Cancer Patient's DNA Mapped for First Time!!
U.S. News and World Report reported yesterday that researchers have been able, for the first time ever, to decode the complete DNA sequence of a person with Acute Myelogenous Leukemia( AML ). The findings are reported in Nature.
Richard K. Wilson, director of the Washington University Genome Sequencing Center, in St. Louis and senior study author, said that there were 8 previously unknown mutations discovered along with 2 that were already known - mutations associated with AML.
"We found mutations in genes that make a lot of sense when normal cells become cancer cells," Wilson explained. "That they seem to be fairly unique to this particular patient says on the one hand that this is a complicated disease. But the complications validate our approach -- we have to look at a number of patients to see not only what is different but what they have in common."
"Technically, this is a great achievement," added Richard Gibbs, director of the Human Genome Sequencing Center at Baylor College of Medicine, in Houston. "This really is a new era, based on genome studies. There is real clinical applicability, and that is what's remarkable about it."
The study laid out the genome of a woman in her fifties who died of AML. The picture is that the mutations that cause a cell to become cancerous happen in sequence. Each mutation pushes the cell more to becoming cancerous until the final mutation occurs. In this woman's case, every tumor cell had nine of the mutations. Since the tenth mutation wasn't found, it is believed to be the last to occur and possibly the tipping point to the cell becoming cancerous.
Gibbs has said that while the changes in this case are complicated that is no reason to be pessimistic. "It is complicated, but that doesn't mean we're not going to understand it."
New technology may someday make it possible to perform genome sequencing for all cancer patients who need it, Gibbs said. "In the past, our ability to get the information has been questioned," he said. "When it was $10 million a shot, that was one thing. If it costs $5,000 or $10,000 per case, there is no argument about getting the information."
The Washington University center has already started genetic sequencing of a second person with AML, which Wilson said was chosen in part because "it is a cancer type that is extremely aggressive, with no good cure. We have seen some pretty good treatments for other cancers, but this one lags behind."
Genome studies are being done for other types of cancer. At the Baylor center, studies are being done for the brain tumor glioblastoma, lung cancer and pancreatic malignancies. At Washington University, studies are being done for lung and breast cancers.
