Posted by: Footler PJ1 MAY 2013
Newcastle disease is a highly contagious viral infection that can affect many species of bird, with symptoms that include loss of appetite, coughing, sneezing and diarrhoea. Some species, such as those in the parrot family, can carry mild strains of the disease for several months without displaying any symptoms, but chickens are highly susceptible to the virus. Hens may stop laying or their eggs may be deformed, and a high proportion of infected birds may die in severe outbreaks. Newcastle disease is notifiable and subject to statutory control under UK and EU legislation.
Newcastle disease virus (NDV) was first considered a possible treatment for cancer in the 1950s. Researchers found that NDV replicated itself many times faster in human cancer cells than in most normal human cells and, furthermore, it could kill those host cells. This, with the knowledge that the virus itself causes only mild symptoms in humans, led to a series of clinical trials in the US, China, Canada, Germany and Hungary. The results of the trials were mixed. Most of the studies involved multiple injections of large amounts of the virus being given to small numbers of patients, many of whom were receiving other cancer therapy at the same time. And they were not randomised or controlled.
The Journal of Virology recently reported the development of a genetically engineered version of NDV that replicates only in the presence of active prostate specific antigen (PSA). The presence of PSA is required to cleave the virus’s modified fusion protein and that need makes it highly specific to prostate cancer cells. The researchers believe that the recombinant virus could eradicate prostate cancer in much lower doses than those used in earlier studies and also seek out metastatic prostate cancer cells. The modified NDV could be injected intravenously or directly into the tumour without many of the adverse side effects typically associated with hormonal treatment for prostate cancer and with cancer chemotherapies generally.
Further research is now under way to develop cell type-specific NDV to treat other types of cancer cell such as breast, pancreas, brain and multiple myeloma.