stem cells?!

Thank you to the submitter of this week’s topic: in light of my last blog, what about stem cells and why all the controversy? This is a fascinating topic and parts are hotly debated. Stem cells come in a several flavors. There are adult stem cells, hematopoetic (white cells in the blood) stem cells, embryonic stem cells (ES) and the most recently identified inducible pluripotent stem cells (iPS). These iPS cells are artificially derived cells that are created from adult cells by forcing the expression of a particular set of genes.

A common characteristic of all stem cells is that they are all slow growing cells that are “immature”. Given the appropriate signals, they can be coerced to develop into any cell in the body. The most easily manipulated are the embryonic stem cells, but these are highly controversial since they come from embryos (usually from ones that are donated after in vitro fertilization techniques. They are the frozen embryos that are not implanted or used in that process). Use of ES cells opens the whole debate about when life begins and it is morally right to use embryos in this manner, even if their fate would be to be frozen permanently? That is a discussion for another day.

The overall goal with stem cells is to isolate them from various sources, including by the way from fat cells in our bodies (I’d donate!), and stimulate them to become whatever cell type is necessary. Have a bad heart? Take stem cells and stimulate them to become heart cells that can be introduced into the ailing heart and “cure” it. In reality, this isn’t close to happening. Stem cells are being studied and understood more and more each day. The field has moved forward quite rapidly and hopefully will be widely used in clinical settings some day. For now, it is too soon to really use them in meaningful clinical ways, especially iPS cells. As more is understood about how these cells grow and (more importantly) how they don’t keep growing, the better their use will be as therapy. Until then, they are being used in cell culture models to understand more about how cells work and develop. A useful and informative by-product to these studies is that this information can be used by non-stem cell researchers to understand how those cells work as well. In other words, the research isn’t limited to just stem cells alone.