As a postdoc in Irving Weissman's laboratory at Stanford University, Amy Wagers earned a reputation for putting other people's findings to the test. In 2002 Wagers published evidence contrary to claims that bone marrow-derived stem cells could transdifferentiate into brain, muscle, and other tissues.
Wagers attended Northwestern University as an undergraduate and liked the program so much that she decided to stay. She began graduate work in 1994 in Geoffrey Kansas' laboratory, where she studied leukocyte trafficking. Wagers spent countless hours shivering in the cold room during cellular adhesion assays, and ate her dinners while counting cells on a TV screen. "She was not going to let anyone out-work her," says Kansas.
Her efforts paid off. In 1998 Wagers found that the cytokine interleukin-12 controls the expression of the enzyme crucial for the formation of ligands for selectins,
A year later Wagers left for a postdoc in Weissman's Stanford lab, and for the next several years she committed herself to understanding the role of circulating stem cells. "We would talk and have ideas and add another project to her load, and she simply couldn't be saturated," says Weissman.
Her work was not without controversy, and still her data are challenged. In 2007, for example, Piero Anversa at Harvard Medical School - whose 2001 findings with Donald Orlic at the National Heart Lung and Blood Institute Wagers had challenged in 2004 - showed "unequivocally" that bone marrow stem cells could transdifferentiate to cardiomyogenic cells (Proc Natl Acad Sci, 104:17783-8, 2007). Anversa says the discrepancy is likely due to different methodologies, while Orlic declined to be interviewed. Kenneth Chien at the Massachusetts General Hospital Cardiovascular Research Center says Wagers' work has made an impact on stem cell therapy research. It "essentially provides a compelling case for hunting and identifying the most appropriate and optimal cardiovascular progenitor" for therapy, says Chien. (See "A Waiting Trial".)
In her laboratory at Harvard's Joslin Diabetes Center, Wagers studies pairs of parabiotic mice that have been sewn together. Her research on their conjoined bodies may answer questions about the role of circulating factors in aging and diseases such as muscular dystrophy.
Though Wagers isn't currently working on testing others' claims, the term "wagerizing" has stuck in Weissman's lab. "If we want to test if something is true, we wagerize it," says Weissman.