NEW DELHI– A common virus that many people contract in childhood may trigger DNA damage that increases the risk of bladder cancer decades later, according to new research from the University of York.
The study, published in Science Advances, examined the BK virus — a widespread childhood infection that typically produces no symptoms and remains dormant in the kidneys for life. While generally harmless, the virus can reactivate in people with weakened immune systems, such as kidney transplant recipients who take immunosuppressant medications. That group has provided scientists with critical insight into how the virus behaves in the body.
Using human urothelial tissue — the cells lining the urinary tract — researchers exposed samples to the BK virus in controlled laboratory settings. They found that the body’s antiviral defenses, specifically enzymes designed to damage viral DNA, can also cause “friendly fire” that harms the cell’s own DNA.
The result is a pattern of DNA mutations that may set the stage for bladder cancer later in life.
“In other types of virus-related cancer, such as cervical cancer, we know that viral DNA integrates with our own genetic material to drive tumor development,” said Dr. Simon Baker of the University of York. “Our results have shown that in the bladder, the tissue’s defensive response to the virus causes DNA changes that can lead to cancer.”
Researchers also observed that DNA damage occurred not only in infected cells but in neighboring “bystander cells” that were not directly infected. Baker said this may help explain why most bladder cancers show no trace of the BK virus when diagnosed years later — the virus itself may be long gone, but the mutation damage remains.
The BK virus typically remains inactive in the kidney, but immunosuppression can allow it to reactivate, damaging the kidneys, ureter, and bladder. Currently, the primary actionable prevention strategy for bladder cancer is smoking cessation. The new findings suggest that identifying and controlling BK virus in early life could eventually open a second pathway for prevention. (Source: IANS)
