A diverse series of 1,2,4-oxadiazoles based substituted compounds were designed, synthesized and evaluated as anticancer agents targeting carbonic anhydrase IX (CAIX). Initial structure-activity analysis suggested that the thiazole/thiophene-sulfonamide conjugates of 1,2,4-oxadiazoles exhibited potent anticancer activities with low μM potencies. Compound OX12 exhibited antiproliferative activity (IC50 = 11.1 µM) along with appreciable inhibition potential for tumor-associated CAIX (IC50 = 4.23 µM) isoform. Therefore, OX12 was structurally optimized and its SAR oriented derivatives (OX17-27) were synthesized and evaluated. This iteration resulted in compound OX27 with an almost two-fold increase in antiproliferative effect (IC50 = 6.0 µM) comparable to the clinical drug doxorubicin and significantly higher potency against CAIX (IC50 = 0.74 µM). Additionally, OX27 treatment decreases the expression of CAIX, induces apoptosis and ROS production, inhibited colony formation and migration of colon cancer cells. Our studies provide preclinical rational for the further optimization of identified OX27 as a suitable lead for the possible treatment of CRC.

中文翻译：

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新型1,2,4-恶二唑-磺酰胺基化合物的合成和SAR研究，这些化合物可作为结直肠癌治疗的潜在抗癌药。

设计，合成和评估了一系列基于1,2,4-恶二唑的取代化合物，并将其作为靶向碳酸酐酶IX（CAIX）的抗癌剂。初步的结构活性分析表明，1,2,4-恶二唑的噻唑/噻吩-磺酰胺共轭物显示出有效的抗癌活性，且μM效力低。化合物OX12表现出抗增殖活性（IC50 = 11.1 µM），并对与肿瘤相关的CAIX具有明显的抑制作用（IC50 = 4.23 µM）。因此，对OX12进行了结构优化，并合成并评估了其SAR定向衍生物（OX17-27）。通过这种迭代，化合物OX27的抗增殖作用几乎增加了两倍（IC50 = 6.0 µM），可与临床药物阿霉素相比，并且对CAIX的效力明显更高（IC50 = 0.74 µM）。另外，OX27处理降低了CAIX的表达，诱导了细胞凋亡和ROS的产生，抑制了结肠癌细胞的集落形成和迁移。我们的研究为进一步优化已鉴定的OX27提供了临床前理由，OX27是可能治疗CRC的合适先导。