By Dave Andrusko

One of the most promising techniques that would bypass altogether the need for embryonic stem cells has taken another important step toward application in human beings. Writing in the online edition of Cell Stem Cell, a team working at Harvard University and Massachusetts-based Advanced Cell Technology reported that it has “come up with the safest way yet to make stem-like cells using a patient's ordinary skin cells, this time by using pure human proteins,” writes Reuters’ Maggie Fox.

We have written many times in this space about variations made on the breakthrough work of Shinya Yamanaka of Kyoto University, who, in 2007, coaxed human skin cells to revert to embryonic state. By injecting four genes into ordinary skin cell, scientists in essence rewind the clock on “adult” skin cell.

The results--so-called induced pluripotent stem cells, or iPS cells--are virtually indistinguishable from embryonic stem cells.  And because it is the patient’s own skin that is used, there is no risk of rejection, an otherwise huge problem.

Study author Robert Lanza, the chief scientific officer at Stem Cell & Regenerative Medicine International, told AFP that they hope to apply to the FDA to begin clinic trials  by the middle of next year.

"This is the first safe method of generating patient specific stem cells," Lanza said. “This technology will soon allow us to expand the range of possible stem cell therapies for the entire human body.” He also told AFP, "This allows us to generate the raw material to solve the problem of rejection (by the immune system) so this is really going to accelerate the field of regenerative medicine.”

The problem for all teams has been in the delivery system—getting the four genes safely into the skin cells. Some researchers used retroviruses, “which integrate their own genetic material into the cells they infect,” as Fox explained. However this boosted the risk of genetic mutation and therefore cancer. Other teams used  genetically engineered molecules to reformat the cells as well as other delivery methods.

However, “Lanza and the team led by Kwang Soo Kim of Harvard University succeeded in delivering the genes by fusing them with a cell penetrating peptide [a protein fragment] which does not pose the risk of genetic mutation," according to AFP’s Mira Oberman.

The two-fold beauty of iPS cells (to quote Oberman), is that “Generating stem cells from skin cells bypasses the controversy and also dramatically increases the availability of patient-specific stem cells.”

Part One