Mice (Cells) to Men (Cells)

There may be—we emphasize, may be—a solution on the horizon that would quiet the current debate over the use of embryonic stem cells, a type of stem cells harvested from human embryos that, in general, require the destruction of an unborn child. This debate has raged on despite the success of generally unobjectionable adult stem cell research.

In this week’s issue of Nature, however, and in the upcoming issue of Cell Stem Cell, Japanese and American researchers from Kyoto University, the Massachusetts Institute of Technology, and Harvard University announced a “reprogramming” technique that has rendered fetal mouse cells “indistinguishable” from embryonic stem cells: they “appear to have all the same traits as [embryonic stem] cells[.]”

Yet disappointingly, initial results were not all positive. The ScienceNOW article reports that of 121 mice embryos that had these specially made stem cells injected, 20% developed tumors after birth. Team leader Shinya Yamanaka of Kyoto University explained that the mortality rate “shows the danger of using retroviral vectors [used to “reprogram” the cells], which can turn on cancer-causing genes.”

Perhaps unsurprisingly, the ScienceNOW article preemptively warns those who oppose embryonic stem cell research (on ethical grounds)—like us—from drawing too much hope from the breakthrough:

In this environment, the reprogramming studies, preliminary as they are, are likely to be seized on by critics of [embryonic stem] cell research as further evidence that there is no need for the contentious practice of destroying early embryos to obtain stem cells. [Harvard’s Konrad] Hochedlinger and others hasten to point out that research needs to progress on all fronts because all systems “have their limitations.”

Of course, it is precisely because of the lack of proper ethical limitations that we hold on to hope that advances in medicine can come without the cost of human lives. And, again, we can’t understand why there is still a push that all fronts—in particular those with ethical concerns and loss of life—progress when there has been greater success with the use of adult stem cells, which does not cost life in order to save it.