Herein, we designed and synthesized a series of novel 2-methylthieno []pyrimidine analogues as tubulin inhibitors with antiproliferative activities at low nanomolar levels. Among them, compound displayed the most potent anti-proliferative activity against six cancer cell lines with an average IC of ∼6.23 nM, better than that of colchicine (IC = 9.26 nM). exerted its anti-cancer activity by suppressing the polymerization of tubulin with an IC of 2.4 μM. Furthermore, the crystal structure of in complex with tubulin was solved by X-ray crystallography to 2.94 Å resolution, confirming the direct binding of to the colchicine site. Moreover, arrested the cell cycle in the G2/M phase of mitosis, subsequently inducing tumor cell apoptosis. Additionally, was able to effectively inhibit the migration of cancer cells. Besides, exhibited significant anti-tumor efficacy in a B16–F10 melanoma tumor model with a TGI of 63.3 % (7 mg/kg) by intraperitoneal () injection. Notably, the combination of with (a PD-L1-targeting small molecule inhibitor reported by our group before) demonstrated enhanced anti-cancer efficacy . These results suggest that is a promising lead compound deserving further investigation as a potential anti-cancer agent.

中文翻译：

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发现新型基于噻吩[3,2-d]嘧啶的微管蛋白抑制剂，与抗 pd-l1 免疫疗法联合使用治疗黑色素瘤，具有增强的抗肿瘤功效


在此，我们设计并合成了一系列新型2-甲基噻吩并[]嘧啶类似物作为微管蛋白抑制剂，在低纳摩尔水平下具有抗增殖活性。其中，化合物对 6 种癌细胞系表现出最有效的抗增殖活性，平均 IC 值为 ∼6.23 nM，优于秋水仙碱 (IC = 9.26 nM)。通过抑制微管蛋白的聚合发挥抗癌活性，IC 为 2.4 μM。此外，通过 X 射线晶体学以 2.94 Å 分辨率解析了 与微管蛋白复合物的晶体结构，证实了 与秋水仙碱位点的直接结合。此外，将细胞周期阻滞在有丝分裂的G2/M期，随后诱导肿瘤细胞凋亡。此外，能够有效抑制癌细胞的迁移。此外，在 B16-F10 黑色素瘤肿瘤模型中表现出显着的抗肿瘤功效，腹腔注射的 TGI 为 63.3%（7 mg/kg）。值得注意的是，与（我们课题组之前报道的一种PD-L1靶向小分子抑制剂）联合使用，显示出增强的抗癌功效。这些结果表明，这是一种有前途的先导化合物，值得进一步研究作为潜在的抗癌剂。