Harvard scientists report they have transformed one type of adult cell directly into another adult cell type, producing the specialized pancreatic beta-cells that secrete insulin.  In what some have called a "groundbreaking advance", three genes were added to pancreatic cells within living mice, and this was enough to directly change the cells into insulin-secreting cells.  Though similar to the reprogramming technique developed by Yamanaka of Japan, this new application eliminates the need to form embryonic type stem cells.  Doug Melton of Harvard reported on the experiments back in June, but this is the first peer-reviewed publication of the results, online in the journal Nature.

Harvard researchers had previously reported production of disease-specific cell lines using the Yamanaka technique. But embryonic types of stem cells continue to show problems forming mature, functional cells, as well as their tendency to form tumors. Melton has worked for years trying to make insulin-secreting cells from embryonic stem cells. This new technique directly turns one type of fully formed adult cell into another type of adult cell, eliminating the problematic step back to embryonic stem cells. It also completely bypasses any need for using embryos or cloning for research.