张宝月 郑一夫 庞晓丛
摘要目的:為了探讨抗肿瘤中药复方的物质基础和网络药理机制,并且阐明中药方剂中各种有效成分的协同作用机理。方法:本文通过收集肿瘤防治相关的中药复方,并从中选取出现频次较高的单味药,使用CNPC和TCMSP数据库进行化学成分的收集,对有效化学成分进行了抗肿瘤作用的物质基础研究;利用TCMID及CTD数据库寻找化学成分的作用基因,在此基础上利用Cytoscape构建网络,进行网络机制研究。结果:收集了65个抗肿瘤中药复方,其中出现频次大于10的单味药有4个,分别为甘草、黄芪、人参和黄芩,其已知化学成分分别为172,70,293和92个,抗肿瘤有效成分主要包括三萜类、黄酮类、多糖类、皂苷类化合物。在化学成分相关基因分析的基础上,构建了化学成分—基因调控网络,蛋白质相互作用网络,基因通路富集网络以及基因疾病网络,以揭示中药复方的多种有效成分的协同作用机制。此外,应用分子对接方法,对化学成分影响较大的基因相关蛋白进行了相互作用分析,包括PTG2、EGFR、PPARG、ESR1、MTOR、AKT1、MAPK1、PPARA和MAPK8。大部分化合物都能作用于多个靶点,主要涉及生物碱、黄酮及其苷、有机酸及二蒽酮等结构类型,代表性的化学成分有水仙苷、芦丁、北豆根碱、黄岑素、汉黄芩甙、异夏佛塔苷、亚叶酸、伪金丝桃素等。结论:本文应用统计学方法、网络药理学方法及分子对接方法,初步揭示了抗肿瘤传统中草药有效成分及其网络作用机制,为中药抗肿瘤多靶点药物设计提供重要信息。
关键词肿瘤;中药;网络药理学;数据挖掘;分子对接
Network Pharmacologybased Study of the Active Constituents of Chinese Medicinal Formulae for Antitumor Mechanism
Zhang Baoyue1,Zheng Yifu2,Pang Xiaocong1,Zheng Xiangjin1,Wang Zhe1,Ding Hong2,Liu Ailin1,Du Guanhua1
(1 Institute of Materia Medica,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100050,China; 2 School of Pharmaceutical Sciences,Wuhan University,Wuhan 430072,China)
AbstractObjective:To investigate the network pharmacology of antitumor Chinese medicinal formulae and explain the synergistic mechanism of various active ingredients of Chinese medicinal formulae.Methods:We collected the antitumor Chinese medicinal formulae and chose several single herbs with the top frequency for further study.The chemical constituents of these herbs were downloaded from databases CNPC and Traditional Chinese Medicine Systems Pharmacology and were analyzed to set up the antitumor material basis.The genes regulated by these constituents were retrieved in Traditional Chinese Medicine integrated database and Comparative Toxicogenomics database.Results:We collected 65 antitumor Chinese medicinal formulae,and 4 single herbs were selected,including Radix Glycyrrhizae,Radix Astragali seu Hedysari,Radix Ginseng and Radix Scutel ariae,which consist of 172,70,293,and 92 known constituents,respectively.Antitumor active ingredients mainly included triterpenoids,flavonoids,polysaccharides,and saponin compounds.The constituentgene network,proteinprotein interaction network,genepathway enrichment network,and genedisease network were constructed based on chemical compositionrelated genetic analysis.Moreover,molecular docking was employed to clarify the interactions between active constituents and key drug targets (PTG2,epidermal growth factor receptor,peroxisome proliferatoractivated receptor gamma,estrogen receptor 1,mammalian target of rapamycin,AKT1,mitogenactivated protein kinase 1 (MAPK1),peroxisome proliferatoractivated receptor alpha,and MAPK8).Most of the constituents could act on multiple targets,whose structures mainly belonged to alkaloids,flavonoids,and their glycosides,organic acids,or dianthrone,and their representative chemical constituents included narcissus glycosides,rutin,dauricine,scutellarin,baicalin,isoschaftoside,and leucovorin.Conclusion:The network mechanism of the effective constituents from traditional Chinese medicines (TCMs) for antitumor therapy was partially uncovered by using statistical methods,network pharmacology methods,and molecular docking methods.This study will provide important information for new drug design with multiple targets for antitumor therapy.
Key WordsTumor; Traditional Chinese medicine; Network pharmacology; Data mining; Molecular docking
中图分类号:R285文献标识码:Adoi:10.3969/j.issn.1673-7202.2018.08.044
肿瘤作为一种严重威胁人类生命健康的恶性疾病,其发病率及死亡率一直呈上升趋势,我国最近统计资料表明,肿瘤引起的死亡人数已经超过心血管疾病,居城市及农村居民死因的首位[12]。目前恶性肿瘤的治疗以传统的手术、放疗和化疗为主,虽然放疗可以杀灭肿瘤细胞,短期抑制其增殖,化学药物对一些肿瘤也有不错的治疗效果,但作用的特异性低,杀伤肿瘤细胞的同时,也抑制人体正常组织细胞的活动,所以大部分药物都有严重的不良反应[3]。
我国中医从《神农本草经》开始就已经认识到了癌症的存在,历代中医名家在攻克癌症的道路上流传下来的方剂是中医药治疗癌症的宝贵遗产,其中约200种中草药已被学者证明确有抗癌作用[4]。相比于传统西方医学针对肿瘤放疗化疗的治疗手段,中药有同样治疗癌症效果的同时,还具有来源广泛、价格低廉、不良反应小等优点,并在提高患者免疫力,改善患者生命质量,防止复发转移,延长生存期等诸多方面发挥着重要作用[5]。中西医结合抗肿瘤治疗时,运用中药可增强放、化疗敏感性,减轻放、化疗不良反应,所以,中药作为辅助疗法协同治疗癌症已经成为我国医院中普遍采取的治疗手段[6]。此外,与西医比较,中医学在个体化治疗方面具有独特的优势,有助于选择适合患者的药物,提高治疗的针对性[7]。
目前,中药复方在肿瘤治疗的整个过程中的不同阶段均发挥了重要作用,疗效也得到充分肯定,成为中药现代研究的热点之一。中药具有多成分,多靶点,多种调节方式的特点。以西方单一靶标和单一成分的研究方法难以反映中药的系统性[8],不能科学地解释中草药复方的物质基础和处方规律。霍普金斯[9]提出了网络药理学研究方法,并且认为药物作用于多个靶点,并通过多个靶点之间的相互作用产生协同作用和衰减作用[10]。网络药理学从相互连接的角度研究问题,这恰恰与中药的核心思想不谋而合。因此,利用网络药理学对中医药进行研究具有独特的优势和巨大的发展潜力。随着近些年中药现代化发展,国内外建立了多个中药数据库,比如TCMID、CTD、TCMSP、HIT、TCMDB@Taiwan等[11]。基于现有数据库的数据挖掘及相关生物信息学分析,结合计算模拟方法,为中药网络机制研究提供了方便有效的方法途径。
本文首先搜集了五大类抗肿瘤的中药复方,包括扶正固本类、清热解毒类、活血化瘀类、软坚散结类、化痰利湿类。根据单味药在复方中出现的频次,从中选取出现频次较高的中草药,对其抗肿瘤物质基础进行了分析研究。在化学成分收集及其对基因调控作用分析的基础上,进行KEGG及GO富集分析,并构建化学成分基因调控网络,蛋白质相互作用网络,基因富集通路网络以及基因疾病网络,以揭示其抗肿瘤的网络机制。最后,对化学成分与基因作用网络进行分析,确定关键基因的对应靶点,并以此建立分子对接模型,来进一步验证化学成分对抗肿瘤靶点的作用機制,为抗肿瘤多靶点药物设计提供重要信息依据。
1材料与方法
11中药复方及单体收集中药用于防治疾病的基本形式是中药复方,即定量的若干种特定中草药植物的混合物。中药复方中含有大量的化学物质,它们是与疾病相关多个靶点相互作用的物质基础。中药复方的收集主要通过以下2个途径:1)通过在方剂现代应用数据库(http://coworkcintcmcom/engine/login_dojsp?u=guest&p=guest321&cnid=12895),以“肿瘤”或“癌症”为关键词进行查询;2)对中国知网及Pubmed数据库进行检索,收集治疗肿瘤中药复方。在此基础上,统计每味中药出现的频次。对出现频次大于10的中草药进行后续的研究。这些中草药植物中所含的化学成分从国家人口与健康科学数据共享平台最新版的中国天然产物化学成分数据库CNPC(http://pharmdatancmicn/cnpc/)以及TCMSP数据库(http://ibtshkbueduhk/LSP/tcmspphp)中收集。
12作用基因及靶点收集对于中药的已知成分,我们利用TCMID(http://wwwmegabionetorg/tcmid/)[12]和CTD(http://ctdbaseorg/)[13]数据库,分析化学成分的作用靶点。TCMID由6个部分组成,即处方、草药、成分、靶标、药物和疾病。TCMID通过对STITCH,Herb Ingredients′ Targets(HIT),以及文献进行数据挖掘来确定化学成分与靶点的潜在关系。CTD提供关于化学成分基因/蛋白质相互作用,化学成分疾病和基因疾病关系信息。其中化学成分与基因/蛋白质相互作用数据来源于已报道的文献。
13作用网络分析我们使用FunRich 212(http://wwwfunrichorg)对中药有效成分调控基因的分布进行分析,并得到共同调控的基因。一方面,对每味中药相关基因进行KEGG及GO富集分析,以分析它们抗肿瘤的作用特点。另一方面,利用Cytoscape_321对共同调控的基因,构建核心调控网络,即化学成分基因网络。利用STRING数据库对基因的相互关系进行预测,构建蛋白质相互作用网络。利用DAVID数据库对中药化学成分调控基因的代谢通路进行GO、KEGG、OMIM富集分析,构建基因通路网络以及基因疾病网络,以揭示其抗肿瘤作用机制。
14相互作用分析利用Cytoscape_321的cytohubba插件从蛋白质相互作用网络中找出关键节点。将有上市药物的靶点或已进入II期临床试验药物的靶点挑选出来,构建分子对接模型。这些靶点蛋白的晶体结构来自PDB(Protein Data Bank)数据库[14]。为了保证分子对接的可靠性,我们选择分辨率<25 且具有配体复合物的蛋白晶体结构,建立分子对接模型。分子对接程序使用Discovery Studio 2016(San Diego,CA,USA)的Libdock软件包。首先去除PDB结构中的水分子,对接的活性口袋由原始配体分子进行定义。对接参数设置之后,我们将晶体结构中的配体分子抽取出来并重新对接至预先定义好的活性口袋,同时计算对接后的配体分子构象与晶体结构中的初始构象之间的均方根差值(Rootmeansquare Deviation,RMSD),从而验证分子对接的可靠性。
2结果
21用于治疗肿瘤的中药复方及化学成分收集通过方剂现代应用数据库及文献检索,共收集到65个治疗肿瘤的中药复方,包括扶正固本类复方、清热解毒类复方、活血化瘀类复方、软坚散结类复方、化痰利湿类复方。然后,对这些复方中单味药出现的频次进行统计分析。见图1。其中出现频次大于10的中草药有4个,分别为甘草、黄芪、人参和黄芩。然后,通过中国天然产物数据库以及TCMSP数据库收集这些单味药的主要化学成分,由于这些化学成分不一定是有效成分,因此我们利用TCMID和CTD数据库,又分析了这4个单味药中已报道的有效成分数据。见表1。
22抗肿瘤的物质基础研究
通过文献调研的方法,对甘草、黄芪、人参、黄芩4种单味药进行了抗肿瘤的物质基础研究。
221甘草甘草中的三萜类、黄酮类化合物及甘草粗提物对结肠直肠癌、乳腺癌、前列腺癌、肝癌、胃癌、膀胱癌、肺癌有显著的抑制作用[15]。Khan等[16]指出,化合物甘草甜素(glycyrrhizin)能明显降低肿瘤坏死因子α(Tumor Necrosis Factor,TNFα)的水平,也减弱了黏液层的消耗以及唾液酸粘蛋白向苏氨粘蛋白的转移;甘草甜素对1,2一二甲肼(DMH)诱导的结肠癌具有很强的化学预防潜力。甘草抗肿瘤活性的相关文献报道中,关于抗乳腺癌的最多。Hsu等[17]指出,化合物光甘草定(glabridin)可以通过抑制黏着斑激酶/Rho信号通路进而抑制MDAMB231人乳腺癌细胞的侵袭,转移和血管生成。Lee等[18]发现化合物isoangustone A是用于治疗前列腺癌的有效的CDK2分子抑制剂。Lin等[19]报道,化合物甘草次酸(Glycyrrhetinic Acid)能有效抑制裸鼠胃癌细胞的形成,通过在G2期诱导胃癌细胞凋亡和阻滞细胞周期发挥作用。Tsai等[20]报道,化合物甘草查耳酮A(licochalcone A)可以抑制人肝细胞癌细胞SKHep1和HA22T/VGH的迁移和侵袭能力。发现该化合物抑制了尿激酶型纤溶酶原激活物(Urokinase Plasminogen Activator,uPA)的活性和表达,并在上述细胞中降低了uPA的转录水平。Yuan等[21]发现,化合物甘草查耳酮B(licochalcone B)显著抑制人膀胱癌T24和EJ细胞株的增殖,并具有浓度和时间依赖性。Tsai等[22]报道,化合物光甘草定抑制人非小细胞肺癌A549细胞的侵袭和转移,并通过抑制FAK/Rho信号通路降低A549介导的血管发生。
222黄芪黄芪中含有多种活性成分,包括多糖类、黄酮类、皂苷类、氨基酸类化合物和多种微量元素。抗肿瘤作用机制主要包括抑制肿瘤细胞增殖、促进肿瘤细胞凋亡、抑制肿瘤细胞迁移、清除自由基、增强机体免疫功能等[23]。Li等[24]研究黄芪多糖对人红白血病K562细胞增殖和凋亡的影响,证明黄芪多糖可能是通过下调细胞周期蛋白Cyclin B和Cyclin E的表达以及上调p21抑癌基因的水平从而抑制K562细胞的增殖。Wang等[25]用流式细胞术观察了经黄芪总黄酮干预的BGC823细胞的细胞周期及凋亡率的变化,发现黄芪总黄酮可剂量依赖地将BGC823细胞的细胞周期阻滞于G0/G1期。Cheng等[26]实验结果表明黄芪甲苷通过蛋白激酶(PKC)α细胞外调节蛋白激酶(ERK1)/2NFκB通路降低基质金属蛋白酶2(Matrix Metallo Proteinase2,MMP2)和基质金属蛋白酶9(Matrix Metallo Proteinase2,MMP9)的表达,从而抑制肺癌细胞A549的转移。Yin等[27]证明黄芪提取液能显著降低Ⅰ期肿瘤中环氧合酶2(Cyclooxygenase,COX2)和血管内皮生长因子(Vascular Endothelial Growth Factor,VEGF)的表达,提示黄芪提取液可能抑制肿瘤细胞的迁移。另有研究[2829]发现,黄芪皂苷、黄芪毛蕊异黄酮和芒柄花黄素均有抗氧化应激的作用,可以清除自由基。此外,黄芪注射液及其多糖不仅能够提高超氧化物歧化酶(Superoxide Dismutase,SOD)活性,降低丙二醛(Malon Dialdehyde,MDA)的含量,清除细胞内氧化应激产生的活性氧(ROS)和活性氮(RNS),而且还能减少自由基生成[30]。Zhang等[31]用流式细胞术检测了经黄芪甲苷口服给药的肺癌小鼠脾脏中调节性T细胞(Regulatory T Cells,Tregs)及L淋巴细胞(Cytotoxic T Lymphocytes,CTLs)的比例,发现脾脏中Treg比例下降,L淋巴细胞比例增加,提示黄芪甲苷可能通过增强机体免疫功能抑制肿瘤的生长。
223人参人参中具有抗肿瘤活性的成分主要有人参皂苷及其代谢产物、人参多糖和人参炔醇。目前文献报道人参对肝癌、胃癌、肺癌、肾癌、鳞癌、鼻咽癌、食管癌、结肠癌、胆囊癌、黑色素瘤、胶质瘤、乳腺癌、乳头瘤、卵巢癌、宫颈癌、子宫内膜癌、膀胱癌、前列腺癌、腹水癌、淋巴瘤、骨髓瘤、骨肉瘤、白血病等肿瘤的增殖具有显著的抑制作用[32]。研究表明20(S)人参皂苷Rg3[3334]、人参皂苷Rd[35]、PNT[36]、PNN[37]等能够抑制肿瘤细胞的有丝分裂及在分裂间期DNA的合成,如在结肠癌细胞中抑制细胞内增殖相关蛋白,增殖细胞核抗原的表达,导致DNA复制和修复减少,从而抑制细胞增殖。人参皂苷Rg3[38]、Rg5[39]、CK[40]及25OHPPD[41]等在多种肿瘤如乳腺癌、胃癌、肺癌、前列腺癌等細胞周期相关蛋白调控阶段发挥作用,最终将肿瘤细胞周期阻滞在G0/G1期。人参皂苷Rg5[39]、Rh2[42]、Rk1[43]、CK[40]、PPD[37]等能诱导肿瘤细胞内源性凋亡;人参皂苷Rh2[42]、Rk1[43]、CK[40]、PPD[41]可以诱导肿瘤细胞外源性凋亡。目前对人参诱导肿瘤细胞分化的研究主要针对于白血病,研究表明人参总皂苷通过促红细胞生成素受体(Erythropoietin Receptor,EpoR)的内化诱导白血病细胞向红系分化[44]。研究表明人参有效成分对多种肿瘤的侵袭与转移具有明显的抑制作用,人参皂苷Rb2[45]、Rg1[46]、Rg3[4748]、Rh1[49]、Rh2[50]、Rd[51]、CK[52]等可通过抑制MMP1、2、3、7、9、13、14等基质金属蛋白酶在癌细胞中表达以避免其破坏细胞外基质(Extra Cellular Matrix,ECM)屏障,从而抑制癌细胞侵袭和转移。
224黄芩黄芩的抗肿瘤作用主要通过黄酮类化合物表现出来,包括黄芩素、黄芩苷、汉黄芩素、千层纸素A等,可通过影响细胞周期、诱导细胞凋亡、抑制端粒酶活性等多种机制发挥抗肿瘤作用[53]。汉黄芩素对肝肿瘤细胞SKHEP1具有增殖抑制作用(IC50=80 μmol/L),可诱导SKHEP1发生凋亡并增强细胞中Caspase3/cpp32基因的活性[54]。Wang等[55]研究发现,黄芩素可诱导HL60细胞线粒体释放细胞色素C,导致细胞内过氧化氢水平升高,从而诱发细胞凋亡并发生DNA断裂,过氧化氢酶可有效阻断黄芩素诱导细胞凋亡导致的DNA断裂,说明黄芩素可能通过ROS介导的线粒体功能失效诱导细胞凋亡。研究表明黄芩素、黄芩苷、汉黄芩素均可抑制肝肿瘤细胞HepG2、Hep3B、SKHEP1的增殖。3种化合物均可将HepG2细胞的细胞周期阻滞于G2/M期,将Hep3B细胞的细胞周期阻滞于G1亚期;黄芩素和汉黄芩素可将SKHEP1细胞的细胞周期分别阻滞于G1亚期和G1期[5658]。Huang等[59]研究发现,汉黄芩素对HL60细胞的生长抑制作用(IC50为50 μmol/L)与端粒酶活性的降低有关。Zhang等[60]研究发现,HNSCC模型小鼠经黄芩中黄酮提取物灌胃后,肿瘤体积显著减小,肿瘤生长抑制率为66%。给予黄芩提取物千层纸素A(40 mg/kg),可使黑色素瘤B16F10小鼠的肿瘤体积减小73%[61]。
23调控基因富集分析
通过利用TCMID和CTD对甘草、黄芪、人参及黄芩4个单味药的有效成分的作用基因进行分析,分别得到521,576,208及678个无重复基因,其中共同作用于80个基因(图2)。我们利用DAVID分别对这4个单味药调控的基因进行了KEGG富集分析。根据富集的基因数目及P值,列出了前5条通路,结果见表2。表2中的所有通路都有文献报道,说明我们实验结果的可靠性。它们的作用通路具有一定相似性,均作用于Tolllike受体信号转导途径。此外,甘草与人参作用更为相似,而黄芪与黄芩作用更相似。利用Funrich 212对它们的GO通路及分子功能进行了富集。从图3可以看出,甘草与人参主要作用于丝氨酸型酶活性,黄芪与黄芩分别主要作用于酪氨酸激酶活性与转录因子活性。从GO_BP富集分析的结果(图4)来看,这4个中药对能量代谢通路及体内代谢相关通路均有较大影响。
24作用网络分析图2表明,4个单味药共同调控80个基因,说明它们存在共同的抗肿瘤机制。因此,我们对共同调控的80个基因进行了富集分析,以揭示这些化学成分对基因的调控作用,作用通路及相关疾病的关系。通过图5可以看出,大部分化学成分可以调控多个基因,是潜在的多靶点化学成分。图6分析了这些基因共同调控的通路,主要包括Tolllike受体信号通路,P53信号通路,脂肪细胞因子信号通路,MAPK(Mitogenactivated Protein Kinase)信号通路,T cell相关免疫信号通路等。从图7我们可以发现,这些中药涉及多种癌症,比如前列腺癌、乳腺癌、黑色素瘤等,此外,这4种中药也对阿尔兹海默病及II型糖尿病相关的信号通路具有一定的作用。
25分子对接通过基因相互作用(图8)及hub基因分析,我们确定了9个有上市药物或已进入II期临床试验药物的靶点,分别为PTG2,EGFR(epidermal growth factor receptor),PPARG(peroxisome proliferatoractivated receptor gamma),ESR1(estrogen receptor 1),MTOR(mammalian target of rapamycin),AKT1,MAPK1,PPARA(peroxisome proliferatoractivated receptor alpha)和MAPK8。通过建立分子对接模型,分析比较化学成分与靶点的相互作用情况。在化学成分与靶点进行分子对接计算之前,对靶点晶体结构中的配体进行redocking验证,通过计算对接后配体与晶体中的配体的空间坐标,计算其RMSD值,当RMSD<25时,说明对接结果是可靠的。从表3中的结果可以看出,其RMSD值均小于25,表明分子对接计算结果是可靠的。随后,基于Figure 5的化学成分与基因的调控网络,我们进一步研究这些有效化学成分与9个核心靶点的相互作用。表4介绍了每个靶点对接后打分排名在前5的化学成分信息及作用靶点信息。大部分化合物都能作用于多个靶点,比如水仙苷、芦丁、北豆根碱、黄岑素、汉黄芩甙、异夏佛塔苷、亚叶酸、伪金丝桃素等,主要涉及生物碱类、黄酮及其苷类、有机酸及二蒽酮类等。这些骨架为多靶点化合物设计提供结构基础。我们以出现频数最高的石蒜碱为例,研究了其与多个靶点相互作用特点。Figure 9举例了作用于多靶点的化合成分水仙苷可以通过氢键、Pi键、离子间的引力与多个靶点结合。
3讨论
中药作为我国传统药物的主要组成部分,几千年来在肿瘤防治中发挥着重要作用。但是由于中药成分复杂,而肿瘤又是多因素复杂性疾病,因此,中药抗肿瘤的药理机制尚不明确。
甘草、黄芪、人参、黄芩中的化合物成分复杂,主要包括三萜类、黄酮类、多糖类、皂苷类、氨基酸类、炔醇类等,均表现出良好的抗肿瘤活性,为这4种单味药的药理网络机制研究奠定了良好的物质基础。
本文通过数据挖掘及计算机模拟等多种方法探讨具有代表性单味药甘草、黄芪、人参、黄芩的抗肿瘤作用机制。我们通过基因富集分析发现,甘草及人参能够影响Toll样及NOD样模式受体信号传导途径,激活免疫应答,增強机体免疫功能。甘草与类固醇激素的合成有密切关系,可以解释甘草抗乳腺癌的报道较多的原因。此外,我们发现甘草能够作用于多种CYP450,这可以解释甘草解药毒、缓解药物烈性的作用。但是也要注意甘草与西药联合应用时,应避免因代谢诱导或抑制产生的不良反应。人参的化学成分除了作用于肿瘤直接相关通路,还能影响脂肪因子信号通路。近年来的研究发现,脂肪组织是一个代谢活跃的分泌器官,可分泌多种与肿瘤相关的脂肪因子,在多种类型肿瘤的恶化过程中,肿瘤微环境中的脂肪细胞代谢和分泌作用受到广泛的重视。肿瘤的发生和转移与肿瘤细胞所处的微环境密切相关[82],因此,人参对脂肪因子信号通路的影响为其抗肿瘤机制研究提供了新的方向。通过KEGG及GO富集分析,我们发现黄芪可以通过影响凋亡通路,p53信号通路,细胞粘附及Toll样信号传导途径,来抑制肿瘤细胞增殖、促进肿瘤细胞凋亡、抑制肿瘤细胞迁移、增强机体免疫功能等,与文献报道一致。此外,我们还发现黄芪可显著影响脂肪因子信号通路及肿瘤微环境。
通過对4个单味药共同调控的80个核心基因的分析,发现其化学成分对基因的调节是多对多的关系。中药的多成分及多基因调控机制,也决定了其广谱抗肿瘤作用。图7表明,这四味中药对多种肿瘤均有作用,包括前列腺癌、小细胞肺癌、甲状腺癌、肾癌、结肠癌、黑色素瘤、子宫内膜癌、慢性粒细胞白血病、胰腺癌及膀胱癌。此外,这4味中药对阿尔茨海默病及II型糖尿病也有调控作用,这可能与其调节体内能量代谢有关,而能量代谢与癌症、老年痴呆、糖尿病均密切相关。从图6中我们可以归纳出中药抗肿瘤作用的几种机制:1)激活免疫应答,提高自身免疫力。可通过调节B细胞、T细胞以及Toll样、NOD样受体信号通路发挥作用;2)改善肿瘤微环境。可通过调节脂肪因子、炎性反应因子及细胞间的粘连发挥作用;3)通过调节抑癌因子p53及激酶相关代谢通路,调节肿瘤细胞增殖、迁移、分化和凋亡。
与之前报道的大多网络药理学的研究相比[8384],本实验有所不同。我们没有对中药来源的化合物进行类药性筛选,而是对所有的化学组分进行了抗肿瘤作用研究,避免了遗漏有药理活性的化合物骨架;此外,我们构建了基因疾病网络,不仅发现这些中药与多种癌症相关,还与其他疾病如阿尔兹海默病等相关的信号通路具有一定的作用;最后,我们不仅建立网络进行预测,还通过分子对接发现了作用于多靶点的化学成分,这些化学成分是中药抗肿瘤作用的重要物质基础,也是研究其作用机理的重要基础,同时为多靶点抗肿瘤新药设计提供了重要信息。
综上所述,本研究以抗肿瘤的中药复方为研究对象,针对中药方剂中出现频次较高的单味药,通过数据挖掘,分析了甘草、黄芪、人参及黄芩所含的有效成分的作用基因、靶点及通路,并构建了化学成分基因调控网络,蛋白质相互作用网络,及基因疾病网络,以揭示中药复方的多种有效成分的协同作用机制。本文的研究方法将为其他单味药的抗肿瘤机制研究提供借鉴,通过研究发现的多靶点活性化学成分,将对于抗肿瘤新药研发提供重要信息依据,同时也为中药抗肿瘤的临床应用提供参考。
参考文献
[1]Chen W,Zheng R,Baade PD,et al.Cancer statistics in China,2015[J].CA Cancer J Clin,2016,66(2):115132.
[2]Chen W,Zheng R,Zhang S,et al.Report of cancer incidence and mortality in China,2010[J].China Cancer,2014,2:61.
[3]Ling CQ,Yue XQ,Ling C.Three advantages of using traditional Chinese medicine to prevent and treat tumor[J].Journal of Integrative Medicine,2014,12(4):331335.
[4]X Liu,X Zhou,J Wang,et al.Research progress in antitumor mechanism of traditional Chinese medicine[J].China Pharm,2016,19:11581162.
[5]Liu LL,Chen J,Shi YP.Advances in studies on antitumor of Chinese materia medica with heatclearing and toxinresolving functions[J].Chinese Traditional & Herbal Drugs,2012,43(6):12031212.
[6]Guo YP,Chen ZJ,JinYun MA.Research status on quality of life in the patients with cancer[J].China Cancer,2008(7):600602.
[7]LI Jie,LIN Hongsheng,HOU Wei.Idea and Strategy of Traditional Chinese Medicine Treatment for Cancer[J].China Cancer,2010,19(11):735738.
[8]Westerhoff HV.Networkbased pharmacology through systems biology[J].Drug Discov Today:Technol,2015,15:1516.
[9]Hopkins A L.Network pharmacology[J].Nat Biotechnol,2007,25(10):1101111.
[10]Hopkins AL.Network pharmacology:the next paradigmin drug discovery[J].Nat Chem Biol,2008,4(11):682690.
[11]Xie T,Song S,Li S,et al.Review of natural product databases[J].Cell Proliferation,2015,48(4):398404.
[12]Xue R,Fang Z,Zhang M,et al.TCMID:Traditional Chinese Medicine integrative database for herb molecular mechanism analysis[J].Nucleic Acids Research,2013,41(Database issue):D10891095.
[13]Mattingly CJ,Colby GT,Forrest JN,et al.The Comparative Toxicogenomics Database(CTD)[J].Environ Health Perspect,2003,111(6):793795.
[14]Pang X,Wang L,Kang,et al.Effects of PGlycoprotein on the Transport of DL0410,a Potential Multifunctional AntiAlzheimer Agent[J].Molecules,2017,22(8):1246.
[15]Rui Yang,Liqiang Wang,et al.Antitumor Activities of Widelyused Chinese Herb Licorice[J].Chinese Herbal Medicines,2014,6(4):274281.
[16]Khan R,Khan AQ,Lateef A,et al.Glycyrrhizic acid suppresses the development of precancerous lesions via regulating the hyperproliferation,inflammation,angiogenesis and apoptosis in the colon of Wistar rats[J].PLoS One,2013,8(2):e56020.
[17]Hsu YL,Wu LY,Hou MF,et al.Glabridin,an isoflavan from licorice root,inhibits migration,invasion and angiogenesis of MDAMB231 human breast adenocarcinoma cells by inhibiting focal adhesion kinase/Rho signaling pathway[J].Mol Nutr Food Res,2011,55(2):318327.
[18]Lee E,Son JE,Byun S,et al.CDK2 and mTOR are direct molecular targets of isoangustone A in the suppression of human prostate cancer cell growth[J].Toxicol Appl Pharmacol,2013,272(1):1220.
[19]Lin D,Zhong W,Li J,et al.Involvement of BID translocation in glycyrrhetinic acid and 11deoxy glycyrrhetinic acidinduced attenuation of gastric cancer growth[J].Nutrition & Cancer,2014,66(3):463473.
[20]Tsai JP,Hsiao PC,Yang SF,et al.Licochalcone A suppresses migration and invasion of human hepatocellular carcinoma cells through downregulation of MKK4/JNK via NFκB mediated urokinase plasminogen activator expression[J].PLoS One,2014,9(1):e86537.
[21]Yuan X,Li T,Xiao E,et al.Licochalcone B inhibits growth of bladder cancer cells by arresting cell cycle progression and inducing apoptosis[J].Food Chem Toxicol,2014,65:242251.
[22]Tsai YM,Yang CJ,Hsu YL,et al.Glabridin inhibits migration,invasion,and angiogenesis of human nonsmall cell lung cancer A549 cells by inhibiting the FAK/rho signaling pathway[J].Integrative Cancer Therapies,2011,10(4):341349.
[23]Deng X,Li QS,Chen Z,et al.Advances in antitumor mechanisms of radix astragali[J].Tradit Chin Drug Res Clin Pharmacol,2016,27(2):307312.
[24]Li Chao,Qian Xinhua,Qian Xinlai,et al.Inhibitory effect of astragalus polysaccharide on the proliferation of human erythroleukemia K562 cells and itsmechanisms[J].Chin J Appl clin Pediatr,2014,29(12):936939.
[25]Wang T,Xuan X,Li M,et al.Retraction Note:Astragalus saponins affect proliferation,invasion and apoptosis of gastric cancer BGC823 cells[J].Diagn Pathol,2017,12(1):67.
[26]Cheng XD,Gu JF,Zhang MH,et al.Astragaloside IV inhibits migration and invasion in human lung cancer A549 cells via regulating PKCαERK1/2NFκB pathway[J].International Immunopharmacology,2014,23(1):304313.
[27]Yin G,Tang D,Dai J,et al.Combination Efficacy of Astragalus membranaceus and Curcuma wenyujin at Different Stages of Tumor Progression in an Imageable Orthotopic Nude Mouse Model of Metastatic Human Ovarian Cancer Expressing Red Fluorescent Protein[J].Anticancer Res,2015,35(6):3193207.
[28]Chen CY,Zu YG,Fu YJ,et al.Preparation and antioxidant activity of Radix Astragali residues extracts rich in calycosin and formononetin[J].Biochem Eng J,2011,56:8493.
[29]Li J,Han L,Ma Y F,et al.Inhibiting effects of three components of Astragalus membranaceus on oxidative stress in Chang Liver cells[J].China journal of Chinese materia medica,2015,40(2):318323.
[30]Pu X,Fan W,Yu S,et al.Polysaccharides from Angelica and Astragalus exert hepatoprotective effects against carbontetrachlorideinduced intoxication in mice[J].Canadian Journal of Physiology & Pharmacology,2015,93(1):3943.
[31]Zhang A,Zheng Y,Que Z,et al.Astragaloside IV inhibits progression of lung cancer by mediating immune function of Tregs and CTLs by interfering with IDO[J].Journal of Cancer Research & Clinical Oncology,2014,140(11):18831890.
[32]Luo LM,Shi YN,Jiang YN,et al.Advance in components with antitumor effect of Panax ginseng and their mechanisms[J].Chin Tradit Herbal Drugs,2017,48:582596.
[33]He BC,Gao JL,Luo X,et al.Ginsenoside Rg3 inhibits colorectal tumor growth through the downregulation of Wnt/βcatenin signaling[J].Int J Oncol,2011,38(2):437445.
[34]Lee SY,Kim GT,Roh SH,et al.Proteomic analysis of the anticancer effect of 20Sginsenoside Rg3 in human colon cancer cell lines[J].Biosci Biotechnol Biochem,2009,73(4):811816.
[35]Lee SY,Kim GT,Roh SH,et al.Proteome changes related to the anticancer activity of HT29 cells by the treatment of ginsenoside Rd[J].Pharmazie,2009,64(4):242247.
[36]Kim JY,Lee KW,Kim SH,et al.Inhibitory effect of tumor cell proliferation and induction of G2/M cell cycle arrest by panaxytriol[J].Planta Med,2002,68(2):119122.
[37]Wang Y,Zhu HT,Huang WS,et al.Role of panaxynol on inhibiting metastasis of human pancreatic carcinoma cell line SW1990 in vitro[J].Chin J Cancer Prev Treat,2015,22(21):16621666.
[38]Park EH,Kim YJ,Yamabe N,et al.Stereospecific anticancer effects of ginsenoside Rg3 epimers isolated from heatprocessed American ginseng on human gastric cancer cell[J].J Ginseng Res,2014,38(1):2227.
[39]Kim SJ,Kim AK.Antibreast cancer activity of fine black ginseng(Panax ginseng Meyer.)and ginsenoside Rg5[J].J Ginseng Res,2015,39(2):125134.
[40]Zhang Z,Du GJ,Wang CZ,et al.Compound K,a Ginsenoside Metabolite,Inhibits Colon Cancer Growth via Multiple Pathways Including p53p21 Interactions[J].Int J Mol Sci,2013,14(2):29802995.
[41]Wang W,Rayburn ER,Hao M,et al.Experimental therapy of prostate cancer with novel natural product anticancer ginsenosides[J].Prostate,2008,68(8):809819.
[42]Cheng CC,Yang SM,Huang CY,et al.Molecular mechanisms of ginsenoside Rh2mediated G1 growth arrest and apoptosis in human lung adenocarcinoma A549 cells[J].Cancer Chemother Pharmacol,2005,55(6):531540.
[43]Kim JS,bJoo EJ,Chun J,et al.Induction of apoptosis by ginsenoside Rk1 in SKMEL2human melanoma[J].Arch Pharm Res,2012,35(4):717722.
[44]Zuo G,Guan T,Chen D,et al.Total saponins of Panax ginseng induces K562 cell differentiation by promoting internalization of the erythropoietin receptor[J].Am J Chin Med,2009,37(4):747757.
[45]Fujimoto J,Sakaguchi H,Aoki I,et al.Inhibitory effect of ginsenosideRb2 on invasiveness of uterine endometrial cancer cells to the basement membrane[J].European Journal of Gynaecological Oncology,2001,22(5):339341.
[46]Li L,Wang Y,Qi B,et al.Suppression of PMAinduced tumor cell invasion and migration by ginsenoside Rg1 via the inhibition of NFκBdependent MMP9 expression[J].Oncol Rep,2014,32(5):17791786.
[47]Lee SG,Kang YJ,Nam JO.AntiMetastasis Effects of Ginsenoside Rg3 in B16F10 Cells[J].J Microbiol Biotechnol,2015,25(12):19972006.
[48]Guo JQ,Zheng QH,Chen H,et al.Ginsenoside Rg3 inhibition of vasculogenic mimicry in pancreatic cancer through downregulation of VE adherin/EphA2/MMP9/MMP2 expression[J].International Journal of Oncology,2014,45(3):1065.
[49]Jung JS,Ahn JH,Le TK,et al.Protopanaxatriol ginsenoside Rh1 inhibits the expression of matrix metalloproteinases and the in vitro invasion/migration of human astroglioma cells[J].Neurochem Int,2013,63(2):8086.
[50]Kim SY,Kim DH,Han SJ,et al.Repression of matrix metalloproteinase gene expression by ginsenoside Rh2 in human astroglioma cells[J].Biochem Pharmacol,2007,74(11):16421651.
[51]Yoon JH,Choi YJ,Cha SW,et al.Antimetastatic effects of ginsenoside Rd via inactivation of MAPK signaling and induction of focal adhesion formation[J].Phytomedicine,2012,19(3/4):284292.
[52]Kim H,Roh HS,Kim JE,et al.Compound K attenuates stromal cellderived growth factor 1(SDF1)induced migration of C6 glioma cells[J].Nutr Res Pract,2016,10(3):259264.
[53]Huynh DL,Sharma N,Kumar SA,et al.Antitumor activity of wogonin,an extract from Scutellaria baicalensis,through regulating different signaling pathways[J].Chinese Journal of Natural Medicines,2017,15(1):1540.
[54]Chen YC,Shen SC,Lee WR,et al.Wogonin and fisetin induction of apoptosis through activation of caspase 3 cascade and alternative expression of p21 protein in hepatocellular carcinoma cells SKHEP1[J].Archives of Toxicology,2002,76(56):351359.
[55]Wang J,Yu Y,Hashimoto F,et al.Baicalein induces apoptosis through ROSmediated mitochondrial dysfunction pathway in HL60 cells[J].International Journal of Molecular Medicine,2004,14(4):62732.
[56]Chang WH,Chen CH,Lu FJ.Different effects of baicalein,baicalin and wogonin on mitochondrial function,glutathione content and cell cycle progression in human hepatoma cell lines[J].Planta Medica,2002,68(2):128132.
[57]Murashima T,Katayama H,Shojiro K,et al.Possible mechanism of growth inhibition by Scutellaria baicalensis in an estrogenresponsive mouse tumor cell line[J].Oncology Reports,2011,25(5):14311438.
[58]Park KI,Park HS,Kang SR,et al.Korean Scutellaria baicalensis water extract inhibits cell cycle G1/S transition by suppressing cyclin D1 expression and matrixmetalloproteinase2 activity in human lung cancer cells[J].J Ethnopharmacol,2011,133(2):634641.
[59]Huang ST,Wang CY,Yang RC,et al.Wogonin,an active compound in Scutellaria baicalensis,induces apoptosis and reduces telomerase activity in the HL60 leukemia cells[J].Phytomedicine International Journal of Phytotherapy & Phytopharmacology,2010,17(1):4754.
[60]Zhang DY,Wu J,Ye F,et al.Inhibition of cancer cell proliferation and prostaglandin E2 synthesis by Scutellaria baicalensis[J].Cancer Research,2003,63(14):40374043.
[61]Lu Z,Lu N,Li C,et al.Oroxylin A inhibits matrix metalloproteinase2/9 expression and activation by upregulating tissue inhibitor of metalloproteinase2 and suppressing the ERK1/2 signaling pathway[J].Toxicology Letters,2012,209(3):211220.
[62]Honda H,Nagai Y,Matsunaga T,et al.Glycyrrhizin and isoliquiritigenin suppress the LPS sensor tolllike receptor 4/MD2 complex signaling in a different manner[J].J Leukoc Biol,2012,91(6):967976.
[63]Yu J,Lou Y.Influence of αglycyrrhizic Acid on Metabolism of Steroid Hormone in Kidney[J].Chinese Journal of Traditional Medical Science and Technology,2006,13(4):246247.
[64]Nakamura S,Watanabe T,Tanigawa T,et al.Isoliquiritigenin Ameliorates IndomethacinInduced Small Intestinal Damage by Inhibiting NODLike Receptor Family,Pyrin DomainContaining 3 Inflammasome Activation[J].Pharmacology,2018,101(56):236245.
[65]Choi JE,Park DM,Chun E,et al.Control of stressinduced depressive disorders by Soochimtanggamibang,a Korean herbal medicine[J].J Ethnopharmacol,2017,196:141150.
[66]Qiao X,Ji S,Yu SW,et al.Identification of key licorice constituents which interact with cytochrome P450:evaluation by LC/MS/MS cocktail assay and metabolic profiling[J].AAPS Journal,2014,16(1):101113.
[67]He YX,Du M,Shi HL,et al.Astragalosides from Radix Astragali benefits experimental autoimmune encephalomyelitis in C57BL/6 mice at multiple levels[J].BMC Complement Altern Med,2014,14(1):313.
[68]Tang D,He B,Zheng ZG,et al.Inhibitory effects of two major isoflavonoids in Radix Astragali on high glucoseinduced mesangial cells proliferation and AGEsinduced endothelial cells apoptosis[J].Planta Medica,2011,77(7):729732.
[69]Xu A,Wang H,Hoo RL,et al.Selective elevation of adiponectin production by the natural compounds derived from a medicinal herb alleviates insulin resistance and glucose intolerance in obese mice[J].Endocrinology,2009,150(2):625633.
[70]YANG Changchun,WEN Jinkun,HAN Mei.Effect of Astragalus membranaceus and Angelica sinensis on Focal Adhesion Kinase expression and apoptosis of cultured vascular smooth muscle cells[J].Chinese Journal of Integrated Traditional and Western Medicine,2003,23(3):201203.
[71]Fei ZW,Zhang XP,Zhang J,et al.Protective effects of Radix Astragali injection on multiple organs of rats with obstructive jaundice[J].Chinese Journal of Integrative Medicine,2016,22(9):674684.
[72]Yeo CR,Yang C,Wong TY,et al.A quantified ginseng(Panax ginseng C.A.Meyer)extract influences lipid acquisition and increases adiponectin expression in 3T3L1 cells[J].Molecules,2011,16(1):477492.
[73]Nakaya TA,Kita M,Kuriyama H,et al.Panax ginseng induces production of proinflammatory cytokines via tolllike receptor[J].J Interferon Cytokine Res,2004,24(2):93100.
[74]Yoon SJ,Park JY,Choi S,et al.Ginsenoside Rg3 regulates Snitrosylation of the NLRP3 inflammasome via suppression of iNOS[J].Biochem Biophys Res Commun,2015,463(4):11841189.
[75]Yanbin L,Yu L,Guangshu Y,et al.2.Chin J Tradit Med Traumatol Orthop,2017,25(5):58.
[76]Lu ZF,Shen YX,Zhang P,et al.Ginsenoside Rg1 promotes proliferation and neurotrophin expression of olfactory ensheathing cells[J].Journal of Asian Natural Products Research,2010,12(4):265272.
[77]Wang Y,Cao HJ,Sun SJ,et al.Total flavonoid aglycones extract in Radix Scutellariae,inhibites lung carcinoma and lung metastasis by affecting cell cycle and DNA synthesis[J].Journal of Ethnopharmacology,2016,194:269279.
[78]Choi BB,Choi JH,Park SR,et al.Scutellariae radix induces apoptosis in chemoresistant SCC25 human tongue squamous carcinoma cells[J].American Journal of Chinese Medicine,2015,43(1):16781.
[79]Cheng P,Wang T,Li W,et al.Baicalin Alleviates LipopolysaccharideInduced Liver Inflammation in Chicken by Suppressing TLR4Mediated NFκB Pathway[J].Frontiers in Pharmacology,2017,8:547.
[80]Liu X,Liu C.Baicalin ameliorates chronic unpredictable mild stressinduced depressive behavior:Involving the inhibition of NLRP3 inflammasome activation in rat prefrontal cortex[J].International Immunopharmacology,2017,48:3034.
[81]LiPing Z,Jin G,ChangFa H,et al.Inhibitory effect of 8 Chinese herbal decoctions on expression of CerbB1 in psorlatic keratinocytes[J].Chin J Integr Tradit West Med,2003(S1):195197.
[82]Zhang Q,Sun LJ,Yang ZG,et al.Influence of adipocytokines in periprostatic adipose tissue on prostate cancer aggressiveness[J].Cytokine,2016,85:148156.
[83]Liang X,Li H,Li S.A novel network pharmacology approach to analyse traditional herbal formulae:the LiuWeiDiHuang pill as a case study[J].Molecular Biosystems,2014,10(5):10141022.
[84]Qi Q,Li R,Li HY,et al.Identification of the antitumor activity and mechanisms of nuciferine through a network pharmacology approach[J].Acta Pharmacol Sin,2016,37(7):963972.
(2017-11-29收稿責任编辑:王明)