基因编辑展示更大治疗潜力
昨日公布的两项研究进展意味着，给生物技术领域带来巨变的基因编辑工具Crispr在治疗遗传性疾病方面展示出了更大的潜力。
The advances were published by two teams of scientists from Massachusetts Institute of Technology and Harvard University, working together at the Broad Institute, their joint facility.
这些进展是由来自麻省理工学院(MIT)和哈佛大学(Harvard University)的两个科学家团队发表的，他们在双方的联合设施布罗德研究所(Broad Institute)一起工作。
One of the groups has adapted Crispr to make it easier to change individual chemical “letters” of DNA in genetic code, rather than inserting or deleting whole genes. Their tool, described in the journal Nature, is known as base editing and can be likened to using a sharp pencil rather than scissors on the genome.
其中一个小组改良了Crispr，以便更容易改变遗传代码中DNA的个别化学“字母”，而不是插入或删除整个基因。根据《自然》(Nature)期刊上所载论文，他们的工具被称为“碱基编辑”(base editing)，可以比作为对基因组使用“削尖的铅笔”，而不是“剪刀”。
The other team, publishing in Science, has made it possible to edit not only DNA, the chemical that stores the genome in all living creatures, but RNA, which converts genetic information into proteins — the workhorse molecules of biology. This is described as like correcting a book with temporary ink that disappears, rather than making an indelible mark.
在《科学》(Science)期刊上发表论文的另一个团队取得的进展是，不仅可以编辑DNA(脱氧核糖核酸，将基因组存储在所有生物中的化学物质)，而且可以编辑RNA(核糖核酸，将遗传信息转化为蛋白质——埋头苦干的生物学分子)。这被形容为用一种会褪色的临时墨水来更改一本书，而不是留下擦不掉的痕迹。
“This is an exciting week for genetic research,” said Helen O’Neill, director of reproductive science and women’s health at University College London, yesterday. “These papers highlight the fast pace of the field and the continuous improvements being made in genome editing, bringing it closer and closer to the clinic.”
“对遗传学研究来说，这是令人振奋的一周，”伦敦大学学院(University College London)生殖科学和妇女保健主任海伦•奥尼尔(Helen O'Neill)昨日表示。“这些论文突显了该领域的快速发展和基因组编辑方面的不断改进，使其越来越接近临床应用。”
“I hope these complementary technologies will together enable a broad suite of research and therapeutic applications,” said David Liu, professor of chemical biology at Harvard, who led the DNA base-editing team.
“我希望这些互补的技术能够结合起来，带来一整套研究和治疗应用，”带领DNA碱基编辑团队的哈佛大学化学生物学教授David Liu表示。
“For some situations where transient editing is desirable, such as acute inflammation, RNA editing may be ideal,” Prof Liu said. “For other applications, such as genetic disease, you’d want to make a one-time change in the genome through DNA base editing.”
“对于需要临时编辑的某些情况，如急性炎症，RNA编辑可能是最理想的，”David Liu表示。“对于其他应用，如遗传疾病，您就需要通过DNA碱基编辑，对基因组作出一次性改变。”
Base editing changes the genome by a single DNA “base” or letter in the four-letter genetic code. Last year Prof Liu’s team published a simple method for converting the letter C to T, and scientists are working to apply the technique in the laboratory.
碱基编辑通过改动单个DNA“碱基”(四字母遗传密码中的字母)来改变基因组。去年David Liu的团队发表了一种将字母C转换为T的简单方法，科学家们正致力于将这种方法应用于实验室。
Last month a Chinese team used it to correct a form of the blood disorder thalassaemia in human embryos.
上月，一个中国团队利用这种方法纠正人胚胎中的地中海贫血(一种血液疾病)。
Now the scientists have discovered how to change A to G, which will greatly extend the range of genetic disorders that could potentially be treated by base editing. These single-letter or point mutations are responsible for thousands of diseases.
现在科学家们发现了如何将A改为G，这将大大延伸有望通过碱基编辑治疗的遗传疾病的范围。这类单字母(点)突变导致数千种疾病。
The Broad Institute team is particularly interested in applying the technology to genetic deafness and blindness and inherited blood diseases.
布罗德研究所团队特别感兴趣的是将该技术应用于遗传性耳聋、失明和遗传性血液病。
The advance in RNA editing comes from a team led by Feng Zhang, who played a key role in the development of Crispr technology. It converts the letter A to G in RNA, the biochemical intermediary between genes and proteins.
RNA编辑的进展来自张锋(Feng Zhang)带领的团队;他曾在Crispr技术的发展中扮演关键角色。新的方法能够将RNA(基因和蛋白质之间的生物化学中介体)中的字母A转换为G。
The researchers say RNA editing offers a safer and more flexible way to make corrections than the permanent changes involved in DNA editing. “It can fix mutations without tampering with the genome, and because RNA naturally degrades, it is a potentially reversible fix,” said David Cox, part of the Broad Institute team.
研究者们表示，就作出修正而言，RNA编辑提供了比DNA编辑所涉及的永久变化更安全、更灵活的方法。“它可以修复突变而不会干扰基因组，而且因为RNA可自然降解，这是一种潜在可逆的修复，”布罗德研究所团队成员戴维•考克斯(David Cox)表示。
While experiments with RNA and DNA base editing are under way in animals and human cell cultures, the scientists say clinical trials on patients are not expected to begin in the near future.
虽然目前已在动物和人类细胞培养物中进行RNA和DNA碱基编辑实验，但科学家们预计，不会在不久的将来进行患者临床试验。
