CANCER STEM CELLS: Another enemy?

LINDA IN YORKSHIRE, 2000
The Wrath of Henry VIII

I had planned to make August a biology-free month.  As I have written before, my plan was to spend most of the month in Alaska and in the Rocky Mountains, the latter period utilizing my new (to me) camper van.  But now, stuck at home with three broken ribs, two cats and a bruised ego, I might as well try to do something useful.  It remains to be seen if what I am about to do actually is useful, but writing about cancer certainly is preferable to watching daytime TV.

In all the reading and thinking about cancer stuff that I have been doing, I guess I have been searching for a magic bullet – some key to the origin or survival of cancer that could be attacked effectively, eradicated  and – viola! – free mankind of cancer forever.  (Actually, of course, I have been thinking of womankind and ovarian cancer most of the time.)  I have become excited in turn by the possibility of designer drugs based on genomics, aspirin (!), shutting down the blood supply to growing tumors, nanoparticles, killer T-cells, miRNA, fiddling with the activity of mutant Myc genes, and lastly, telomeres.  You can track this evolving enthusiasm by starting at the beginning and reading all 61 of my previous blog postings; if you survive, you will understand.  Now I have a new enthusiasm – cancer stems cells.

You know what stem cells are; they are cells that can turn into other kinds of cells.  If a cell in your skin dies, its place can be taken by the division of another skin cell.  However, that skin cell cannot divide and produce a substitute for a muscle cell, or a bone cell, or anything else – except another skin cell.  It has lost what the biologists call, I think, “potency”.  By contrast, stem cells are “pluri-potent”, meaning that they can turn into (produce) several different kinds of cells.  Embryonic stem cells, the subject of much inflamed political rhetoric, can turn into anything –they are “totipotent”.  What about cancer cells?

Well, there is a train of thought – called the “cancer stem cell hypothesis” - that holds that tumors are sustained and allowed to grow by the presence of their own stem cells.  There is evidence that the recovery of a tumor after it is blasted by chemo (or radiation?) is enabled by the presence of these “immortal”cancer  stem cells.  Three studies summarized by the NCI Cancer Bulletin for August 7^th (are you getting it yet?) confirm this idea, which has been circulating for quite some time but apparently is not universally accepted.  So,if the CSC hypothesis is correct, it would seem that we could cure cancer if only we could devise some sort of biochemical trickery to cause the cancer stem cells to croak.  No doubt this wouldn’t be simple; recall my Babushka doll analogy of a few blogs back. 

Stay tuned.  I have plenty of time on my hands so I will labor to get up to speed on this topic.  In the meantime: I know that some people reading this blog know vastly more about biology and cancer than I do.  How about “Commenting” if something I say is confusing, contradictory, or dead wrong?  I would appreciate it.