Killing Cancer Stem Cells
My second cancer post in a row. Rafe must have made my news antennae more sensitive to the issue.
The Broad Institute announced that they have identified a compound that kills breast cancer stem cells: salinomycin. What’s particularly cool is the way they went about it. Evidently, cancer stem cells tend to lose their “stemness” in the lab, making it hard to run tests on them. The Broad team overcame this challenge by figuring out how to convert regular cancer cells to stem-like cells to get a stable population.
With this foundation in place, they constructed a large-scale screening operation and searched for activity in thousands of compounds. Once they identified active compounds, they tested them on mice. Lo and behold, salinomycin dramatically reduced (100 to 1) the cancer stem cell population in mice with breast cancer.
Even better, they can apply this same technique to any cancer that produces solid tumors maintained by stem cells.
Possible Insight 
It’s a nice approach in theory, but the problem is that the “cancer stem cell” concept is flawed. See the NY Times article for the criticism of this approach.
Also, there’s a great and telling quote (wish I could find the original) that goes something like “We can cure any kind of cancer you have… as long as you are a mouse.” Ironically though, the mouse models used by Broad Institute and all other cancer research these days — i.e. mice that were transplanted with human cancers — were very hard to create. This article touches on that briefly. Thus, if I were a betting man (and you know that I am), I would say that the work done at the Broad Institute will have little impact on real human cancer understand or treatment.
rafefurst
August 19, 2009 at 9:13 am
1. Flawed is too strong a word in my opinion. It has its opposition, but it seems even from the NYT article that there’s huge value in using this in combination with existing therapies. When compared to existing options, chemotherapy sure seems to have a long list of flaws as well, but untreated cancer is also not without its flaws. 🙂 I see huge value in combining a stem cell attack with chemo, but I have ZERO expertise in the subject.
2. Mice were a “constant” in the study, so the test was relative with respect to the substances tested, not absolute in the sense that one drug’s effectiveness was tested. It sounds that it is quite likely that this substance with be better at killing stem cells than other substances tested. I guess i don’t understand why we would ever test anythign on animals if it was not useful in carrying over to humans (except for the fun component of course!
).
I just have a hard time with these two criticisms, considering that in the world of economics we never come close to this type of scientific methodology. It may be far from perfect, but it’s more practical and methodical than most social sciences, whose flaws the world seems to forget very quickly.
Alex Golubev
August 19, 2009 at 3:40 pm