Design, synthesis, and biological evaluation of KA7, a novel quinolone-based sorafenib analogue with potent anticancer and immunomodulatory activities

Although multi-kinase inhibitors like sorafenib remain an important treatment option for advanced malignancies, their toxicity and resistance to treatment are problems. Enhancing its structure by making changes to the scaffold offers a viable way to boost safety and effectiveness. In this study, 2-(4-chlorobenzylamino)-6-(pyridin-4-yloxy) quinolin-4(1<i>H</i>)-one (KA7), a novel sorafenib analogue, is synthesized and biologically evaluated. KA7 was synthesized by replacing the urea component of sorafenib with a quinolone scaffold. Then, KA7 was characterized by NMR and HRMS. MTT tests were used to calculate the IC₅₀ and assess cytotoxicity against breast (MDA-231, MCF-7), glioblastoma (U87), and lung (A549) cancer cells. Flow cytometry was used to evaluate cell death induction (apoptosis/necrosis), cell cycle analysis, and autophagic activity. The analysis of cytokine release in LPS-stimulated THP-1 macrophages allowed for the determination of KA7's immunomodulatory potential. Our results indicated that KA7 exhibited IC₅₀ values lower than those of sorafenib in both U87 and A549 cells, with similar effects observed in MCF-7 cells, demonstrating dose-dependent cytotoxicity. Flow cytometry also revealed a significant increase in apoptosis and G1 phase cell cycle arrest across all cancer cell lines tested. Autophagy induced by KA7 was confirmed through acridine orange staining. In the macrophage model, KA7 increased levels of anti-inflammatory cytokines (IL-8 and IL-10) while decreasing pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6), supporting an immunomodulatory profile akin to that of sorafenib. In conclusion, KA7 exhibits strong anticancer properties, inducing apoptosis, arresting the G1 cell cycle, stimulating autophagy, and displaying positive immunomodulatory effects. According to these results, KA7 is a promising lead chemical for additional preclinical testing as a potent sorafenib substitute.