Casein Kinase inhibitor A51

Casein Kinase inhibitor A51 (CKIα inhibitor A51) is a novel pan-specific CKI (CSNK1) inhibitor (Kd=0.5-20 nM, CKIα Kd=5.3 nM) that co-targets the transcriptional kinases CDK7 and CDK9, with hardly inhibition of CDK8, CDK13, CDK11a, CDK11b, and CDK19; target both CDK7 and CDK9 with low nM Kd values; induces leukemia cell apoptosis at <160 nM, in correlation to the capacity to stabilize p53; shows high and selective sensitivity against leukemic CFUs in colony-forming unit (CFU) assay, without effect on normal hematopoietic CFUs; blocking CKIα together with CDK7 and/or CDK9 synergistically stabilize p53, deprive leukemia cells of survival and proliferation-maintaining SE-driven oncogenes, induce apoptosis, abolishes the expression of MYC, MDM2, and the anti-apoptotic oncogene MCL1; demonstrates therapeutic efficacy with preserved hematopoiesis and leukemia cure potential in AML mouse models.