Head of Japan's Riken Institute Apologizes Over Stem-Cell Papers

By Alexander Martin 

TOKYO--The head of Japan's Riken science institute on Friday issued an apology over two disputed papers in Nature on stem cells, saying they contained "serious errors."

Ryoji Noyori, a Nobel laureate, bowed deeply at a news conference in Tokyo and said the institute was examining whether to retract the papers.

The lead author of the papers, Haruko Obokata, also issued a statement of apology, joined by co-authors Yoshiki Sasai and Hitoshi Niwa.

"I sincerely apologize for the confusion, and humbly accept the various suggestions made about the flaws in our paper," Dr. Obokata and her co-authors said in the statement. "I am currently contacting other co-authors on the possibility of retracting the papers."

Riken issued an interim report into problems with the papers, which were published in the journal Nature in late January. The report said there were inappropriate elements in parts of the papers that didn't amount to research misconduct. It said more investigation was required for other parts of the papers.

The Nature papers said mouse stem cells could easily be created in a laboratory dish by dipping blood cells into a mild acid solution. If the technique could be adapted to work on human cells, it would promise to transform the treatment for a range of diseases.

But following growing suspicions over some of the images and text used in the studies, one of the co-authors said Monday that he has urged Dr. Obokata to retract the papers. Riken has said, however, that as a general rule, a retraction couldn't be made unless all the authors agree.

Charles Vacanti, another co-author and a tissue engineer at Harvard Medical School and Brigham and Women's Hospital in Boston, has so far defended the paper, saying the questions raised didn't affect the findings of the study.

Earlier Friday, Dr. Obokata offered a defense over some of the allegations made against her.

In an email to The Wall Street Journal, Dr. Obokata responded to suspicions of plagiarism in her dissertation for a doctorate in engineering that she received in 2011 from Japan's Waseda University.

Portions of the document posted online by an anonymous blogger who has been tracking suspicions over the stem-cell studies were almost identical to text posted on a U.S. National Institutes of Health website.

"The doctoral dissertation that is currently making the rounds in the media is not the version that has passed (the university's) screening, but a rough draft," Dr. Obokata told The Wall Street Journal in an email sent early Friday morning.

She said she had reprinted certain text and images in the rough draft. She said that version didn't contain citations or corrections. Dr. Obokata said she has asked the university to retract what she described as the rough-draft version of her dissertation.

A spokesman for Waseda said the university was unaware of such a request and didn't know about any additional versions of the dissertation. The spokesman said the university's investigation into suspicions raised about the dissertation was continuing.

Write to Alexander Martin at alexander.martin@wsj.com

By Alexander Martin and Toko Sekiguchi 

TOKYO--A prestigious Japanese research institute ensnared in controversy over two high-profile papers on stem cells apologized Friday, saying the work contained "serious errors."

Ryoji Noyori, a Nobel laureate and president of the government-funded Riken institute, bowed deeply at the beginning of a packed, four-hour-long news conference in Tokyo and said the institute was examining whether to retract the papers, which had appeared to offer a revolutionary new approach to creating stem cells.

Dr. Noyori repeatedly referred to Haruko Obokata, the 30-year-old lead author of the papers, as "immature" and "sloppy." He said an investigation was continuing into the most serious allegations--in particular, the question of why three images in the papers were nearly identical to three images included in Dr. Obokata's 2011 doctoral dissertation at Japan's Waseda University.

The stem-cell papers were published in late January in the journal Nature, which has said it is investigating the irregularities.

The controversy has highlighted the race for improved methods of creating stem cells, long seen as a potential source of cures for heart disease, diabetes and other ailments. It has also pointed to apparent lax controls at one of Japan's top scientific institutions.

Dr. Obokata, who has avoided public comment since the allegations emerged, offered a defense on some points in an email to The Wall Street Journal. She said she was "very hurt" by the media hoopla surrounding the research and responded to suspicions of plagiarism in her dissertation. Portions of the dissertation posted online were almost identical to text posted on a U.S. National Institutes of Health website.

"The doctoral dissertation that is currently making the rounds in the media is not the version that has passed [the university's] screening but a rough draft," Dr. Obokata wrote in the email. She said that version didn't contain citations or corrections.

Dr. Obokata said she has asked the university to retract what she described as the rough-draft version. A spokesman for Waseda said, however, that the university was unaware of such a request or of the existence of a rough draft. He said the university's investigation into the dissertation was continuing.

Riken officials said that Dr. Obokata was in Kobe, western Japan, and that her research had been suspended.

Riken released a statement of apology it said was signed by Dr. Obokata and two of her co-authors. They said they "humbly accept the various suggestions made about the flaws in our paper" and were discussing a retraction with other co-authors.

But according to Riken, Dr. Obokata maintained that the paper's errors, including the inclusion of a duplicated image of a placenta, were mistakes and not intentional deception.

Riken's interim report on its internal investigation concluded that there was "inappropriate handling" of data in two instances, both of which Dr. Obokata acknowledged but called them accidental errors. The investigators said they had interviewed four scientists including Dr. Obokata.

The Nature papers said mouse stem cells could easily be created in a laboratory dish by dipping blood cells into a mild acid solution. If the technique could be adapted to work on human cells, it would promise to transform the treatment for a range of diseases. However, other scientists have so far failed to replicate the Nature findings. Riken officials said they weren't aware of any successful replication efforts outside of Riken.

Masatoshi Takeichi, the head of Riken's Center for Developmental Biology, said he advised Dr. Obokata and two other scientists to consider retracting the papers when the duplication of images between the Nature papers and the 2011 dissertation became clear.

"I personally cannot understand why something like this happened," he said.

A total of 14 Japanese and American and Japanese researchers were involved in writing the two Nature papers. Riken said that as a general rule, a retraction couldn't be made unless all the authors agreed. Charles Vacanti, another co-author and a tissue engineer at Harvard Medical School and Brigham and Women's Hospital in Boston, has defended the paper, saying the questions raised didn't affect the findings of the study.

In a statement Friday, Dr. Vacanti said, "In the absence of compelling evidence that the data presented is incorrect, I do not believe that the manuscripts should be retracted." But he said he would speak further with the co-authors before making a final recommendation on whether to retract.

At the news conference, reporters repeatedly questioned whether the new type of stem cells allegedly created by the Obokata group actually existed. Riken said determining that wasn't the goal of the investigation.

"That conclusion cannot be reached without examination by a third party using scientific data," Dr. Takeichi said.

Write to Alexander Martin at alexander.martin@wsj.com