The BK virus, which most people become infected in childhood, may lead to the development of bladder cancer in adulthood. - scientists say. This virus can hide in the kidneys and activate when immunity is weakened, for example due to age or treatment of a chronic disease.
The BK virus, which belongs to the family of polyomaviruses, takes its name from the initials of the patient, from whom it was first isolated in 1971. It is very common - it is estimated that antibodies to the BK virus are up to 90 percent. adults, and we catch it in early childhood. Most infections are asymptomatic - only some people have mild symptoms similar to a cold, but they only develop when there are accompanying urinary problems.
This virus can hide in the kidneys and activate when immunity is weakened, for example due to age or treatment of a chronic disease. It is very dangerous for people after kidney transplantation, as it may lead to the development of nephropathy of the transplanted kidney and, consequently, rejection of the transplant.
A new study proves that it can also be dangerous for another reason - it damages the cells of the bladder and, as a result, even causes bladder cancer.
Smoking is believed to be the main risk factor for bladder cancer - toxic substances inhaled with smoke get to the kidneys, and then to the bladder, where they remain with the urine, damaging the cells of the bladder walls.
However, when researchers at the University of York examined DNA from bladder tumors, they found no patterns of DNA damage that theoretically should arise from carcinogens in cigarette smoke. It turned out, however, that the bladder cancer DNA contains damage typical of APOBEC proteins - infection with the BK virus causes a significant increase in their concentration.
To prove that the BK virus might be responsible for the patterns of DNA damage seen in bladder cancer, researchers used lab-grown human bladder cells, which they infected with the virus. In an in vitro model, they noticed that the BK virus could infect directlythe epithelium of the human urinary tract, as a result of which many processes take place at the molecular level, the consequence of which is gene damage and the initiation of carcinogenesis processes - changes leading to the formation of cancer.
As the lead author of the study, Dr. Simon Baker of the Department of Biology at the University of York explained: "Our findings change the understanding of what causes bladder cancer to date, showing that BK virus infections are a risk factor for bladder cancer because they force the bladder epithelial cells to to use APOBEC proteins, which then damage DNA. "
To reduce the incidence of bladder cancer, researchers emphasize the need to develop a BK vaccine, similar to the HPV vaccine, that has successfully reduced the incidence of cervical cancer.