美国首次对人类胚胎进行基因编辑

The MIT Technology Review published on Wednesday a news report about the first-known experiment to create genetically modified human embryos in the United States using a gene-editing tool called CRISPR.

Shoukhrat Mitalipov, director of the Oregon Health & Science University's Center for Embryonic Cell and Gene Therapy, reportedly led the new research. Mitalipov and the university would not confirm details of the research to CNN.

"Results of the peer-reviewed study are expected to be published soon in a scientific journal. No further information will be provided before then," according to an emailed statement from the university's press office. Another researcher cited in the MIT report, the Salk Institute's Jun Wu, did not reply to CNN's request for comment.

Previously, Mitalipov and his colleagues reported the first success in cloning human stem cells in 2013, successfully reprogramming human skin cells back to their embryonic state. In 2007, a research team led by Mitalipov announced they created the first cloned monkey embryo and extracted stem cells from it.

The MIT Technology Review reported that the researchers in Portland, Oregon, edited the DNA of a large number of one-cell embryos, specifically targeting genes associated with inherited diseases in those embryos. The MIT Technology Review could not determine which disease genes had been chosen for editing in the new research.

Previously, scientists in China were the first in the world to reveal attempts to modify genes in human embryos using CRISPR. Three separate papers were published in scientific journals describing various studies in China on gene editing in human embryos.

Yet the research has already generated attention and controversy.

"This is pushing the research faster than I thought we would see," said Dana Carroll, professor of biochemistry at the University of Utah, "if the MIT Technology Review report rings true." Carroll has used CRISPR in his own studies, but was not involved in the new research.

The controversy surrounding gene-editing in human embryos partly stems from concern that the changes CRISPR makes in DNA can be passed down to the offspring of those embryos later in life, from generation to generation. Down the line, that could possibly impact the genetic makeup of humans in erratic ways.

"There is also considerable concern about off-target effects, such as making mutations at sites in the genome other than the intended target," said Carroll. In other words, an edit made in one area of DNA possibly could cause problems in another, as a ripple or domino effect, which could be concerning.

Some CRISPR critics also have argued that gene-editing may give way to eugenics and to allowing embryos to be edited with certain features in order to develop so-called designer babies.

Though, not all experts are too concerned.

The enthusiasm surrounding gene-editing in human embryos partly stems from the promise CRISPR has shown in editing away and treating devastating intractable diseases. Earlier this year, the National Academies of Sciences, Engineering, and Medicine published a report on human genome editing, addressing potential applications of gene editing, including the possible prevention or treatment of disease.

《麻省理工技术评论》杂志16日报道，美国使用基因编辑工具CRISPR进行了本国首例转基因人类胚胎实验。

据报道，俄勒冈卫生科学大学胚胎干细胞与基因治疗中心主任舒赫拉特?米塔利波夫是这项新研究的领头人。舒赫拉特及校方不愿向CNN透露研究的细节。

该大学新闻办公室的邮件声明称：“同行评审的结果将在近日发表在一家科学杂志上。在此之前无法透露更多信息。”《麻省理工技术评论》中提到的另一位研究员，索尔克研究所的吴军（音译）也没有回复CNN的置评请求。

据报道，舒赫拉特及其同事在2013年首次成功克隆人类干细胞，重新编码人类皮肤细胞，使其恢复到胚胎状态。2007年，舒赫拉特领导的研究小组宣布他们创造了首个克隆猴胚胎并从中提取了干细胞。

《麻省理工技术评论》报道称，俄勒冈州波特兰市的研究人员专门以遗传疾病相关基因为靶基因，对大量单细胞胚胎进行DNA编辑。该杂志不能确定这项新的研究选择哪些致病基因进行编辑。

此前，中国科学家在全球首次公开了使用基因编辑技术修改人类胚胎基因的尝试，在科学杂志上发表了三篇不同的论文，介绍中国在人类胚胎基因编辑方面的各项研究。

但是，美国的研究仍然引发了关注与争议。

犹他大学生物化学系教授德纳?卡罗尔说：“如果《麻省理工技术评论》的报道是真的，那么这项研究的速度已经超出了我的预期。”卡罗尔曾在自己的研究中使用基因编辑技术，但并没有参与这项新研究。

围绕着人类胚胎基因编辑存在争论，部分原因是因为担心基因编辑技术对DNA的改变日后会一代接一代传给那些胚胎的后代。这样一来，可能会对人类基因组成产生不稳定的影响。

卡罗尔说：“对于脱靶效应的担忧也很多，比如导致目标基因组以外的基因发生突变。”换句话说，对DNA的一个区域进行编辑可能在另一区域引发问题，就像是连锁反应或多米诺骨牌效应，这点也值得担忧。

一些基因编辑技术批评者还认为，基因编辑可能会给优生创造条件，致使人们为了孕育出所谓的“定制婴儿”而编辑胚胎的某种特征。

不过，并非所有专家都忧心忡忡。

科学家们热衷于人类胚胎基因编辑研究，部分原因是基因编辑技术已经展现出消除和治疗致命性疑难杂症的前景。今年早些时候，美国国家科学院、工程院和医学院发表了一份关于人类基因组编辑的报告，讨论了基因编辑的潜在应用，比如预防或治疗疾病的可能。