From: William John (anthropy@inwave.com)
Date: Tue Dec 29 1998 - 07:18:20 MST
-----Original Message-----
From: William John [mailto:anthropy@inwave.com]
Sent: Tuesday, December 29, 1998 8:05 AM
To: ISML
Subject: immortality enzyme studied
see also The Transhuman Transformation Series:
http://thefuturist.net/WebBioTech1-Cloning.html
http://thefuturist.net/WebBioTech2-Regen.html
http://thefuturist.net/WebBioTech3-Genome.html
http://thefuturist.net/WebBioTech4-GeneTherapy.html
http://thefuturist.net/WebBioTech5-Banking.html
http://thefuturist.net/WebBioTech6-Implants.html
http://thefuturist.net/WebBioTech7-Uploading.html
http://thefuturist.net/WebBioNanoTech.html
http://thefuturist.net/WebBioCryoTech.html
http://thefuturist.net/WebBioOmega.html
http://www.infobeat.com/stories/cgi/story.cgi?id=2557799568-8b0
07:20 PM ET 12/28/98
'Immortality Enzyme' Is Studied
'Immortality Enzyme' Is Studied
By JOSEPH B. VERRENGIA=
AP Science Writer=
Appearing forever young like Dick Clark is everybody's dream.
But, biologists wonder, what good is immortality if all those extra
years are accompanied by cancer?
That's the quandary posed by the discovery earlier this year
that a body substance called telomerase is an ``immortality
enzyme'' that encourages cells to keep dividing indefinitely
instead of dying with age.
Scientists theorized that telomerase could be used to slow the
aging process. At the same time, some feared that the enzyme could
cause cancer by allowing cell division to run amok.
Now, new experiments by the same University of Texas team of
researchers have concluded that such fears are groundless.
The researchers watched human cells divide hundreds of times in
test tubes and concluded that telomerase does not by itself turn
healthy cells into malignant ones. In fact, they said the enzyme
may offer promising new ways to treat cancer.
``Telomerase does not cause cancer progression,'' said Woodring
Wright of the UT Southwestern Medical Center in Dallas, a co-author
of the study, published Tuesday in the January issue of the journal
Nature Genetics. ``The abnormalities seen in cancer are due to
other mutations.''
Other researchers said the experiment is too limited to
exonerate telomerase.
They said that while telomerase may not cause cancer by itself,
it appears to play a fundamental role in the growth of cancerous
cells, even if the cancer itself is triggered by, say, radiation or
a virus.
``There is no simple statement that telomerase is irrelevant to
cancer,'' said Ronald DiPinho of the Dana Farber Cancer Institute
of Harvard University. ``It's a very complex subject.''
Thomas Cech, a 1989 Nobel laureate and biochemistry professor at
the University of Colorado, said the Texas researchers looked only
at the effects of adding telomerase to a normal cell, not what
happens when telomerase is blocked in a cancer cell.
A year ago, Wright and colleague Jerry Shay published research
demonstrating that telomerase enables cells to keep on dividing and
avoid the normal process of aging and death.
Normally, human cells divide about 75 times over a lifetime. But
each time a cell divides, the telomere, or the protective end of a
chromosome, erodes. Eventually, the telomere becomes too short to
protect the chromosome. When that happens, the cell can no longer
divide and eventually dies.
By the time a person is an adult, most of their healthy cells no
longer contain any telomerase. But 90 percent of cancer cells have
been found to have telomerase, raising suspicions that telomerase
is linked to cancer.
In test-tube experiments, Wright and Shay showed that normal
cell death can be avoided by inserting a gene that instructs the
cell to produce telomerase.
As of late December, the cells had divided as many as 220 times
beyond their typical lifespan, and none exhibited cancerous traits
such as abnormalities in chromosomes, the researchers said.
At least a dozen pharmaceutical companies are in the early
stages of developing drugs that would shut down telomerase and
starve cancer of the tumor growth substance critical to its
survival.
Telomerase also is being considered for use in unclogging blood
vessels, restoring circulation involved in some forms of blindness,
and accelerating the healing of skin grafts.
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