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Scientists Hope Proteins Study Yields Key to Cancer
10/2/2005
The Palm Beach Post
By Jeff Nesmith
Washington -- After Nancy was diagnosed with breast cancer in
2002, she had a mastectomy, radiation and chemotherapy. Six months later it
appeared that her tumors were eliminated.
"All my blood work and scans have been A-OK since then," she said two
months ago in a message she left on an Internet breast cancer support forum.
Like other participants, she signed her message with her first name only.
But last May, efforts to deal with complications from gallbladder surgery
caused her shocked surgeons to discover that her lungs were "riddled"
with cancer, she said. The tests and scans had been wrong.
"Tests came back that it was BC," Nancy, 43, told the other breast cancer
victims who exchange experiences, sympathy and encouragement on the computer
forum, "and since then we have found out it is in a bunch of places in my
bones."
"Just wanted to say hi," she wrote. "I never thought things
would get so bad so quickly. . . . I am absolutely scared to death."
Nancy is among
25 percent of breast cancer patients whose suffering and fear appear in large
part due to the aberrant behavior of a protein that scientists know as
"Human Epidermal Growth Factor Receptor 2," or just Her2.
One of several hundred thousand different proteins in the human body, Her2
normally sits quietly in the membrane of a cell until another molecule latches
onto it and turns it on. Once activated, Her2 turns on other proteins involved
in controlling the way the cell functions.
For reasons not fully understood, Her2 sometimes runs amok, multiplying
enormously. In scientific terms, the protein is "over-expressed."
When that happens, Her2 abandons its role in regulating a normal cellular
activity and triggers a rampage of chemistry, leading to proliferation of
breast cancer, as well as some other cancers.
Drugs such as Taxol and Herceptin have been used by oncologists to suppress the
growth of tumors and at least temporarily cause them to shrink. Success has
been modest and varied.
In the hope of one day finding more drugs for cancer and other diseases, the
National Institutes of Health has set out on a new approach to understanding
proteins and controlling their behavior.
Several hundred thousand different kinds of proteins in the human body control
countless chemical actions within and between cells. They determine whether we
produce antibodies to influenza virus, whether we develop or resist cancer,
whether our thoughts are clear and lucid or lead us into the scrambled
confusion of schizophrenia. They cause lightning bugs to glow and help
earthworms find mates in the darkness of dirt.
Working with collaborating scientists at Emory University
and eight other research centers, NIH hopes to open a new avenue for studying
proteins.
Raymond Dingledine, chairman of the department of pharmacology at the Emory
University School of Medicine, explained that proteins are much more than tiny
lumps of "stuff." Each is intricately designed by nature for a
specific function.
When another protein or a small molecule attaches itself to an irregular spot
on the protein's surface, the protein may wiggle or reshape itself, excite
other proteins or shut down completely.
NIH officials hope the small molecules will be like a set of keys that turn the
gadgets on and off. With such a key in hand, a scientist can block a particular
protein in a tissue culture or a laboratory animal and learn a lot about the
protein's normal activity.
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