The Human Genome and Cancer
Will the spectacular advances in sequencing the human genome mean that we will finally have a cure for cancer? Not yet, according to the heads of the two pioneering efforts to map the human genetic code. Possibly not even in the next decade, they say. But at some point shortly thereafter ...
Dr. Francis Collins, the director of the National Human Genome Research Institute (NHGRI), and Dr. J. Craig Venter, the president of Celera Genomics, recently discussed the incredible progress that is being made in mapping the human genetic code. Collins heads the federal government's DNA mapping program, while Venter is his primary counterpart in the private sector.
Within the next decade, they both agree, scientists will have a much better understanding of the major genetic factors that cause certain inherited diseases such as some cancers, diabetes and lupus. And once we have this understanding, they say, drugs will soon follow to target specific diseases in a remarkably specific-and highly effective-fashion.
Both Collins and Venter believe that the complete sequencing of the entire human genome will be accomplished within three years. And each of their efforts appear to be within mere months of completing broad drafts covering about 90 percent of the sequence.
The most current findings of both groups were simultaneously published in February 2001 issues of the journals Nature (The Human Genome Project) and Science (Celera Genomics).
"The consequences are going to be enormous," says Collins. He forecasts that as many as a dozen accurate, predictive genetic tests for specific diseases will be perfected by 2010. Along with them, he says, will come individually tailored prevention strategies regarding nutrition, health practices and even genetically based vaccines.
Much of tomorrow's drug therapy will therefore be guided by a patient's genetic profile. And cancer patients are expected to be the primary beneficiaries.
According to data from the Pharmaceutical Researchers and Manufacturers of America, an industry trade group, there are currently more than 150 promising new cancer drugs in the biotechnology pipeline that will be directly spurred by gene-mapping initiatives, followed remotely by 35-40 new drugs for infectious diseases, and even fewer for HIV/AIDS and heart disease.
At a recent meeting of the National Congress on the Future of Genomics, Biotechnology, and Pharmaceuticals in Medical Care, NHGRI's Collins asserted that the new drugs that will result from the mapping of the human genome will be nothing short of revolutionary.
"You will have very detailed molecular information about genes and their protein products," he said, "enabling you to design a drug that goes right to the heart of the problem-not some downstream step, but right at the center of it to fix it."
And yet a cautionary flag was thrown out by William Haseltine, the CEO of Human Genome Sciences. Given the current technology and the time needed to bring drugs to market, he said, "the rate at which disease genes are identified will far outstrip the development of cures."
What is being lost in this onslaught of new information is the ability of doctors themselves to fully absorb all of these lightning-fast genetic advances, warns Collins. Patients are being bombarded with headlines touting potential cures for their ailments, and they are coming to their doctors for guidance. But many doctors simply do not have sufficient formal training in genetics, he asserted.
Collins cited the need for "a major education effort" aimed directly at healthcare professionals, possibly involving organizations such as the American Medical Association and the American Nurses Association.
Collins' fears are clearly warranted. In a survey of 1,958 dieticians, occupational and physical therapists, psychologists and other healthcare workers, Dr. Virginia Lapham of Georgetown University Medical Center in Washington, DC and colleagues found that 80 percent of these clinicians do not have formal training in genetics, yet 70 percent of them have been called upon at some point to provide genetic advice to their patients.
Writing in the journal Genetics in Medicine, the researchers noted that about two-thirds of these professionals would clearly welcome more training in genetics, but the availability of appropriate continuing education programs is seriously lacking.
Lapham's team called for intense medical education efforts so that practitioners can meet the exploding patient demand for answers to genetic questions-most of which did not even exist a few years ago.
SOURCES:
National Human Genome Research Institute (http://www.nhgri.nih.gov)
Pharmaceutical Researchers and Manufacturers of America
Pharmacy Today, 2001; 7(1):1,12
National Congress on the Future of Genomics, Biotechnology, and Pharmaceuticals in Medical Care, Arlington, Virginia
Science, February 16, 2001; 291:1304-1351
Nature, February 15, 2001; 409:860-921
Genetics in Medicine, July/August 2000; 2:226-231
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