Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Via Archirafi 32, 90123, Palermo, Italy.
Dipartimento di Medicina Sperimentale e Clinica, Università; Magna Græcia di Catanzaro, 88100, Catanzaro, Italy; Net4Science srl, Academic Spinoff, Università; Magna Græcia di Catanzaro, 88100, Catanzaro, Italy.
Eur J Med Chem. 2023 Jun 5;254:115372. doi: 10.1016/j.ejmech.2023.115372. Epub 2023 Apr 12.
Unsatisfactory outcomes for relapsed/refractory lymphoma patients prompt continuing efforts to develop new therapeutic strategies. Our previous studies on pyrrole-based anti-lymphoma agents led us to synthesize a new series of twenty-six pyrrolo[3',4':3,4]cyclohepta[1,2-d] [1,2]oxazole derivatives and study their antiproliferative effects against a panel of four non-Hodgkin lymphoma cell lines. Several candidates showed significant anti-proliferative effects, with IC's reaching the sub-micromolar range in at least one cell line, with compound 3z demonstrating sub-micromolar growth inhibitory effects towards the entire panel. The VL51 cell line was the most sensitive, with an IC value of 0.10 μM for 3z. Our earlier studies had shown that tubulin was a prominent target of many of our oxazole derivatives. We therefore examined their effects on tubulin assembly and colchicine binding. While 3u and 3z did not appear to target tubulin, good activity was observed with 3d and 3p. Molecular docking and molecular dynamics simulations allowed us to rationalize the binding mode of the synthesized compounds toward tubulin. All ligands exhibited a better affinity for the colchicine site, confirming their specificity for this binding pocket. In particular, a better affinity and free energy of binding was observed for 3d and 3p. This result was confirmed by experimental data, indicating that, although both 3d and 3p significantly affected tubulin assembly, only 3d showed activity comparable to that of combretastatin A-4, while 3p was about 4-fold less active. Cell cycle analysis showed that compounds 3u and especially 3z induced a block in G2/M, a strong decrease in S phase even at low compound concentrations and apoptosis through the mitochondrial pathway. Thus, the mechanism of action of 3u and 3z remains to be elucidated. Very high selectivity toward cancer cells and low toxicity in human peripheral blood lymphocytes were observed, highlighting the good potential of these agents in cancer therapy and encouraging further exploration of this compound class to obtain new small molecules as effective lymphoma treatments.
复发/难治性淋巴瘤患者的治疗效果不尽如人意，促使人们不断努力开发新的治疗策略。我们之前对基于吡咯的抗淋巴瘤药物的研究促使我们合成了一系列 26 种吡咯并[3',4':3,4]环庚[1,2-d][1,2]恶唑衍生物，并研究了它们对一系列四种非霍奇金淋巴瘤细胞系的抗增殖作用。一些候选化合物表现出显著的抗增殖作用，在至少一种细胞系中的 IC 值达到亚微摩尔范围，化合物 3z 对整个细胞系表现出亚微摩尔的生长抑制作用。VL51 细胞系对 3z 最为敏感，IC 值为 0.10 μM。我们之前的研究表明，微管蛋白是我们许多恶唑衍生物的主要靶标。因此，我们研究了它们对微管蛋白组装和秋水仙碱结合的影响。虽然 3u 和 3z 似乎不针对微管蛋白，但 3d 和 3p 表现出良好的活性。分子对接和分子动力学模拟使我们能够合理地解释合成化合物与微管蛋白的结合模式。所有配体对秋水仙碱结合位点都表现出更好的亲和力，证实了它们对该结合口袋的特异性。特别是，3d 和 3p 观察到更好的亲和力和结合自由能。这一结果得到了实验数据的证实，表明尽管 3d 和 3p 都显著影响微管蛋白组装，但只有 3d 表现出与 combretastatin A-4 相当的活性，而 3p 的活性则低约 4 倍。细胞周期分析表明，化合物 3u，特别是 3z，诱导 G2/M 期阻滞，即使在低浓度化合物时 S 期也明显减少，通过线粒体途径诱导细胞凋亡。因此，3u 和 3z 的作用机制仍有待阐明。在人外周血淋巴细胞中观察到对癌细胞的高选择性和低毒性，这突出了这些药物在癌症治疗中的良好潜力，并鼓励进一步探索这类化合物以获得新的小分子作为有效的淋巴瘤治疗药物。
