Targeting EGFR with thiazolidin-4-ones: Structure-guided design, synthesis, and in silico profiling for anticancer...

A series of 5-benzylidene-2-hydrazinomethine-thiazolidin-4-one derivatives 5a-y was designed and synthesized based on advanced EGFR TKIs. In vitro EGFR inhibition screening identified twelve compounds with activity comparable to or exceeding that of gefitinib and osimertinib. Thirteen compounds were selected from the NCI for single-dose assay leading to five-dose evaluation of four promising candidates. Compound 5c emerged as the most promising candidate with an IC₅₀ value of 0.090 μM outperforming osimertinib (0.540 μM) and closely matching gefitinib (0.076 μM). In the NCI-60 panel, 5c showed a mean GI% of 84.70 % in single-dose and GI₅₀ values between 2.77 and 20.70 μM in five-dose assays. Cell cycle analysis of 5c revealed G₀/G₁ arrest in 74.55 % of treated cells versus 58.29 % in controls. Apoptosis reached 26.51 % (vs. 0.65 %) and necrosis of 3.15 % (vs. 1.63 %). Gene expression analysis elicited upregulation of caspase-3 (5.565-fold), caspase-9 (3.549-fold) and Bax (5.029-fold) alongside downregulation of Bcl-2 (0.356-fold). Against mutant EGFR forms, 5c maintained activity with IC₅₀s between 0.147 and 0.703 μM. Molecular docking supported this activity showing favorable binding energies compared to gefitinib. Compound 5c met Lipinski's, Veber's and Eagan's criteria for oral bioavailability. ADME and toxicity profiles suggested a safer profile than both gefitinib and osimertinib, including lower immunotoxicity (0.74 vs. 0.99) and negligible hepatotoxic, neurotoxic and respiratory risks. These findings highlight 5c as a selective and potent EGFR TKI with strong therapeutic potential.