As we recently learned in class, scientists are attempting to use viruses to treat cancer and according to this article, scientists are inching closer and closer to success. The idea to use viruses to treat cancer stems from the discovery that when sick with a virus, cancer patients tended to go into remission.
Even though cancer cells can replicate quickly, they can’t defend against attacks as well as regular cells can. Thus the search is on for a virus that won’t damage normal cells but will attack cancer cells. Many viruses were tried, for example, the “cat plague” which was inserted into rural cats, and in most cases failed due to the return of the cancer or the development of a deadly infection.
However, in the 1990s, various steps were made by a few doctors that allowed this research to progress. First, in 1991, Dr. Martuza of Harvard Medical School attempted using the HSV (herpes simplex virus) type 1 as a cancer fighter. He modified the virus by taking certain genes out and then injected the modified virus into mice with brain cancer. The mice first went into remission and then unfortunately died. Around the same time, Dr. Bernard Roizman of the University of Chicago found a master gene in the herpes virus that when removed could only slow tumor growth and could no longer overpower healthy cells. In 1996, Dr. Ian Mohr in NYU altered the crippled virus even more and attacked cancer cells with it until a mutant of the virus evolved and was able to replicate in those cells. Dr. Mohr and a student then made it so that the virus didn’t attack the immune system.
There are some great benefits using viruses to attack cancer. Viruses not only attack the cancer, but get stronger over time, unlike chemotherapy. They also produce an immune response that helps to attack the virus. The side effects of this viral treatment are less detrimental than those of chemotherapy . These side effects include nausea, fatigue, and aches.
Most recently, an engineered form of vaccinia by the name of JX-594 is being tested against liver cancer and has already helped in doubling the survival rate of patients with this cancer. Though there are still hurdles to overcome, it is clear that great progress has been made thus far.