Enzyme Behind Breast Cancer Mutations Identified

Researchers at the University of Minnesota have uncovered a human enzyme responsible for causing DNA mutations found in the majority of breast cancers. The discovery of this enzyme -- called APOBEC3B -- may change the way breast cancer is diagnosed and treated.
The findings from a team of researchers led by Reuben Harris, Ph.D., associate professor of biochemistry, molecular biology and biophysics and also a researcher at the Masonic Cancer Center, University of Minnesota, are published in the latest edition of Nature.
"We strongly believe this discovery will change the way mutations in cancer are viewed and, hopefully, it will allow cancer researchers to develop new treatments approaches that can prevent these mutations before they become harmful," said Harris.
Harris' quest to learn more about mutations in cancer initially began with HIV research. This previous work by Harris' lab and others indicated that APOBEC3B and related enzymes function normally to protect from infectious viruses like HIV-1.
During these studies, Harris' team developed specific tests to quantify the expression of each of the seven APOBEC3 genes, including APOBEC3B.
Harris and his team were able to apply these tests to the problem of mutation in breast cancer, showing only APOBEC3B is over-expressed in patients' breast cancer cell lines and tumors.