Systematic, genome-wide scans of two types of cancer — breast cancer and colorectal
cancer — have revealed important new findings about the genetic underpinnings
of these diseases, a team of researchers at the Johns Hopkins Kimmel Cancer Center
in Baltimore, Md., an NCI-designated Cancer Center, reports in the September
7 online issue of Science*. The Johns Hopkins group, which included Victor E.
Velculescu, M.D., Ph.D., Ken Kinzler, Ph.D., and Bert Vogelstein, M.D., reports
that by sequencing the protein-coding regions of some 13,000 genes within each
of the tumors, they identified nearly 200 mutated genes, most of which were not
previously known to play a role in cancer. Observed changes were not duplicated
from one tumor type to the other, and the spectrum of mutations in the breast
cancers was substantially different than in the colon cancers.
?The results from the genome-wide sequencing of only 11 breast tumors and 11
colon tumors at Johns Hopkins University are truly remarkable,? said National
Institutes of Health (NIH) Director Elias A. Zerhouni, M.D. ?This groundbreaking
work provides a dramatic proof of concept that this research approach holds great
promise for providing an understanding of the genomic contributions to cancer.
It also provides confirmation that the strategy selected for The Cancer Genome
Atlas (TCGA) pilot project at the NIH is likely to produce important discoveries
and impact cancer care.?
TCGA was launched as a three-year, $100 million pilot project to determine whether
large-scale genome sequencing and other genomic technologies could help researchers
comprehensively identify the genetic changes that cause cancer. The pilot project,
launched in December 2005, is a collaboration between the National Cancer Institute
and the National Human Genome Research Institute.
?The findings at Johns Hopkins are just the beginning,? said National Human
Genome Research Institute Director Francis S. Collins, M.D., Ph.D. ?As TCGA is
launched and reaches full production, it will significantly and rapidly expand
the amount and types of genetic information revealed about cancer. We anticipate
that as TCGA scales up, we may be able to identify the majority of genetic changes
that cause the most important and common forms of the major cancers. In fact,
the large number of mutations reported in this paper offers a glimpse of what
is yet to come and provides exciting new directions for drug discovery in breast
and colon cancer.?
?There are already a few excellent examples where the discovery of specific
genetic changes has led to the development of effective, targeted treatments
for cancer,? said NCI Deputy Director Anna D. Barker, Ph.D. ?Drugs such as Herceptin
for breast cancer and Gleevec for chronic myelogenous leukemia and gastrointestinal
stromal tumors have offered proof of concept that this is a high-value strategy.
The report from the team at Johns Hopkins is very promising — both for TCGA and
for this approach to drug discovery. Maximizing the numbers of targets available
for drug development in a specific cancer means that patients will ultimately
receive more personalized, less toxic therapies.?
NIH will be announcing two major milestones in the development of The Cancer
Genome Atlas pilot project in the next week.
For more details about The Cancer Genome Atlas, please go to http://cancergenome.nih.gov.
For more information about cancer, please visit the NCI Web site at http://www.cancer.gov,
or call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).
Additional information about NHGRI can be found at its Web site, http://www.genome.gov.