Molecular remnants may limit potential of reprogrammed stem cells
Barbra Streisand probably wasn’t thinking about reprogrammed stem cells when she crooned “The Way We Were,” but it turns out that the cells also retain misty watercolor memories of their former selves.
By most standards, a cocktail of four proteins can reprogram skin or blood into stem cells nearly indistinguishable from those isolated from embryos (SN: 11/24/07, p. 323; SN Online, 8/24/08). But two new studies show that reprogrammed cells, known as induced pluripotent stem cells or iPS cells, hold on to molecular memories of their former identities.
The findings, published online July 19 in Nature and Nature Biotechnology, could be a blessing and a curse for researchers who hope to transform the reprogrammed cells into adult cell types for transplant into patients or for studying how certain genetic diseases influence cell development.
All stem cells aren’t equally flexible, scientists have fo