Epithelial cells perform a critical barrier function in vivo, and the integrity of this barrier is maintained by rigid cell-cell and cell-ECM contacts. If such contacts are disrupted and the detached cells fail to re-adhere quickly, apoptosis is initiated. Our lab has shown that suspended epithelial cells extend microtubule-based plasma membrane protrusions (microtentacles) that promote reattachment to neighboring cells and extracellular substrates.

 

While this phenomenon appears to be a feature of healthy epithelial tissues, it is significantly enhanced in highly invasive tumor cells, and has been directly observed in circulating tumor cells isolated from blood samples of patients with advanced metastatic disease (Balzer, E. and Chumsri, S unpublished data). Our lab is seeking to test the hypothesis that microtentacles promote metastasis by facilitating the extravasation and/or survival of circulating tumor cells. Specifically, my research focuses on defining the molecular interplay between the actin and tubulin cytoskeletons that forms the mechanistic basis for the extension of these microtentacles, in an effort to understand how this process is naturally exploited by cancer cells.