In vitro mechanisms involved in the regulation of cell survival by lithium chloride and IGF-1 in human hormone-dependent breast cancer cells (MCF-7)

► Lithium chloride exerts a dose-dependent biphasic effect on MCF-7 cell survival. ► IGF-1 is the potent endogenous inhibitor of GSK-3β in MCF-7 cells. ► IGF-1 involves the PI3K/Akt pathway to inhibit GSK-3β in MCF-7 cells. ► LiCl directly inhibits GSK-3β in MCF-7 cells.