Discovery of new pyrazole-4-carboxamide analogues as potential anticancer agents targeting dual aurora kinase A and B.

Aurora kinases A and B are critical regulators of cell division and cytokinesis. Abnormal expression of Aurora kinases A and B causes chromosomal instability and disrupts several tumor suppressor and oncoprotein-controlled pathways. As a result, there has been a spike in interest in developing inhibitors against these kinases as anticancer treatments. This paper addresses the discovery, anticancer evaluation and druggability study of new pyrazole-4-carboxamide analogues as kinases inhibitors. Among the compounds, 6k demonstrated the highest cytotoxicity against HeLa and HepG2 cells, with IC of 0.43 μM and 0.67 μM, respectively. It selectively inhibited Aurora kinases A and B, with IC values of 16.3 nM and 20.2 nM, respectively, in comparison to other kinases. Molecular investigations revealed that 6k induced the inhibition of phosphorylated Thr288 (Aurora kinase A) and phosphorylated Histone H3 (Aurora kinase B), confirming its mechanism of action. Beside, compound 6k arrested the cell cycle at the G2/M phase by modulating cyclinB1 and cdc2 protein levels and increasing the Sub-G1 cell population. It also significantly increased polyploidization (>8 N) and abnormal mitosis, likely due to Aurora kinase inhibition. Furthermore, 6k boosted apoptosis through the intrinsic route, with elevated levels of p53, Bak, Bax, cleaved caspase-3, and cleaved PARP. Moreover, docking and MD simulations validated kinase inhibition-induced anticancer effects. Additionally, 6k satisfied drug-likeness parameters and remained stable in the in vitro metabolism. These findings indicate that 6k warrants further in vivo pharmacokinetic and pharmacodynamics investigations.