MRT199665 is a potent and ATP-competitive, selective MARK/SIK/AMPK inhibitor with IC50s 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[1]. MRT199665 causes apoptosis in MEF2C-activated human acute myeloid leukemias (AML) cells[2]. MRT199665 inhibits the phosphorylation of SIK substrate CRTC3 at S370[3].
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[1]. MRT199665 (1 nM-100 μM; 48 hours) reduces leukemia growth[2].MRT199665 treatment can block MEF2C S222 phosphorylation in acute myeloid leukemias (AML) cells.MRT199665 (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[2]. Western Blot Analysis[2] Cell Line: OCI-AML2 and MOLM-13 cells
[1]. Clark K, et al. Phosphorylation of CRTC3 by the salt-inducible kinases controls the interconversion of classically activated and regulatory macrophages. Proc Natl Acad Sci U S A. 2012 Oct 16;109(42):16986-91. [2]. Brown FC, et al. MEF2C Phosphorylation Is Required for Chemotherapy Resistance in Acute Myeloid Leukemia. Cancer Discov. 2018 Apr;8(4):478-497. [3]. Hutchinson LD, et al. Salt-inducible kinases (SIKs) regulate TGFβ-mediated transcriptional and apoptotic responses.Cell Death Dis. 2020 Jan 22;11(1):49.