AZD-5438 is an effective inhibitor of CDK, for CDK1(IC50=16 nM), CDK2(IC50=6 nM), CDK9(IC50=20 nM).

CDK1:16 nM, CDK9:20 nM, CDK2:6 nM

在SW620异种移植物模型中,AZD5438对于各种细胞周期蛋白（phH3,磷酸核仁素,PP1a等）有以剂量依赖的抑制作用.对于不同类型的癌症（乳腺癌,结肠癌,肺癌,前列腺癌和卵巢癌）,AZD5438通过口服可以对肿瘤产生抑制作用.

AZD5438会抑制p25-cdk5和糖原合成激酶3β的激酶活性,IC50分别为14 nM和17 nM。 在肿瘤细胞系中（肺,结肠直肠,乳腺,前列腺,和血液肿瘤）,AZD5438（IC50=0.2 -1.7 μM）通过抑制cdk-依赖性底物的磷酸化作用诱导细胞周期阻滞,从而抑制细胞增殖。在细胞周期素依赖性激酶中,AZD5438对于其活性能够有效抑制,E-cdk2（IC50=6 nM）,A-cdk2（IC50=45 nM）,B1-cdk1（IC50=16 nM）,D3-cdk6（IC50=21 nM）,T-cdk9（IC50=20 nM）。

Recombinant Kinase Assays [1]: The ability of AZD5438 to inhibit cdk activity is examined using a scintillation proximity assay with recombinant cdk-cyclin complexes of cyclin-Ecdk2, cdk2-cyclin A, cdk4-cyclin D, and recombinant retinoblastoma substrate (amino acids 792-928) or cdk1-cyclin B1 with a peptide substrate derived from the in vitro p34cdc2 phosphorylation site of histone H1 (biotin-X-Pro-Lys-Thr-Pro-Lys-Lys-Ala-Lys-Lys-Leu). The activity of AZD5438 against recombinant cdk5/p25 (at 2 μM ATP) is determined in a scintillation proximity assay-based assay using peptide substrate (AKKPKTPKKAKKLOH). Inhibition of glycogen synthase kinase 3β activity is determined with scintillation proximity assay based on the use of human purified glycogen synthase kinase 3βenzyme and eukaryotic initiation factor 2B substrate (at 1 μM ATP). AZD5438 is screened against active recombinant human cdk6-cyclin D3, cdk7-cyclin H/MAT1 (cdk activating kinase complex), and cdk9-cyclin T using the kinase selectivity screening service.

AZD5438 is tested against solid tumor cell lines. Briefly, cells are incubated for 48 hours with AZD5438 at a range of concentrations. At the end of incubation, the cells are pulsed with 5-bromo-2′-deoxyuridine (BrdUrd) and the amount of DNA synthesis is measured. The IC50 for inhibition of proliferation is specifically determined independently of cell death. Multiple myeloma cell lines are seeded into 96-well plates in RPMI 1640 supplemented with 10% FCS and glutamine and dosed with AZD5438 for 72 hours. Cell growth is measured using AlamarBlue and GI50 values are calculated with reference to pretreatment control values.(Only for Reference)