Molecular Clock to Predict Breast Cancer Risk

May 14, 2008
Scientists discovered a chemical reaction that can indicate the woman's risk of developing breast cancer.

UT Southwestern Medical Center researchers found that the chemical process in the genes called methylation can provide useful information about precancerous changes in the breast cells.

Methylation is a process when small molecules of methyl group get attached to the gene and "turn it off". The more cells get divided during the methylation act, the more it is likely to indicate the risk of developing breast cancer.

This process serves as a molecular clock determining a cancer risk. Tracking the changes of methylation levels can give the scientists useful information at what point a cancerous process is likely to start.

During the study, Dr. Euhus and his team took samples of cells from 164 women divided into three groups: women who had breast cancer, women having high risk of cancer, and women having low risk of cancer. The researchers measured the methylation levels of five cancer-suppressor genes that work to prevent cancer development in the breast.

Dr. Euhus developed a computer program to evaluate breast cancer risk for participants in the study. The results showed that the level of methylation of RASSF1A and other genes increased during the years of ovarian cycling.

However, this doesn't mean that molecular clock always goes forward as there are ways to turn it back. For example, it is known that having children early in life can reduce the risk of developing breast cancer and molecular clock will indicate the decline in methylation level for some genes.