Re: AGING: Accumulation of DNA damage

From: Robert J. Bradbury (
Date: Mon Jun 26 2000 - 22:24:30 MDT

On Mon, 26 Jun 2000, Scott Badger wrote:

> --- "Robert J. Bradbury" <> wrote:
> ... discussing DNA Damage accumulation as being a
> component of the aging problem...

> You've probably taken this into consideration, but
> would Dr. West's research tend to refute this hypothesis?

Actually, Dr. West, according to people at the LifeEx conference,
this weekend has been fairly careful about what he has been saying.
The lead person on the Science article however has not (and I've sent
him a letter telling him just that!).

> "Now, in a major new paper published in the April 28,
> 2000 issue of the journal Science (1), a group led by
> Dr. Michael West has reported what may be the most
> revolutionary advance in cloning research so far. They
> have found that cloning can totally reverse cellular
> aging."

This is probably a misquote by the Life Extension Foundation
*or* is a very specific comment regarding "cellular aging",
where that is defined specifically as the loss of telomeres.

I have no doubt that they have restored telomeres -- however
restoring telomeres in cells that "happen" to have a mutated
p53 gene is a recipe for causing cancer at a much earlier
age than it might otherwise occur. It will be interesting
to see, once we have large populations of cloned animals if
their cancer rates are higher (in addition to their
miscarriages, post-birth death rates and deformaties).

You *also* may want to take into account that when researchers
do gene knock-out's in mice they often end up with *no* effect.
That is because they are discovering the biochemical systems
have "back-ups". That makes perfect sense since it is thought
that the mammalian genome is a proto-genome (of the Drosophila
level of complexity) that has been duplicated twice. So
unless the functions of many genes have been diverted or lost
there could be as many as 3 backups per gene.

So, the question you have to ask yourself after the accumulation
of DNA damage (whether in your evolutionary history or in
the formation of your body [DNA polymerase doesn't copy
"perfectly"] or in your 20, 30, 40, ... years of life) is
"whether you feel lucky?"

Well do ya?


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