Stem-Cell Scientist Dies

Yoshiki Sasai, a prominent organogenesis researcher who was a coauthor on two retracted stem cell studies, has died of apparent suicide at 52, officials say.

Aug 5, 2014
Tracy Vence

WIKIMEDIA, NIHYoshiki Sasai, a principal investigator within the RIKEN Institute’s Center for Developmental Biology who was a coauthor on both of the now-retracted stimulus-triggered acquisition of pluripotency (STAP) papers, has killed himself, Kobe police said on Tuesday (August 5). Sasai was 52.

Officials confirmed his suicide in a statement to Reuters, which reported that in March, Sasai had been hospitalized for stress and exhaustion in the wake of the high-profile investigation into his team’s stem cell work. In his position at RIKEN, he supervised the lead author on the STAP research, Haruko Obokata, who was found guilty of research misconduct.

Ryoji Noyori, RIKEN president, expressed “deep regret over the loss of an irreplaceable scientist,” Reuters reported. “Mr. Sasai contributed greatly in the field of developmental biology and was an internationally renowned researcher,” said Yoshihide Suga Chief Cabinet Secretary for the Japanese government.

In 2008, a team led by Sasai “showed that stem cells can be coaxed into balls of neural cells that self-organize into distinctive layers,” The Scientist reported last year at this time. The work paved the way for future work toward developing lab-grown cerebral organoids. Before that, Sasai led pioneering research on growing early-stage mouse eyes and partial, functional mouse pituitary glands from stem cells in the lab.

“This is . . . an immense loss to the research community,” Phil Campbell, editor-in-chief of the journal that published both of the controversial STAP papers said in a statement following Sasai’s death. “Yoshiki Sasai was an exceptional scientist and he has left an extraordinary legacy of pioneering work across many fields within stem cell and developmental biology, including organogenesis and neurogenesis,” Nature’s Campbell added.

“This is a tragedy and thoughts go out to his family, friends, and lab members,” wrote Paul Knoepfler from the University of California, Davis, who was been covering the STAP cell saga on his blog since the papers were first published. “Sasai was a top scholar in the stem cell field.”

Hat tip: Retraction Watch