IN THIS ISSUE .
June 20, 2007
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Cool Movie: Fly Cells Live
If a picture is worth a thousand words, what's a movie worth?
For researchers studying cell migration, a new "documentary"
of fruit fly cells (bright green) traversing an egg chamber
could answer longstanding questions about cell movement. Historically,
researchers have been unable to watch this cell migration
unfold in living ovarian tissue in real time. But by developing
a culture medium that allows fly eggs to survive outside their
ovarian homes, scientists can now observe the nuances of cell
migration as it happens. Such details may shed light on how
immune cells move to a wound and why cancer cells spread to
other sites. Courtesy of cell biologist Denise Montell of
Johns Hopkins University School of Medicine.
Montell lab home page (no longer available)
abstract (from the June 2007 issue of Developmental Cell)
Viral DNA Helps Cold Sores Recur
A cold sore might go away, but the virus that caused it won’t.
That’s because the herpes simplex virus 1 (HSV-1) hides
out in nerve cells, silencing all but one viral gene. This
stealthy maneuver stems from a DNA segment called an “insulator,”
according to new work by geneticist Jumin Zhou of the Wistar
Institute. Insulators can prevent other DNA elements from
activating genes. The finding marks the first time an insulator,
found in a range of organisms, has been identified in a virus.
By keeping just a fragment of the viral genome active, the
HSV-1 insulator allows infected cells to survive and the virus
to re-emerge. It also presents a potential drug target for
clearing up cold sores once and for all.
abstract (from the May 2007 issue of the Journal of Virology)
Natural Rhythms Linked to Body Weight
Biological clocks set the sleep-wake cycle in humans and
most creatures, and new research suggests they also help control
body weight. Knowing that the gene nocturnin plays a role
in biological clock activity, neuroscientist Carla Green of
the University of Virginia bred lab mice without the gene.
When she fed these mice a high-fat diet, the rodents stayed
thin. Mice with the nocturnin gene eating the same unhealthy
diet, however, gained considerable weight and had fatty livers.
The research suggests a new link between biological clocks
and body weight.
This work was also supported by NIH's National Eye Institute
and National Institute of Diabetes and Digestive and Kidney
abstract (from the June 5, 2007, issue of PNAS)
Scientists Steer Bacteria Toward Chemical
If scientists could steer bacteria to specific targets, the
microbes could deliver drugs to tumor cells, remove pollutants
from the soil, or perform other useful tasks. In a step in
this direction, Justin Gallivan, a chemist at Emory University,
has successfully programmed E. coli to detect and follow specific
chemical signals. To do this, Gallivan’s team equipped
the bacteria with a riboswitch, a piece of RNA that turns
genes on or off when bound to certain molecules. The researchers
believe that riboswitches can help guide other types of bacteria
toward medically or environmentally significant targets.
abstract (from the May 30, 2007, issue of the Journal
of the American Chemical Society)
Promise of New, Improved Gleevec®
Gleevec® is a drug used to treat rare forms of leukemia
and gastrointestinal cancer. But the cancers can develop resistance
to it. By adding just four atoms at a key point in the drug,
a research team led by bioengineer Ariel Fernandez of Rice
University has synthesized a version of the molecule that
appears to be effective against the drug-resistant cancers.
If the molecule works in humans, it could provide new treatment
options for those whose cancer no longer responds to Gleevec®.
lab home page (link is no longer available)
abstract (from the May 1, 2007, online edition of Cancer