Gene clue to how virus causes cancer
12 April 2012
Virologists and immunologists at Imperial and the University of Zurich have identified mutations in Epstein-Barr virus (EBV) that increase the capacity of the virus to cause cancer, in a study published on 12 March in the Journal of Clinical Investigation. The research reveals that EBV carries a tumour suppressor gene – the first such gene known in a cancer- causing virus.
EBV is one of the most common viruses in humans, persistently infecting more than 90 per cent of the population. The virus can remain in the body for many years without any obvious symptoms, but it also causes glandular fever and is associated with several types of cancer, including lymphoma.
The new research has found that EBV normally carries a gene that suppresses cancer, at least in part by making infected cells secrete a protein called CXCL10 that alerts the host immune system. Mutations that inactivate this gene allow the virus to escape detection by the immune system and cause cancer.
“This is the first known example of a cancer-causing virus carrying a tumour suppressor gene,” said Professor Martin Allday (Medicine), who led the study with Professor Christian Münz of the University of Zurich. “We can speculate that this gene might help ensure the long-term survival of the host without serious disease, which allows the virus to persist in human populations. “The findings have highlighted the importance of factors like CXCL10 that attract immune cells in the surveillance of tumours. Understanding how these factors are regulated and work in tumours may assist in the development of better strategies for manipulating the immune system in cancer therapies.”
— Sam Wong, Communications and Development