The discovery of the molecular mechanism behind the aggressive head and neck cancer was unveiled by the researchers at the San Francisco VA Medical Center (SFVAMC). It is a highly malignant form of cancer with a very high death rate. They have discovered the triple interaction between CD44, hyaluronan (HA), and LARG. CD44 is a surface receptor molecule that plays an important role in a variety of cellular functions. Hyaluronan (HA) is a complex carbohydrate found in the connective tissues between cells. LARG is a signal activator found in tumor cells. The triple interaction results in the initiation of two molecular pathways that simultaneously cause tumor cell growth and tumor cell migration.
Lilly Bourguignon, PhD, a research career scientist at SFVAMC and a professor of medicine at the University of California, San Francisco is the lead author. The study results are reported In Press section of the Journal of Biological Chemistry. Bourguignon and her team found that HA mediates the interaction between CD44 and LARG in a way that stimulates a molecular pathway called RhoA. It causes the tumor cell's cytoskeleton to reorganize such that the tumor cells migrate to other sites in the body, resulting in cancer metastasis. Then the HA-mediated CD44/LARG complex binds with epidermal growth factor receptor (EGFR), located on the tumor cell's surface.