In September 2013, an outbreak of an avian virus infected pigeons in Moscow. The birds displayed erratic behavior such as flying into buildings, cars, and people, stumbling around on the ground, and simply falling out of the sky. Many of the birds were not only lethargic but adopted a droopy-headed, stumbling walk reminiscent of the portrayals of a zombie walk. The pigeons had what is known as Newcastle disease virus (NDV). NDV can be fatal to 100 percent of the birds in a flock which has not been vaccinated against the disease. It is highly contagious. The same disease seen in these Moscow birds, however, holds promise as a possible cancer treatment.
While there is currently no existing treatment for birds afflicted with the Newcastle disease virus, this very factor may play a part in having NDV become an effective cancer treatment. NDV is not simply limited to birds such as pigeons or poultry stock. Approximately 96 percent of humans are also susceptible to the disease. While humans also can have NDV, the symptoms generally range from things such as a runny nose to the possibility of conjunctivitis or laryngitis. In other words, in humans the majority of the symptoms are relatively minor.
Avian symptoms are based upon a number of factors. Depending on the type of bird, the particular strain of NDV, whether that bird has any concurrent disease or has a preexisting immunity, the symptoms in each bird can vary wildly. Newcastle disease virus is so virulent in some species of birds, though, that even those that are vaccinated against it can still become infected. It is even possible for a vaccinated bird to contract NDV and die even without showing any symptoms at all. But even though the disease is so highly contagious in birds, it also replicates quicker and more easily in human cancer cells than it does in healthy human cells. The fact that it does so makes this bird disease capable of holding promise as a human cancer treatment.
There are two types of strains of NDV, lytic and nonlytic. The term lytic means that something causes an actual destruction of cells. Lytic strains of Newcastle disease virus seem to kill human cancer cells directly. Additionally, even the nonlytic strains of NDV seem to be beneficial to cancer patients. The nonlytic strain still kills the cancer cells although it does it more slowly than the lytic strain. The nonlytic strain interferes with the cell metabolism. In fact, the disease actually prefers to reproduce itself in human cancer cells, choosing those cells over healthy non-cancerous ones. NDV reproduces at a rate of up to 10,000 times faster in human cancer cells over normal ones.
Because humans do not generally have a preexisting immunity to this, because it is primarily an avian virus, about 96 percent of the human population do not have the ability to fight off the virus. Given the fact that humans are susceptible to the disease and that the virus targets human cancer cells, the possibility exists that NDV may be used in the care and treatment of human cancer patients. There are, to date, over 100 types of diagnosable human cancers. While not the leading cause of death in the United States, cancer is second only to cardiac arrest as a cause of death.
Already, clinical studies have been run to determine on anti-cancer therapies involving the usage of Newcastle disease virus. Enough laboratory trials have taken place that researchers have been able to isolate the effects of particular strains of NDV on different types of cancer. While additional research continues to be conducted, this bird disease currently appears to hold promise as a possible treatment for human cancer.
By Dee Mueller
on twitter @TuesdayDG