从精准医学谈药物设计的微观结构

On the molecular drug design from viewpoint of precision medicine

精准医学应用"组学"和系统生物学在分子水平上分析患者的病因,并以靶向治疗手段对患者做个体化处治。精准医学与药物密切相关。药物作为治疗手段和物质供给侧,在精准医学中主要体现两个方面:针对特定的靶标或机制进行新药研发;针对疾病的分子特征对患者做个体化治疗的临床应用。基于特定靶标研发新分子实体是实施精准医疗的前提与保障;而精准医疗的效果和发现的线索又反馈于新药深化研究,二者相互依存和促进。在精准医学的框架下,新药研究所涵盖的大都是熟知内容:靶标的发现与确证;靶标与适应证的关联(概念验证);先导物的发现与优化;临床前研究的药效、药代和不良反应与临床试验的关联;药品设计、产业化和药物经济学的精益化等。从分子水平的视角看,药物的疗效源于药物分子的特定原子或基团与生物大分子的互补性和在三维空间的相互结合,这些原子基团或片段的严格排布映射了与效应靶标的精确结合。靶标蛋白即使发生微小的残基改变,也会导致大分子的构象变化,这时药物的分子结构必须做精细的微调以适配变化了的结构(构象)要求以避免脱靶作用。为了进行个体化治疗,需要根据患者生物标示物的分子特征选择有针对性的药物,因而需要研制多种新分子实体。本文列举一些实例试图解析在精准医学时代药物分子设计的某些趋势。

Precision medicine （PM） involves the application of ＂omics＂ analysis and system biology to analyze the cause of disease at the molecular level for targeted treatments of individual patient. Based on the targeted treatment PM is closely related to pharmaceuticals, which, as a therapeutic means and supply front, mainly embody the two aspects： drug discovery/development, and clinical administration. Innovation of new molecular entities with safety and specific efficacy is the prerequisite and guarantee for the PM practice; on the other hand, the outcome and clues in clinical PM feedback to new drug research. PM and drug research/ application are interdependent and promote each other. Aimed at precision medicine, drug discovery and development involve well-known contents： the discovery and validation of targets, the association between target functions and indications （proof of concept）, lead discovery and optimization, the association between preclinical investigations and clinical trials, the lean of industrialization and pharmacoeconomics. At the molecular level the therapeutic efficacy originates from the interactive binding between specific atoms or groups of the drug molecule and the complementary atoms or groups of the macromolecular target in three-dimensional space. The strict arrangement of such critical atoms, groups, or fragments reflect specific features for a precise binding to the corresponding target. An alteration of amino acid residues in mutational targets leads to the change in conformation of the target protein, and an accurate structure of drug is necessary for binding to the mutant species and avoiding off-targeting effect. For the tailoring of clinical treatment to the individual patient design and development of various new molecular entities are critical for treatment choice according to the molecular features of biological markers of patients. This article provides some examples and methods of drug design and development in the new period.