TUESDAY, July 1 (HealthDay News) -- Scientists have discovered
that they can use a kind of dimmer switch to stop a "cancer signal"
from contributing to the development of tumors.
The findings don't represent a cure, and no one knows if they
will even lead to better treatments for cancer. But the research
does clear a pathway for scientists to follow as they determine
which "switches" they need to turn off to stop cancer in its
tracks, said study senior author Dr. Dean Felsher, an associate
professor of medicine and oncology at Stanford University School of
Medicine.
"You do not have to completely shut off a cancer switch to have
a beneficial effect on cancer," he said. "It's a useful improvement
over how we've been understanding things."
Normally, cells are programmed to commit suicide if they detect
that they're damaged. "The cell says, 'I shouldn't be alive,
something is wrong with me, I'm broken.' And it decides to kill
itself," Felsher said.
But in some cases, the cells don't automatically kill themselves
as they're programmed to do. Instead, proteins send signals that
tell the cells to keep growing, said William Tansey, a professor at
Cold Spring Harbor Laboratory who studies how tumors develop. "As a
result of this push, cancer can develop."
A gene known as Myc is considered a major player in this
process. At times, it doesn't cause problems. But its "Jekyll and
Hyde" nature can turn it into a villain that sends marching orders
to cells, Felsher said.
In the new research, Felsher and colleagues worked with
genetically engineered mice to develop a way to slightly adjust the
Myc switch instead of turning it on or off.
The study was published in the July 1 issue of
Cancer Research.
The researchers found that by turning down the Myc switch, like
using a dimmer switch on a lamp, they could shrink tumor cells to
normal sizes and restore their ability to die as they're supposed
to.
The findings suggest that researchers trying to turn off the
signal may not need to go that far, Felsher said. "Before, we
thought there were these switches that you had to turn on and off,"
he said. "Now, we've added a dimmer. To me, that's really
exciting."
But he cautioned that there's no treatment based on this
approach yet, and fixing the genetic signals won't work for every
type of cancer.
However, scientists have implicated the Myc signal in cancers of
the immune system and the lungs. "It is estimated that problems
with Myc contribute to the cancer-related deaths of as many as
70,000 Americans every year," said Tansey. "So, it's a huge
issue."
As for the current study, Tansey said it's an "important
step."
"But cancer is a very tough problem," he said, "and a cure will
only come once all its facets have been revealed, and the
technology required to manipulate the cancers refined."
More information
Learn more about cancer genetics from the
National Cancer Institute.