TCS-PIM-1-4a (SMI-4a) is a pan-Pim kinases inhibitor that blocks mTORC1 activity via activation of AMPK. TCS-PIM-1-4a kills a wide range of both myeloid and lymphoid cell lines (IC₅₀ values ranging from 0.8 μM to 40 μM)^[1][2]. IC50 & Target: Pim^[1] In Vitro: TCS-PIM-1-4a (10 μM; 24-48 hours; 6812/2 cells and Jurkat cells) treatment increases the population of cells in the G1 phase from 44.3% to 68.4% and from 56.2% to 67.1% in 6812/2 and Jurkat, respectively. S-phase cells are decreased in 6812/2, whereas only small changes are seen in Jurkat cells consistent with the lesser G1 block^[1].
TCS-PIM-1-4a (5 μM; 6 hours; 6812/2 cells and Jurkat cells) induces cell death by the induction of apoptosis^[1].
TCS-PIM-1-4a (5 μM; 4-8 hours; 6812/2 cells and Jurkat cells) prevents the increase in 4E-BP1 protein levels and inhibits mTOR-directed phosphorylation on Thr37/46^[1]. In Vivo: TCS-PIM-1-4a (SMI-4a; 60 mg/kg; oral gavage; twice daily; for 21 days; nu/nu nude mice) treatment causes a significant delay in the tumor growth without any change in the weight, blood counts, or chemistries^[1].