Cell signaling is a method of communication between cells and their external environment, as well as communication between different molecules within a single cell. Changes in cell signaling can result in cell proliferation, cell death or cell mutation. An excess of cell proliferation is another name for cancer. HER2 (human EGF receptor 2) is involved in many signaling pathways, and is believed to be responsible in part for the rapid cell division seen in some breast tumors. Patients whose tumors express HER2 show a decreased average survival time after diagnosis.
Research continues in my laboratory into the mechanism of breast tumor growth and the effects of estrogen treatment on growth rates and cellular signaling from HER2. New techniques have involved the use of siRNA (small interfering RNA) in an effort to prevent production of HER2, and to determine if other signaling molecules compensate to allow the tumor cells to continue their growth.
Another study in my lab involving cell signaling is the examination of cell signaling in mammalian cells infected by the bacterium Francisella tularensis, which has been categorized as a biothreat agent. Current work includes characterization of proteins in the infected mammalian cells through mammalian cell culture, Western blotting, and fluorescent microscopy. Our studies suggest many changes in cell signaling activation based on time of infection, resulting in programmed cell death.