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[TeddyB]

http://www.scienceda...31105081236.htm

"This resistance against treatment is caused by a mutation at the ATP-binding site, which prevents the inhibitors from inactivating the enzyme."

Are they reffering to the t315 mutation?

[Trey]

It is poorly written, but is talking about kinase mutations in general.  The point of the article is that researchers think they have found that Gleevec tends to make the ABL in BCR-ABL tend toward the "open configuration", i.e., open for accepting the ATP messenger signal, which tells the leukemic WBC to divide -- that is generally not a good thing.  This would be in contrast to the normal state of ABL which generally sustains an equilibrium between open and closed configurations.  However, this would presumably mean that if Gleevec is working well, it will eliminate the leukemic cells faster since more leukemic cells are open to Gleevec binding.  But if Gleevec is not working well, it tends to make the leukemic cells divide faster than Gleevec can keep up.  This probably also applies to Tasigna, but probably not to Sprycel which works in both open and closed configurations.  Another compound they are investigating tends to close the ATP binding loop, which would possibly keep the leukemic cells from dividing (maybe, maybe not).  They suggest therapy using both drugs.  But as I see it, this second drug would make Gleevec far less effective as it closes the ATP binding loops, so Gleevec could not work.  Overall it is a piece of information in the massive puzzle, and therefore may have some usefulness, or maybe not.