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February
24, 2003
UND
research team studies biomarkers
to discover new clues for treating cancer
GRAND
FORKS, N.D. - In the battle against cancer, researchers are studying
how cancerous cells provide clues known as biomarkers that can help
doctors diagnose and treat their patients more effectively.
Mary Ann (M.D., Ph.D.) and Donald (Ph.D.) Sens, a husband-and-wife
research team at the University
of North Dakota School of Medicine and Health Sciences, say
that when some types of cancer cells overproduce a specific protein,
the information can be used to determine the cancer's stage of development
and how aggressively to treat it.
The Sens' two cancer research projects - both funded by the National
Institutes of Health (NIH) - relate to a protein called metallothionein
(pronounced met-aloe-THIGH-oh-neen). Normally, cells produce metallothionein
to protect themselves from cadmium, a toxic heavy metal. In their
research, the Sens have found that metallothionein is overexpressed
in some human cancers.
"What
we do is study samples of human tissue and ask how the expression
of this protein correlates to how a cancer operates," says
Donald. "It becomes important in breast, bladder and prostate
cancers. By identifying biomarkers, we try to define the seriousness
of an early cancer, which determines whether to treat it very aggressively
or not as aggressively."
In their search for cancer-related biomarkers, the Sens rely on
excess diagnostic human tissue samples that have been discarded
as medical waste. Using these samples, they have developed models
of tumor cell lines, enabling them to bypass animal testing.
"This is called retrospective research because we're looking
at samples from pre-existing specimens," says Mary Ann, a pathologist
and chair of the Department of Pathology at the UND medical school.
"When we test a new biomarker for prostate cancer, we need
to determine if it can predict what will happen.
"I look at the tissue sample under a microscope to see if
it has a certain protein. If it does, I ask whether it makes a difference.
I already have the answer because I'm looking at a sample from 20
years ago and I know what happened to the patient."
The Sens' research could influence the decisions doctors make about
how cancers are treated today.
"With the information biomarkers provide, we can say, yes,
this is a bad cancer or, no, this cancer is not going to progress,"
Donald explains. "We also know that when metallothionein is
overexpressed, it interferes with Cisplatin, a chemotherapy drug
used to treat cancer patients."
In addition to research on using biomarkers as a diagnostic tool,
the Sens have a second NIH grant to study the cause of metallothionein
overexpression in the kidneys and what happens when it occurs.
"We use our tissue culture models in the lab to manipulate
genes and discover how a biomarker really works," says Donald.
"We take the metallothionein gene, put it in a cell that doesn't
normally have it and see what happens.
"We're attempting to prove that it starts binding up all the
extra zinc in the cell because zinc is very similar to cadmium.
But to live, you need zinc as a mineral," he says. "When
metallothionein takes zinc from many other proteins that need it,
the cell loses its proper mechanism for growth control."
Some of the Sens' work on the metallothionein protein as a biomarker
has been published in the American Journal of Pathology (Metallothionein
Isoform 3 Overexpression Is Associated with Breast Cancers Having
a Poor Prognosis - July 2001) and Environmental Health Perspectives
(Metallothionein Isoform 3 as a Potential Biomarker for Human Bladder
Cancer - March 2000).
Mary Ann Sens became the chair of the medical school's pathology
department last August. She and Donald came from the University
of West Virginia, bringing with them a research team that includes
assistant professors Scott Garrett, Ph.D., and Seema Somji, Ph.D.,
and graduate students Volkan Gurel and Seongmi Park, as well as
two, $1.2 million NIH research grants, each for four years.
H. David Wilson, M.D., vice president for health affairs and dean
of the medical school at UND, says bringing in the Sens and their
research team transforms a department that was traditionally focused
on education to one engaged in both education and research. Helping
to make it possible was start-up funding for new faculty from the
North Dakota Biomedical Research Infrastructure Network (BRIN) through
the state's Experimental Program to Stimulate Competitive Research
(EPSCoR).
"The start-up package, including the funding from BRIN, was
very helpful," says Wilson. "Our commitment to the Sens
includes whatever they need from the medical school standpoint,
plus the assistance from BRIN and EPSCoR. Putting all of our funding
dollars together obviously made us very competitive."
Donald Sens says, "We had two young people in our laboratory
who were extremely good and this was an opportunity to bring them
along. North Dakota wanting to develop research was a unique opportunity
to move the program without disrupting it."
"With Mary Ann and Donald Sens, we have high quality people
who are going to be here for the long haul. Suddenly, we're thought
about on the national map," says Wilson.
Download
high-resolution photos to accompany this news release.
Contact information:
Mary Ann Sens, chair, UND School of Medicine and Health Sciences
Department of Pathology, at (701) 777-2630 or msens@medicine.nodak.edu
Donald Sens, professor, UND School of Medicine and Health Sciences
Department of Surgery, at (701) 777-2561 or dsens@medicine.nodak.edu
H. David Wilson, dean, UND School of Medicine and Health Sciences,
at (701) 777-2514 or hdwilson@medicine.nodak.edu
John Shabb, North Dakota BRIN director, at (701) 777-4946 or jshabb@medicine.nodak.edu
Patrick Miller, public information professional, North Dakota Biomedical
Research Infrastructure Network, (701) 777-6377 or pmiller@medicine.nodak.edu
Pamela Knudson, director of public affairs, UND School of Medicine
& Health Sciences, (701) 777-4305 or pamelak@medicine.nodak.edu
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