Was it all too good to be true? Concerns have been raised over a paper that claims to have turned adult cells into stem cells with just a 30-minute dip in acid.

An investigation has been launched by RIKEN in Japan into the research results of one of their members of staff – Haruko Obokata. At the end of last month, Obokata and her colleagues published two papers in the journal Nature showing that an acidic environment turned adult mouse cells into “totipotent” stem cells. These can become any cell in the body or placenta. Some team members later told New Scientist that they had repeated the experiment using human cells.

The technique holds great promise for regenerative medicine because it could be used to create any cell in the body without needing to reprogram genes, or use cells from embryos.

Over the weekend, some blogs reported issues with images in one of the papers. Specifically, two images of different placentas appear very similar, and an image of a genome analysis appears to have another genome analysis spliced into it. Spliced images are sometimes used but should be explained.


Honest mistake

Issues have also been raised over duplicated images in a related paper by Obokato, published in 2011 (Tissue Engineering Part A, DOI: 10.1089/ten.tea.2010.0385).

Charles Vacanti at Harvard Medical School, a co-author on all the papers, says he is aware of the mix-up on some images in the 2011 paper. He contacted the journal to request an erratum. He says the mistake did not affect any of the data, conclusions or any other component of the paper, and that it looks like an “honest mistake”.

A spokesperson for the journal says it is investigating the latest allegations, and a RIKEN representative says their institution believes that the research results are valid but has launched an investigation and will make their findings public as soon as they are available.

Meanwhile, several researchers have struggled to repeat the stem cell experiments. “We’ve tried a few times but always unsuccessfully. I have to say, unfortunately, that I am now very sceptical of the published results,” says José Silva, a stem cell researcher at the University of Cambridge.

Too little information

It may merely be a case of not enough information: Sally Cowley, head of the James Martin Stem Cell Facility at the University of Oxford, says her lab has not yet attempted to replicate the production of these “STAP” cells because the full protocol is not available. “I emailed Obokata for a detailed protocol, but have had no reply,” she says.

“It is a failure of the biomedical sciences publishing system in general, in my opinion, that there is rarely enough detail to be able to reproduce procedures accurately,” she adds. Cowley hopes this high-profile example will encourage papers to supply detailed protocols as a matter of course.

Vacanti has said that he is happy to make the detailed protocol public.

Teruhiko Wakayama, a co-author on these papers told Nature that even he has had difficulties in reproducing the experiment – although he had repeated it independently before the papers were published.

Obokata has not responded to New Scientist‘s request for comment.