"This sucks. Riken’s response"。 STAP細胞の非実在を示すkahoさんの記事が U.C.Davis の Knoepfler 研に投稿される。ついに世界にネタバレか。ドロンボー一味を叩け！の巻き。
◎Non-existence of STAP cell : diary of kaho
15:10 March 5, 2014 diary by kaho
This sucks. Riken’s response.
They announced ‘Essential technical tips for STAP cell’, but it says nonsense. Because no STAP cells exist. I don’t say wrong ways of writing paper but literally ‘non-existence’. I’ve provided evidences but unaccepted.
Many problems have been pointed out, including fabrication of figures and plagiarism, wrong interpretation of data. They would by themselves deserve retraction. But I don’t say them. They have been already discussed elsewhere, and I want to point more essential matter, i.e. non-existence of STAP cells.
Why can you say STAP cells do not exist? I’m not an insider of the paper. So, I don’t know who made the mistakes and what s/he intended. But I can prove their fabrication, or complete falsehood at least. They spoke out their fabrication to the world unawares.
From which data? See the raw data of the next-generation sequencing. One of the two papers performed ChiP-seq experiment. And the authors released the data some time after publication (it should have been done immediately, though). Briefly, this experiment reads chromosomal sequence as a control, named ‘input’. Since the data record almost random DNA fragments of the cell, you can reconstruct its chromosomal structure by looking carefully.
The paper claims that initialization occurred by stimulating T cells with acid. The initialization was distinguished by rearrangement of TCR, from selection of pre-existing stem cells like Muse cells. TCR means T cell receptor, which is cut and ligated so as single cell to produce single kind of antibody. That results in difference of DNA length between T cells and the other cells, and you can see whether the cell has once experienced differentiation to T cell. Strangely, occurrence of the rearrangement in mice made from STAP stem cells was not described in the paper. People requested this data from the beginning of the buzz, but it hadn’t been presented.
To this proper opinion, I’d been thinking ‘you can do it’. This is the ‘input’. Since this data is just around 50 basepairs, the whole sequence cannot be reconstructed. But, the rearrangement can be detected by loss of the cut-off sequence. Since genomic rearrangement shortens specific position of chromosome, a part of the sequence will be lost. If STAP cells are made from T cells, CD45+ cells and STAP cells are expected to have shortened TCR region compared to ES cells.
When I started this analysis, I just wanted a light sense of superiority by finding something that cell biologists cannot do. The result was surprising: first, CD45+ cells exhibit slight TCR rearrangement, while STAP cells and low-pH-exposed CD45+ cells did not had the rearrangement. I thought my way of analysis might be wrong, so analyzed data from defferent T cells, and confirmed TCR rearrangement. In other words, STAP cells do not derive from T cells.
At this point, I suspected contamination of stem cells by incomplete purification T cells. It was too optimistic. Low-PH treatment almost destroy T cells. Then, why STAP stem cells were claimed to have TCR rearrangement? It does not mean low skill of experiment or mistakes.
The truth will be unveiled by comparison of the ‘input’. I’ll write on this matter another day because so long and complicated.
◎Non-existence of STAP cell #2 : Diary of kaho
4:27 March 6, 2014 diary by kano
I’m surprised with huge responses to my last blog, beyond my expectation. As several people guessed, I would be ‘an insider’ from outsider’s view of the institute, although I am not directly involved in the papers of matter.
Inside the institute, I act with real name, and there’s no intention of hiding myself. I want to solve the problem within the institute as much as possible, otherwise I would provide all the information to outside.
The aim of my action is rapid withdrawal of the papers and pursuit of the truth as much as possible, with an anger to the damage to trust on science and the institute, and also a fear for possible restriction on my research activity that may be caused by leaving the matter obscure.
Confident I am that scientific facts on my side, but not confident at all with political battle. I had thought of writing more evidences, but I will put off because the situation demands me to shoot second and third arrows without showing my strategy to the authors of the papers.
The comparison data of ‘input’ described in the previous blog, can be viewed from the addresses below. As the blog cannot post a picture, use UCSC Genome Browser instead. Anyone can reproduce the same result using publicly open data.
Here is a giveaway. What it means will be unveiled soon.