Design, synthesis, antitumor estimation, and molecular docking of new imidazothiazolediones as potential dual EGFR and IDO1 inhibitors and apoptosis stimulators.
A novel set of imidazo[2,1-b]thiazolediones 4a,b and 5a-d, with anticipated EGFR and IDO1 inhibition activities, was designed and prepared. These novel derivatives were evaluated in the NCI 60 cell line panel in which the superior compounds 5b and 5d were chosen for further evaluation of their five dose cytotoxicity toward the most sensitive cancer cells namely non-small cell lung cancer EKVX and HOP-92, breast HS 578 T, and normal WI-38 cells. The presence of a substituted benzylidene moiety at position-2 of the imidazothiazole scaffold in compounds 5a-d positively influences anticancer activity, with the phenylallylidene moiety at position-6 exhibiting superior cytotoxic effects compared to the 2-thienylidene moiety. Among the examined hybrids, 5d showed significant antiproliferative effect against HS 578 T tumor cell. To explore the underlying cell-death mechanisms, secondary biological evaluations were conducted, including cell-free EGFR and IDO1 enzymatic inhibition, apoptosis assay, and cell cycle analysis. In cell-free biochemical assays, the most active derivatives demonstrated a promising potential dual inhibitory profile against EGFR and IDO1, with compound 5d exhibiting sub-micromolar activity against both target enzymes, providing a plausible biochemical rationale for its potent cell killing. Furthermore, compound 5d induced cell cycle arrest at the G2/M phase and triggered apoptosis in HS 578 T cells, as supported by the up-regulation of Caspase-3 and Bax accompanied by the down-regulation of Bcl-2. In-silico ADMET profiling and molecular docking simulations further supported the favorable drug-like properties and binding modes of the key compounds within the target active sites. Overall, these findings highlight compound 5d as a promising lead candidate for further optimization and cellular mechanistic validation in anti-cancer drug discovery.