DNA Use a Shot in Arm for Biotech : * Science: The technology could have a $1-billion annual market diagnosing diseases such as AIDS and cancer. But some fear that it may have serious implications for privacy and civil liberties.
When the remains of some soldiers killed in the Persian Gulf War were returned to the military’s pathology labs in Delaware last year, dental records and fingerprints proved useless in establishing their identities. The men had died so violently in an explosion inside their tank that it was impossible, using conventional scientific techniques, to determine which families should be notified.
But using a breakthrough DNA-identification technology, scientists at the laboratories of pharmaceutical giant Hoffman-La Roche helped the Army regroup the remains of the soldiers, matching arms and trunks by studying their genetic makeup. And by examining the DNA of the soldiers’ parents, wives and children, the pathologists were able to return them to their families with assurances the man they buried would be their own.
In one case, the Army was able to identify a soldier’s remains by comparing their genetic makeup to tiny bits of hair left behind in his electric razor.
The remarkable technology that helped the military identify the soldiers is called DNA amplification. It makes a person’s unique genetic blueprint spring to life from even the most microscopic fragment of tissue.
When the Defense Department announced last week that it plans to establish a DNA database with genetic fingerprints of all 1.5 million service members to identify casualties of future wars, the potential market for the technology received a huge boost.
Already, DNA amplification’s capacity to identify disease in the living is making it one of the hottest processes in biotechnology. Analysts say products such as tests for AIDS and cancer using a type of gene amplification known as PCR--short for polymerase chain reaction--could, along with genetic dog tag-type uses, amount to a $1-billion to $2-billion-a-year market.
The potential value of DNA amplification was highlighted last summer when Hoffman-La Roche paid a surprisingly high $300 million to biotechnology firm Cetus for its PCR gene amplification technology.
Hoffman-La Roche expects to increase last year’s $15-million PCR research budget to $22 million in 1992. The technique is part of the fast-growing diagnostics sector of pharmaceuticals, which is rapidly increasing its share in Hoffman-La Roche’s total sales.
Already, the company is marketing kits to diagnose Lyme disease and cystic fibrosis, and it is getting ready to sell tests for cancer and tuberculosis and to identify paternity. Although Hoffman-La Roche is the only company using the PCR process, other companies are exploring ways to tap into the potential market for genetic identification.
Scientists have been working feverishly to explore ways to use PCR for almost a decade. First developed in 1983 by researchers at Cetus Corp., based in Emeryville, Calif., PCR by 1988 was such a hot scientific topic that more articles were published on PCR in scientific journals than on any other subject except high-temperature superconductivity. But it is only now, as PCR-based products begin to hit the market in force, that its true power is becoming apparent.
DNA amplification helps find a bit of DNA--something like looking for a needle in a haystack--by making the DNA reproduce itself millions of times and, in effect, creating a haystack of needles. The identifying technique works by taking one strand of DNA--the microscopic building block of genes that is unique to each human being and to each type of virus--and replicating an identifiable part of it in the same way DNA divides naturally. Polymerase, an enzyme that makes DNA replicate when cells divide, is made to attach itself to a part of the DNA chain and make that part replicate itself millions of times. When enough strands have been created by this process, tests can reveal the presence in a blood sample of the targeted DNA--for example, the DNA of the AIDS virus.
While PCR is one of the hottest and potentially most profitable technologies in the pharmaceuticals industry today, it is also one of the most controversial.
Its power to reveal and catalogue the genetic traits of large numbers of individuals could have serious implications for privacy and civil liberties.
The FBI and at least three states, including California, are developing a database of samples of tissue from convicted felons, for example, that would help connect individuals to any hair or semen they might leave at the site of a crime in the future. According to Marcia Eisenberg, a research scientist at Hoffman-La Roche, 15 states have laws allowing them to collect genetic data bases on felons. PCR is among a number of technologies used in forensic DNA analysis.
Civil rights advocates have sharply criticized the military and law enforcement genetic database development, saying there are inadequate safeguards for the privacy of individuals. If a soldier is accused of a crime, for example, information in the military database might be used to help convict him.
Privacy activists are worried that the large scale of the Army’s database could set a precedent and encourage calls for “genetic social security numbers” or widespread genetic screening.
On the other hand, the ability to identify biological tendencies before they are readily apparent also could be a great boon to the prevention and treatment of deadly and debilitating disease.
“Virtually any disease a human could have, we think we’ll have some method of identifying susceptibility to it by looking at DNA,” says Tom McMahon, president of Hoffman-La Roche’s diagnostics division.
Doctors and researchers are excited about DNA amplification because it has vast potential for diagnosing diseases. Using the technology, doctors can discover cancer or AIDS long before they can be diagnosed by other means. In infants, for example, common AIDS tests that identify antibodies against the virus don’t work because a baby picks up the antibodies from its mother even if it hasn’t caught the virus from her. PCR technology can help identify the presence of the DNA of the virus itself, even in tiny quantities.
How PCR Gene Amplification Works PCR, or polymerase chain reaction, makes DNA, the “genic fingerprint” unique to each person --and to each disease--visible by making it reproduce millions of times. In effect, instead of using a stronger magnifying glass to look at a tiny object, the process makes the object multiply until it becomes visible. PCR can identify a soldier killed in action from even a tiny piece of his or her tissue. It can link a criminal to a crime from blood or semen left behind. And it can identify tiny quantities of the AIDS virus or of cancerous cells long before they can be diagnosed by other means.
1. A blood sample is heated to separate strands of DNA. Distinctive AIDS DNA segments, or “primers,” are added.
2. The primers look for the matching segment of AIDS DNA in the blood sample. If it is present, they attach themselves to it.
3. Polymerase, an enzyme, is added to the sample. It attaches to the targeted distinctive sections of DNA.
4. The polymerase triggers the targeted sections of DNA to reproduce millions of times.
5. When enough DNA segments are made, the disease can be detected by a test.
Source: Hoffman-La Roche
