Downregulation of SOK1 promotes the migration of MCF-7 cells

SOK1 is a member of the germinal center kinase (GCK-III) subfamily but little is known about it, particularly with respect to its role in signal transduction pathways relative to tumor metastasis. By stably transfecting SOK1 siRNA into the MCF-7 breast cancer cell line we found that SOK1 promotes the migration of MCF-7 cells, as determined using wound-healing and Boyden chamber assays. However, cell proliferation assays revealed that silencing SOK1 had no effect on cell growth relative to the normal cells. Silencing SOK1 also had an effect on the expression and phosphorylation status of a number of proteins in MCF-7 cells, including FAK and GM130, whereby a decrease in SOK1 led to an increase in the expression of these proteins.

► SOK1 is a member of GCK-III subfamily. It is activated by oxidative stress or chemical anoxia. ► Barr’s group have found that autophosphorylation of SOK1 is triggered by binding to the Golgi matrix protein GM130 and made the cells migration through dimeric adaptor protein 14-3-3. ► But what we found is that downregulation of SOK1 promotes cell migration and leads to the upregulation of GM130 and Tyr861 of FAK in MCF-7 cells.