新型CD20核酸适配体的筛选及鉴定  

Selection and identification of a novel DNA aptamer against CD20 molecule

作　　者：张李钰 胡燕[1] 曹蓓蓓[1] 段金虹[1] 刘喆[2] 杨先达[1] 

机构地区：[1]中国医学科学院基础医学研究所病理生理系,北京100005 [2]北京协和医学院北京协和医院临床遗传学实验室,北京100005

出　　处：《基础医学与临床》2014年第5期628-632,共5页Basic and Clinical Medicine

基　　金：科技部重大科学计划(2011CB933504)

摘　　要：目的研发能特异性识别CD20分子的DNA适配体,使其作为肿瘤靶向分子为非霍奇金淋巴瘤的新型靶向治疗提供依据。方法体外合成含有21个随机寡核苷酸、全长为59个碱基的DNA文库,以CD20胞外表位肽为靶标,利用指数富集的配体系统进化技术(SELEX),从文库中筛选CD20适配体;利用流式细胞术评估适配体的富集程度、适配体与CD20多肽,适配体与CD20阳性细胞的结合特性;用MFold软件预测适配体预计结构。结果经多轮筛选获得了能识别CD20结构的全新DNA适配体CE4-1;它能特异性地识别CD20阳性淋巴瘤细胞,与白蛋白及CD20阴性细胞的结合较弱,与经胰蛋白酶处理的CD20阳性细胞的结合也减弱。结论该新型适配体能选择性识别CD20结构及CD20阳性细胞,在CD20阳性淋巴瘤的靶向诊疗方面具有应用潜能。Objective To develop a CD20 aptamer that may potentially serve as a tumor-homing ligand for targeted therapy against non-Hodgkin＇s lymphoma （NHL）.Methods A single-stranded 59nt DNA library containing 21 nt random oligonucleotides was synthesized.A new CD20 aptamer termed CE4-1 was developed with SELEX technique,using a CD20 epitope as the target.Flow cytometry was performed to monitor the enrichment of the selected DNA pool,and the binding properties of CE4-1 towards CD20 structure and CD20-positive cells.The structure of CE4-1 was predicted by MFold software.Results The DNA aptamer CE4-1 could selectively bind with CD20 structure and CD20-positive cells,with minimal cross reactivity to BSA and CD20-negative cells.Additionally,trypsin treatment greatly reduced the binding of CE4-1 to CD20-positive cells.Conclusions A novel CD20 aptamer CE4-1 may recognize CD20 structure and CD20-positive cells selectively,which may have application potentials in targeted therapy against the CD20-positive tumors.

关 键 词：适配体 SELEX CD20 

分 类 号：R733.1[医药卫生—肿瘤]