药物靶点研究

药物靶点研究学号：09810068研究生：王兴旺导师：张武教授谢江副教授介绍1药物靶点概念•药物靶点是指药物在体内的作用结合位点，包括基因位点、受体、酶、离子通道、核酸等生物大分子。•现代新药研究与开发的关键首先是寻找、确定和制备药物筛选靶—分子药靶。选择确定新颖的有效药靶是新药开发的首要任务。迄今已发现作为治疗药物靶点的总数约500个，其中受体尤其是G-蛋白偶联的受体（GPCR）靶点占绝大多数，另还有酶、抗菌、抗病毒、抗寄生虫药的作用靶点。合理化药物设计（rationaldrugdesign）可以依据生命科学研究中所揭示的包括酶、受体、离子通道、核酸等潜在的药物作用靶位，或其内源性配体以及天然底物的化学结构特征来设计药物分子，以发现选择性作用于靶点的新药。2经济效益分析（1）利用HMGCoA还原酶作为药物靶标开发了一系列他汀类降脂药物，仅2000年，该类药物的销售额达120亿美元，并以每年15%~20%的速度增长。（2）Novartis公司利用慢性粒细胞性白血病(CML)相关蛋白Bcr-Abl为靶标，在短时间内开发出有效治疗CML的新药—高活性Bcr-Abl激酶抑制剂STI571(Gleevac)。因此，生物医药公司纷纷投入大量人力和财力，寻找治疗重要疾病的新型药物靶点。随着生命科学的迅速发展，对于疾病发生机制了解的逐渐深入，各种新的研究技术不断涌现，也同时出现了许多新的靶标发现技术。讨论•药物靶点开发新药的原理是什么？3药物靶点发现方法1、从有效单体化合物着手发现药物靶点2、以正常组织与病理组织基因表达差异发现靶点3、通过定量分析和比较研究在正常和疾病状态下蛋白质表达谱的改变发现靶点4、以蛋白质相互作用为基础发现药物靶标5、应用RNA干扰技术特异的抑制细胞中不同基因的表达，通过细胞的表型变化发现靶标构建癌症扰动蛋白质相互作用网络发现凋亡细胞药物靶点Constructionofacancer-perturbedprotein-proteininteractionnetworkfordiscoveryofapoptosisdrugtargets.摘要背景：癌症是由于基因异常情况引发的，比如致癌基因突变或肿瘤抑制基因，他们改变了下游的信号转换路径和蛋白质相互作用。通过对致癌蛋白和正常细胞蛋白的相互作用比较可以阐明致癌作用机制。Background:Canceriscausedbygeneticabnormalities,suchasmutationsofoncogenesorTumorsuppressorgenes,whichalterdownstreamsignaltransductionpathwaysandproteinproteininteractions.Comparisonsoftheinteractionsofproteinsincancerousandnormalcellscanshedlightonthemechanismsofcarcinogenesis.研究结果和结论Results:Weconstructedinitialnetworksofprotein-proteininteractionsinvolvedintheapoptosisofcancerousandnormalcellsbyuseoftwohumanyeasttwo-hybriddatasets（两个人类双杂交数据集）andfouronlinedatabases.Next,weappliedanonlinearstochasticmodel,（非线性随机模型）maximumlikelihoodparameterestimation,（极大似然参数估计）andAkaikeInformationCriteria(AIC)toeliminatefalse-positive（假正值）protein-proteininteractionsinourinitialproteininteractionnetworksbyuseofmicroarray（微阵列芯片）data.ComparisonsofthenetworksofapoptosisinHeLa(humancervicalcarcinoma)cells（宫颈癌细胞）andinnormalprimaryLungfibroblasts（纤维母细胞）providedinsightintothemechanismofapoptosisandallowedidentificationofPotentialdrugtargets.ThepotentialtargetsincludeBCL2,caspase-3andTP53.OurcomparisonOfcancerousandnormalcellsalsoallowedderivationofseveralpartyhubsanddatehubsinthehumanprotein-proteininteractionnetworksinvolvedincaspaseactivation.Conclusion:Ourmethodallowsidentificationofcancer-perturbedprotein-proteininteractionsinvolvedinapoptosisandidentificationofpotentialmoleculartargets（分子靶点）fordevelopmentofAnticancerdrugs.Figure3Flowchartforidentificationofpotentialdrugtargetsinthecancer-perturbednetworkusingmicroarray（微阵列芯片）data.Figure1Globalprotein-proteininteractionsofapoptosisincancerousandnormalcells.(A)Apoptotic（细胞凋亡）protein-proteininteractionnetworkinHeLacells,showing183nodesand552edges.(B)Apoptoticprotein-proteininteractionnetworkinnormalprimarylungfibroblasts,showing175nodesand547edges.Eachinteractionwascalculatedtwiceandonlyinteractionswithtwo'1'scoresafterAICevaluationwasconsidered'true'interactions(seeSupplementaryTable1fordetailedinformation).Allprotein-proteininteractionnetworksinthisstudywereconstructedwithOspreyversion1.2.0.AB讨论•为什么拿宫颈癌和正常的纤维母细胞进行比较？Figure-2Cancer-perturbedprotein-proteininteractionsintheapoptosisnetwork.(A)'Gain-of-function'network,showing140nodesand157edges.(B)'Loss-of-function'network,showing126nodesand162edges.ColorsofnodesrepresentGeneOntologyannotations.SupplementaryTables2and3listproteinswithdetailedGeneOntologyannotations,withrankingaccordingtothedegreeofperturbation.ABFigure4Dynamic（动态）protein-proteininteractionsincaspaseformation.(A)Protein-proteininteractionswithinthehubcaspasesofcancercellsduring0–8hoursafterinductionofapoptosis.Distinctinteractionsatdifferenttimesaremarkedwithboldlines.(B)During4–30hoursafterinductionofapoptosisincancercells.(C)During0–8hoursafterinductionofapoptosisinnormalcells.(D)During4–36hoursafterinductionofapoptosisinnormalcells(seeSupplementaryTables5and6).Figure5Graphicalrepresentationofindividualproteininteractionsandcooperativeproteininteractions.Ourdynamic（动态）proteininteractionequationincludesthreeindividualorbinaryprotein-proteininteractionstothetargetproteinx[t](proteinx1[t],x2[t],andx3[t])andonecooperativeinteractionbetweenproteinx1[t]andx2[t]tothetargetproteinx[t].adenotestheinfluenceofatargetproteinatonetimepointtothetargetproteinatthenexttimepoint;bidenotesindividualorbinaryinteractionofproteiniwithtargetproteinx[t];andcijdenotesthecooperativeinteractionabilityofproteiniandproteinjonthetargetproteinx.Table2:Truthtableofall16eventsinthesamplespaceofcomparisonsofindividualinteractionofproteiniandproteinjbetweenHeLaandnormalcellsIfaninteractionisabsentinnormalcells,butpresentincancercells,wecallitgain-of-function;ifaninteractionispresentinnormalcellsbutnotincancerouscells,wetermitloss-of-function.讨论•能否从以上解决问题的方法得到启发解决生物信息问题？