A small RNA called miR-34 impedes the activation of pluripotency-associated genes, reports a paper published online in Nature Cell Biology this week. The work goes on to suggest that inhibiting the action of this RNA may increase the efficiency of reprogramming.
During the development of a fertilized egg into an organism, pluripotent stem cells differentiate into various cell types, including lung cells, blood cells and cells of the nervous system. Differentiated cells can be changed back to the pluripotent state in the laboratory by inducing the expression of a specific set of pluripotency-associated genes in a process called reprogramming. p53, a protein that suppresses tumour formation, has previously been shown to repress the ability to revert differentiated cells into the pluripotent state. Lin He and colleagues found that p53 induces the expression of miR-34. They then showed that deletion of the genetic sequence that encodes miR-34 increased reprogramming efficiency without compromising the pluripotency or proliferation status of the reprogrammed cells.
These findings could have implications for the ability to make stem cells in the laboratory for use in research.