A series of 5-FU-Genistein hybrids were synthesized and their structures were elucidated by spectroscopic analysis. The chemopreventive potential of these compounds was evaluated in human colon adenocarcinoma cells (SW480 and SW620) and non-malignant cell lines (HaCaT and CHO-K1). Hybrid 4a displayed cytotoxicity against SW480 and SW620 cells with IC50 values of 62.73 ± 7.26 µM and 50.58 ± 1.33 µM, respectively; compound 4g induced cytotoxicity in SW620 cells with an IC50 value of 36.84 ± 0.71 µM. These compounds were even more selective than genistein alone, the reference drug (5-FU) and the equimolar mixture of genistein plus 5-FU. In addition, hybrids 4a and 4g induced time- and concentration-dependent antiproliferative activity and cell cycle arrest at the S-phase and G2/M. It was also observed that hybrid 4a induced apoptosis in SW620 cells probably triggered by the extrinsic pathway in response to the activation of p53, as evidenced by the increase in the levels of caspases 3/8 and the tumor suppressor protein (Tp53). Molecular docking studies suggest that the most active compound 4a would bind efficiently to proapoptotic human caspases 3/8 and human Tp53, which in turn could provide valuable information on the biochemical mechanism for the in vitro cytotoxic response of this compound in SW620 colon carcinoma cell lines. On the other hand, molecular dynamics (MD) studies provided strong evidence of the conformational stability of the complex between caspase-3 and hybrid 4a obtained throughout 100 ns all-atom MD simulation. Molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) analyses of the complex with caspase-3 showed that the interaction between the ligand and the target protein is stable. Altogether, the results suggest that the active hybrids, mainly compound 4a, might act by modulating caspase-3 activity in a colorectal cancer model, making it a privileged scaffold that could be used in future investigations.
我们合成了一系列 5-FU -染料木素混合物,并通过光谱分析阐明了它们的结构。在人结肠腺癌细胞(SW480 和 SW620)和非恶性细胞系(HaCaT 和 CHO-K1)中评估了这些化合物的化学预防潜力。杂交化合物 4a 对 SW480 和 SW620 细胞具有细胞毒性,IC50 值分别为 62.73 ± 7.26 µM 和 50.58 ± 1.33 µM;化合物 4g 对 SW620 细胞具有细胞毒性,IC50 值为 36.84 ± 0.71 µM。这些化合物的选择性甚至高于单独的染料木素、参考药物(5-FU)以及染料木素和 5-FU 的等摩尔混合物。此外,杂交化合物 4a 和 4g 诱导了时间和浓度依赖性的抗增殖活性,并使细胞周期停滞在 S 期和 G2/M。研究还观察到,杂交种 4a 可诱导 SW620 细胞凋亡,这可能是由 p53 激活后的外显子通路触发的,caspases 3/8 和肿瘤抑制蛋白(Tp53)水平的升高证明了这一点。分子对接研究表明,活性最强的化合物 4a 能与促凋亡的人类 caspases 3/8 和人类 Tp53 有效结合,这反过来又能为该化合物在 SW620 结肠癌细胞系中产生体外细胞毒性反应的生化机制提供有价值的信息。另一方面,分子动力学(MD)研究提供了强有力的证据,证明在 100 ns 全原子 MD 模拟中获得的 caspase-3 与杂交 4a 复合物的构象稳定性。分子力学泊松-玻尔兹曼表面积(MM-PBSA)分析表明,配体与目标蛋白之间的相互作用是稳定的。总之,研究结果表明,在结直肠癌模型中,活性杂交化合物(主要是化合物 4a)可能会通过调节 caspase-3 的活性而发挥作用,使其成为一种可用于未来研究的特殊支架。