AlkB homolog 2 (ALKBH2) is a Fe (II) and 2-oxoglutarate (2OG)-dependent DNA demethylase. It has been reported to be highly expressed in many cancers including glioblastoma (GBM) and affected disease progression by regulating gene expression. Small molecule inhibitors of ALKBH2 might be used as disease intervention reagents or chemical tools for bio-functional studies of ALKBH2, but currently no potent and selective ALKBH2 inhibitors are reported. We herein disclose a new potent and selective ALKBH2 inhibitor (AH2-15c), which showed an IC50 value of 0.031 ± 0.001 μM in a fluorescence polarization (FP) assay and exhibited more than 200-fold selectivity towards ALKBH2 versus other AlkB subfamily members. Since AH2-15c showed very low cellular activity due to its poor cell membrane permeability originating from the carboxyl group, we investigated the un-hydrolyzed counterpart AH2-14c. AH2-14c could directly bind to ALKBH2 and increase the abundance of DNA N3-methylcytosine (3meC) modifications in GBM U87 cells, with a superior effect to AH2-15c. In addition, AH2-14c exhibited much better activities of anti-viability, anti-proliferation and anti-migration against U87 cells. Collectively, we discovered the first potent and selective ALKBH2 inhibitor, which could be taken as a foundation for future drug development and mechanism of action studies.

中文翻译：

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烟酰胺衍生物作为 DNA 去甲基化酶 ALKBH2 抑制剂的发现及构效关系研究


AlkB 同源物 2 （ALKBH2） 是一种 Fe （II） 和 2-氧代戊二酸 （2OG） 依赖性 DNA 去甲基化酶。据报道，它在包括胶质母细胞瘤 （GBM） 在内的许多癌症中高度表达，并通过调节基因表达影响疾病进展。ALKBH2 的小分子抑制剂可用作 ALKBH2 生物功能研究的疾病干预试剂或化学工具，但目前尚无强效和选择性 ALKBH2 抑制剂的报道。我们在此披露了一种新的有效选择性 ALKBH2 抑制剂 （AH2-15c），它在荧光偏振 （FP） 测定中显示 IC50 值为 0.031 ± 0.001 μM，并且对 ALKBH2 的选择性是其他 AlkB 亚家族成员的 200 倍以上。由于 AH2-15c 由于源自羧基的细胞膜通透性差而显示出非常低的细胞活性，因此我们研究了未水解的对应物 AH2-14c。AH2-14c 可直接与 ALKBH2 结合并增加 GBM U87 细胞中 DNA N3-甲基胞嘧啶 （3meC） 修饰的丰度，效果优于 AH2-15c。此外，AH2-14c 对 U87 细胞表现出更好的抗活力、抗增殖和抗迁移活性。总的来说，我们发现了第一个有效的选择性 ALKBH2 抑制剂，可以作为未来药物开发和作用机制研究的基础。