Sorting the Genetics Puzzle of Breast Cancer: TGen Researcher and collaborators use technology to categorize breast cancers based on DNA Activity
February 24,2003
Sorting the Genetics Puzzle of Breast Cancer: TGen Researcher and
collaborators use technology to categorize breast cancers based on
DNA Activity
Phoenix, Monday, Feb. 24 Most cases of breast cancer are due to
unknown causes. In fact, cancer specialists believe that the
condition we call "breast cancer" is actually several different
diseases with different origins.
A researcher at the Translational Genomics Research Institute
(TGen), along with collaborators at the National Institutes of
Health and in Sweden used a new gene chip technology to divide
breast cancers into different groups based on their DNA activity.
Their findings are reported in the paper Molecular classification
of familial non-BRCA1/BRCA breast cancer, which appears in the Mach
4 issue of the Proceedings of the National Academy of
Sciences.
This study illustrates perfectly of how the tools stemming from
the Human Genome Project are positively effecting cancer research,
said Jeffrey M. Trent, Ph.D., TGen president and scientific
director, as well as the papers senior author. At TGen, were using
those tools to power research and deliver these innovations to the
individual patient.
About one in every ten cases of breast cancer runs in families.
Several years ago, researchers found two genes, BRCA1 and BRCA2
that cause breast cancer. But those two genes account for only a
quarter of familial breast cancers, and researchers have so far
been unable to identify additional breast cancer genes.
These non-BRCA1/BRCA2 breast cancers (termed BRCAx) probably
comprise a diverse group, meaning that the frequency of genetic
change leading to the development of breast cancer may differ in
different populations.
"We hope that using this kind of global approach to analyzing
complex diseases such as breast cancer will help explain why the
cancers develop, with the long-term goal being improved and
individualized treatment," said Ingrid A. Hedenfalk, PhD, of Lund
University and Malm University Hospital in Sweden, first author of
the study.
Gene chips are a relatively new tool for studying the relationship
between genes and disease. A chip, also known as a microarray, is a
postage-stamp sized glass slide dotted with an orderly array of
minuscule dabs of DNA from a particular tissue.
Microarrays can be used to monitor the simultaneous activity of
thousands of genes in a single cell such as a breast cancer
cell.
Hedenfalk and her colleagues in Sweden, and at the National Human
Genome Research Institute in Bethesda, MD, had previously shown
that these gene expression patterns were different in cancers
caused by abnormalities in the BRCA1 gene compared with cancers
caused by mutations in BRCA2. They were able to divide the tumor
cells into two different groups based on gene expression
profiles.
The researchers have now applied that same technique to BRCAx
cancers, the familial breast cancers not caused by mutations in
BRCA1 or BRCA2.
"We found that the breast cancers included in our study could be
separated into two distinct groups based on differences in their
gene expression fingerprints," said Hedenfalk.
The gene chip studies grouped together breast cancer tissue from
members of the same family--mother and daughter or two sisters,
which suggests that the underlying cause of each family's cancer is
hereditary, Hedenfalk pointed out.
"Our findings illustrate the power of profiling. Instead of using
the lens of the microscope were now using the lens of genetics to
determine where a genetic alteration may occur and further solve
the puzzle of breast cancer, noted Hedenfalk.
For Trent, its further evidence that TGens multi-disciplinary
approach creates a critical mass across a broad spectrum that is
positioned to profoundly affect human health. As the pace of
discovery continues to accelerate, TGen is committed to fostering
scientific creativity and excellence in disease-focused
research.
TGen, located in Phoenix, Arizona, is a research institute whose
mission is to make and translate genomic discoveries into advances
in human health.
