Aging of cells stopped?

Michael Gregory gregorym at uthscsa.edu
Fri Jan 23 21:59:18 EST 1998


Andreas John wrote:
> 
> Hallo!
> 
> Last week I heard that researchers found a way to stop the aging of
> cells and of creatures. Can someone please explain to somebody who
> is not an expert in this field how aging works and how they have
> stopped it? Please answer to aj at ithe.rwth-aachen.de
> 
> Andreas John


Briefly, as I heard it (have not read a report yet), the researches
introduced the Telomerase gene into cultured cells ( I assume
fibroblasts) and let the cells serially divide.  Normally
non-transformed cells (i.e. not cancerous) will only serially divide up
to a given number of divisions (passages), their so called Hayflick
limit.
The cells engineered with the Telomerase gene continued to divided past
their maximum Hayflick limit.  How many times? I don't know. Whether the
cells are now "immortal" without being cancerous also remains to be
shown. 
The Telomerase gene produces a protein, Telomerase, with helps maintain
the ends of DNA.  The "standard comparison" is to that of the plastic
coating on the ends of shoelaces. The Telomerase adds a repeated
sequence of DNA (the "plastic cap") to the ends of chromosomes (our
genetic shoelaces).  One aging theory proposes that this mechanism is
the genetic "clock", because in most cells of an organism the Telomerase
gene is not expressed (germ cells being an exception). Thus, over time
our "plastic caps" slowly break off and our genetic shoe laces unravel
(figuratively speaking that is).

Now I think it is still a bit premature to can say that the "aging" of
cells has been stopped. But hey, the scientific community is no better
than any other and we like the all the press attention we can get (Press
attention = research dollars). I can tell you that the aging of
"creatures" has not been stopped. These researches just showed that
engineering a certain gene into cells in culture -i.e. a totally
artificial environment, when compared to an organism- leads to the cells
dividing a maximum number of times than is normal.

To protect myself: I am not an expert in this field (yet!). Go head and
flame me on the scientific parts. My opinions you will just need to
bear!

Michael Gregory
UT Health Science Center, 
San Antonio, TX



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