Structure-activity relationship and anticancer mechanism of febuxostat-1,2,3-triazole hybrids inducing DNA damage and...

Leveraging febuxostat's liver-targeting properties and the pharmacological versatility of the 1,2,3-triazole scaffold, we designed and synthesized a series of novel febuxostat-linked 1,2,3-triazole derivatives and systematically evaluated their anticancer activity against HepG2 hepatocellular carcinoma cells. Structure-activity relationship analysis revealed that para-substitution of the triazole on the phenyl ring, particularly when combined with a fluorine atom on the benzyl group, markedly enhanced cytotoxicity, with compounds 10c, 10f, and 10 h reducing HepG2 cell viability below 50%. Among these, compound 10 h demonstrated the most potent antiproliferative effect (IC₅₀ = 4.05 ± 0.67 μM), significantly outperforming the reference drug 5-fluorouracil (IC₅₀ = 17.43 ± 4.66 μM), while exhibiting minimal toxicity toward normal liver L02 cells (IC₅₀ > 40 μM). Mechanistic studies revealed that 10 h induced DNA damage and replication stress, as evidenced by increased p-H2AX and S-phase accumulation, accompanied by decreased total levels of PARP-1, caspase-9, and caspase-3, indicating activation of the intrinsic apoptotic pathway. Molecular docking suggested that 10 h binds strongly to human topoisomerase IIα (docking score - 8.341 vs -6.871 for meta-substituted 12 h), supporting a mechanism involving direct enzyme interaction. In vivo, 10 h significantly suppressed tumor growth in a HepG2 xenograft model without overt toxicity. Collectively, these findings establish 10 h as a highly potent and selective anticancer lead compound, acting via DNA damage-induced S-phase arrest and mitochondrial-mediated apoptosis, and highlight its potential for further development as a liver cancer therapeutic.