ONE catastrophic event could result in hundreds of mutations, and get cancers started much more quickly than usual. This unexpected discovery challenges the received wisdom that cancers occur only after several mutations have taken place independently over time.
Peter Campbell at the Wellcome Trust Sanger Institute in Cambridge, UK, was studying genes from someone with leukaemia when he spotted that a chromosome had apparently been smashed into hundreds of fragments and stuck back together, Humpty Dumpty-like. The result was a random mosaic of genetic material containing a number of cancer-causing mutations.
"The first patient was a chance finding and we didn't know what to make of it," says Campbell. His team then sequenced genomes from over 700 people with a range of cancers, and found the same pattern of damage in around 2 to 3 per cent of them (Cell, DOI: 10.1016/j.cell.2010.11.055).
Rather than committing cell suicide, as would be expected after such serious damage, some cells appear to have stitched the chromosome fragments back together. In some cases there were up to three cancer-causing mutations, suggesting those cells have taken a "significant leap on the road to cancer", says Campbell.
Although there are other known situations in which genetic mutations are linked, what's different here is that the damage is localised, says Ronald DePinho at Harvard Medical School in Boston. "It shows [mutations] can happen in a narrow window."
The team are unsure what causes these chromosomes to become "completely pulverised", but speculate that radiation could be to blame. Campbell now plans to study the history of people with this damage to discover whether there is anything distinctive about their occupation or the number of X-rays they've had.
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Sun Jan 16 14:55:52 GMT 2011 by Michael Dowling
What's the difference if mutations occur in one fell swoop,rather than accumulating over time? The end result,cancer,is the same in each case.
Sun Jan 16 16:49:45 GMT 2011 by Marc
So, it could be possible that events that cause trauma to the body may be potentially responsible for advancing cancer cells, or maybe even damaging existing healthy cells.
I'd bet this may even result in them learning more about how cancer works and how the effects could be lessened or even to treatment against cells corrupting further as it should be easier if you know the potential triggers.
Sorry if that seems a little condescending but it was a silly question lol.
Mon Jan 17 00:13:15 GMT 2011 by Michael Dowling
| still don't see how this is a major discovery,except for the finding that cells try to patch up major chromosomal damage rather than commit suicide.If initiating cancer requires mutations in chromosomes A,B,C,C,D and E,it seems to me that sequential mutations in A,mutations in B,and so on,are equivalent to one massive insult that causes mutations to all the chromosomes at once.
Mon Jan 17 00:53:38 GMT 2011 by insomniac
I think they're saying that a single event can provide sufficient mutations to cause a cancer, whereas before they thought there had to be a number of events, and as such the probability of getting cancer from any one event rises.
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