Monday, May 1, 2000
Real vs. Unreal
Merlin should have lived so long
While the magician Merlin of King Arthur's court was said to
have lived backward, getting younger as time moved forward, it is unlikely that
even cloning technology will ever make that situation a reality. The apparent
rejuvenation of donor cells used for nuclear transfer cloning of cows, and cells
from the resulting cows themselves, may have positive implications for engineered
cell therapies. But only time will tell whether the cows cloned by Advanced Cell Technology Inc. will live longer or healthier lives.
At this point, it is clear that the technology requires cloning
of a patient's cells, creation of an embryo from those cells, and harvesting
of cells from that embryo. By advocating cloning and use of embryos for therapeutic
use, the company is thus pressing the envelope of the public debate on embryo
research, which opponents liken to Nazi experiments and proponents cite as the
source for miraculous cures (see "Sound Bites on Stem Cells", A7).
On less emotional terms, the technical implications of the
Advanced Cell work are also wide open for scientific debate, demonstrating that
the real outcomes of stem cell research must endure the more mundane, stepwise
process of scientific discovery.
Proliferation is key
In last week's Science paper, Advanced Cell (Worcester, Mass.) and colleagues showed that somatic cells derived from cow fetuses that had been cloned from aged cow donor cells appeared younger by several measures than cells from normal cow fetuses. The cloned cells had longer telomeres (the ends of chromosomes that typically shorten with cellular age); higher levels of expression of an aging-related marker gene; and were able to divide in culture for a greater number of doublings than normal