Biological Investigation of Novel Pyrazole-Based Anticancer Scaffolds: A Trinity of Synthetic Methodologies on...

Aurora kinase A (AURKA) is a key regulator of mitotic progression and is frequently overexpressed in human malignancies, making it an attractive therapeutic target for the development of targeted anticancer agents. The present study aimed to design and synthesize sixteen novel pyrazole derivatives (Pz-01 to Pz-16) as potential AURKA-targeted anticancer agents and to evaluate their anticancer activity, AURKA-binding potential, and SAR using integrated experimental and computational approaches. The synthesized compounds were screened for cytotoxic activity against human breast cancer (MCF-7 and MDA-MB-231) and cervical cancer (HeLa) cell lines. Among the evaluated derivatives, Pz-10 emerged as the most potent analogue, exhibiting significant antiproliferative activity against MCF-7 cells (IC₅₀ = 22.30 ± 2 μM), comparable to the reference drug doxorubicin, while demonstrating moderate activity against MDA-MB-231 cells (IC₅₀ = 27.60 ± 3 μM). Structure-based molecular docking revealed that Pz-10 adopted a favourable binding orientation within the ATP-binding pocket of AURKA, which was further supported by MM-GBSA binding free-energy calculations and favourable predicted pharmacokinetic properties, indicating excellent oral absorption and drug-like characteristics. To validate the stability of the predicted binding mode, 200 ns molecular dynamics simulations were performed, demonstrating persistent protein-ligand interactions, stable hydrogen-bonding networks, and minimal structural fluctuations throughout the simulation trajectory, consistent with the behaviour of the reference inhibitor. SAR analysis identified hydroxyl substitution on the pyrazole scaffold as a critical determinant of antiproliferative activity and target engagement, whereas bulky halogenated and nitro substituents were associated with reduced biological activity. Collectively, these findings identify Pz-10, together with the structurally related Pz-11, as promising pyrazole-based lead molecules for the development of AURKA-targeted anticancer therapeutics and provide valuable structural insights for the future optimization of selective mitotic kinase inhibitors.