By Robert Hazen, George Mason University
With only a few years of research under our belts, no one in gene therapy can predict at all where this research might lead 50 or 100 years down the road. Thus, it’s imperative to draw some ethical distinctions. We have to consider some of the ethical implications of the genetic alteration of humans and where are we going to draw the line.
Gene Therapy and Cancer Treatment
The most promising application and invention of gene therapy would be the ones made in the area of cancer treatment. It is borne out of the fact that future research in cancer lies in the identification and understanding of cancer-susceptibility genes, and, of course, the way they act on cells.
The growing recognition of a genetic basis of cancer points to new approaches for its treatment that actually involve fixing genes—a gene therapy. A physician can determine which genes are defective, and at which checkpoints damage is occurring. This would allow us to develop drugs that target these potential vulnerabilities. We may be able to artificially control those checkpoints.
Someday ,we can hope that therapies are going to be tailored to specific genetic fingerprints of each person’s cancer. But that requires discovering and identifying a growing list of inherited and acquired cancer susceptibilities, and determining the best treatments for each individual.
This is a transcript from the video series The Joy of Science. Watch it now, on Wondrium.
When Do We ‘Need’ Gene Therapy?
Clearly, very few people would draw the line in saying we shouldn’t cure a genetic disease in a child who is going to die. If we have an infant who’s not going to survive past his or her fifth or sixth birthday, and we can apply a gene therapy—for example, just a viral nose spray—we’re going to do it; at least most people are.
But then, what about lesser ailments? What about crippling arthritis, which can be a hereditary thing? What about bad eyesight? Would we give our child a nose spray if it was guaranteed to increase the IQ by 20 points? Interestingly, these aren’t just hypothetical questions. Biologists are now studying the possibility of gene therapy for hair loss. The substantial roadblock here is that no one’s discovered exactly which gene causes baldness; but the idea is that someday we may be able to have a shampoo that causes our hair to grow again.
Engineering a 47th Chromosome
On a much more sobering note, some geneticists suggest engineering a 47th chromosome, which can be injected into an embryo. That 47th chromosome could have genes that fix genetic diseases, give us new abilities, new insights that perhaps adjust behavioral patterns. What do we think about that—a 47th chromosome that’s engineered and injected into everyone? Whether it is a good idea or not, it’s clearly something society is going to have to deal with.
Someday, when we’ve learned the language of genes and their regulations, humans may gain the ability to design entirely new organisms. Given the youthfulness of molecular genetics, and its extraordinary pace of discovery, it seems inevitable that someday we’re going to be able to modify human traits and abilities, and we’re going to be able to produce clones of virtually any imaginable organism, with desirable characteristics of our own choosing.
Then, the central question of genetics is not going to be, what is the language of life, but rather, what limits are we going to place on these abilities? Goethe spoke for our generation, as well as his own, when he said,
It is not possible to wait, with new explorations, until man is a moral being.
Genetic Modifications in Animals
Some of genetic modifications have become quite routine in experimental animals such as fruit flies and in mice. Common genetic modification procedures seen involve injecting modified genetic material, a transgene, into many of the fertilized eggs. In a few eggs, the new DNA may be incorporated into the host genome—although, once again, there’s very little control over exactly where that’s going to happen.
For example, scientists have made a few mice with predisposition to specific types of cancer; wonderful animals for research purposes, even though most of the experiments on the mice are going to fail as we can’t apply the same protocol to humans.
These techniques have a side benefit, by the way: they provide researchers with wonderful clues about an animal’s development. By locating the site of a transgene within the mouse genome, for example, we can see how gene expression occurs. We can see the regulatory proteins and where they occur and understand tumor formation in a much more rigorous way, just by modifying the mouse genome. Again, we can’t do that with humans.
Our Collective Sense of Values and Ethics
This raises very serious ethical questions. Most people consider such efforts acceptable if they’re applied towards mice, with an effort to understand the origin of cancer. But how far can you push these ethical questions? That’s something for each of us to consider, and they are questions which are going to be raised more and more, as we’re more able to alter genetic material in humans.
To conclude, human diseases are perhaps the greatest need, the most daunting challenge, in genetic research. Both inherited genetic diseases and acquired cancers occur when several genes are defective. Repair of these defective genes could save many, many lives, but this technology clearly raises numerous ethical questions.
It’s imperative that progress in science, therefore, be accompanied by progress in our collective sense of values and ethics.
Common Questions about Gene Therapy and Ethical Implications
The future research in cancer lies in the identification and understanding of cancer-susceptibility genes, and, of course, the way they act on cells.
Some geneticists talk about engineering a 47th chromosome, which can be injected into an embryo. That 47th chromosome could have all sorts of good genes: genes that fix genetic diseases, give us new abilities, new insights that perhaps adjust behavioral patterns.
Common genetic modification procedures seen involve injecting modified genetic material, a transgene, into many of the fertilized eggs.
