Damning report says data falsified in stem cell study
The misconduct verdict against a stem cell researcher is unlikely to be the end of the story, writes Elizabeth Finkel.
Japan’s prestigious Riken research centre, investigating problems in papers claiming that the application of stress to ordinary blood cells could reprogram them as stem cells, has found the lead researcher guilty of scientific misconduct. But that is unlikely to be the end of the story.
Haruko Obokata and her co-authors including Charles Vacanti from Harvard dazzled the world in January with two papers in Nature magazine. They upended accepted principles by claiming that ordinary white blood cells, if triggered by mild stress such as an acid bath or squeezing, could be transformed into something remarkable: pluripotent stem cells capable of forming any organ. She named the technique STAP, for stimulus-triggered acquisition of pluripotency. But within two weeks the dazzling claim lost its shine with rumours that Obokata had tampered with her data and researchers blogging that they could not repeat this all-too-simple technique.
The investigating Riken committee released an equivocal first report on 14 March: yes, there had been “inappropriate behaviour” but not necessarily misconduct.
The final report released on 1 April did not equivocate, however, finding Obokata guilty of “fabrication” by joining two different images together to make the final result more impressive, and “falsification” by co-opting an image from her PhD thesis that documented different results.
The vital question of whether the findings are valid is still up in the air.
An unrepentant Obokata rejected the judgment.
“I am filled with feelings of indignation and surprise,” she said in a statement, adding that she intends to appeal. She claimed that she tampered with the data only to improve clarity and it did not undermine the authenticity of her work.
And indeed the vital question of whether her findings are valid is still up in the air. Her work may be sloppy, but did she actually stumble on a finding of Copernican dimensions? Surprisingly, this was not part of the remit of Riken's investigation, although they have said they will now try to replicate the results. “It’s curious that two months after publishing in Nature, they are now going to see if the results are reproducible,” notes Martin Pera, program leader of Stem Cells Australia.
Harvard University’s Vacanti, who supervised part of Obokata’s work in his lab, has always maintained his scientists could reproduce the results. And while most people haven’t been able to repeat the findings, on the same day that Riken released its damning report, Kenneth Lee at the University of Hong Kong blogged that he was able to, at least partly. When he took skin cells (fibroblasts) from newborn mice and squeezed them, they activated genes that heralded a return to the pluripotent state. “I am shocked and amazed by the … results,” he wrote on the scientific blog ResearchGate.
Interestingly it did not work if he exposed these cells to the acid bath. Perhaps this is not so surprising. Obokata’s acid technique was optimised for blood cells; different cells might have different triggers.
Pera, however, cautions against doing science by twitter or blog. “In terms of confirmation, there’s no fast track to peer review.”
And so the story continues.