Identification of novel inhibitors of Aurora A with a 3-(pyrrolopyridin-2-yl)indazole scaffold.

A novel series of 3-(pyrrolopyridin-2-yl)indazole derivatives were synthesized and biologically evaluated for their anti-proliferative effects on five human cancer cell lines. As a result, all of them exhibited vigorous potency against HL60 cell line with IC50 values ranging from singe digital nanomolar to micromolar level. Besides, a majority of them displayed modest to good antiproliferative activities against the other four cell lines, including KB, SMMC-7721, HCT116, and A549. Particularly, compound 2y, as the most distinguished one in this series, demonstrated IC50 values of 8.3nM and 1.3nM against HL60 and HCT116 cell lines, respectively. Afterwards, for exploring the molecular target, compounds2d, 2g and 2y were further selected to evaluate the inhibitory activities against a panel of kinases. Finally, they were identified to be targeting Aurora A kinase with significant selectivity over other kinases, such as CHK1, CDK2, MEK1, GSK3β, BRAF, IKKβ and PKC.