THE ESSENTIAL
- Nearly 12,000 new cases of bladder cancer were diagnosed in France in 2012, according to Health Insurance.
- This cancer mainly affects men, with more than 80% of cases.
- The average age of diagnosis of bladder cancer is 70 years old.
Bladder cancer is the seventh most common cancer in France, according to health insurancewhich defines it as a “excessive growth of abnormal cells in the inner lining or lining of the bladder”. The main risk factor is smoking, which causes more than 50% of bladder cancers in men and regarding 40% in women. Occupational exposure to toxic substances as well as certain medications are also involved.
An enzyme might promote bladder cancer
According to a new study published in the journal Cancer Research, there would be another risk factor: an enzyme called APOBEC3G. It is a protein made by the body that helps fight certain viruses by preventing them from multiplying. But it might also promote the development of bladder cancer.
To act, the enzymes stop the replication of the virus by stopping a certain type of cytosines in the genetic code. Cytosines are a type of molecules that participate in the formation of cytidine which makes it possible to create nucleic acids, including DNA. But the action of enzymes can also modify the genetic code permanently, which would have an impact on the development of certain cancers.
“Our results suggest that APOBEC3G is an important factor in bladder cancer progression and should be considered as a target for future treatment strategies.“says Bishoy Faltas, an oncologist and one of the study’s authors, in a university statement. With his team, in 2016, they had already discovered that the genetic mutations produced by the APOBEC3G enzymes promote the development of cancers and improve its resistance to cancer treatments. Because of their presence, the immune system would also be less able to detect and therefore fight cancer.
Towards a cure for bladder cancer
During their recent work, the scientists checked the action of the enzyme on mice. The aim was to see if APOBEC3G played a role in bladder cancer. For this, they removed the APOBEC3G present in rodents and replaced it, in a first group, with its human version. In the other group it was simply removed. Next, the mice were exposed to a bladder cancer-promoting chemical.
Results: Those with APOBEC3G were 76% more likely to develop bladder cancer, compared to 56% in the group where APOBEC had simply been removed. After thirty weeks, the dead mice represented a third of the first group, as they had twice as many tumor mutations, while all of the second survived.
In the future, the researchers hope that their work can lead to the development of new cancer treatments, which will specifically target the APOBEC3 enzymes.
