TOKYO- - Tying up a loose end of a long-running stem cell research fiasco, yet another RIKEN investigating committee released yet another report in Tokyo today. It concludes that the so-called stimulus-triggered acquisition of pluripotency (STAP) stem cells, as well as the chimeric mice and teratomas supposedly derived from those cells, "all originated in cultures contaminated with (embryonic stem) cells, a fact that refutes all of the main conclusions of the two papers" that reported the the supposed breakthrough method of reprogramming adult cells. Those two papers, an article and a letter, appeared online at Nature on 29 January.
The committee determined that 3 supposed STAP stem cell lines were actually likely to be 3 previously existing embryonic stem (ES) cell lines. "It is unlikely that there was accidental contamination by three different ES cells, and it is suspected that the contamination may have occurred artificially," the committee concluded in a report released today. However the panel could not find conclusive evidence of deliberate contamination, nor of who might be responsible. "We cannot, therefore, conclude that there was research misconduct in this instance," the committee reported.
However, the committee did find "research misconduct involving fabrication" in the production of two images in the article that had no supporting experimental data. The images are Fig. 5c: Growth curves of STAP stem cells and Fig. 2c: DNA methylation. The committee laid responsibility for the fabrications on Haruko Obokata, the lead author of both papers.
The committee's announcement came a week after a separate RIKEN group announced it could not reproduce the STAP cell method even with Obokata's help. The same day, Obokata resigned from the RIKEN Center for Developmental Biology (CDB) in Kobe, home to most of the research team.
A previous investigating committee had looked at the...Continue Reading »