Creating Pluripotent Stem Cells

In addition to stem cells that are isolated from the body, scientists have found a way to create stem cells by using various reprogramming techniques in the laboratory. Two such reprogramming techniques are the creation of induced pluripotent stem cells and the use of somatic cell nuclear transfer.

In 2007  the announcement that Japanese researcher Shinya Yamanaka had created pluripotent stem cells using skin cells and not embryos caused great excitement in the stem cell community due to the possibility that they may have the same properties and benefits as ES cells. These stem cells are called “induced pluripotent stem cells” (also known as iPS and iPSC) and are created from adult (non-pluripotent) cells often
skin cells. Typically this involves the reprogramming of some of the cells through the introduction of genes commonly found in stem cells. Yamanaka introduced the reprogramming genes through viral vectors using retroviruses that transcribe the genes into the host cell DNA, which raised concerns about the effects of the retroviruses on the cell.  Stem cell researchers have been able to confirm these results and view this development with great enthusiasm as iPS cells are a less controversial source of stem cells, but potentially have the same properties and benefits as hES cells.

In 2009, a Canadian-Scottish research team led by Andras Nagy was the first of several teams to announce a method to create iPS cells without the use of retroviruses. 1  This is an important development as it could lead to greater application of iPS cells, which are a less controversial source of stem cells.  Continuing research using iPS cells is needed in order to determine whether iPS cells are as malleable as hES cells, but also because iPS cells may be an extremely powerful tool for creating stem cell lines as disease models. However, further questions about the ethical status of iPS cells have been raised that require consideration:  it has been suggested that like hES cells, iPS cells can also generate germ cells, ova and sperm cells. If this is the case, hES cells and iPS cells may not be as ethically distinct as first suggested.