Nature has retracted two papers published in January on the creation of so-called 'STAP' cells, after all co-authors agreed to the retractions.
Dr Haruko Obokata was lead author on two papers that claimed to outline the creation of stem cells from blood cells using a simple acid bath, and that these cells had the ability to become placental tissue (see BioNews 740). These so-called 'stimulus-triggered acquisition of pluripotency' (STAP) cells received worldwide media and scientific attention as a potential new source of stem cell, but doubts were soon raised about the validity of the papers after researchers were unable to replicate the findings and questions were raised about the images used (see BioNews 743).
The RIKEN Institute in Japan, where Dr Obokata is based at the Center for Developmental Biology, launched an investigation into allegations of fraud and data mishandling in the production of the papers (BioNews 743; 746). It concluded that Dr Obokata was guilty of 'scientific misconduct' on two counts of intentional data manipulation, finding that she had fabricated data by swapping images and had reused images that had been included in her doctoral thesis.
Dr Obokata publicly apologised for the errors (see BioNews 750) but stood by the study findings, refusing to retract her work. An appeal against the misconduct verdict was rejected in May, however, and the Institute advised Dr Obokata to retract the papers (see BioNews 753). Reports emerged of new evidence questioning the authenticity of the STAP cells in June (see BioNews 757).
After initially agreeing to retract only one of the two papers, Dr Obokata finally agreed to retract both of them in June. Senior author Professor Charles Vacanti, from Harvard Medical School and Brigham and Women's Hospital, was also said to support the retraction, having initially defended the research papers. Nature explained that requests for retractions with the unanimous support of the co-authors are usually authorised and it announced the retraction of both papers on 2 July.
In a statement, Dr Obokata apologised again to the RIKEN and also her co-authors, saying: 'I deeply regret the fact that the problems with the STAP cell papers were caused both by failures in my own management of data and with failures by myself as an author including how I shared and verified samples and data with my co-authors'. She vowed to prove the existence of STAP cells: 'I plan to continue to put my utmost efforts into demonstrating the reality of the STAP phenomenon and STAP cells'.
But the retraction notice includes additional errors that had not been investigated by RIKEN that cast doubt on the existence of STAP cells, including image mislabelling and 'discrepancies' in the genetic background between the donor mice and reported STAP cells.
Nature made an apology for the mistakes, saying: 'These multiple errors impair the credibility of the study as a whole and we are unable to say without doubt whether the STAP-SC phenomenon is real'.
In an editorial, Nature said that it plans to review its own policy on checking papers for submission, saying: 'The episode has further highlighted flaws in Nature's procedures and in the procedures of institutions that publish with us'. The RIKEN Institute also faces reform after a report recommended the closure of the centre where the research was carried out (see BioNews 758).
Commenting on the retractions, Dr Dusko Ilic, senior lecturer in stem cell science at King's College London, said: 'It is easy to be judgmental, and pointing fingers after all is over'.
'Gaining knowledge is difficult. It requires both time and
persistence, I hoped that Haruko Obokata would prove at the end all
those naysayers wrong. Unfortunately, she did not. The technology, indeed, sounded
too good to be true, though I still find fascinating how a 30-year-old
scientist could pass scrutiny of her co-workers and multiple reviewers
in Nature with a complete fabrication', he said.