Discovery of N-benzylbenzamide-based allosteric inhibitors of Aurora kinase A.

Aurora kinases (AurkA/B/C) regulate the assembly of bipolar mitotic spindles and the fidelity of chromosome segregation during mitosis, and are attractive therapeutic targets for cancers. Numerous ATP-competitive AurkA inhibitors have been developed as potential anti-cancer agents. Recently, a few allosteric inhibitors have been reported that bind to the allosteric Y-pocket within AurkA kinase domain and disrupt the interaction between AurkA and its activator TPX2. Herein we report a novel allosteric AurkA inhibitor (6h) of N-benzylbenzamide backbone. Compound 6h suppressed the both catalytic activity and non-catalytic functions of AurkA. The inhibitory activity of 6h against AurkA (IC50 = 6.50 µM) was comparable to that of the most potent allosteric AurkA inhibitor AurkinA. Docking analysis against the Y-pocket revealed important pharmacophores and interactions that were coherent with structure-activity relationship. In addition, 6h suppressed DNA replication in G1-S phase, which is a feature of allosteric inhibition of AurA. Our current study may provide a useful insight in designing potent allosteric AurkA inhibitors.

Sulfonamide-based 4-anilinoquinoline derivatives as novel dual Aurora kinase (AURKA/B) inhibitors: Synthesis, biological evaluation and in silico insights.

Aurora kinases (AURKs) were identified as promising druggable targets for targeted cancer therapy. Aiming at the development of novel chemotype of dual AURKA/B inhibitors, herein we report the design and synthesis of three series of 4-anilinoquinoline derivatives bearing a sulfonamide moiety (5a-d, 9a-d and 11a-d). The % inhibition of AURKA/B was determined for all target quinolines, then compounds showed more than 50% inhibition on either of the enzymes, were evaluated further for their IC50 on the corresponding enzyme. In particular, compound 9d displayed potent AURKA/B inhibitory activities with IC50 of 0.93 and 0.09 µM, respectively. Also, 9d emerged as the most efficient anti-proliferative analogue in the US-NCI anticancer assay toward the NCI 60 cell lines panel, with broad spectrum activity against different cell lines from diverse cancer subpanels. Docking studies, confirmed that, the sulfonamide SO2 oxygen was involved in a hydrogen bond with Lys162 and Lys122 in AURKA and AURKB, respectively, whereas, the sulfonamide NH could catch hydrogen bond interaction with the surrounding amino acid residues Lys141, Glu260, and Asn261 in AURKA and Lys101, Glu177, and Asp234 in AURKB. Furthermore, N1 nitrogen of the quinoline scaffold formed an essential hydrogen bond with the hinge region key amino acids Ala213 and Ala173 in AURKA and AURKB, respectively.