May 20, 2024


 An important paper which claimed that a type of adult stem cell was as versatile as embryonic stem cells now appears to be flawed. In 2002, Catherine Verfaillie, of the University of Minnesota, discovered that stem cells taken from the bone marrow of mice could grow into an array of tissues, including brain, heart, lung and liver. Without any encouragement from her, the paper was used by opponents of embryonic stem cell research as proof that adult stem cells were viable alternatives to those taken from embryos.

Dr Verfaillie’s results proved hard to repeat. Some other scientists were unable even to isolate the cells, called multipotent adult progenitor cells (MAPCs). When the magazine New Scientist examined the original paper more closely, it found that some data from her original paper in Nature and another of her papers published at the same time were identical, even though they were supposed to refer to different cells. This led to an investigation by the University of Minnesota, which recently concluded that identification of her cells was "significantly flawed" and that interpretations of her data were potentially incorrect". Dr Verfaillie, who is now at the Catholic University in Leuven, Belgium, has accepted the results of the investigation. It appears that the duplication was an oversight, and that there is no question of falsification.

Nonetheless, to make a complicated story even more complicated, Verfaillie’s work is far from being totally discredited. In collaboration with a leading sceptic of her work, Irving Weissman, of Stanford, she has succeeded in making MAPCs rebuild the blood system in mice. "What our paper will help do is get everybody to look at [her work] again," says Weissman.