Endocytic trafficking of cell surface receptors plays an essential role in cellular homeostasis by regulating many aspects of cell biology including signalling and cell adhesion. Surface receptors such as epidermal growth factor receptor (EGFR) and integrins are key players in cell motility and metastasis. Compelling evidence reveals that deregulation of endocytic trafficking of surface receptors such as EGFR and Î±5Î²1 integrin is strongly associated with many human pathologies including metastasis. Recent studies implicate the tumour suppressor p53 in control of recycling of surface receptors to promote invasive migration, but the role of trafficking pathways in oncogene-induced transformation is not well understood. The aim of this study was to investigate the roles that oncogenes play in trafficking of specific surface receptors to promote migration and invasion. Focusing on oncogenic PIK3CA and KRAS mutants associated with breast, lung, pancreatic and ovarian cancers, stable inducible cells were generated in ânormalâ epithelial cells to determine their effect on endocytic trafficking and cell behaviour. Biochemical trafficking assays showed that different oncogenes significantly increase surface levels and endocytic recycling of EGFR and Î±5Î²1 integrin. These changes in endocytic trafficking upon oncogene induction resulted in altered cell migration and invasion in 3D matrix. A CRISPR/Cas9 screen identified knockout of a number of recycling regulators including members of Rab11/Rab4 GTPases that are required for both oncogene-driven elevated recycling of EGFR and Î±5Î²1 integrin and cell motility. These findings provide novel evidence that oncogenes manipulate endocytic recycling pathways that control EGFR and Î±5Î²1 integrin trafficking to promote invasion and migration.
|Date of Award||1 Aug 2021|
- The University of Manchester
|Supervisor||Philip Woodman (Supervisor) & Patrick Caswell (Supervisor)|