MRT199665 is a potent and ATP-competitive, selective MARK / SIK / AMPK inhibitor with IC 50 s of 2/2/3/2 nM, 10/10 nM, and 110/12/43 nM for MARK1/MARK2/MARK3/MARK14 , AMPKα1/AMPKα2 , and SIK1/SIK2/SIK3 , respectively MRT199665 causes apoptosis in MEF2C-activated human acute myeloid leukemias (AML) cells MRT199665 inhibits the phosphorylation of SIK substrate CRTC3 at S370 In Vitro MRT199665 (1 μM; pre-treated for 1 h) increases LPS (100 ng/mL; stimulated for up to 24 h)-stimulated IL-10 mRNA and Nurr77 mRNA production, and IL-10 secretion. MRT199665 (1 nM-100 μM; 48 hours) reduces leukemia growth. MRT199665 treatment can block MEF2C S222 phosphorylation in acute myeloid leukemias (AML) cells.\nMRT199665 (10 nM-1000 nM; 12 hours) leads to a dose-dependent reduction in total and pS222 MEF2C. MRT199665 also causes a decrease of total MEF2C protein. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Western Blot AnalysisCell Line: OCI-AML2 and MOLM-13 cells Concentration: 10, 100, 500, and 1000 nM Incubation Time: 12 hours Result: Led to a dose-dependent reduction in total and pS222 MEF2C, causing more than 40% reduction in MEF2C phosphorylation at 10 nM as compared to untreated cells. Cell Proliferation AssayCell Line: Human AML cell lines OCI-AML2, MV4-11, MOLM-13 and Kasumi-1 with endogenous MEF2C phosphorylation; human AML cell lines NB-4, HEL, HL-60 and U937 lacking MEF2C Concentration: 1 nM, 10 nM, 100n M, 1 μM, 10 μM, 100μM Incubation Time: 48 hours Result: Human AML cell lines with endogenous MEF2C phosphorylation (OCI-AML2, MV4–11, MOLM-13 and Kasumi-1) were more sensitive as compared to cell lines lacking MEF2C (NB-4, HEL, HL-60 and U937), with mean IC 50 of 26±13 versus 990±29 nM, respectively. Form:Solid IC50& Target:MARK1 2 nM (IC 50 ) MARK2 2 nM (IC 50 ) MARK3 3 nM (IC 50 ) MARK4 2 nM (IC 50 ) SIK1 110 nM (IC 50 ) SIK2 12 nM (IC 50 ) SIK3 43 nM (IC 50 ) NUAK1 3 nM (IC 50 ) NUAK2 120 nM (IC 50 ) AMPKα1 10 nM (IC 50 ) AMPKα2 10 nM (IC 50 ) MELK 29 nM (IC 50 ) TBK1 5400 nM (IC 50 ) IKKε 7700 nM (IC 50 ) BRSK2 10000 nM (IC 50 )