基因編輯展示更大治療潛力

Crispr, the gene-editing tool transforming biotechnology, is showing even greater promise for treating genetic disease thanks to two developments unveiled yesterday.

昨日公布的兩項研究進展意味著，給生物技術領域帶來巨變的基因編輯工具Crispr在治療遺傳性疾病方面展示出了更大的潛力。

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.

這些進展是由來自麻省理工學院(MIT)和哈佛大學(Harvard University)的兩個科學家團隊發(fā)表的，他們在雙方的聯(lián)合設施布羅德研究所(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.

其中一個小組改良了Crispr，以便更容易改變遺傳代碼中DNA的個別化學“字母”，而不是插入或刪除整個基因。根據(jù)《自然》(Nature)期刊上所載論文，他們的工具被稱為“堿基編輯”(base editing)，可以比作為對基因組使用“削尖的鉛筆”，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《科學》(Science)期刊上發(fā)表論文的另一個團隊取得的進展是，不僅可以編輯DNA(脫氧核糖核酸，將基因組存儲在所有生物中的化學物質)，而且可以編輯RNA(核糖核酸，將遺傳信息轉化為蛋白質——埋頭苦干的生物學分子)。這被形容為用一種會褪色的臨時墨水來更改一本書，而不是留下擦不掉的痕跡。

“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.”

“對遺傳學研究來說，這是令人振奮的一周，”倫敦大學學院(University College London)生殖科學和婦女保健主任海倫•奧尼爾(Helen O'Neill)昨日表示。“這些論文突顯了該領域的快速發(fā)展和基因組編輯方面的不斷改進，使其越來越接近臨床應用。”

“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.

“我希望這些互補的技術能夠結合起來，帶來一整套研究和治療應用，”帶領DNA堿基編輯團隊的哈佛大學化學生物學教授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.”

“對于需要臨時編輯的某些情況，如急性炎癥，RNA編輯可能是最理想的，”David Liu表示。“對于其他應用，如遺傳疾病，您就需要通過DNA堿基編輯，對基因組作出一次性改變。”

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.

堿基編輯通過改動單個DNA“堿基”(四字母遺傳密碼中的字母)來改變基因組。去年David Liu的團隊發(fā)表了一種將字母C轉換為T的簡單方法，科學家們正致力于將這種方法應用于實驗室。

Last month a Chinese team used it to correct a form of the blood disorder thalassaemia in human embryos.

上月，一個中國團隊利用這種方法糾正人胚胎中的地中海貧血(一種血液疾病)。

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.

現(xiàn)在科學家們發(fā)現(xiàn)了如何將A改為G，這將大大延伸有望通過堿基編輯治療的遺傳疾病的范圍。這類單字母(點)突變導致數(shù)千種疾病。

The Broad Institute team is particularly interested in applying the technology to genetic deafness and blindness and inherited blood diseases.

布羅德研究所團隊特別感興趣的是將該技術應用于遺傳性耳聾、失明和遺傳性血液病。

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編輯的進展來自張鋒(Feng Zhang)帶領的團隊;他曾在Crispr技術的發(fā)展中扮演關鍵角色。新的方法能夠將RNA(基因和蛋白質之間的生物化學中介體)中的字母A轉換為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.

研究者們表示，就作出修正而言，RNA編輯提供了比DNA編輯所涉及的永久變化更安全、更靈活的方法。“它可以修復突變而不會干擾基因組，而且因為RNA可自然降解，這是一種潛在可逆的修復，”布羅德研究所團隊成員戴維•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.

雖然目前已在動物和人類細胞培養(yǎng)物中進行RNA和DNA堿基編輯實驗，但科學家們預計，不會在不久的將來進行患者臨床試驗。