An Investigation on the Role of Non-canonical Hedgehog Signalling in Cell Migration

Cells communicate via extracellular signals that can drive activation of intracellular signalling pathways to elicit a variety of cellular responses. One signalling pathway essential in embryonic development and also associated with some malignancies is the Hedgehog (Hh) signalling pathway. Recently, Hh signalling has been implicated in stimulating cytoskeletal changes and cell migration; however, the mechanisms involved are not well established. Using scratch wound-healing migration assays, I showed that conditioned media (CM) obtained from cells that secrete Sonic Hedgehog (Shh) ligand was able to induce cell migration in mouse fibroblasts. However, removing Shh from the CM only partially reduced the induced migratory effects, suggesting that there are other major players in CM important for cell migration. Lastly, I identified HeLa-derived platelet-derived growth factor as one of the main driving forces in CM for cell migration. These studies provide a cautionary tale to the use of CM to monitor complex cellular behaviours.M.Sc