The evolutionary struggles from which mutants arise have been documented in almost every living system. In this issue of the JCI, Varela and colleagues extend this list of systems to include neural derivatives of human embryonic stem cells, which they show exhibit a repeated gain of material from chromosome 1q. Although this raises safety issues for therapeutic use of such cells, the frequent observation of a particular change may direct screening strategies for detection and removal of these unwanted cellular variants.
Neil J. Harrison
NSCs can be derived efficiently from a number of sources and have potential for use in regenerative medicine. However, culture adaptation of this stem cell will eventually generate variants deemed unsuitable for the clinic. These culture-adapted mutant stem cells will likely self renew rather than differentiate or die, acquiring characteristics reminiscent of tumor cells.