The Other Side of Stem Cells

OK, enough on Mr. Rogers. Who would have thought he would cause such animosity?

Back to research reports. I know some of you find this interesting, but frankly, it's as much for me as it is for you. I need to read about it and understand it before I can pass it on to you in a simpler form, and that helps me understand what kinds of treatments are out there. We teachers know that the best way to learn something is to teach it to someone else.

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Really interesting article in a recent edition of The Economist, called "Cancer Stem Cells: The Root of All Evil?" Lots of great cancer research looks at developing new treatments, or refining currently-used treatments, or comparing treatments. But the Holy Grail of cancer research is finding out what causes cancer in the first place. We know, basically, what cancer is: unchecked growth of cells that won't die off the way normal cells do, causing tumors that take resources from the rest of the body. But what causes the unchecked growth of a tumor in the first place?

According to this article, it has to do with cancer stem cells.

In general, stem cells are immature cells that have not grown into specific types of cells. We all have millions of stem cells, waiting to mature into specialized cells that will replace those cells that die off naturally (or are killed off). For example, a stem cell transplant works by killing off tumors and a problematic immune system and replacing it with immature stem cells that will grow quickly and replace the killed-off cells, creating a new immune system. Go stem cells!

As the article describes, this is all just a theory, but it's being tested, and it works like this: Just like all of the healthy cells in the body, cancer cells are born from stem cells. But there's a difference between the stem cells and mature cells.

Mature cells grow by dividing into two equal cells the original cell and a copy of itself. So a skin cell creates two identical skin cells, the old one and a new copy. The cells can only divide a limited number of times, and then they die off. So they need to be rpelaced by new cells, which can then divide a few times themselves. That's where stem cells come in.

Stem cells are different from mature cells: when a stem cell divides into two, one of the two stays a stem cell, while the other grows into a new, specialized cell. So a skin stem cell will create one new skin cell, but the other will remain a stem cell. This is how we have a constant supply of new cells -- the stem cells are always there, waiting to create one new, specialized cell. The body has a limited number of stem cells.

According to the theory described in the article, cencer stem cells are the problem: when we treat cancer, we treat the mature cancer cells (the mature cells that have grown from the cancer stem cell), but we never get to the stem cells that are still sitting there. Read the article to get more on the fascinating research that has gone into showing that stem cells are different from their mature cells, and how it has effected cancer research.

If the cancer stem cell theory proves to be correct (and it may not be -- the article gets into the controversy surrounding it), then researchers might have a better chance of developing new, targeted treatments that will get at the root cause of the cancer, not just the tumors that develop.

Very intersting stuff.