In vitro activity: AZD1152 displays>3000-fold selectivity for Aurora B as compared with Aurora A which has an IC50 of 1.368 μM. AZD1152 has even less activity against 50 other serine-threonine and tyrosine kinases including FLT3, JAK2, and Abl. AZD1152 inhibits the proliferation of hematopoietic malignant cells such as HL-60, NB4, MOLM13, PALL-1, PALL-2, MV4-11, EOL-1, THP-1, and K562 cells with IC50 of 3-40 nM, displaying ~100-fold potency than another Aurora kinase inhibitor ZM334739 which has IC50 of 3-30 μM. AZD1152 inhibits the clonogenic growth of MOLM13 and MV4-11 cells with IC50 of 1 nM and 2.8 nM, respectively, as well as the freshly isolated imatinib-resistant leukemia cells with IC50 values of 1-3 nM, more significantly compared with bone marrow mononuclear cells with IC50 values of>10 nM. AZD1152 induces accumulation of cells with 4N/8N DNA content, followed by apoptosis in a dose- and time-dependent manner.

Kinase Assay: AZD1152 displays>3000-fold selectivity for Aurora B as compared with Aurora A which has an IC50 of 1.368 μM. AZD1152 has even less activity against 50 other serine-threonine and tyrosine kinases including FLT3, JAK2, and Abl.

Cell Assay: Cells are exposed to various concentrations of AZD1152 for 24 or 48 hours. Cell proliferation is measured by 3H-thymidine uptake (isotope added 6 hours before harvest), and the concentration that induced 50% growth inhibition (IC50) is calculated from dose-response curves. Cell cycle analysis is performed by flow cytometry. Cell apoptosis is measured by annexin V–FITC apoptosis detection kit.