In the Ligon lab, we are interested in how cells function in the three-dimensional world. We study the internal structure of the cell, the cytoskeleton, and how it is organized to generate and maintain the complex 3D shape of differentiated cells. We also study how cells interact with their environment, in particular how cancer cells interact with the tissue surrounding the tumor, also known as the tumor microenvironment. We use a combination of live-cell imaging and other cell biological, biochemical and molecular techniques to examine cell structure, dynamics and function in the context of the living cell. Some cells, such as those of the nervous system, have elaborate three-dimensional shapes that are essential to their specialized activities. We study the microtubule cytoskeleton, a complex network of protein polymers that are essential to establish and maintain cell structure. Microtubules have several functions in the cell: they are mechanical and structural elements; they serve as tracks for long-distance movements of organelles and other cargoes; and they can play a direct role in biochemical signaling cascades. We are investigating how certain sub-populations of microtubules are biochemically specialized for specific cellular functions by a combination of sub-cellular location, post-translational modifications, and interactions with other proteins. We are also investigating the role of the tumor microenvironment in the metastatic progression of cancer cells. Both the cells and the non-cellular elements of the tissue surrounding a tumor can play a significant role in whether or not a tumor cell will become invasive. We are using the tools of cell biology and biochemistry, as well as novel biomimetic materials, to explore the role of abnormal cell-cell interactions and cell-matrix interactions in a breast cancer model system.