基因修复β-地中海贫血患者诱导多能干细胞可否成为治疗的希望?

Gene therapy with induced pluripotent stem cells: a hope for beta thalassemia?

背景:对于重型β-地中海贫血,目前惟一的根治方法就是造血干细胞移植,但由于合适供者来源受限及费用昂贵,大部分患者难以得到救治。体细胞重编程技术如今已日臻成熟,在患者诱导多能干细胞中进行基因修复成为了β-地中海贫血治疗的希望。目的:通过论述ZFNs、TALENs、CRISPR/Cas 3种基因编辑技术体现CRISPR/Cas的优势,以及论述基因编辑技术在动物模型疾病治疗中的初步实验结果,从而展望基因编辑技术对β-地中海贫血进行基因治疗并且应用于临床的可能性。方法:以"beta thalassemia,genetic therapy,genome editing,homologous recombination,iPSCs"为英文检索词,以"β-地中海贫血,诱导多能干细胞"为中文检索词,由第一作者检索1989至2015年Pub Med数据库、中国期刊全文数据库,查阅近年β-地中海贫血的发生率和分布情况以及β-地中海贫血基因治疗的相关文献,最终保留67篇文献。结果与结论:随着基因编辑技术的发展,出现了3种定向基因编辑技术,包括ZFNs、TALENs、CRISPR/Cas技术。以地中海贫血患者来源的诱导多能干细胞为靶细胞,通过ZFNs、TALENs及CRISPR/Cas9技术对疾病基因进行纠正,完成对致病基因的治疗。CRISPR/Cas系统相对于其他基因编辑技术更加简单快捷、安全高效,应用也更加广泛,利用CRISPR/Cas9系统修复β-地中海贫血患者诱导多能干细胞、生殖细胞、受精卵、胚胎中β珠蛋白基因,将为今后临床的应用奠定基础。

BACKGROUND： Beta thalassaemia is a monogenic disease, which lacks effective clinical treatments. Hematopoietic stem cell transplantation currently is the only radical treatment for beta thalassaemia, but the limits of suitable donor and costs minimize its clinical application.Given the technology of reprogramming using somatic cells is well established,gene therapy using induced pluripotent stem cells has become the new direction of beta thalassaemia treatment.OBJECTIVE：To put forward the advantages of CRISPR/Cas9 technology in gene therapy of beta thalassaemia in the future by summarizing the mechanisms of three kinds of gene editing technologies and the preliminary experimental results in animal models.METHODS：In order to search relevant articles about beta thalassaemia,the first author retrieved Pub Med database and CNKI（from 1989 to 2015）using the key words of＂beta thalassemia,genetic therapy,genome editing,homologous recombination,i PSCs＂in English and Chinese,respectively.After eliminating literatures which were irrelevant to research purpose or containing a similar content,67 articles were chosen for further analysis.RESULTS AND CONCLUSION：Gene editing technology has made considerable progress and three kinds of directed gene editing technologies have been developed,including ZFNs,TALENs,CRISPR/Cas technology.By targeting induced pluripotent stem cells from thalassemi patients,these three kinds of gene editing technologies have been expected to correct pathogenic genes of thalassemia.The CRISPR/Cas system is more simple,rapid,safe and efficient than the others.The CRISPR/Cas9 system is expected to repairβ-globin genes in the induced pluripotent stem cells,germ cells,fertilized eggs and embryos from beta thalassaemia patients,laying the foundation for future clinical application.