RACK1 downregulation suppresses migration and proliferation of neuroblastoma cell lines

Neuroblastoma is the most common extracranial solid tumor in childhood, whose molecular mechanism on clinically heterogeneous behavior is still unclear. Receptor for activated C-kinase 1 (RACK1) has been shown to be involved in the regulation of growth and migration in many types of cells. Two types of human neuroblastoma cell lines, SK-N-SH and SK-N-BE (2), were used to explore the role of RACK1 in neuroblastoma cell migration and proliferation. Cell migration and proliferation were detected by a transwell system and colorimetric bromodeoxyuridine (BrdU) ELISA, respectively. The expressions of RACK1, N-Myc, phospho-Src(Tyr416), phospho-Src(Tyr527), phospho-Akt, phospho-ERK1/2 and phospho-p38 were analyzed by Western blotting. The expression of RACK1 was then repressed by target RNA interference (RNAi) in both types of neuroblastoma cells, and the expression of signaling molecules, migration and proliferation of cells was analyzed. Compared with SK-N-SH, the migration and proliferation of SK-N-BE(2) cells was remarkably higher which was accompanied by higher expression of RACK1 and phospho-Src(Tyr416). RACK1 RNAi repressed cell migration and proliferation, and decreased the expression of phospho-Src(Tyr416) in both cell lines. In summary, RACK1 was expressed in the neuroblastoma cells and positively regulated cell migration and proliferation probably via modulating the activation of Src on Tyr416 residue.