GSK-3 inhibition in vitro and in vivo enhances antitumor effect of sorafenib in renal cell carcinoma (RCC)

► Sorafenib treatment upregulated GSK-3β levels in RCC cells. ► Pharmacologic inhibition of GSK-3 suppressed xenograft RCC tumor growth. ► Inhibition of GSK-3 enhanced antitumor effect of sorafenib in vitro and in vivo.