Investigating the role of vesicle trafficking in chemotactic invasion of breast cancer cells

[摘要] Chemotaxis underlies many physiological processes and is also hijacked by metastatic cancer cells to enter blood or lymphatic vessels enabling travel around the body. Using a novel migration assay we sought to determine the molecular mechanisms by which vesicle trafficking regulates chemotactic invasion. We show that dynamin is necessary for EGF-dependent migration and proceeding RNAi studies found clathrin-mediated endocytosis, but not caveolar endocytosis, to be necessary for migration in MDA-MB-231 cells. Using TIRF microscopy to investigate a role for endocytosis of integrins during chemotactic invasion we found no significant colocalisation of focal adhesion markers with endocytic markers. Inhibiting endocytosis also had no effect on the number or localisation of focal adhesions. Studies investigating EGFR showed that during EGF-directed chemotactic invasion of human breast cancer cells, EGFR endocytosis is polarised to the front of migrating cells and occurs via clathrin-mediated endocytosis. Analysis of exocytic trafficking of EGFR found this to be polarised towards the front of cells during chemotactic invasion. Finally we used FLIM-FRET microscopy to show that cells migrating in an EGF-dependent manner have increased signalling of Scr and Akt Biosensors. These experiments begin to investigate the link between endocytosis and signalling, an area not yet very well studied.

[发布机构] University:University of Birmingham;Department:School of Biosciences

[关键词] Q Science;QM Human anatomy