Mouse Pluripotency from Adult Cells

Mouse Pluripotency from Adult Cells

A press release about a study to appear in the journal Cell reports that researchers from several different Japanese institutes have derived pluripotent stem cells with embryonic stem-cell like properties from fibroblasts, which are structural fibers in connective tissue. The researchers selected 24genes which had previously been found to play a role in early embryos and embryonic stem cell identity, and found that 4 of them (Oct3/4, Sox2, c-Myc, and Klf4) could induce pluripotency in fibroblast cells from embryo and adult mice. The researchers call these cells “induced Pluripotent stem cells,” or iPS. They also found that when the new cells were injected under the skins of mice, a number of different kinds of tumors with characteristics of the three main “germ” tissues in mammals. When the iPS were injected into mouse blastocysts, they aided in the development of the mouse embryos.

There are still a lot of unknowns: are the cells truly pluripotent, or do they have some limits on their development that have not yet been identified? What is the risk of abnormal development, mutation, or cancer with these cells? Do human cells use the same proteins? Can cells other than fibroblasts be induced into pluripotency with some or all of these factors? Nevertheless, I think this is an important finding and one that needs to be pursued aggressively.

I also want to point to this as an example of how embryonic stem cell research has results—without the information about embryo and embryonic stem cell development, the researchers would not have been able to limit their investigations to 24 genes. It is certainly the case that adult stem cells have more therapeutic uses than embryonic stem cells right now, but the research that is done on the embryonic stem cells contributes important knowledge to what adult stem cells do.