The complexity of cellular dedifferentiation: implications for regenerative medicine.

Cellular dedifferentiation underlies topical issues in biology, such as regeneration and somatic cell nuclear transfer (SCNT), and signifies the withdrawal of cells from a given differentiated state into a 'stem cell'-like state that confers pluripotency. Recently, there has been growing interest in exploiting the dedifferentiation process to obtain autologous stem cell lineages for use in regenerative medicine. This approach holds great promise, particularly in view of the ethical concerns invoked over the use of human embryonic stem cells in research and the problem of transplant rejection. However, new insights provided by the study of this process in plants and animals have highlighted the complexity and hazards of cellular dedifferentiation.