Japanese Stem Cell Scientist Commits Suicide

Yoshiki Sasai, a senior scientist from Japan, has committed suicide. The 52-year-old researcher was associated with a stem cell research controversy.

Sasai's body was found hanging on a stairway handrail Tuesday at the government-affiliated science institute Riken in Kobe, western Japan, The Japan Times reported.

Sasai was the deputy director of the Riken Center for Developmental Biology at Riken and an adviser to Haruko Obokata, 30, who was involved in the STAP study controversy. Obokata announced late May that she has agreed to retract the STAP study papers from Nature.

Police said that Sasai left notes addressed to colleagues and the center. Police hasn't disclosed the contents of these "suicide notes" yet, The Guardian reported.

Sasai had earlier said that he was "deeply ashamed" over the errors in the research papers, Associated Press reported.

The STAP Cell research

Obokata and team had published two papers in the prestigious journal Nature detailing a breakthrough study in stem cell research. The new technique of reprogramming stem cells was called "stimulus-triggered acquisition of pluripotency (STAP)".

David Cyranoski - in an article published in Nature, March 14, 2014 - had outlined the details of the case history. According to the article, other scientists attempting to reproduce Obokata and team's results reported several problems with the research. A leading scientist at Riken had also advised Obokata to retract the papers.

In April this year, Sasai said in a news conference that he believed that the papers should be retracted. He added that some parts of the research were valid and could lead to breakthroughs in stem cell research, the Wall Street Journal reported.

According to WSJ, Ryoji Noyori - Riken president and Nobel laureate said - in a statement that he was shocked to hear the news and that he deeply regretted the loss of a researcher "invaluable to the global scientific community."