A set of proteins involved in the body’s natural defences produces a large number of mutations in human DNA, according to a study led by researchers at the National Institutes of Health. The findings suggest that these naturally produced mutations are just as powerful as known cancer-causing agents in producing tumors.
The proteins are part of a group called apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) cytidine deaminases. The investigators found that APOBEC mutations can outnumber all other mutations in some cancers, accounting for over two-thirds in some bladder, cervical, breast, head and neck, and lung tumours.
The scientists published their findings online July 14 in the journal Nature Genetics. Dmitry Gordenin, Ph.D., is corresponding author of the paper and a senior associate scientist at the National Institute of Environmental Health Sciences (NIEHS), part of NIH. He said scientists knew the main functions of APOBEC cytosine deaminases were to inactivate viruses that attack the body and prevent ancient viruses present in the human genome from moving around and causing disrupting mutations. Because they are so important to normal physiology, he and his collaborators were surprised to find a dark side to them — that of mutating human chromosomal DNA…Read More