Fighting Cancer Through Your Genes

Nov. 6, 2008— -- It is the great mystery of cancer: Why do healthy cells in the body start growing uncontrollably and cause disease? Researchers have taken an important step toward answering that question by looking at the genetics of cancer.

And for the first time in the lab, scientists have decoded an entire genome of someone who has the disease, according to a new study.

"This is the first time that we've been able to look at the entire set of genes from a cancer patient, and that is key because that's going to help us understand what goes wrong," said Dr. Richard Wilson of Washington University in St. Louis, the senior author on the study.

Using donated cells from a woman who died of leukemia, researchers compared the individual genes -- all 20,000 of them -- from her cancer cells, to those from her normal, healthy cells.

Using DNA sequencing, they were able to identify 10 genetic "mutations," or mistakes in the cancer cells that could have caused her cancer. Out of the 20,000 genes, 10 defective genes, which developed later in life, appeared to spiral out of control.

One of the newly discovered abnormal genes blocks chemotherapy drugs from ever getting inside the cancer cells to kill them.

Four others appear to turn off a cell's "early warning system" that would normally prevent a healthy cell from ever turning into a cancer cell.

"If those genes are mutated or de-activated, there's a very good chance the cancer can start to grow out of control," Wilson told ABC News.

The study, conducted at Washington University over many months, was published today in the medical journal Nature.