Partially or fully differentiated cells can acquire, or be reprogrammed for, stem cell-like pluripotency, according to two studies published this week.

The research adds to a growing body of work on the subtleties of pluripotency, since last November's landmark somatic cell reprogramming achievement.

The first group, led by Rudolph Jaenisch at the Whitehead Institute, demonstrated in their Cell paper published today (April 17) that fully differentiated mouse B lymphocytes can be reprogrammed to a pluripotent state when given a cocktail of transcription factors. Until now it was unclear whether such cells could be induced for pluripotency.

The second study, led by Stanford University School of Medicine researcher Michael Clarke and published in Nature yesterday (April 16), used genetic mutations to induce pluripotency. They engineered triple mutant mice deficient in three genes that repress the differentiation of blood cells and found that those mice were able to not only reconstitute their blood, but that their blood cells acquired the ability to self-renew. The three genes are expressed in cancers, suggesting that early progenitors can acquire the ability to self-renew through mutation.

The results may shed some light on what happens to progenitor blood cells when they become cancerous and are able to proliferate unchecked. "The data fit in with other data that suggest that progenitor cells in acute leukemia in mice can have functions that look stem cell-like," Janis Abkowitz, University of Washington researcher, told The Scientist. "On one level it gives insight into how cancers might develop in the hematopoietic system."

There is a growing dialogue about the properties that define true stem cells, Abkowitz said, and how other stem cell-like cells may behave over time. This will help researchers in the future understand how these types of cells behave clinically and under different conditions, she added.