrenia pathology. Our results show the high potential of using proteomic methods for the validation of animal models of schizophrenia and to identify new proteins involved in the pathophysiological mechanisms of schizophrenia.     

大鼠海马的表达蛋白质组学实验研究

目的：用蛋白质组学方法初步分析大鼠海马蛋白质的表达。方法：提取大鼠海马蛋白质样品后,用双向凝胶电泳对其分离,经考马斯亮蓝染色后,产生大鼠海马蛋白质双向凝胶电泳图谱。从凝胶上切割分离的蛋白质,经胰蛋白酶胶内酶解,通过基质辅助激光解吸／电离飞行时间质谱（MALDI-TOF-MS）对酶解后的肽段进行分析。根据肽段质谱数据,经数据库（NCBI）检索,对蛋白质进行鉴定。结果：鉴定了37种具有明确功能的蛋白质,它们分别属于代谢酶、细胞骨架蛋白、热休克蛋白、抗氧化蛋白、信号传导蛋白、蛋白酶体相关蛋白、神经元特异蛋白及神经胶质蛋白。另外,鉴定了3种未知功能蛋白。结论：为建立大鼠海马蛋白质组数据库提供必要的资料,为在大鼠模型上研究神经疾病发病机理奠定基础。     

Extensive analysis of the human platelet proteome by two-dimensional gel electrophoresis and mass spectrometry

Platelets play a key role in the control of bleeding and wound healing, contributing to the formation of vascular plugs. Under pathologic circumstances, they are involved in thrombotic disorders, including heart disease. Since platelets do not have a nucleus, proteomics offers a powerful alternative approach to provide data on protein expression in these cells, helping to address their biology. In this publication we extend the previously reported analysis of the pI 4-5 region of the human platelet proteome to the pI 5-11 region. By using narrow pI range two-dimensional electrophoresis (2-DE) for protein separation followed by high-throughput tandem mass spectrometry (MS/MS) for protein identification, we were able to identify 760 protein features, corresponding to 311 different genes, resulting in the annotation of 54% of the pI 5-11 range 2-DE proteome map. We evaluated the physicochemical properties and functions of the identified platelet proteome. Importantly, the main group of proteins identified is involved in intracellular signalling and regulation of the cytoskeleton. In addition, 11 hypothetical proteins are reported. In conclusion, this study provides a unique inventory of the platelet proteome, contributing to our understanding of platelet function and building the basis for the identification of new drug targets.     

蛋白质组中蛋白质磷酸化研究进展

随着后基因组时代的到来 ,对生命体器官、组织或细胞的全部蛋白质的表达、修饰及相互作用的研究已成为蛋白质组学的重要任务。蛋白质磷酸化是细胞内信号转导和酶调控最常见的机制之一 ,人类基因组约 2 %的基因编码 5 0 0种激酶和 10 0种磷酸酶。蛋白质磷酸化和去磷酸化作为原核和真核细胞表达调控的关键环节 ,了解其对功能的影响可以深入理解生命系统在分子水平的调控状况。目前蛋白质组磷酸化研究仍是功能基因组面临的重大课题 ,本文对此作一综述     

The effect of environmental salinity on the proteome of the sea bass (Dicentrarchus labrax L.)

The European sea bass, Dicentrarchus labrax L., tolerates a range of salinities from freshwater to hyper-saline. To study differences in protein expression, fish were reared in both freshwater and seawater. After 3-month acclimation, gill and intestine epithelia were collected and the soluble protein extracted. In all, 362 spots were differentially expressed in the gills and intestines of fishes reared in seawater compared to those from freshwater. Fifty differential protein spots were excised from a colloidal Coomassie-stained gel. Nine separate protein spots were identified unambiguously by mass spectrometry and database searching. Among the six proteins over-expressed in gill cells in seawater, five were cytoskeleton proteins and one was the aromatase cytochrome P450. In gill cells under freshwater conditions, the two over-expressed proteins identified were the prolactin receptor and the major histocompatibility complex class II β -antigen. In intestinal cells under freshwater conditions, the Iroquois homeobox protein Ziro5 was upregulated over ninefold. The expression of these proteins, their possible direct or indirect roles in the adaptation of D. labrax to salinity, and their correspondences with a previous study are discussed.     

Comparative proteomic analysis between the invasive and commensal strains of Staphylococcus epidermidis

Staphylococcus epidermidis is one of the major causative agents for nosocomial infections. To reveal the pathogenesis factors, we performed the comparative proteomic analysis of invasive ATCC35984 and commensal ATCC12228 strains by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight-mass spectrometry. The differentially expressed proteins were involved in carbohydrate metabolism, sugar binding, lipid degradation and amino acid binding. In addition, we demonstrated that the trap gene was transcribed by 3.657+/-0.156 (P<0.01) -fold higher in ATCC35984 than in ATCC12228. Levels of accumulation-associated protein (AAP) were found to be low by the immuno-dot blotting assay in ATCC12228, which is unable to form biofilm. Our results suggest that the target of RNAIII activating protein and AAP may contribute to S. epidermidis virulence and biofilm formation.     

Cellular and extracellular proteome analysis of Streptococcus mutans grown in a chemostat

The oral pathogen, Streptococcus mutans, was grown under glucose limitation in a chemostat at pH 7.0 and a dilution rate of 0.1 h(-1) to mimic the conditions prevailing in a healthy human oral cavity in between meal times. Solubilized cellular and extracellular proteins were separated by two-dimensional gel electrophoresis (2-DE) and, following tryptic digestion, 421 protein spots analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry or electrospray ionization-tandem mass spectrometry. Analyses of the mass spectral data showed that the proteins matched the translation products of 200 different open reading frames (ORFs) deduced from contigs of the S. mutans UA159 genome and thus represented proteins derived from approximately 11% of the total ORFs of the bacterium. Of the identified proteins, 172 (including one surface protein) were characterized in the cellular fraction, and the remaining 28 (including two surface proteins) were uniquely identified from the culture fluid. The expression and therefore the existence of 30 proteins previously designated as 'hypothetical' or with no known function was confirmed. 2-DE of whole cell lysates revealed only a single intrinsic membrane protein. This is consistent with proteomic analyses of other Gram-positive bacteria where hydrophilic proteins represent the vast majority of those characterized.     

A reference map of a human pituitary adenoma proteome

In order to compare the proteomes from different cell types of pituitary adenomas for our long-term goal to clarify the molecular mechanisms that participate in the formation of pituitary adenoma, and to detect any tumor-related marker for an "early-stage" diagnosis, the two-dimensional gel electrophoresis (2-DE) reference map of a pituitary adenoma tissue proteome is described here. A vertical, two-dimensional (2-D) polyacrylamide gel electrophoresis system and PDQuest image analysis software have been used to provide a high level of between-gel reproducibility and to accurately array each protein expressed in a pituitary adenoma tissue. Mass spectrometry (matrix-assisted laser desorption/ionization-time of flight MALDI-TOF and liquid chromatography-electrospray ionization-quadrupole-ion trap LC-ESI-Q-IT) and protein databases were used to characterize each protein in the 2-D gel. The results demonstrate that a good reproducibility of the 2-D gel pattern was attained. The position deviation of matched spots among four 2-D gels was 1.95 +/- 0.45 mm in the isoelectric focusing direction, and 1.70 +/- 0.53 mm in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis direction. A total of ca. 1000 protein spots were separated by 2-DE, and 135 protein spots that represent 111 proteins were characterized with mass spectrometry (96 spots for MALDI-TOF, 39 spots for LC-ESI-Q-IT). The characterized proteins include pituitary hormones, cellular signals, enzymes, cellular-defense proteins, cell-structure proteins, transport proteins, etc. Those proteins were located in the cytoplasmic, cellular membrane, mitochondrial, endoplasmic reticulum, nuclear, ribonucleosome, extracellular fractions, or were secreted in plasma, etc. Those identified proteins contribute to a functional profile of the pituitary adenoma proteome. These data will be used to expand the proteome database of the human pituitary, which can be accessed in the website http://www.utmem.edu /proteomics.     

Glycosylation and its implications in breast cancer

Introduction: For decades, the role of glycans and glycoproteins in the progression of breast cancer and other cancers have been evaluated. Through extensive studies focused on elucidating the biological functions of glycosylation, researchers have been able to implicate alterations in these functions to tumor formation and metastasis.

Areas covered: In this review, we summarize how changes in glycosylation are associated with tumorigenesis, with emphasis on breast cancers. An overview of the changes in N-linked and O-linked glycans associated with breast cancer tumors and biofluids are described. Recent advances in glycomics are emphasized in the context of continuing to decipher the glycosylation changes associated with breast cancer progression.

Expert opinion: While changes in glycosylation have been studied in breast cancer for many years, the clinical relevance of these studies has been limited. This reflects the inherent biological and clinical heterogeneity of breast cancers. Glycomics analysis lags behind the advances in genomics and proteomics, but new approaches are emerging. A summary of known glycosylation changes associated with breast cancer is necessary to implement new findings in the context of clinical outcomes and therapeutic strategies. A better understanding of the dynamics of tumor and immune glycosylation is critical to improving emerging immunotherapeutic treatments.     

青年和老年人结肠上皮的比较蛋白质组学研究

衰老的大肠上皮不仅多种生理功能下降,而且对大肠癌在内的多种衰老相关的肠道疾病易感性显著增加,但结肠上皮衰老及衰老的结肠上皮对癌症易感的分子机制仍然不清楚.为此,应用双向凝胶电泳(2-DE)技术分离青年人及老年人的正常结肠上皮的总蛋白质,图像分析识别差异表达的蛋白质点,基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)对差异表达的蛋白质点进行鉴定,免疫组化和实时定量(real-timequantitative)PCR检测部分差异蛋白,在青年人和老年人结肠上皮中的表达水平.得到了分辨率较高、重复性较好的青年人和老年人结肠上皮的2-DE图谱,质谱分析鉴定了17个结肠上皮衰老相关的蛋白质,免疫组化和real-timequantitativeRT-PCR证实了部分差异蛋白质的表达水平.研究结果提示,线粒体功能受伤、抗氧化能力下降是结肠上皮衰老的重要原因,4个差异蛋白质即guaninenucleotide-bindingproteinbetasubunit-likeprotein(Rack1)、stress-70protein、40SribosomalproteinSA和chlorideintracellularchannelprotein1可能与衰老的结肠上皮对癌症易感有关.     

蛋白质组研究的技术体系及其进展

随着后基因组时代的到来,蛋白质组研究越来越受到国内外科学工作者的密切关注, 我国国家自然科学基金委员会已把蛋白质组研究列为重大科研项目.概述了蛋白质组研究中的基本技术,包括双向凝胶电泳的样品制备和分离、蛋白质的检测、凝胶图像分析、蛋白质的鉴定以及蛋白质数据库构建等,并就蛋白质鉴定的常用方法如氨基酸组成分析方法、蛋白质末端序列分析、肽质量指纹谱作了详细阐述.直观地列出了蛋白质组研究的技术体系流程图,着重介绍了蛋白质组研究的最新技术及其进展.     

Proteome map of normal rat retina and comparison with the proteome of diabetic rat retina: new insight in the pathogenesis of diabetic retinopathy

We have employed proteomics to establish a proteome map of the normal rat retina. This baseline map was then used for comparison with the early diabetic rat retinal proteome. Diabetic rat retinae were obtained from Dark Agouti rats after 10 wk of streptozotocin-induced hyperglycaemia. Extracted proteins from normal and diabetic rat retinae were separated and compared using 2-DE. A total of 145 protein spots were identified in the normal rat retina using MALDI-MS and database matching. LC-coupled ESI-MS increased the repertoire of identified proteins by 23 from 145 to 168. Comparison with early diabetic rat retinae revealed 24 proteins unique to the diabetic gels, and 37 proteins absent from diabetic gels. Uniquely expressed proteins identified included the HSPs 70.1A and 8, and platelet activating factor. There were eight spots with increased expression and 27 with decreased expression on diabetic gels. Beta catenin, phosducin and aldehyde reductase were increased in expression in diabetes whilst succinyl coA ligase and dihydropyrimidase-related protein were decreased. Identification of such changes in protein expression has given new insights and a more comprehensive understanding of the pathogenesis of diabetic retinopathy, widening the scope of potential avenues for new therapies for this common cause of blindness.     

Membrane protein analysis of human breast cancer cell line MCF-7 by different membrane washing methods

Membrane and membrane-associated proteins are rich in known or potential pharmaceutical drug targets for carcinogenesis. In order to systemically analyze membrane proteins of human breast cancer, we isolated membrane from MCF-7 cells by sequential extraction by washing with three different buffers, namely, phosphate buffer (5 mM, pH 8.0), Tris (40 mM, pH 9.5), and sodium carbonate (100 mM pH 11). The extracted proteins were separated by two-dimensional gel electrophoresis (2-DE) using cup-loading and were then analyzed by peptide mass fingerprinting (PMF). A total of 137 spots from the gels of the three procedures were successfully identified. They corresponded to 79 distinct proteins. Among them, 22 exclusive proteins belonging to each washing procedure were also found, including P-glycoprotein, endoplasmin, Stress-70 protein, ADAM 10, protein disulfide isomerase, and glutamate receptor. These results indicate phosphate buffer to be the most beneficial for enrichment of peripheral membrane proteins, and sodium carbonate is beneficial for the presentation of integral membrane proteins but usually with poor resolution. The reference maps and identified proteins will serve as a basis for the further investigation of breast cancer, especially the proteomic comparison among different cell types of breast cancer, or among the different stages in the drug interfering process of the MCF-7 cell line.     

Proteomic analysis of selected prognostic factors of breast cancer

The incidence of breast cancer is on the rise but as yet there is no guaranteed beneficial treatment for many of the sufferers. The treatments specific for breast and other hormone-sensitive cancers work well at times, however, the population of women that they will benefit is relatively small. Many are limited to surgical, chemotherapy, and radiotherapy options. Here, using two-dimensional electrophoresis (2-DE) in conjunction with a silver stain and Western blotting approach, we attempt to locate selected known prognostic markers for breast cancer. With these results, we can exclude these proteins from the future search for potential pharmaceutical targets, using the same techniques. The proteins that were located include the estrogen receptor-alpha, beta-casein, cytokeratin 7, calponin and bax. For each protein an estimated M(r) and pI was gained. Each protein was found in multiple variants. By locating these proteins the number of unknown proteins found on the 2-DE gel has been reduced, helping the future search for novel markers that are shown as being differentially expressed between healthy and cancerous tissue samples.     

Advances in plant proteomics-key techniques of proteome

Following the completion of genome sequen-cing of model plants,such as rice (Oryza sativa L.) and Arabidopsis thaliana,the era of functional plant genomics has arrived which provides a solid basis for the develop-ment of plant proteomics.We review the background and concepts of proteomics,as well as the key techniques which include:(1) separation techniques such as 2-DE (two-dimensional electrophoresis),RP-HPLC (reverse phase high performance liquid chromatography) and SELDI (surface enhanced laser desorption/ionization) protein chip; (2) mass spectrometry such as MALDI-TOF-MS (matrix assisted laser desorption/ionization-time of flight- mass spectrometry) and ESI-MS/MS (elec-trospray ionization mass spectrometry/mass spectro-metry); (3) Peptide sequence tags; (4) databases related to proteomics; (5) quantitative proteome; (6) TAP (tandem affinity purification) and (7) yeast two-hybrid system.In addition,the challenges and prospects of pro-teomics are also discussed.