WIKIMEDIA, NISSIM BENVENISTYA new study attempting to nail down the existence of very small embryonic-like stem cells (VSELs)—seemingly pluripotent cells first reported in mouse bone marrow in 2005, and later identified in human blood and bone marrow—finds convincing evidence that the cells are not real. Lead author Irving Weissman of Stanford University School of Medicine called reports of VSELs a “distraction,” drawing excitement as well as time and money away from the more established stem cell types.
Others agreed. “In a rapidly evolving field, exciting and provocative early stage findings can often be subject to over-interpretation,” said Martin Pera, chair of Stem Cell Sciences at the University of Melbourne in Australia, who was not involved in the study. “This work shows that it is absolutely critical for multiple laboratories to confirm rigorously the developmental potential of candidate stem cells, before a new finding is accepted as dogma, or forms the basis for science policy decisions.”
The discoverer of VSELs, Mariusz Ratajczak of the Developmental Biology Research Program at the University of Louisville, stands by his research, however, and suggests methodological issues may explain other researchers’ inability to isolate the cells. And, as he has since his initial discovery in 2005, he emphasized ...
