c**i
发帖数: 265 | 1 http://www.nature.com/news/replications-ridicule-and-a-recluse-the-controversy-over-ngago-gene-editing-intensifies-1.20387
Replications, ridicule and a recluse: the controversy over NgAgo gene-
editing intensifies
As failures to replicate results using the CRISPR alternative stack up, a
quiet scientist stands by his claims.
David Cyranoski
08 August 2016
SHIJIAZHUANG, CHINA
A controversy is escalating over whether a gene-editing technique proposed
as an alternative to the popular CRISPR–Cas9 system actually works.
Three months ago, Han Chunyu, a biologist at Hebei University of Science and
Technology in Shijiazhuang, reported that the enzyme NgAgo can be used to
edit mammalian genes. Now, an increasing number of scientists are
complaining that they cannot replicate Han’s results — although one has
told Nature that he can.
Han says he receives dozens of harassing calls and texts each day, mocking
him and telling him that his career is over — but he is convinced that the
technique is sound. He also told Nature that he had submitted a detailed
protocol to the online genetic-information repository Addgene on 8 August,
at Addgene’s request, and hopes that this will help efforts to reproduce
his work. Nature Biotechnology, which published the research, is
investigating the matter.
The stakes are high. Over the past few years, the CRISPR–Cas9 system has
transformed biology. But it has also made scientists hungry for other
methods to expand the gene-editing toolkit: NgAgo is one of several that
have emerged. “A lot of us are really cheerleading and hoping that it works
,” says geneticist George Church of Harvard Medical School in Boston,
Massachusetts.
CRISPR–Cas9 uses small genetic sequences to guide an enzyme to cut DNA in a
particular location. Inspired, Han looked through the literature for other
guidable protein ‘scissors’, and came across a family of proteins called
Argonaute, or Ago, that fitted the bill. Others had flagged the proteins as
potential gene editors.
Former biochemist Fang Shimin alleged on his website that the NgAgo paper
was irreproducible.
In the paper, Han’s team reports using a wide variety of genetic sequences
to guide one of these proteins, NgAgo, to edit eight different genes in
human cells and to insert genes at specific points on chromosomes (F. Gao et
al. Nature Biotechnol. 34, 768–773; 2016).
Crucially, NgAgo very specifically cut only the target genes, says Han,
unlike CRISPR–Cas9, which sometimes edits the wrong genes. And whereas
CRISPR–Cas9 requires a certain genetic sequence to be near the cutting site
to initiate its activity, NgAgo does not, which could broaden its potential
applications, adds Han.
The initial reaction to the work in China was laudatory, including a visit
to the lab by China Central Television. It was overwhelming, says Han, who
is a reclusive figure. His hobbies include collecting teas and playing an
ancient stringed instrument called the guqin. He doesn’t like to travel and
has never left China: a trip to visit a collaborator in Hangzhou in March
was the first time the 42 year old had boarded a plane. Before his paper
came out, “I was completely unknown”, says Han, who spoke to Nature at his
laboratory and a nearby restaurant.
Doubts about the research first surfaced at the beginning of July, when Fang
Shimin, a former biochemist who has become famous for exposing fraudulent
scientists, wrote on his website New Threads (xys.org) that he had heard
reports of failed reproduction efforts, and alleged that Han’s paper was
irreproducible. Criticism grew on various Chinese sites.
Geneticist Gaetan Burgio published failed attempts to replicate the NgAgo
experiments on his blog.
On 29 July, the controversy went inter-national when Gaetan Burgio, a
geneticist at the Australian National University in Canberra, posted
thorough details of his failed attempts to replicate the experiment on his
blog. Normally, his posts get a few dozen hits, but this one spiked to more
than 5,000.
On the same day, geneticist Lluís Montoliu, at the Spanish National Centre
for Biotechnology in Madrid, e-mailed his colleagues at the International
Society for Transgenic Technologies to recommend “abandoning any project
involving the use of NgAgo” to “avoid wasting time, money, animals and
people”. The e-mail was leaked and posted on Fang’s website.
Since then, an online survey by Pooran Dewari, a molecular biologist at the
MRC Centre for Regenerative Medicine in Edinburgh, UK, has found only 9
researchers who say that NgAgo works — and 97 who say that it doesn’t.
Two researchers who initially reported success with NgAgo in an online chat
group now say that they were mistaken. Debojyoti Chakraborty, a molecular
biologist at the CSIR-Institute of Genomics and Integrative Biology in New
Delhi, says that he repeated a specific section of Han’s paper that
described using NgAgo to knock out a gene for a fluorescent protein that had
been introduced into a cell. The glow was reduced, so Chakraborty assumed
that NgAgo had disabled the gene. But after sequencing the DNA, he found no
evidence of gene editing. He now says that the reduction in fluorescence
must have had some other cause.
Jan Winter, a PhD student in genomics at the German Cancer Research Center
in Heidelberg, says that he had a similar experience. “I will retry the
experiment in the upcoming weeks, but so far I think it won’t work,” he
says.
Geneticist Lluís Montoliu recommends abandoning any project involving the
use of NgAgo for gene-editing.
Han says that he has only got the system to work on cells cultured in his
laboratory, and it failed in cells that he purchased. He later found the
purchased cells to be contaminated with bacteria called mycoplasma, and says
that others might be having the same problem. He adds that some graduate
students might be working too fast and not being careful with reagents.
Winter disagrees: “I do not think it is a problem of the scientists doing
something wrong.”
One researcher in China, who works independently from Han’s research group
and who doesn’t want his name to be entangled in the public controversy,
told Nature that he had tested NgAgo in a few kinds of cell and found that
it was able to induce genetic mutations at the desired sites — a finding
that he verified by sequencing. He adds that the process was less efficient
than CRISPR–Cas9, and requires tweaking to improve the efficiency. “But,
in short, it worked,” he says.
Two more Chinese scientists, who also asked not to be named, say they have
initial results showing that NgAgo works but still need to confirm with
sequencing.
“It might, might work,” says Burgio, “but if so, it’s so challenging
that it’s not worth pursuing. It won’t surpass CRISPR, not by a long shot.”
The failure of NgAgo “would be disappointing, but then there is work for us
left to do to see whether other Argonaute systems can get it to work
somehow,” says microbiologist John Van der Oost of Wageningen University in
the Netherlands, a co-author of the 2014 analysis of Argonaute proteins
that laid the groundwork for their use in gene editing (D. C. Swaarts et al.
Nature 507, 258–261; 2014).
This week, Nature Biotechnology sent a statement to Nature’s news team,
saying that “several researchers” have contacted the journal to report
that they cannot reproduce the results, and that “the journal is following
established process to investigate the issues”. A spokesperson declined to
comment on the nature or duration of the investigation. (Nature
Biotechnology is published by Nature’s publisher, Springer Nature; Nature’
s news and comment team is editorially independent of the publisher’s
research editorial teams.)
Hebei University says that it will ask Han to repeat the experiment so that
it can be verified by an independent party within a month, according to
Chinese state media. | w***9
发帖数: 804 | 2 韩副主席戴了手套，设备看起来非常新。
【在 c**i 的大作中提到】
: http://www.nature.com/news/replications-ridicule-and-a-recluse-the-controversy-over-ngago-gene-editing-intensifies-1.20387
: Replications, ridicule and a recluse: the controversy over NgAgo gene-
: editing intensifies
: As failures to replicate results using the CRISPR alternative stack up, a
: quiet scientist stands by his claims.
: David Cyranoski
: 08 August 2016
: SHIJIAZHUANG, CHINA
: A controversy is escalating over whether a gene-editing technique proposed
: as an alternative to the popular CRISPR–Cas9 system actually works.
| n**********g
发帖数: 196 | 3 仇老师敢在个人微博实名说可以重复，到了正儿八经的学术界为何要匿名呢？我只能对
此表示呵呵了 | g*****a
发帖数: 1112 | 4 有趣。 本版老ID怎么看？
【在 n**********g 的大作中提到】
: 仇老师敢在个人微博实名说可以重复，到了正儿八经的学术界为何要匿名呢？我只能对
: 此表示呵呵了
| a********e
发帖数: 275 | 5 所以说，匿名就是一个joke。
匿名，就是可以对说的话不负责。
【在 n**********g 的大作中提到】
: 仇老师敢在个人微博实名说可以重复，到了正儿八经的学术界为何要匿名呢？我只能对
: 此表示呵呵了
| f*******9
发帖数: 723 | 6 买买提上也是，大不了换个ID
【在 a********e 的大作中提到】
: 所以说，匿名就是一个joke。
: 匿名，就是可以对说的话不负责。
| P****R
发帖数: 22479 | 7 开始进入状态了。
【在 c**i 的大作中提到】
: http://www.nature.com/news/replications-ridicule-and-a-recluse-the-controversy-over-ngago-gene-editing-intensifies-1.20387
: Replications, ridicule and a recluse: the controversy over NgAgo gene-
: editing intensifies
: As failures to replicate results using the CRISPR alternative stack up, a
: quiet scientist stands by his claims.
: David Cyranoski
: 08 August 2016
: SHIJIAZHUANG, CHINA
: A controversy is escalating over whether a gene-editing technique proposed
: as an alternative to the popular CRISPR–Cas9 system actually works.
| m****a
发帖数: 270 | 8 国内各政治因素复杂，各位大佬顾忌太多，站出来公开质疑这种惹是生非，不但没好处
，反而弄不好还被打击报复的事情是几乎没有人愿意去干的。
【在 n**********g 的大作中提到】
: 仇老师敢在个人微博实名说可以重复，到了正儿八经的学术界为何要匿名呢？我只能对
: 此表示呵呵了
| S**********e
发帖数: 620 | 9 hcy捏造数据，草拟大业的事情，重复他实验的人绝大多数都身受其害，影响极度恶劣
。要把鸭捻下来，还得如此费劲。
所以说，syg上去了还没什么作为，那就是一个joke。
【在 m****a 的大作中提到】
: 国内各政治因素复杂，各位大佬顾忌太多，站出来公开质疑这种惹是生非，不但没好处
: ，反而弄不好还被打击报复的事情是几乎没有人愿意去干的。
| S**********e
发帖数: 620 | 10 如此杰出青年当吻衲，真是操蛋的年代！
【在 n**********g 的大作中提到】
: 仇老师敢在个人微博实名说可以重复，到了正儿八经的学术界为何要匿名呢？我只能对
: 此表示呵呵了
| | | j*********g
发帖数: 463 | 11 仇子龙咋又匿名了？这些mitbbs的老ID们人品不是一般的差啊…
neverthink老ID怎么看？ | m****a
发帖数: 270 | 12 One researcher in China, who works independently from Han’s research group
and who doesn’t want his name to be entangled in the public controversy,
told Nature that he had tested NgAgo in a few kinds of cell and found that
it was able to induce genetic mutations at the desired sites — a finding
that he verified by sequencing. He adds that the process was less efficient
than CRISPR–Cas9, and requires tweaking to improve the efficiency. “But,
in short, it worked,” he says.
Two more Chinese scientists, who also asked not to be named, say they have
initial results showing that NgAgo works but still need to confirm with
sequencing.
第一个匿名的科学家是仇老板么？怎么只说可以切割想要的基因，完全没提不可以切割
文章中报道的基因的事，结论是“it worked”，等于给hcy占了一次台。
后两人尼玛到现在还在测序，测个鸡毛啊，比印度科学家还慢。
【在 S**********e 的大作中提到】
: hcy捏造数据，草拟大业的事情，重复他实验的人绝大多数都身受其害，影响极度恶劣
: 。要把鸭捻下来，还得如此费劲。
: 所以说，syg上去了还没什么作为，那就是一个joke。
| s*********y
发帖数: 292 | 13 真的假不了，假的真不了。现在看起来NgAgo做Genome editing几乎不可能是真的
Nature都说这事儿了，我也不咋胡了，我就搬个小板凳看这事儿到最后是个什么结果 | m****a
发帖数: 270 | 14 转一个 Nature news 下面的了评论，直接冲着方舟子去的。
DONGXIAO YUE•2016-08-08 08:06 PM
The following is a summary of some very heated debate in China on the Han
NgAgo paper. 1. Fang's rash accusation of fraud was a mere result of his
misunderstandings of the Han paper and molecular biology in general. Even
one of Fang's ardent supporters pointed out to him that he misinterpreted
the electrophoresis bands presented in the paper. Fang further mistook
distances between target sites for DNA segment size deltas. 2. Another named
person, who was Fang's main source, has been discredited in a direct online
debate, for failing to consider NgAgo's effect of removing 1 to 20 nts at
the target site. 3. As stated in Han's paper, the guide can be loaded only
when the NgAgo protein is in the process of expression. Dr. Burgio admitted
that he did not follow a starred procedure in Han's published protocol. Thus
far, the accusations of fraud have been shown to be unfounded. A single
successful replication is sufficient to qualitatively vindicate Han's result
. Hopefully, the suspicion and ridicule will trigger more curiosity and
research to bring about more definitive answers, instead of misguided
abandonment of a potentially potent tool for gene editing. | P****R
发帖数: 22479 | 15 一个controversy，其实已经宣判韩春雨科学生涯的死刑。
在西方科学界，一旦挂上controversy这个称号，你的文章基本是完蛋了。
【在 s*********y 的大作中提到】
: 真的假不了，假的真不了。现在看起来NgAgo做Genome editing几乎不可能是真的
: Nature都说这事儿了，我也不咋胡了，我就搬个小板凳看这事儿到最后是个什么结果
| w****a
发帖数: 139 | 16 科学网挺韩派大将岳东晓,这段话里除了方，还批了本论坛的jessecai
named
online
【在 m****a 的大作中提到】
: 转一个 Nature news 下面的了评论，直接冲着方舟子去的。
: DONGXIAO YUE•2016-08-08 08:06 PM
: The following is a summary of some very heated debate in China on the Han
: NgAgo paper. 1. Fang's rash accusation of fraud was a mere result of his
: misunderstandings of the Han paper and molecular biology in general. Even
: one of Fang's ardent supporters pointed out to him that he misinterpreted
: the electrophoresis bands presented in the paper. Fang further mistook
: distances between target sites for DNA segment size deltas. 2. Another named
: person, who was Fang's main source, has been discredited in a direct online
: debate, for failing to consider NgAgo's effect of removing 1 to 20 nts at
| U*C
发帖数: 89 | 17 仇教授为啥匿名呢，要不然就可以写到自己的CV里了。。。
又一篇Nature嗯 | P****R
发帖数: 22479 | 18 岳东晓是物理系的，懂基因编辑？
【在 w****a 的大作中提到】
: 科学网挺韩派大将岳东晓,这段话里除了方，还批了本论坛的jessecai
:
: named
: online
| P****R
发帖数: 22479 | 19 应该给Nature去信，告诉岳东晓是个物理学者，不可能懂生物学。
【在 w****a 的大作中提到】
: 科学网挺韩派大将岳东晓,这段话里除了方，还批了本论坛的jessecai
:
: named
: online
| j****n
发帖数: 3370 | 20 这年头物理系懂生物的多了去了
话说这年头 哪个理工科专业的不懂生物？数学 物理 化学 化工 机械 材料等系做生物
的乌泱乌泱的 ee cs等也不少参与生物的项目。也许再过几年，那群读艺术 体育的估
计也会做生物了
【在 P****R 的大作中提到】
: 应该给Nature去信，告诉岳东晓是个物理学者，不可能懂生物学。
| | | m****a
发帖数: 270 | | w****a
发帖数: 139 | 22 看来成功重复是违反党纪国法的，只能走地下
【在 m****a 的大作中提到】
: 财新网还是这么的犀利
: 《自然》新闻：三位匿名中国科学家为韩春雨背书
: http://china.caixin.com/2016-08-09/100975834.html
| j****n
发帖数: 3370 | 23 教堂都接受采访了 怎么不再说下到底有没重复出来
【在 c**i 的大作中提到】
: http://www.nature.com/news/replications-ridicule-and-a-recluse-the-controversy-over-ngago-gene-editing-intensifies-1.20387
: Replications, ridicule and a recluse: the controversy over NgAgo gene-
: editing intensifies
: As failures to replicate results using the CRISPR alternative stack up, a
: quiet scientist stands by his claims.
: David Cyranoski
: 08 August 2016
: SHIJIAZHUANG, CHINA
: A controversy is escalating over whether a gene-editing technique proposed
: as an alternative to the popular CRISPR–Cas9 system actually works.
|
|
