A leading Japanese scientist who was embroiled in the STAP cell controversy has been found dead in an apparent suicide.
Professor Yoshiki Sasai, deputy chief of RIKEN's Center for Developmental Biology, supervised and co-authored two papers that were later retracted following an investigation into fraud and academic misconduct relating to the actions of the senior author, Dr Haruko Obokata, who was found guilty of falsifying information (see BioNews 761).
Professor Sasai, who was cleared of direct misconduct but faced criticism of his supervision of Dr Obokata, has been described as 'one of the brightest stars in stem-cell research' and was known for his work on turning stem cells into other cells. Speaking to the BBC, Professor Robin Lovell-Badge, a stem cell researcher from the MRC National Institute for Medical Research, described Professor Sasai as 'an excellent scientist who made some fundamental discoveries'.
The Japanese press reports that the two retracted papers were initially rejected by Nature, but were eventually published after Professor Sasai joined the research team. Professor Sasai had claimed he was only involved in the final stages of the project.
RIKEN spokesperson, Satoru Kagaya, said a security guard discovered Professor Sasai's body at the RIKEN with three letters addressed to Dr Obokata and senior members of the Institute, with two other notes left on his secretary's desk.
Professor Sasai avoided the public eye during the STAP controversy, but Kagaya explained how Professor Sasai's health had deteriorated and that he had been receiving medical treatment. 'He seemed exhausted. I could tell he was tired even on the phone', Kagaya said. Dr Obokata, who is also reportedly receiving treatment, was said to be devastated on hearing the news.
His death coincided with the scheduled release of results from an experiment attempting to replicate the creation of STAP cells, which Professor Sasai was not involved in. The report has now been postponed.
Iekuni Ichikawa, a professor at Shinshu University, said, 'Mr Sasai could have played a significant role in revealing the truth behind the issues involved'. However, others have spoken out against the manner in which RIKEN has handled the investigations. Masaya Toyama, professor emeritus at Osaka University, said RIKEN should have conducted a full investigation from the very start and come to a swift decision.
'Along with the additional investigation, RIKEN suspended discussions over punishments to be meted out to the researchers involved. The affected researchers are having to bear great psychological burdens as their punishments have been left undecided', he said.
Teruo Kishi, professor emeritus at the University of Tokyo and who headed the reform panel that recommended changes to the Center for Developmental Biology (see BioNews 758), said: 'If RIKEN had drawn a clear line at an early stage, Mr Sasai could have made a fresh start as he has made great achievements as a researcher so far'.
He added: 'I suspect RIKEN did not account for such a worst-case result. It should bear great responsibility'.
Professor Lovell-Badge added to the mounting criticism, saying: 'Maybe some lessons can come from this - that you have to be a little bit more proportionate in the way these things are dealt with'.