9-ING-41, a small-molecule glycogen synthase kinase-3 inhibitor, is active in neuroblastoma.

Advanced stage neuroblastoma is a very aggressive pediatric cancer with limited treatment options and a high mortality rate. Glycogen Synthase Kinase-3β (GSK-3β) is a potential therapeutic target in neuroblastoma. Using immunohistochemical staining, we observed positive GSK-3β expression in 67% of human neuroblastomas (34 out of 51 cases). Chemically distinct GSK-3 inhibitors (AR-A014418, TDZD8 and 9-ING-41), suppressed the growth of neuroblastoma cells whereas 9-ING-41, a clinically relevant small molecule GSK-3β inhibitor with broad spectrum pre-clinical antitumor activity, being the most potent. Inhibition of GSK-3 resulted in a decreased expression of the antiapoptotic molecule XIAP and…