Investigation of cancer cell migration with TFM and FRET sensors
Migration is one of the important characteristics of mesenchymal cells. However, the heterogeneity of mesenchymal cell migration impedes us from gaining further understanding of its underlying machinery. Recently, by applying quantitative microscopy and systematic analysis methods to this process of several different cell lines, our lab has successfully characterized two distinct mesenchymal cell migration modes, termed “Continuous” and “Discontinuous”. We also demonstrated that these two migration modes represent fundamentally distinct migratory strategies. This provides us with tools and know-how for further studies. From previous PhD study, I've earned experience in traction force microscopy (TFM). With TFM, the force field of a single cell could be mapped spatio-temporally by analyzing the movements of fluorescent beads embedded in a soft gel, on which cells are cultured. The FRET sensors, which were developed specifically for each small GTPases, could provide the spatio-temporal information of GTPase activities. In the planned studies, I will apply the TFM technique combined with FRET sensors on the two distinct mesenchymal cell migration modes to investigate the force field and GTPase acitivty differences in time and space. The focal adhesion size and lifetime will also be taken into account simultaneously as we have demonstrated that they control fundamental cell-matrix adhesion properties. By applying systematic and quantitative analysis of the traction force and cell-matrix adhesion properties on the two distinct mesenchymal cell migration modes, much more critical and fundamental characteristics could be identified, which might lead us to further understanding of underlying biological mechanisms of these two migration modes.