| [ printer-friendly
version ]
An "on-off" switch for
genes
Researchers led by Richard Mulligan, PhD, director
of Gene Therapy Research at Children's Hospital Boston, have created a simple
system for turning genes on and off that may have major implications
for medicine. With this technique, shown to work in mice, a gene could be
activated by a drug or even by natural conditions in the body. For example,
in a diabetic, a gene governing insulin production could be made
to respond to a spike in blood sugar.
The technique involves inserting a
special DNA sequence into a patient's own gene or one introduced by
gene therapy. This sequence encodes a ribozyme, a snippet of genetic
material that spontaneously cuts itself in two. When this cutting happens,
the gene can't make the
protein it's programmed to make. Inhibiting the cutting—as with
a drug—turns the gene on when it's needed.
"Current gene-regulation
methods are more complex and require an "activating" protein
that can cause side effects," says Mulligan. "The ribozyme-based
system is easier to turn on and off, allowing a treatment to be
halted for safety reasons, and is more adaptable to different therapeutic
uses." Laising
Yen, PhD, of Molecular Medicine, was first author on the study,
reported in the September 23 Nature.
| |
| Igor Splawski, PhD (left),
and Mark Keating, MD. |
Genetic syndrome causes arrhythmias and atypical autism
Children's researchers
have found that calcium channel-blocking drugs may treat a rare genetic
syndrome that is often fatal by age 2. Named Timothy syndrome, it causes a
variety of problems, including heart arrhythmias, webbed hands and feet and
autism.
Led by Igor Splawski, PhD, in the Cardiovascular Research
Division, and Howard Hughes Medical Institute investigator Mark
Keating, MD, the researchers found 17 affected children and showed
that the syndrome arises from a single, subtle gene mutation. The mutation
affects a calcium channel found in cells throughout the body, so many organ
systems are affected.
In future studies, Splawski and Keating will investigate
whether calcium channel blockers can ameliorate Timothy syndrome,
and whether this type of calcium channel is involved in other forms of autism.
They will also continue looking for other genes and calcium channels involved
in arrhythmias. Their report appears in the October 1 issue of
Cell.
Beaker bytes is a monthly column in Children's News.
If you have received a grant, launched a new study or have
a paper accepted for publication, contact Nancy Fliesler
at ext. 5-2426 or via email at nancy.fliesler@childrens.harvard.edu.
|
