The disease poliomyelitis, often just called polio, which crippled millions of children until a vaccine was developed in the 1950s, is now being turned into something beneficial. The same inactivated virus used in the vaccine seems to also, when introduced into a type of brain tumor called glioblastoma multiforme, destroy the tumor from the inside. Researchers have discovered that cancer cells have receptors that turn out to invite poliovirus infection.
The poliovirus vaccine, invented by Jonas Salk, was first made available in 1955. It was the first major advance in combating poliomyelitis, which at the time affected tens of thousands of children annually—in fact, the worst polio outbreak in the United States occurred in 1952 and 1953, with twice the average number of cases in the latter year. Thanks to the vaccine, however, polio was almost entirely eradicated in the U.S. by 1985, and fewer than 300 cases were reported worldwide in 2012.
Glioblastoma accounts for more than half of all brain tumors, and affects almost 10,000 Americans. Though rare, it’s deadly, even with treatment; most patients receiving radiation therapy and chemotherapy nonetheless die of the condition in less than a year and a half. White or Asian people who are more than 50 years old are at the most risk, with slightly higher prevalence in men than in women. The cause is poorly understood, but links have been found with exposure to lead and to the industrial plastic polyvinyl chloride, and to the mosquito that spreads malaria.
Although radiation and chemotherapy have been of limited effectiveness, other treatments are available. Surgery is sometimes performed to remove the tumor, though this is, obviously, extremely risky. In addition, results are mixed, and the surgical option doesn’t always prevent the cancer from recurring. Some new treatments use targeted intravenous medication to focus on specific features of cancer cells, killing them. Researchers at Duke University have discovered that is somewhat how poliovirus functions as a cancer treatment. The treatment uses a form of the ancient disease specifically designed to be harmless to healthy human cells. The virus is introduced directly into the tumor, where it destroys the cancer from within while also triggering the immune system to attack it.