Design, synthesis and biological evaluation of a new series of imidazothiazole-hydrazone hybrids as dual EGFR and Akt inhibitors for NSCLC therapy

In search of small molecules for targeted therapy of non-small cell lung carcinoma (NSCLC), an efficient four-step synthetic route was followed for the synthesis of new imidazothiazole-hydrazone hybrids, which were assessed for their cytotoxic effects on human lung adenocarcinoma (A549) and human lung fibroblast (CCD-19Lu) cells. Among them, compounds 4, 6, 13, 16, 17 and 21 exhibited selective cytotoxic activity against A549 cell line. In vitro mechanistic studies were performed to assess their effects on apoptosis, caspase-3, cell cycle, EGFR and Akt in A549 cells. Compounds 6, 16, 17 and 21 promoted apoptotic cell death more than erlotinib. According to the in vitro data, it is quite clear that compound 6 promotes apoptosis through caspase-3 activation and arrests the cell cycle at the G0/G1 phase in A549 cells. Compounds 16 and 17 arrested the cell cycle at the S phase, whereas compounds 4, 13 and 21 caused the cell cycle arrest at the G2/M phase. The most effective EGFR inhibitor in this series was found as compound 13, followed by compounds 17 and 16. Furthermore, Akt inhibitory effects of compounds 16 and 17 in A549 cells were close to that of GSK690693. In particular, it can be concluded that the cytotoxic and apoptotic effects of compounds 16 and 17 are associated with their inhibitory effects on both EGFR and Akt. Molecular docking studies suggest that compounds 16 and 17 interact with crucial amino acid residues in the binding sites of human EGFR (PDB ID: 1M17) and Akt2 (PDB ID: 3D0E). Based on the in silico data, both compounds are predicted to possess favorable oral bioavailability and drug-likeness. Further studies are required to benefit from these compounds as anticancer agents for targeted therapy of NSCLC.