Researchers discover unique marker to identify breast cancer protein

The research, led by Linda H. Malkas, Ph.D., Vera Bradley Professor of Oncology and professor of medicine, and Robert J. Hickey, Ph.D., associate professor of medicine, involves a protein, PCNA, that plays a vital role in the processes that control cell replication, repair and death. The research team identified an antibody that can differentiate between the normal form of PCNA and the altered form found in breast cancer cells, Dr. Malkas said.

“That version, or isoform, of PCNA appears to be expressed uniquely in malignant breast cells, and the antibody we developed is the first to recognize that isoform, and so is good for differentiating malignant from non-malignant cells,” said Dr. Malkas.

The research is being published in the Proceedings of the National Academy of Sciences Online Early Edition for the week of Dec. 4-8, 2006.

Despite educational efforts and improved diagnostic and treatment tools, more than 40,000 women die of breast cancer each year, Dr. Malkas noted. As a result, there is great interest in techniques that could enable earlier, reliable detection of cancer in its early stages, and to discover malignant cells left after cancer treatment.

The article notes that the antibody discovered by the IU scientists may be useful in the future in a variety of ways, such as screening for early stage cancers, monitoring patients whose cancer is in remission, identifying patients at higher risk of relapse or having their cancer spread, or in imaging systems to identify the locations of tumors in the body.

Dr. Malkas said that initial tests have found the altered form of the PCNA protein in other types of cancer as well, including esophageal, colon, neuroblastoma and ovarian cancers.