Masonic Cancer Center researchers 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.

DNA mutations are essential for cancer development and APOBEC3B appears to be a biological “double-edged sword.” The enzyme protects some cells from viruses such as HIV-1 yet produces mutations giving rise to cancer in others.

The researchers hope that their discovery will allow cancer researchers to develop new treatment approaches that can prevent these mutations before they become harmful. If further studies confirm that high APOBEC3B levels indicate the early presence of breast cancer, a simple blood test could be a strategy for early detection.

Another goal would be to find a way to block APOBEC3B from causing mutations, just as sunscreen prevents sun from causing mutations leading to melanoma.