A Scientific Fork in the Road?

For several decades I taught medical students that the scientific basis of cancer chemotherapy was based on the concept that tumors were composed of cells which had been triggered to grow more rapidly and with different controls than normal cells. As a result our efforts to counter this proliferative abnormality had to be directed at discovering and targeting the slight alteration which allowed the differential growth rates of the tumor cells. Well, it turns out now that we should turn our attention to a different model. Recent evidence out of Canada suggests that it is stem cells which make cancers grow. This is based on the finding that tumor cells are quite diversified and some of them have very little proliferative potential and are thus unworthy targets of our chemotherapeutic agents currently in use. In fact, the evidence now is that when stem cells are removed the bulk of the tumor cells are not particularly nasty. So, if a tumor cell does not have the abnormal cell division potential, it poses very little threat. It turns out that in one study only 1 cell in 40,000 colon cancer tumor cells was responsible for all the growth in the tumor. Ergo, we need to change our thinking about cancer chemotherapeutic targeting.

I am struck by the way in which this could mesh with an observation by others that when we try to use embryonic stem cells to cure such things as diabetes in animal models, we almost always end up with cancers. This sad fact is no deterrent to the liberals who will not be content until we create embryos on a massive scale to pursue what now seems a dead-end in stem cell research as opposed to the use of adult stem cells which have been shown to be effective in 78 different medical conditions. This perhaps because the adult stem cells cause the proliferation of cells which are deficient in a given medical condition. Thus, nerve cell regeneration, pancreatic cells which make insulin, and other conditions are amenable to treatment with adult stem cells, but not with embryonic stem cells which have not yet differentiated.