An enzyme that protects human cells from viruses may contribute to cancer development. Reported by Cornell University.
In the study, the researchers used a bladder cancer cell model to examine the role of the enzyme APOBEC3G in the development of the disease. They found that it significantly increased the number of mutations in tumor cells, increased the genetic diversity of the tumor, and accelerated the lethal outcome. The APOBEC3 family of enzymes has the ability to induce RNA or DNA mutation by chemically modifying the cytosine nucleotide. Normally the enzyme needs to fight retroviruses such as HIV – it tries to interfere with the replication of the virus by causing cytosines in the viral gene material to mutate.
There are a number of mechanisms that prevent the body from damaging its own DNA. But experimentation showed that they don’t work very reliably. The researchers modified the animals’ genome and allowed them to produce human APOBEC3G. They were then exposed to a bladder cancer-promoting chemical that mimics cigarette smoke carcinogens.
It turned out that they were much more likely (76%) to develop this type of cancer compared to mice (53%) in which APOBEC3G was not produced. Also, after 30 days of observation, almost a third of the mice with APOBEC3G died from cancer, while all mice in the control group survived.
In this context, the authors suggest that suppressing the action of APOBEC3G could form the basis of a new type of anticancer therapy.