Engineering the Medicine of the Future
by Mamon Abrahim
We have come a long way in the field of medicine in the past several decades. New medicines are constantly being pumped out in pharmaceutical labs every day and we have managed to almost eliminate certain diseases that once plagued humanity, such as poliomyelitis and smallpox. Despite these advances, however, there are still ailments that medicine cannot cure. Diseases like HIV/AIDS and cancer affect millions every year. Due to the complexity of the mechanisms behind these conditions, modern medicine has yet to adequately target them. Scientists have suggested that a new approach may be needed, perhaps looking at medicine in a completely different way. One breakthrough that has yielded promising results is genetically engineered viruses.
Genetic engineering is a relatively new field in science. Up until the 1980s, it was very difficult for scientists to learn about genes, let alone change them. The Human Genome Project itself took six years to plan and another 13 years to complete! The great deal of money, technology and time required to sequence made it all the more challenging for scientists to compare and contrast different genes. With recent advances in technology, however, it has become exceedingly cheap and efficient to sequence genomes. This improvement in technology has meant that scientists can now sequence more genes from different samples and subsequently note the function of each gene. In addition, the technology has allowed scientists to turn off and on certain genes, thereby changing key features of the sample.
This is essentially how genetically engineered viruses work as well. Viruses are chosen specifically because of their low amount of genes in comparison to bacteria. Because they have much fewer genes than other organisms, scientists have a good idea about what most of the genes in a virus do. They choose a virus that they believe can give them the result they want with little modification. Then, they turn switch the desired genes on and off and observe for the desired effect.
The technology is no longer just a theory, as scientists have already genetically engineered multiple viruses. In fact, tests have been conducted with human patients and the results are nothing short of astonishing.
One study conducted by the Institute of Cancer Research in the United Kingdom tested the effects of a genetically engineered herpes virus on skin cancer. Contemporary treatments for cancer suppress the immune system in order to halt tumor growth, which in turn makes the normal body cells vulnerable to viral attacks. Because viruses thrive by injecting copies of themselves into cells and then replicating until the cell is destroyed, they are of particular interest to cancer researchers.
In this case, the herpes virus was used by removing two key genes that allowed it to infect healthy cells. Scientists then injected the virus into the tumors. To mush delight, they found that viruses would inject themselves into the cancerous cells, replicate and then destroy the cell. Once the viruses had destroyed the cancer cells, the host body’s immune system simply destroyed the genetically engineered virus. 400 patients with otherwise inoperable cancer were treated and many of them lived, on average, twice as long as those with the same form of cancer who did not receive that treatment. 10 percent of the patients went into remission with no signs of cancer. The others showed no negative effects from the treatment.
This is not the first time that a virus has been genetically engineered. The primary instance actually came in 1968 when the tobacco mosaic virus genome was changed to express polylysine, a protein used for cell adherence.
Beyond the positive effects, there are concerns and setbacks about the technology as well. The main concern for genomic engineering is the lifespan of the virus. Because the body is vaccinated for the virus prior to injection, the immune system tends to attack the virus before any significant damage to the tumor has been done. In this way there is a constant need to choose the right virus with the right infectivity, potent enough to infect humans and reproduce quickly but not enough as to damage the human host. Research for the right host is currently ongoing.
For now, while we are not likely to see this therapy used in hospitals anytime soon, the results do look promising. We may even see the research expanded to include other forms of diseases that are difficult to treat, such as HIV and AIDS. All we can do right now is wait optimistically, for the cure for a major disease may be fast approaching.