Design, synthesis, and preliminary antitumor mechanism of benzimidazole derivatives

Fourteen novel benzimidazole derivatives were designed, synthesized, and evaluated for their antitumor activities against four human cancer cell lines, A549 (lung carcinoma), 5637 (bladder cancer), PC-3 (prostate cancer), and K562 (chronic myelogenous leukemia- CML), using the MTT assay. Among these, compound E12 demonstrated the most potent activity against the K562 cells, exhibiting significant growth inhibition with an IC 50 value of 11.07 μM, while demonstrating low toxicity towards the normal HEK-293 (embryonic kidney) cell line, with an IC 50 greater than 40 μM. Flow cytometry analysis revealed that E12 induced apoptosis, increased reactive oxygen species levels, decreased mitochondrial membrane potential, and caused cell cycle arrest at the G2/M phase. Additionally, western blot analysis showed that E12 effectively inhibited BCR-ABL expression, upregulated Bax expression, and downregulated Cyclin B1 and CDK-1 expression to induce apoptosis. Molecular docking results also showed that compound E12 had a strong binding ability with the BCR-ABL protein, and the binding energy was -9.3 kcal/mol. These findings suggest that E12 is a promising candidate for further development as an anti-chronic myeloid leukemia drug.