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It seems that one problem with having a DNA based genome is the existence of transposons. These things can be considered the simplest form of life: mobile stretches of DNA that duplicate themselves and hop around in the genome. They are the ancient enemy of DNA-based life, possibly dating back to the
RNA world before DNA came into use as genetic material. I have linked some reviews that hopefully folks interested will be able to open. One problem with transposons is they hop into the middle of a gene the organism needs, screwing it up. Another problem is that all the transposons hanging around become "junk DNA", which the organism is obligated to replicate, but that does no good.
Knowing that these things are in the genome, waiting to start hopping, means that there must be many failsafes intended to keep them in check. But now consider cancer. Cancer is a disease of multicellular critters. For a cell to become cancerous implies both genetic instability (mutation) and a failure of some of the failsafe mechanisms by which cells kill themselves (apoptosis) if the cell perceives that it has become screwed up and out of control.
If cancer cells are losing their self-control because of uncontrolled mutation, sometimes they might also lose the ancient failsafes that suppress transposons. You would never be able to detect such a cancer cell by analysing it because presumably the transposons would replicate and hop madly about, causing damage even the cancer cell could not withstand.
It may be possible to make a drug that blocks one or more failsafe against transposons, and have it be selectively toxic against cancer. If a cancer cell has lost many but not all of the protective mechanisms against transposons, blocking that remaining one could be devastating for the cancer. The normal cells have other backup anti-transposon systems in place, and so could fall back on them when one was blocked.
This should be testable in cancer cell culture. One could do quantitative PCR for transposon sequences before and after treatment with a drug intended to unlease transposons.
[bungston, Nov 12 2004]
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||"In business news today, BUNGCO bought out embattled drug-maker rival Merck in a hostile takeover bid of $0.23 per share.
||Neat idea :-) However, I'm not sure
that it follows that cancer cells are
predisposed to transposon-hopping. I
guess they should be more mutation-
prone, if only because they are
replicating faster and must have already
lost some of the checks against
mutation-induced apoptosis. But I
think it's a long shot to hope that they'd
be that much more susceptible to
having their transposons "released" to
Also, is it not likely that some cancers
are induced by hopping transposons in
normal cells? If so, by raising the risk
of hopping in all the normal cells of the
body, you'd run the risk of creating
more cancerous cells than you'd kill.
Still a neat idea, though! [+]