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Researchers scrutinize findings on stem cells

Questions raised after reports on new process

Dr. Charles Vacanti, senior author on one paper, remains confident in the findings.Yoon S. Byun/Globe Staff/Globe staff

A prestigious Japanese research institution is investigating scientific papers that last month reported the controversial discovery that stem cells could be created simply by bathing mature cells in a weak acid.

Dr. Charles Vacanti, a Brigham and Women’s Hospital anesthesiologist who is the senior author on one of the papers reporting the discovery and a coauthor on another, said that early this week one of his Japanese coauthors from the RIKEN Center for Developmental Biology notified him of a problem in the paper for which he was a coauthor.

A photo of glowing placental cells was incorrectly included in the paper, Vacanti said. He said that he and his coauthors are submitting a correction to the journal Nature, to remove the extra picture. That problem does not indicate a broader scientific flaw with the work, he said, and added he still expects other laboratories to be able to repeat the technique — an important step in science to show that results are legitimate.

A spokeswoman for RIKEN said in an e-mail that outside researchers alleged improprieties in the data that she would not elaborate on. The institution opened an investigation Feb. 13. Vacanti said there is no such investigation at Brigham and Women’s.


“RIKEN believes that the research results are valid but launched an investigation,” Juliette Savin, a spokeswoman, wrote in an e-mail. “We have asked specialists both outside and inside RIKEN to conduct this investigation.”

The two studies published in Nature in late January have been subject to unusually intense and public scrutiny because of the novelty of the potentially groundbreaking claims that they make about how to create stem cells, which they called STAP cells. It is common for researchers to question results following a new paper, particularly one with controversial or surprising findings.


A comment thread on PubPeer, a website that scrutinizes published scientific work, has pointed out potential image manipulation. Questions have also been raised about images used in an earlier, 2011 paper that helped lay the groundwork for the new study. It is unclear at this stage whether those allegations will be found true, and if they do hold up, whether they indicate a serious problem or a simple mistake.

A crowdsourced website that has been collecting the results of efforts to repeat the technique has thus far yielded nine reports of mostly anonymous, preliminary reports of failures. But many of those attempts are using different types of cells than the ones the researchers reported using. A news story in the journal Nature reported that 10 prominent stem cell scientists surveyed by Nature had not yet had success in repeating the experiment.

Vacanti acknowledged that there has been a “frenzy” around the new papers, but said he remains confident in the findings.

“With regards to the reproducibility of these results, independent groups collaborated on the work reported in the two papers, and STAP cells were independently obtained in those labs,” Rebecca Walton, a spokeswoman for Nature, wrote in an e-mail. “Any paper that is submitted to Nature, independent of its topic, is considered on its own merits and is evaluated carefully according to our editorial procedures.”

The Nature news story reported that Teruhiko Wakayama, a cloning expert who now works at Yamanashi University and is the senior author on one of the papers, said that even he has had trouble reproducing the basic result because there are subtleties to the technique.


Wakayama replicated the technique in his lab before the study was published, but hasn’t done it successfully since then, he told Nature.

“It looks like an easy technique — just add acid — but it’s not that easy,” Wakayama told Nature. “I did it and found it myself. I know the results are absolutely true.”

The RIKEN spokeswoman said that scientists there did not know how long the investigation would take, but that the results would be made public.

Carolyn Y. Johnson can be reached at