Can the sequence of the human genome be used to find genes that cause cancer?
A study published in 2006 in the journal Science suggests that it can.
Researchers at Johns Hopkins University in Baltimore, Md., compared the protein-coding regions of genes in 22 samples of breast and colorectal cancer to the corresponding “normal” sequences. After eliminating errors and normal variations, the study yielded 189 candidate cancer genes, most of which had never been seen in tumors before.
Francis Collins, M.D., Ph.D., long-time director of the National Human Genome Research Institute who retired in mid-2008, called the study “a big shot in the arm” for The Cancer Genome Atlas project.
Not so fast, say other scientists who believe the sequencing project is misdirected, premature and too expensive.
Jonathan King, Ph.D., professor of Molecular Biology at MIT and a founder of the Council of Responsible Genetics, worries that the emphasis on genetics has overshadowed prevention.
“I’m not arguing against getting all of the information we can about the nature of tumors,” King says. “But the information collection should not take the form that obscures the basic fact: most human cancers are caused by carcinogens that act on you in your lifetime.
“Recognition that carcinogens damage the genes in tumor cells opens the avenue to prevention as a major anti-cancer strategy,” he says. “At the present time, however, research in this area is totally inadequate and woefully under-funded, and has almost disappeared.”
Margaret Spitz, M.D., professor and chair of Epidemiology at the University of Texas M.D. Anderson Cancer Center in Houston, disagrees.
“Most of the really important environmental causes of cancer have been identified,” says Spitz, who serves on the National Cancer Institute’s Board of Scientific Advisors and who was a member of the working group that recommended The Cancer Genome Atlas project.
“But the epidemiologic focus should now be on studying these exposures in the context of the genetic background of the subjects,” she says. “There are good epidemiologic studies ongoing. Of course, we should fund more, but we don’t have unlimited resources.”
That’s worth emphasizing, particularly since the technology required by The Cancer Genome Atlas project hasn’t been developed yet.
“There’s no way they can afford even for over a billion dollars to screen all the genes in all the tumors they want,” says Mark Skolnick, Ph.D., whose team at the University of Utah and Myriad Genetics cloned and developed diagnostic tests for the breast and ovarian cancer genes BRCA1 and BRCA2.
“But they know the cost of sequencing went down 1,000 fold during the time of the Human Genome Project, and they expect it to go down 1,000 fold again,” Skolnick says. “… So they’re going to push the frontier.”