Dr. Yoshiki Sasai, aged 52, has died in an apparent suicide at the RIKEN Institute in Japan today. Dr. Sasai was a Japanese biologist famous for his work in developing new methods of growing and developing stem cells. He was the first scientist to grow an optic cup, which is part of the development of the human eye that serves as a foundational part of the retina, out of stem cells in 2011. Dr. Sasai also won several prestigious scientific awards for his work. However, his career had taken a sudden downward turn in the last year due to a scientific debacle involving one of his colleagues at RIKEN, Haruko Obokata.
Dr. Sasai served as the supervisor at the RIKEN Institute for a researcher named Obokata, who is a much younger scientist who had trained at the prestigious Waseda University. Ms. Obokata claimed in a paper published in the journal Nature that she had developed a method of easily developing a line of stem cells, that were called STAP cells, which could be transformed into any tissue. If this finding had been reproduced in following studies, the potential implication for healthcare and biological research would have been great. But several researchers noted that Obokata’s work were replications of her doctoral dissertation, which was completely unrelated to the paper published in Nature. It is now believed that her findings were created either by extreme error or fraud.
While Obokata has recalled, or has offered to recall, her doctoral dissertation and her work published in Nature, Dr. Sasai had also fallen under heavy criticism. While he and several other researchers, who had been co-authors of Obokata’s studies, had been found innocent of involvement in the potential fraud, he was believed to have failed to follow institutional guidelines. As Obokata’s supervisor, Dr. Sasai was responsible for checking the data before publication and ensuring that the researchers followed ethical and professional guidelines. RIKEN had investigated both Obokata and Dr. Sasai, eventually finding Obokata guilty of falsifying data and stating that Dr. Sasai had failed in his supervisory role. But, the retraction of the paper and the allegations that he had failed professionally in this event weighed heavily on Dr. Sasai. Dr. Sasai had made public statements discussing his shame and embarrassment concerning the retraction before his death.
Dr. Sasai is believed to have died by hanging in a stairway within the RIKEN Institute. A security guard found Dr. Sasai this morning and called the police. The police have claimed that Dr. Sasai had left behind at least five apparent suicide notes. These were allegedly addressed to his colleagues at the RIKEN Institute and other prominent researchers. There are rumors that one of the notes was addressed to Obokata, directing her to replicate the STAP cells in further research.
Dr. Sasai received his doctorate from Kyoto University Medical School in 1993 and was a research fellow at the UCLA School of Medicine before joining RIKEN Institute in 2000. His death has sparked many biologists and researchers to eulogize him as a prominent and talented figure in the community. The director of the RIKEN Institute for Developmental Biology, Masatoshi Takeichi, has expressed condolences to Dr. Sasai’s family and friends.
