The first cancer patient ever to be fully decoded has yielded a set of mutations that scientists suspect may have caused or encouraged her disease.
Gene Mutation in Cancer Cells
In earlier studies, fewer genes have been searched for the mutations, which are genetic mistakes. The ones discovered in this research didn’t occur in the womb but later in life, like the majority of gene mutations that cause cancer.
Scientists found 10 gene mutations contained only in cancer cells of the woman in her 50s who died from leukemia. Evidently, the mutations encouraged abnormal growth and allowed it to resist chemotherapy, or drug treatment.
Eventually, researchers say the findings will lead to new cancer treatment plans, as well as helping doctors make better choices about existing therapies. They expect it will be particularly helpful in breast, brain and lung cancers, as well as leukemia.
First of Many Gene Mutation Studies
Senior study author Richard K. Wilson, director of Washington University’s Genome Sequencing Center, noted that this is only the first of many such patients whose entire genome – all their DNA – will be sequenced. Together, they’ll provide a host of clues about what happens in the genes when cancer starts to take hold.
Dr. Wilson envisions a future only 5 to 20 years distant where DNA sequencing can be done with a drop of blood on a chip that can be inserted into a computer to generate a report about which drugs in what combination will work best for that particular patient.
The project was made possible by recent advances that reduced the cost and effort needed to analyze 100 million pieces of DNA. Still, it took $1 million and several months to complete. The current study found eight more gene mutations than the two mutations previous research methods would have located, and analyzed 20,000 or so genes rather than just a few hundred.
Cancer Gene Mutation Skepticism
Even so, earlier research has led to the production of so-called targeted drugs, such as Herceptin and Gleevec, which zero in on particular cell defects. In fact, some in the scientific community thought sequencing the full genome was wasted effort, according to Dr. Wilson.
Financial backing came from a private source, while the National Cancer Institute contributed little and late after funding preliminary research. The cancer institute is now supporting efforts to decode other cancer genomes.
For further information: “DNA sequencing of a cytogenetically normal acute myeloid leukaemia genome,” by Timothy J. Leyine et al, Nature, 456, 66-72 (6 November 2008).
