Gene therapy moves forward
Despite their promise, technologies to correct defective
genes have been plagued by safety problems leading
to unintended — and sometimes fatal — outcomes. But
scientists are inching toward safer, more effective gene
therapies that may one day treat a range of diseases, from
psychiatric disorders to autoimmune diseases to cancers.
Studies in animals and isolated cells in the lab are showing promise. In mice, correcting gene function reverses
depression-like behaviors (SN: 11/20/10, p. 14), blindness
(SN: 7/17/10, p. 11) and type 1 diabetes.
Researchers have also pushed forward on tests of gene
therapy in humans. Small clinical trials have had preliminary
CLOCKWISE FROM TOP: © BETTMANN/CORBIS; P. DE BAKKER; COURTESY OF J.C. BRUUSGAARD/UNIV. OF OSLO
from fat tissue into coronary
arteries could limit damage after a heart attack (SN:
12/18/10, p. 15).
Disease transplants Organ
donors can unwittingly
share a toxic bonus, such as
brain-seeking amoebas, case
reports reveal (SN Online:
Say what? Teen hearing-loss rates have risen by a
third since tests in the 1980s
and ’90s (SN: 9/11/10, p. 14).
New stem cell source
Injecting stem cells harvested
Muscle memory Muscles
store memories of past
fitness in the form of extra
nuclei (bright green, below)
that allow muscle cells to
rebound quickly after a
period of disuse. The find
Scientists hope to one day use gene therapy to treat dis-
eases such as severe combined immunodeficiency, which
confined David Vetter (left, in 1973) to a plastic bubble.
success in treating several rare disorders, though not without risks. A study published in the July 22 New England
Journal of Medicine reports that eight to 11 years after
nine children underwent gene therapy for severe combined
immunode;ciency (widely known as bubble boy syndrome),
seven of the children had improved immune systems. Four
of the children, however, developed leukemia, and one died.
Researchers also report in the Nov. 11 New England
Journal the successful treatment of two boys with a rare
immune disease called Wiskott-Aldrich syndrome. Introducing a functional copy of the disease-causing gene
improved the boys’ symptoms, and both were doing well
more than two years after the therapy.
Gene therapy still faces many hurdles before it can
become a common, safe and effective treatment, but today
things look more hopeful, researchers say. “We’re certainly
in much better shape than we were 10 or 15 years ago,”
says Cynthia Dunbar of the National Institutes of Health in
Bethesda, Md. “Things looked pretty grim in the 1990s, but
now there are clear clinical advances moving us forward.”
suggests that working out
early in life could help
stave off frailness later (SN:
9/11/10, p. 15).
HIV advances Giving an antiretroviral drug mix to men at high risk of HIV may help prevent infection (SN: 12/18/10, p. 16). For women ot already infected, a new vaginal gel shows promise
as a preventive (SN: 8/14/10,
p. 9). Research also shows
that HIV drugs could pre-
vent millions of TB cases in
Africa (SN Online: 2/21/10).
Scientists find that having
high levels of the tumor-
suppressing protein p21 may
fend off HIV (SN: 11/20/10,
p. 9). What’s more, people
infected with HIV but able to
keep the virus in check often
make a variant form of the
HLA-B protein (above), new
work shows (SN: 6/5/10, p. 8;
SN: 12/4/10, p. 12).
Genetic TB prognosis
Profiles of gene activity in
the blood of people infected
with tuberculosis can help
predict who will get sick,
and possibly head off lung
damage or save people from
(SN: 9/11/10, p. 14).