Regulation of Actin-Myosin Cytoskeletal Changes in Involved in Cancer Metastasis

摘要

Advanced imaging techniques based on fluorescent resonant energy transfer (PRET) has been devised to probe the dynamic regulation of myosin in tumor metastasis. Myosin activity is regulated mainly through the phosphorylation of myosin regulatory light chain (RLC) EtC is the target of multiple signaling cascades. Using a PRET-based biosensor, we have studied the activity and localization of myosin light chain kinase (MLCK) simultaneously. The biosensor highlights the transient recruitment of MLCK to the stress fibers prior to contraction. More importantly, it shows that MLCK is highly active in the lamella of migrating cells, but not the retracting. This unexpected result highlights a potential role for MLCK-mediated myosin contractility in the lamella as a driving force for migration. These findings provide significant ground work for further delineating the role of myosin-mediated motility in metastatic potential of breast cancer cells. Our preliminary results also show that microtubule disruption by nocodazole leads to transient stress fiber association of MtCK, indicating MLCK as a potential signaling link between the microtubule network and the actomyosin system.