Specific Inhibition of GSK-3β by Tideglusib: Potential Therapeutic Target for Neuroblastoma Cancer Stem Cells

Neuroblastoma is an embryonic tumor that represents the most common extracranial solid tumor in children. Resistance to therapy is attributed, in part, to the persistence of a subpopulation of slowly dividing cancer stem cells (CSCs) within those tumors. Glycogen synthase kinase (GSK)-3β is an active proline-directed serine/threonine kinase, well-known to be involved in different signaling pathways entangled in the pathophysiology of neuroblastoma. This study aims to assess the potency of an irreversible GSK-3β inhibitor drug, Tideglusib (TDG), in suppressing proliferation, viability, and migration of human neuroblastoma cell lines, as well as its effects on their CSCs subpopulationin vitroandin vivo. Our results showed that treatment with TDG significantly reduced cell proliferation, viability, and migration of SK-N-SH and SH-SY5Y cells. TDG also significantly inhibited neurospheres formation capability in both cell lines, eradicating the self-renewal ability of highly resistant CSCs. Importantly, TDG potently inhibited neuroblastoma tumor growth and progressionin vivo. In conclusion, TDG proved to be an effectivein vitroandin vivotreatment for neuroblastoma cell lines and may hence serve as a potential adjuvant therapeutic agent for this aggressive nervous system tumor.