Strategies for translating proteomics discoveries into drug discovery for dementia

Tauopathies,diseases characterized by neuropathological aggregates of tau including Alzheimer's disease and subtypes of fro ntotemporal dementia,make up the vast majority of dementia cases.Although there have been recent developments in tauopathy biomarkers and disease-modifying treatments,ongoing progress is required to ensure these are effective,economical,and accessible for the globally ageing population.As such,continued identification of new potential drug targets and biomarkers is critical."Big data"studies,such as proteomics,can generate information on thousands of possible new targets for dementia diagnostics and therapeutics,but currently remain underutilized due to the lack of a clear process by which targets are selected for future drug development.In this review,we discuss current tauopathy biomarkers and therapeutics,and highlight areas in need of improvement,particularly when addressing the needs of frail,comorbid and cognitively impaired populations.We highlight biomarkers which have been developed from proteomic data,and outline possible future directions in this field.We propose new criteria by which potential targets in proteomics studies can be objectively ranked as favorable for drug development,and demonstrate its application to our group's recent tau interactome dataset as an example.

Serum proteins differentially expressed in gestational diabetes mellitus assessed using isobaric tag for relative and absolute quantitation proteomics

BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM.

Proteomics Study of Benzene Metabolite Hydroquinone Induced Hematotoxicity in K562 Cells

Objective Hydroquinone(HQ),one of the phenolic metabolites of benzene,is widely recognized as an important participant in benzene-induced hematotoxicity.However,there are few relevant proteomics in HQ-induced hematotoxicity and the mechanism hasn’t been fully understood yet.Methods In this study,we treated K562 cells with 40μmol/L HQ for 72 h,examined and validated protein expression changes by Label-free proteomic analysis and Parallel reaction monitoring(PRM),and performed bioinformatics analysis to identify interaction networks.Results One hundred and eighty-seven upregulated differentially expressed proteins(DEPs)and 279 downregulated DEPs were identified in HQ-exposed K562 cells,which were involved in neutrophilmediated immunity,blood microparticle,and other GO terms,as well as the lysosome,metabolic,cell cycle,and cellular senescence-related pathways.Focusing on the 23 DEGs and 5 DEPs in erythroid differentiation-related pathways,we constructed the network of protein interactions and determined 6 DEPs(STAT1,STAT3,CASP3,KIT,STAT5B,and VEGFA)as main hub proteins with the most interactions,among which STATs made a central impact and may be potential biomarkers of HQ-induced hematotoxicity.Conclusion Our work reinforced the use of proteomics and bioinformatic approaches to advance knowledge on molecular mechanisms of HQ-induced hematotoxicity at the protein level and provide a valuable basis for further clarification.

Comparative proteomics analysis reveals the domesticated Lepista sordida primordium differentiation regulation mechanism and the subsequent different development patterns in the pileus and stipe

The wild Lepista sordida is a kind of precious and rare edible fungus.An excellent strain of it by artificial domestication was obtained,which was high-yield and high in iron content.In this study,high-throughput comparative proteomics was used to reveal the regulatory mechanism of its primordium differentiation in the early fruiting body formation.The mycelium before the primordium differentiation mainly expressed high levels of mitochondrial functional proteins and carbon dioxide concentration regulatory proteins.In young mushrooms,the highly expressed proteins were mainly involved in cell component generation,cell proliferation,nitrogen compound metabolism,nucleotide metabolism,glutathione metabolism,and purine metabolism.The differential regulation patterns of pileus and stipe growth to maturity were also revealed.The highly expressed proteins related to transcription,RNA splicing,the production of various organelles,DNA conformational change,nucleosome organization,protein processing,maturation and transport,and cell detoxification regulated the pileus development and maturity.The proteins related to carbohydrate and energy metabolism,large amounts of obsolete cytoplasmic parts,nutrient deprivation,and external stimuli regulated the stipe development and maturity.Multiple CAZymes regulated nutrient absorption,morphogenesis,spore production,stress response,and other life activities at different growth and development stages.

Comparative proteomics reveals the response and adaptation mechanisms of white Hypsizygus marmoreus against the biological stress caused by Penicillium

White Hypsizygus marmoreus is a popular edible mushroom.Its mycelium is easy to be contaminated by Penicillium,which leads to a decrease in its quality and yield.Penicillium could compete for limited space and nutrients through rapid growth and produce a variety of harmful gases,such as benzene,aldehydes,phenols,etc.,to inhibit the growth of H.marmoreus mycelium.A series of changes occurred in H.marmoreus proteome after contamination when detected by the label-free tandem mass spectrometry(MS/MS)technique.Some proteins with up-regulated expression worked together to participate in some processes,such as the non-toxic transformation of harmful gases,glutathione metabolism,histone modification,nucleotide excision repair,clearing misfolded proteins,and synthesizing glutamine,which were mainly used in response to biological stress.The proteins with down-regulated expression are mainly related to the processes of ribosome function,protein processing,spliceosome,carbon metabolism,glycolysis,and gluconeogenesis.The reduction in the function of these proteins affected the production of the cell components,which might be an adjustment to adapt to growth retardation.This study further enhanced the understanding of the biological stress response and the growth restriction adaptation mechanisms in edible fungi.It also provided a theoretical basis for protein function exploration and edible mushroom food safety research.

iTRAQ-based proteomics reveals the mechanism of action of Yinlai decoction in treating pneumonia in mice consuming a high-calorie diet

Objective:To uncover the underlying mechanisms of action of the Yinlai decoction on high-calorie dietinduced pneumonia through proteomics analysis.Methods:Based on the Gene Expression Omnibus(GEO)database,lung tissue samples from normal and high-fat diet(HFD)fed mice in the GSE16377 dataset were selected as test cohorts to identify differentially expressed genes and conduct bioinformatics analyses.In the animal experiments,mice were randomly divided into the control(N),high-calorie diet pneumonia(M),and Yinlai decoction treatment(Y)groups.Mice in the M group received high-calorie feed and a 0.5 mg/mL lipopolysaccharide solution spray for 30 min for 3 d.The mice in the Y group were intragastrically administered 2 mL/10 g Yinlai decoction twice daily for 3 d.Pathological evaluation of the lung tissue was performed.Differentially expressed proteins(DEPs)in the lung tissue were identified using quantitative proteomics and bioinformatics analyses.The drug-target relationships between Yinlai decoction and core DEPs in the lung tissue were verified using AutoDock Vina and Molecular Graphics Laboratory(MGL)Tools.DEPs were verified by western blot.Results:GEO data mining showed that an HFD altered oxidative phosphorylation in mouse lung tissue.The Yinlai decoction alleviated pathological damage to lung tissue and pneumonia in mice that were fed a high-calorie diet.A total of 47 DEPs were identified between the Y and M groups.Enrichment analysis revealed their association with energy metabolism pathways such as the tricarboxylic acid cycle(TCA)and oxidative phosphorylation.The protein-protein interaction network revealed that Atp5a1,Pdha1,and Sdha were the target proteins mediating the therapeutic effects of Yinlai decoction.Molecular docking results suggested that the mechanism of the therapeutic effect of Yinlai decoction involves the binding of brassinolide,praeruptorin B,chrysoeriol,and other components in Yinlai decoction to Atp5a1.Conclusion:The Yinlai decoction alleviated lung tissue damage and pneumonia in mice that were fed a high-calorie diet by regulating the TCA and oxidative phosphorylation.Our study highlights the importance of a healthy diet for patients with pneumonia and provides a scientific basis for the prevention and treatment of pneumonia through dietary adjustments.

Proteomics for early prenatal screening of gestational diabetes mellitus

In this editorial,we comment on the article by Cao et al.Through applying isobaric tags for relative and absolute quantification technology coupled with liquid chromatography-tandem mass spectrometry,the researchers observed significant differential expression of 47 proteins when comparing serum samples from pregnant women with gestational diabetes mellitus(GDM)to the healthy ones.GDM symptoms may involve abnormalities in inflammatory response,complement system,coagulation cascade activation,and lipid metabolism.Retinol binding protein 4 and angiopoietin like 8 are potential early indicators of GDM.GDM stands out as one of the most prevalent metabolic complications during pregnancy and is linked to severe maternal and fetal outcomes like pre-eclampsia and stillbirth.Nevertheless,none of the biomarkers discovered so far have demonstrated effectiveness in predicting GDM.Our topic was designed to foster insights into advances in the application of proteomics for early prenatal screening of GDM.

Ultrasensitive proteomics depicted an in-depth landscape for the very early stage of mouse maternal-to-zygotic transition

Single-cell or low-input multi-omics techniques have revolutionized the study of pre-implantation embryo development.However,the single-cell or low-input proteomic research in this field is relatively underdeveloped because of the higher threshold of the starting material for mammalian embryo samples and the lack of hypersensitive proteome technology.In this study,a comprehensive solution of ultrasensitive proteome technology(CS-UPT)was developed for single-cell or low-input mouse oocyte/embryo samples.The deep coverage and high-throughput routes significantly reduced the starting material and were selected by investigators based on their demands.Using the deep coverage route,we provided the first large-scale snapshot of the very early stage of mouse maternal-to-zygotic transition,including almost 5,500 protein groups from 20 mouse oocytes or zygotes for each sample.Moreover,significant protein regulatory networks centered on transcription factors and kinases between the MII oocyte and 1-cell embryo provided rich insights into minor zygotic genome activation.

Tandem Mass Tag-based proteomics analysis reveals the vital role of inflammation in traumatic brain injury in a mouse model

Proteomics is a powerful tool that can be used to elucidate the underlying mechanisms of diseases and identify new biomarkers.Therefore,it may also be helpful for understanding the detailed pathological mechanism of traumatic brain injury(TBI).In this study,we performed Tandem Mass Tag-based quantitative analysis of cortical proteome profiles in a mouse model of TBI.Our results showed that there were 302 differentially expressed proteins in TBI mice compared with normal mice 7 days after injury.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that these differentially expressed proteins were predominantly involved in inflammatory responses,including complement and coagulation cascades,as well as chemokine signaling pathways.Subsequent transcription factor analysis revealed that the inflammation-related transcription factors NF-κB1,RelA,IRF1,STAT1,and Spi1 play pivotal roles in the secondary injury that occurs after TBI,which further corroborates the functional enrichment for inflammatory factors.Our results suggest that inflammation-related proteins and inflammatory responses are promising targets for the treatment of TBI.

Charcot-Marie-Tooth-1A and sciatic nerve crush rat models:insights from proteomics

The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models:the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease.In this study,we sought to highlight and compare the protein signature of these two pathological situations.Indeed,the identification of protein profiles in diseases can play an important role in the development of pharmacological targets.In fact,Charcot-Marie-Tooth-1A rats develop motor impairments that are more severe in the hind limbs.Therefore,for the first time,protein expression in sciatic nerve of Charcot-Marie-Tooth-1A rats was examined.First,distal sciatic nerves were collected from Charcot-Marie-Tooth-1A and uninjured wild-type rats aged 3 months.After protein extraction,sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry was employed.445 proteins mapped to Swiss-Prot or trEMBL Uniprot databases were identified and quantified.Of these,153 proteins showed statistically significant differences between Charcot-Marie-Tooth-1A and wild-type groups.The majority of these proteins were overexpressed in Charcot-Marie-Tooth-1A.Hierarchical clustering and functional enrichment using Gene Ontology were used to group these proteins based on their biological effects concerning Charcot-Marie-Tooth-1A pathophysiology.Second,proteomic characterization of wild-type rats subjected to sciatic nerve crush was performed sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry.One month after injury,distal sciatic nerves were collected and analyzed as described above.Out of 459 identified proteins,92 showed significant differences between sciatic nerve crush and the uninjured wild-type rats used in the first study.The results suggest that young adult Charcot-Marie-Tooth-1A rats(3 months old)develop compensatory mechanisms at the level of redox balance,protein folding,myelination,and axonogenesis.These mechanisms seem insufficient to hurdle the progress of the disease.Notably,response to oxidative stress appears to be a significant feature of Charcot-Marie-Tooth-1A,potentially playing a role in the pathological process.In contrast to the first experiment,the majority of the proteins that differed from wild-type were downregulated in the sciatic nerve crush group.Functional enrichment suggested that neurogenesis,response to axon injury,and oxidative stress were important biological processes.Protein analysis revealed an imperfect repair at this time point after injury and identified several distinguishable proteins.In conclusion,we suggest that peripheral neuropathies,whether of a genetic or traumatic cause,share some common pathological pathways.This study may provide directions for better characterization of these models and/or identifying new specific therapeutic targets.

Differentially expressed whey proteins of donkey and bovine colostrum revealed with a label-free proteomics approach

This study aimed to analyze and compare the differentially expressed whey proteins(DEWPs)of donkey and bovine colostrum using high-performance liquid chromatography with tandem mass spectrometry-based proteomics.A total of 620 and 696 whey proteins were characterized in the donkey and bovine colostrum,respectively,including 383 common whey proteins.Among these common proteins,80 were identified as DEWPs,including 21 upregulated and 59 downregulated DEWPs in donkey colostrum compared to bovine colostrum.Gene Ontology analysis revealed that these DEWPs were mainly related to cellular components,such as extracellular exosome,plasma membrane,and mitochondrion;biological processes,such as oxidation-reduction process,cell-cell adhesion,and small guanosine triphosphate(GTP)ase-mediated signal transduction;and molecular functions,such as GTP binding,GTPase activity,and soluble N-ethylmaleimide-sensitive factor(NSF)attachment protein receptor activity.Metabolic pathway analysis suggested that the majority of the DEWPs were associated with soluble NSF factor attachment protein receptor interactions in vesicular transport,fatty acid biosynthesis,and estrogen signaling pathways.Our results provide a vital insight into the differences between donkey and bovine colostrum,along with important information on the significant components as nutritional and functional factors to be included in infant formula based on multiple milk sources.

Label-free quantitative proteomics analysis models in vivo and in vitro reveal key proteins and potential roles in sciatic nerve injury

Background:The underlying mechanism of sciatic nerve injury(SNI)is a common motor functional disorder,necessitates further research.Methods:A rat model of SNI was established,with the injury group subjected to compressive injury of the right sciatic nerve exposed at the midpoint of the thigh and the sham surgery group undergoing the same surgical procedure.An oxygen-glucose deprivation model was employed to simulate in vitro SNI in PC12 cells.Following data acquisition and quality control,differentially expressed proteins(DEPs)in each model were identified through differential analysis,and enrichment analysis was used to explore the potential functions and pathways of the DEPs.Venn diagrams were drawn,and DEPs from both in vivo and in vitro SNI models were imported into the STRING database to construct a protein-protein interaction network and screen for hub proteins.Results:After the peptide segments obtained from rat nerve blockade and PC12 cells met quality requirements,258 DEPs were identified in rat nerve samples,and 119 DEPs were screened in PC12 cells.Enrichment analysis revealed that DEPs in the rat model were predominantly concentrated in biological functions such as myogenic cell proliferation and signaling related to lipid and energy metabolism.DEPs in the in vitro model were mainly enriched in biological processes such as phagocytosis and were associated with lipid transport and metabolism.Two hub proteins,amyloid precursor protein(APP)and fibronectin 1(FN1),were identified through MCC,MCODE,and Degree scoring.Both PC12 cells and external validation sets showed relatively higher expression of APP and FN1 in injured samples.Results of gene set enrichment analysis indicated that these two proteins were associated with metabolic pathways,such as biosynthesis of glycosaminoglycan chondroitin sulfate and biosynthesis of unsaturated fatty acids.Conclusion:APP and FN1 are potential key molecules involved in SNI and are associated with various metabolic pathways in nerve repair.These findings provide a theoretical basis for the development of therapeutic targets for SNI.

Plant Proteomics in the Post-genomic Era

Proteomics is one of the most active research fields in the post-genomic era. Here we briefly introduce the scientific background of the origination of proteomics and its content, research method. The new developments of proteomics at the levels of individual plants, tissues, organs and organells, as well as its applications in the area of plant genetic diversity, mutant characterization, and plant physiology, etc are reviewed. At last, the challenge and prospect of proteomics are discussed.

从Genomics,Proteomics到Cytomics,还是从Cytometry到Cytomics

Cytomics是一个特殊名词,她将cyto-与-omics连在一起,代表着一个崭新的领域。Cyto-主要来自分析细胞学(analyticalcytology或cytometry),而-omics主要来自蛋白质组学(proteomics)及其决定者基因组学(genomics)。经过三十余年的发展,分析细胞学可以通过分子探针将异质性的或混杂的细胞群体分为不同的细胞组份(cytomes),而基因组学和蛋白质组学的技术已能鉴定出某一物种的整套基因组和蛋白质组。因此,我们认为,细胞组学的任务是分离细胞组,并在基因组和蛋白质组层面确定其赖以存在和转变的分子基础。细胞组学的实施需要两大系列技术,一是细胞组分离技术,二是分离后再分析技术。这些技术的发展将使我们最终理解基因组并利用之,也必将拓展出更新的领域。

Glycoproteins and glycoproteomics in pancreatic cancer

Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immunoresponse and chemoresistance. Abnormal expression in sugar moieties can impact the function of various glycoproteins, including mucins, surface receptors, adhesive proteins, proteoglycans, as well as their effectors and binding ligands, resulting in an increase in pancreatic cancer invasiveness and a cancerfavored microenvironment. Recent advance in glycoproteomics, glycomics and other chemical biology techniques have been employed to better understand the complex mechanism of glycosylation events and how they orchestrate molecular activities in genomics, proteomics and metabolomics implicated in pancreatic adenocarcinoma. A variety of strategies have been demonstrated targeting protein glycosylation and polysaccharides for diagnostic and therapeutic development.

Effects of calcium application on apple fruit softening during storage revealed by proteomics and phosphoproteomics

Fruit ripening has been reported to be related to calcium(Ca),but the underlying mechanisms by which Ca regulates this process remain largely unknown.In order to study the changes of proteins and enriched phosphopeptides,we conducted TMT labeling,bio-material-based PTM enrichment based on mass spectrometry in Ca-treated‘Golden Delicious’(GD)apple fruit(Malus×domestica).This dataset presents a comprehensive overview of the critical pathways involved in fruit ripening.A total of 47 proteins and 124 phosphoproteins significantly changed in Ca-treated fruit,which are crucial for regulating the cell wall and cytoskeleton,Ca-mediated signaling and transport,ethylene production,protein fate,especially ubiquitination-based protein degradation,and primary and secondary metabolisms.Our results indicated that Ca inhibited the abundance of polygalacturonase(PG)activity and increased the phosphorylation level of CSLD3.PG and phosphorylation were involved in cell wall degradation,thereby delaying fruit softening.As a secondary messenger,Ca-mediated signaling subsequently triggered downstream mitogen-activated protein kinases(MAPK)cascades and activated the membrane,transport,and ROS signaling.Moreover,MdEIN2,a key enzyme involved in the ubiquitin of protein modification,increased at Ser753 and Ser758 in Ca-treated fruit.Furthermore,diverse primary and secondary metabolisms including glycolysis,fatty acid metabolism,and oxidation respiratory chain were modulated to prevent fruit softening.These results provide basic information from protein and phosphorylation levels for apple fruit ripening during storage,which may be helpful for apple fruit storage control.

An integrated approach utilizing proteomics and bioinformatics to detect ovarian cancer

Objective: To find new potential biomarkers and establish the patterns for the detection of ovarian cancer. Methods: Sixty one serum samples including 32 ovarian cancer patients and 29 healthy people were detected by surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS). The protein fingerprint data were analyzed by bioinformatics tools. Ten folds cross-validation support vector machine (SVM) was used to establish the diagnostic pattern. Results: Five potential bio- markers were found (2085 Da, 5881 Da, 7564 Da, 9422 Da, 6044 Da), combined with which the diagnostic pattern separated the ovarian cancer from the healthy samples with a sensitivity of 96.7%, a specificity of 96.7% and a positive predictive value of 96.7%. Conclusions: The combination of SELDI with bioinformatics tools could find new biomarkers and establish patterns with high sensitivity and specificity for the detection of ovarian cancer.

Identification of squamous cell carcinoma associated proteins by proteomics and loss of beta tropomyosin expression in esophageal cancer

AIM： To assess the proteome of normal versus tumor tissue in squamous cell carcinoma of the esophagus （SCCE） in Iranian patients and compare our results with former reports by using proteomics. METHODS： Protein was extracted from normal and tumor tissues. Two dimensional electrophoresis was carried out and spots with differential expression were identified with mass spectrometry. RNA extraction and RT-PCR along with immunodetection were performed. RESULTS： Fourteen proteins were found whose expression levels differed in tumor compared to normal tissues. Mass spectrometric analysis resulted in the identification of β-tropomyosin （TMβ）, myosin light chain 2 （and its isoform）, myosin regulatory light chain 2, peroxyredoxin 2, annexin I and an unknown polypeptide as the down regulated polypeptides in tumor tissue. Heat shock protein 70 （HSP70）, TPM4-ALK fusion oncoprotein 2, myosin light polypeptide 6, keratin I, GH16431p and calreticulin were the up-regulated polypeptides found in tumor tissue. Several of these proteins, such as TMβ, HSP70, annexin Ⅰ, calreticulin, TPM4-ALK and isoforms of myosins, have been well recognized in tumorigenesis of esophageal or other types of cancers. CONCLUSION： Our study not only supports the involvement of some of the formerly reported proteins in SCCE but also introduces additional proteins found to be lost in SCCE, including TMβ.

Natural taurine promotes apoptosis of human hepatic stellate cells in proteomics analysis

AIM:To study the differential expression of proteins between natural taurine treated hepatic stellate cells and controls, and investigate the underlying regulatory mechanism of natural taurine in inhibiting hepatic fibrosis.METHODS: A proteomic strategy combining two-dimensional gel electrophoresis and ultraperform ance liquid chromatographyelectrospray ionizationtandem mass spectrometry (UPLCESIMS/MS) was used to study the differential expression of proteins and Western blotting was used to validate the results. Gene ontology (GO) method was utilized to analyze the functional enrichment of differentially expressed proteins. Flow cytometry was performed to compare the apoptosis rate between taurinetreated and untreated hepatic stellate cells (HSCs).RESULTS: Nineteen differentially expressed proteins (11 upregulated and 8 downregulated) were identifiedby 2D/MS, and the expression profiles of GLO1 and ANXA1 were validated by Western blotting. GO analysis found that these differentially expressed proteins were enriched within biological processes such as "cellular apoptosis", "oxidation reaction" and "metabolic process" in clusters. Flow cytometric analysis showed that taurinetreated HSCs had a significantly increased apoptosis rate when compared with the control group.CONCLUSION: Natural taurine can promote HSC apoptosis so as to inhibit hepatic fibrosis.

Identification of Annexin A1 protein expression in human gastric adenocarcinoma using proteomics and tissue microarray

AIM:To study the differential expression of Annexin A1(ANXA1)protein in human gastric adenocarcinoma.This study was also designed to analyze the relationship between ANXA1 expression and the clinicopathological parameters of gastric carcinoma.METHODS:Purified gastric adenocarcinoma cells(GAC)and normal gastric epithelial cells(NGEC)were obtained from 15 patients with gastric cancer by laser capture microdissection.All of the peptide specimens were labeled as18O/16O after trypsin digestion.Differential protein expressions were quantitatively identified between GAC and NGEC by nanoliter-reverse-phase liquid chromatography-mass/mass spectrometry(nanoRPLC-MS/MS).The expressions of ANXA1 in GAC and NGEC were verified by western blot analysis.The tissue microarray containing the expressed ANXA1 in 75 pairs of gastric carcinoma and paracarcinoma specimens was detected by immunohistochemistry(IHC).The relationship between ANXA1 expression and clinicopathological parametes of gastric carcinoma was analyzed.RESULTS:A total of 78 differential proteins were identified.Western blotting revealed that ANXA1 expression was significantly upregulated in GAC(2.17/1,P<0.01).IHC results showed the correlations between ANXA1protein expression and the clinicopathological parameters,including invasive depth(T stage),lymph node metastasis(N stage),distant metastasis(M stage)and tumour-lymph node metastasis stage(P<0.01).However,the correlations between ANXA1 protein expression and the remaining clinicopathological parameters,including sex,age,histological differentiation and the size of tumour were not found(P>0.05).CONCLUSION:The upregulated ANXA1 expression may be associated with carcinogenesis,progression,invasion and metastasis of GAC.This protein could be considered as a biomarker of clinical prognostic prediction and targeted therapy of GAC.