Cyclopenta[B]Indole Derivative Inhibits Aurora B In Primary Cells

The Aurora family of kinases is closely involved in regulating cell division. Inhibition of Aurora A and B with small molecules is currently being investigated in clinical trials for the treatment of different cancers. It has also been evaluated as a treatment option against different autoimmune diseases in preclinical studies. Here, we present a cyclopenta[b]indole derivative capable of inhibiting Aurora B selectively in kinase assays. To evaluate the Aurora B inhibition capacity of the compound, we used a kinase IC50 assay as well as a suppression assay of proliferating primary cells. In addition, we examined if the cells had gained a phenotype characteristic for Aurora B inhibition after treatment with the compound. We found that the compound selectively inhibited Aurora B (IC50 = 1.4 mu M) over Aurora A (IC50 > 30 mu M). Moreover, the compound inhibited proliferating PBMCs with an IC50 = 4.2 mu M, and the cells displayed reduced phosphorylation of histone H3 as well as tetraploidy, consistent with Aurora B inhibition.