Project 459020

Breast cancer is the leading cause of cancer-related deaths in women worldwide. Metastasis, which is the spread of cancer cells from a primary tumor to other areas in the body, remains the main cause of patient related death. Awareness of the importance of metastasis and our basic scientific understanding of the metastatic process has improved substantially over the past few decades. However, many aspects of metastasis are still not well defined and our ability to identify and treat patients at high risk for metastasis is limited. Consequently, breast cancer patients face uncertainty, not knowing if or when their cancer may come back. Then, when the cancer returns, and metastatic growths are detected, very few effective treatments are in place to eliminate the disease. Thus, identifying individuals at a high-risk of metastasis and developing new therapies for these individuals is greatly needed. We have identified a sugar on the surface of aggressive breast cancer cells, called polysialic acid (polySia) and have discovered that it is uniquely attached to certain proteins (polySia proteins). In healthy humans, polySia-proteins act like a non-stick coating and allows cells to move around the body. This is important for some cells types because they need to move around the body. However, it is equally important that cells in tissues such as breast, lung, and liver, do not contain proteins with polySia and remain attached to adjacent cells. In BCa cells we have observed polySia on different proteins and we think that these polySia-proteins are unique to BCa and may cause the cells to move around the body in very precise ways and direct them to specific organs. We plan to study these polySia-proteins and figure out how they help BCa cells move around the body and help tumors cell to invade. If we can show that they are important for metastasis then we can start looking at ways to stop them which could result in new treatment options for women with aggressive BCa.