Scientists at the University of Wisconsin-Madison have used detailed, high-tech analysis to examine the differences between human embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC).
Their findings, published online in the journal Nature Methods, for the first time measured the differences between ESC and iPSC in terms of their proteins (the workhorses of the cell that provide structure, function, and identity for a cell), phosphorylation of proteins (a common type of protein modification used to control protein activity), and RNA (an intermediate messenger from DNA that codes for specific proteins.) The results indicate that there is significant similarity between ESC and iPSC, with less than 1 percent difference.
ESC research relies on the destruction of a young human embryo, while iPS cells are produced by adding a few genes to normal cells, such as skin, thereby reprogramming the cell to look and act like an ESC, yet without the use of embryos, eggs, or cloning techniques. The iPS cells thus have a couple of advantages over ESC, including their ethical production as well as the ability to produce pluripotent stem cells directly from any person, to study disease or for potential transplant matching (though the latter has not been proven.) The similarities indicate, however, that iPSC are more than adequate alternatives to ESC.
The study points out that some differences do still exist between ESC and iPSC, likely as a result of the different origins of the two stem cell types, and that further studies will examine those differences. But the authors state in their paper that “These differences do not appear to appreciably alter cellular function in the pluripotent state,” as in not affecting the growth and function of iPSC as a stem cell, and the “remarkable similarity between ESCs and iPSCs.”
It’s time to stop the destruction of embryos for experiments, and focus on ethical science.