Aldehyde dehydrogenases (ALDHs) are overexpressed in various tumor types including prostate cancer and considered a potential target for therapeutic intervention. 4-(Diethylamino)benzaldehyde (DEAB) has been extensively reported as a pan-inhibitor of ALDH isoforms, and here, we report on the synthesis, ALDH isoform selectivity, and cellular potencies in prostate cancer cells of 40 DEAB analogues; three analogues (14, 15, and 16) showed potent inhibitory activity against ALDH1A3, and two analogues (18 and 19) showed potent inhibitory activity against ALDH3A1. Significantly, 16 analogues displayed increased cytotoxicity (IC₅₀ = 10–200 μM) compared with DEAB (>200 μM) against three different prostate cancer cell lines. Analogues 14 and 18 were more potent than DEAB against patient-derived primary prostate tumor epithelial cells, as single agents or in combination treatment with docetaxel. In conclusion, our study supports the use of DEAB as an ALDH inhibitor but also reveals closely related analogues with increased selectivity and potency.

中文翻译：

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4-(二乙氨基)苯甲醛支架的扩展探索对前列腺癌醛脱氢酶活性和抗增殖活性的影响

醛脱氢酶 (ALDH) 在包括前列腺癌在内的各种肿瘤类型中过度表达，被认为是治疗干预的潜在靶点。4-(二乙氨基)苯甲醛 (DEAB) 已被广泛报道为 ALDH 同种型的泛抑制剂，在这里，我们报告了 40 种 DEAB 类似物在前列腺癌细胞中的合成、ALDH 同种型选择性和细胞效力；三种类似物（14、15和16 ）显示出对 ALDH1A3 的有效抑制活性，两种类似物（18和19）显示出对 ALDH3A1 的有效抑制活性。值得注意的是，16 种类似物显示出增加的细胞毒性（IC ₅₀= 10–200 μM) 与 DEAB (>200 μM) 相比对三种不同的前列腺癌细胞系。类似物14和18对患者来源的原发性前列腺肿瘤上皮细胞比 DEAB 更有效，作为单一药物或与多西紫杉醇联合治疗。总之，我们的研究支持使用 DEAB 作为 ALDH 抑制剂，但也揭示了密切相关的类似物，具有更高的选择性和效力。