BREAST CANCER RESEARCH
Microsatellite instability in early onset breast cancer
Z Rudzki, G Suthers
About 10 per cent of women who develop breast cancer have a family history of cancer. Approximately half of these women will have a mutation in one of the two genes thought to be responsible for the initiation of the cancer but the remainder do not. Thus other genetic factors are important. Colon cancer is found in some families with a strong history of breast cancer and the genes responsible for colon cancer have been identified. These genes function to maintain the accuracy of DNA replication and if they are mutated, errors occur during replication and these are most easily seen in the microsatellite loci. Microsatellite loci are regions of short repeated sequences of DNA that are scattered throughout the human genome. Because of their repetitive nature, they are difficult to replicate accurately when the cell divides. Thus a relatively simple screening test for inherited colon cancer is looking for abnormalities at these loci, a phenomenon known as microsatellite instability. The finding of such microsatellite instability in women with breast cancer would infer that the same genes that cause colon cancer are also involved in some cases of breast cancer.
This project is being carried out as part of an Honours project for a student from the University of South Australia
The Molecular Pathology Unit is also involved in two major collaborative projects by being a member of the:
• Kathleen Cuningham National Consortium for Research on Familial Breast Cancer.
• International Collaborative Group for Hereditary Non Polyposis Colon Cancer.