【作者】 罗浩铭；

【导师】 杨晓虹；

【作者基本信息】 吉林大学 ， 生物化学与分子生物学， 2014， 博士

【摘要】 癌症的致死率已排名第二，据世界卫生组织统计，2000年，全球新患癌症人数为1010万，死亡数620万，到2008年，数字分别上升至1266万和756万，而到2015年，估计将有1500万人新患癌症。对于癌症预防与治疗的研究迫在眉睫，近些年来，科学家们逐渐揭示了癌症的发病机制。目前，通过诱导癌细胞凋亡来达到治疗癌症的目的是抗癌药物研发的热点之一。细胞凋亡(Apoptosis)是由基因编码调控的细胞主动死亡的过程，与癌症的发生发展有着密切的联系。Caspase-3在细胞凋亡中担任凋亡执行因子，通常情况下，caspase-3以低活性酶原Procaspase-3的形式存在，只有当Procaspase-3被活化后才能发挥功能，Procaspase-3在大部分癌细胞中的表达水平高于正常细胞，所以，Procaspase-3的激动剂成为抗肿瘤的药物研究的靶点之一。PAC-1（procaspase-3activating compound-1）是第一个被发现的可以直接作用于Procaspase-3的小分子化合物。有研究表明，其抗肿瘤细胞U937的IC50值可以达到0.92μM。同时，PAC-1对其它多种肿瘤细胞均有显著的抑制活性，有望成为低毒高效的抗肿瘤药物。本论文的工作是基于PAC-1的结构进行分析、设计并合成新化合物，以期发现在活性、选择性上优于PAC-1的化合物。课题中共合成了三类、34个全新目标化合物，结构均通过1H-NMR、MS确证结构。实验中对目标化合物测定了HL-60、K562和HCT-8三种肿瘤细胞的体外抑制活性以及对正常细胞HLF的抑制活性。结果表明本文所设计的PAC-1类似物大多显示出了明显的抗肿瘤细胞的活性。其中化合物LHM-8-3和LHM-8-7都显示了较好的抑制HL-60肿瘤细胞的活性，IC50值分别达到0.15μM和0.09μM。本文基于生物学评价的结果，对化合物结构与抗肿瘤细胞活性的关系进行了初步讨论，总结了多种取代基团和取代位置对其活性的影响，根据药理活性结果，我们发现哌嗪环并非是不可或缺的基团，与肼基连接的芳香环上的羟基只有在2位的时候才会表现出较好的药理活性。以苄基形式与直链胺连接的芳环上，对位连接甲氧基化合物的药理活性要明显好于间位连接甲氧基的化合物；而在对位连接异丙基的化合物比连接叔丁基的化合物的药理活性优秀，说明此位点与受体对接的空间较小，对取代基的大小有一定的选择性，连接异丙基的化合物活性最好。以上初步的构效关系讨论对进一步开展此项研究工作具有指导作用。低氧诱导因子-1（Hypoxia inducible factor-1，HIF-1）是一种具有转录活性的核蛋白，广泛存在与哺乳动物细胞内，通过调控靶基因对血管生成，细胞存活，pH起调节作用，在诸如贫血，肿瘤生成和肾病等疾病中发挥重要的作用。有研究表明，脯氨酸羟化酶是HIF-1降解的限速酶，小分子脯氨酸羟化酶抑制剂可以通过抑制PHD的活性达到稳定HIF-1的作用，从而上调其下游靶基因促红细胞生成素（erythropoietin,EPO）的水平，达到治疗贫血的效果。目前，可口服的小分子脯氨酸羟化酶抑制剂作为抗贫血药物是药物研发的热点之一。本文还对目标化合物抑制脯氨酸羟化酶的活性能力进行了研究，发现目标化合物均表现出了较好的活性。为了探索目标化合物抑制脯氨酸羟化酶的作用机制，我们测定了它们对铁离子的螯合能力，发现在其浓度明显对HIF-1α起稳定作用的时候，该浓度下，目标化合物的铁离子螯合能力很小，所以我们推测这一系列化合物可能起到2-酮戊二酸类似物的作用，与脯氨酸羟化酶结合阻止HIF-1α羟化反应的发生，从而达到稳定HIF-1α的作用。我们根据活性数据结果，初步分析了此类化合物的构效关系，为设计和改良小分子脯氨酸羟化酶抑制剂指示了方向、提供了理论依据。更多还原

【Abstract】 Cancer mortality ranks second in all the diseases. According to statistics byWHO, there were10.1million new cancer cases,6.2million cancer deaths in2000and the numbers increased to12.66million and7.56million respectively in2008.Even it is estimated to be15million new cancer cases in2015. Therefore it is urgentto research and develop of prevention and treatment for cancer. Recently scientistshave made headway with the pathogenesis of cancer. Till now Apoptosis induction isone of the hotspot of developing anti-tumor drugs.Apoptosis is the process of programmed cell death (PCD) that relates to initiationand development of cancer. The Caspase-3plays a central role in the execution-phaseof cell apoptosis. Caspase-3exists as inactive proenzymes Procaspase-3that onlyworks after activation. The expressions of Procaspase-3in most of tumor cells arehigher than normal cells so that Procaspase-3agonist has become a promising targetof anti-tumor therapy. PAC-1（procaspase-3activating compound-1）is the firstdeveloped small molecular compound working on Procaspase-3directly. Its IC50foranti-tumor cell U937was reported to reach as high as0.92μM. Meanwhile it showedconsiderable inhibitive activity to other many tumor cells so that it is a promisinganti-tumor drug with high efficiency but low toxicity.This thesis tried to analyze structure of PAC-1to design and synthesis newcompounds which own higher activity and selectivity than PAC-1. Three types of34totally new compounds were synthesized and their structures were confirmed by1H-NMR and MS.The in vitro inhibitive activity of target compounds to tumor cells of HL-60,K562and HCT-8and normal cell of HLF was determined. Results showed significantanti-tumor activity from most of designed PAC-1analogues. Especially LHM-8-3andLHM-8-7demonstrated great inhibitive activity on HL-60, which their IC50reachedto0.15μM and0.09μM respectively.On the basis of the biological result, the structure-activity relationship wasdiscussed and the effect of substituent group and positions on activity wassummarized. The piperazine ring is not the indispensable group according to the pharmacological activity tests. Good pharmacological activity only existed whenhydroxyl group of aromatic ring connecting to diazanyl group was in position2.Compounds with methoxy group in para-position of aromatic ring in form of benzylgroup connecting with straight-chain amine showed much higher activity thancompounds with methoxy group in meta-position. The same trend was found incompounds with isopropyl group against methoxy group in para-position. The resultsabove illustrated that the space of the position connecting to receptor was so smallthat had selectivity on size of substituent group. The structure-activity relationshipdiscussed above has the role of direction for further research.Hypoxia inducible factor-1(HIF-1) is a nucleoprotein with transcriptionalactivities widely existing in mammalian cells. HIF-1affects angiogenesis, cellsurvival and pH by target gene regulation. They play crucial roles in diseases likeanemia, cancer and nephrosis. It was reported that proline hydroxylase (PHD) is therate-limiting enzyme of HIF-1degradation. Small molecular PHD inhibitors stabilizeHIF-1by inhibiting the PHD activity to up regulate its target gene erythropoietin(EPO) for treatment of anemia. Currently, oral dosage forms of small molecular PHDinhibitors have been the hotspot of developing anti-anemia drugs.In this research, target compounds were investigated to have good PHD inhibitionactivity. In order to explore their inhibition mechanism, iron ion chelated ability oftarget compounds were measured. It was found that concentration of targetcompounds could stabilize HIF-1α and in this concentration iron ion chelated abilityof target compounds was quite small. The phenomenon above revealed that thesecompounds played the same role as2-ketoglutaric acid analogues which combinedwith PHD to block the hydroxylation reaction of HIF-1α for stabilization. Thestructure-activity relationship was preliminarily discussed based on the biologicalresults. It provides the theory basis for design and modification of small molecularPHD inhibitors.更多还原