"Jumping" DNA: A Tool for Finding Cancer Genes
Researchers have developed a new method of inducing cancer in mice and then rapidly identifying the genes involved. The mice are engineered to carry bits of DNA called transposons that, in the presence of a particular protein, jump randomly around the chromosomes of mouse cells, occasionally landing in genes and causing mutations.
As genetic mutations accumulate, the mice develop aggressive tumors and die. Researchers can pinpoint which genes were mutated by tracking molecular "tags" that mark where the transposons inserted themselves. Commonly mutated genes in mouse tumors may be versions of cancer genes in people.
"We think this is a powerful way to identify cancer genes for many different cancers," says Dr. Neal Copeland of the Mouse Cancer Genetics Program in the National Cancer Institute's (NCI's) Center for Cancer Research. "A number of the cancer genes we have found so far in the mice are known cancer genes in humans." Read more
The Cancer Genome: An Important Project for a New Era
Why do colon polyps in some patients never amount to more than a benign nodule, while in other patients they progress to a mortal threat? Why do two patients with the "same" type and stage of breast cancer respond so differently to the same treatment? The answers lie in gaining a deeper understanding of the genetic differences between cancer types. Working with the National Human Genome Research Institute (NHGRI), NCI hopes to undertake a project to characterize the human cancer genome, which we believe will allow us to gain such an understanding and much more.
Although we know more about the molecular basis of many cancers than we did just 5 years ago, the heterogeneity of these approximately 200 diseases has precluded a comprehensive understanding of the genetic aberrations that fuel them. A more systematic understanding could elucidate the cellular pathways that spur cancer cell growth and enable their spread throughout the body. This information, in turn, will provide a catalog of therapeutic targets and allow clinical trials to focus on patients who are most likely to respond to an agent based on knowledge of patients' tumor genetics. And these are just some of the expected benefits. Read more