简介:Tumormetastasisisthedominantcauseofdeathincancerpatients.However,themolecularandcellularmechanismsunderlyingtumormetastasisarestillelusive.Theidentificationofproteinmoleculeswiththeirexpressionscorrelatedtothemetastaticprocesswouldhelptounderstandthemetastaticmechanismsandthusfacilitatethedevelopmentofstrategiesforthetherapeuticinterventionsandclinicalmanagementofcancer.Proteomicsisasystematicresearchapproachaimingtoprovidetheglobalcharacterizationofproteinexpressionandfunctionundergivenconditions.Proteomictechnologyhasbeenwidelyusedinbiomarkerdiscoveryandpathogeneticstudiesincludingtumormetastasis.Thisarticleprovidesabriefreviewoftheapplicationofproteomicsinidentifyingmolecularfactorsintumormetastasisprocess.Thecombinationofproteomicswithotherexperimentalapproachesinbiochemistry,cellbiology,moleculargeneticsandchemistry,togetherwiththedevelopmentofnewtechnologiesandimprovementsinexistingmethodologieswillcontinuetoextenditsapplicationinstudyingcancermetastasis.
简介:ChengandChurchalgorithmisanimportantapproachinbiclusteringalgorithms.Inthispaper,theprocessoftheextendedspaceinthesecondstageofChengandChurchalgorithmisimprovedandtheselectionsoftwoimportantparametersarediscussed.Theresultsoftheimprovedalgorithmusedinthegeneexpressionspectrumanalysisshowthat,comparedwithChengandChurchalgorithm,thequalityofclusteringresultsisenhancedobviously,theminingexpressionmodelsarebetter,andthedatapossessastrongconsistencywithfluctuationontheconditionwhilethecomputationaltimedoesnotincreasesignificantly.
简介:DNAsequencescanbetreatedasfinite-lengthsymbolstringsoverafour-letteralphabet(A,C,T,G).Asauniversalandcomputablecomplexitymeasure,LZcomplexityisvalidtodescribethecomplexityofDNAsequences.Inthisstudy,aconceptofconditionalLZcomplexitybetweentwosequencesisproposedaccordingtotheprincipleofLZcomplexitymeasure.AnLZcomplexitydistancemetricbetweentwononnullsequencesisdefinedbyutilizingconditionalLZcomplexity.BasedonLZcomplexitydistance,aphylogenetictreeof26speciesofplacentalmammals(Eutheria)withthreeoutgroupspecieswasreconstructedfromtheircompletemitochondrialgenomes.Onthedebatethatwhichtwoofthethreemaingroupsofplacentalmammals,namelyPrimates,Ferungulates,andRodents,aremorecloselyrelated,thephylogenetictreereconstructedbasedonLZcomplexitydistancesupportsthesuggestionthatPrimatesandFerungulatesaremorecloselyrelated.
简介:单个核苷酸多型性(SNP)是决定任何二个无关的个人之间的差别的基因变化。各种各样的人口组能用SNP与对方被区分开来。例如,HapMap数据集与大约1000万SNP有四个人口组。为人的进化,种族变化,和人口赋值上的更多的卓见,我们建议发现哪个SNP在决定人口组是重要的然后作为输入特征用这些相关SNP分类不同人口。在这研究,我们开发了评价措施的修改t测试并且把它用于HapMap遗传型数据。第一,我们为赋值包括F统计和增进知识的海角与另外的特征重要性措施比较评价所有SNP。第二,我们作为输入选择最高度评价的SNP的不同数字到一个分类器,例如支持向量机器,以便发现最好的特征相应于最好的分类精确性的子集。试验性的结果证明建议方法在发现在决定人口组是重要的SNP是很有效的,与减少的计算负担和更好的分类精确性。
简介:Thethree-dimensional(3D)structurepredictionofproteinsisanimportanttaskinbioinformatics.Findingenergyfunctionsthatcanbetterrepresentresidue-residueandresidue-solventinteractionsisacrucialwaytoimprovethepredictionaccuracy.Thewidelyusedcontactenergyfunctionsmostlyonlyconsiderthecontactfrequencybetweendifferenttypesofresidues;however,wefindthatthecontactfrequencyalsorelatestotheresiduehydrophobicenvironment.Accordingly,wepresentanimprovedcontactenergyfunctiontointegratethetwofactors,whichcanreflecttheinfluenceofhydrophobicinteractiononthestabilizationofprotein3Dstructuremoreeffectively.Furthermore,afoldrecognition(threading)approachbasedonthisenergyfunctionisdeveloped.Thetestingresultsobtainedwith20randomlyselectedproteinsdemonstratethat,comparedwithcommoncontactenergyfunctions,theproposedenergyfunctioncanimprovetheaccuracyofthefoldtemplatepredictionfrom20%to50%,andcanalsoimprovetheaccuracyofthesequence-templatealignmentfrom35%to65%.