Pandher Ruby, Xue Chengyuan, Gamble Laura D, Milazzo Giorgio, Di Giacomo Simone, Murray Jayne, Cheung Leanna, Ferrucci Francesca, Palombo Marta, Purgato Stefania, Burkhart Catherine A, Fedtsova Natalia, Gleiberman Anatoli S, Purmal Andrei A, Korotchkina Lioubov, Nikiforov Mikhail A, Makarov Sergei S, Telfer Thomas J, Codd Rachel, Marshall Glenn M, Scott David A, Osterman Andrei L, Gudkov Andrei V, Perini Giovanni, Haber Michelle, Norris Murray D
Children's Cancer Institute, Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW 2031, Australia.
Department of Pharmacy and Biotechnology, University of Bologna, Bologna 40126, Italy.
Proc Natl Acad Sci U S A. 2025 Jun 10;122(23):e2420011122. doi: 10.1073/pnas.2420011122. Epub 2025 Jun 2.
Despite Myc oncoproteins being major causal factors in human cancer, they remain "undruggable." The oncogene is one of the most powerful prognostic markers for the childhood cancer neuroblastoma and represents an important target for developing novel therapeutics. Here, we report the finding and characterization of M606, a selective small molecule inhibitor of MYCN, which was identified by screening a diverse chemical library. M606 reduced MYCN protein levels in neuroblastoma cell lines and upregulated hypoxia-inducible factor 1 alpha (HIF1A). Using siRNA-mediated knockdown of , , or in HepG2 and BE(2)-C cells followed by M606 treatment, we demonstrated that Myc downregulation and HIF1A upregulation were two independent effects of M606 treatment. M606 selectively targeted neuroblastoma cell lines expressing higher levels of MYCN protein and delayed neuroblastoma development in the transgenic mouse model. Metabolomic analysis showed that M606 modulated glucose metabolism, consistent with a hypoxic response and iron deprivation. Biochemical characterization of M606 not only confirmed its iron-chelating properties but also revealed its ability to downregulate promoter activity, which could be rescued by the addition of iron. Luciferase assays identified the minimal promoter region required for the M606 response, which contained overlapping E2F transcription factor binding sites. Further evaluation defined a key role for E2F3 in the M606-mediated response. The finding of a potent cell-permeable iron chelator that can chelate iron to directly downregulate transcription via an E2F3-mediated response represents a potentially valuable therapeutic approach in the treatment of cancers overexpressing Myc oncoproteins.
尽管Myc癌蛋白是人类癌症的主要致病因素，但它们仍然“难以成药”。该癌基因是儿童癌症神经母细胞瘤最有力的预后标志物之一，也是开发新型治疗方法的重要靶点。在此，我们报告了M606的发现和特性，M606是一种通过筛选多样化化学文库鉴定出的MYCN选择性小分子抑制剂。M606降低了神经母细胞瘤细胞系中的MYCN蛋白水平，并上调了缺氧诱导因子1α（HIF1A）。在HepG2和BE(2)-C细胞中使用siRNA介导的对、或的敲低，随后进行M606处理，我们证明Myc下调和HIF1A上调是M606处理的两个独立效应。M606选择性靶向表达较高水平MYCN蛋白的神经母细胞瘤细胞系，并延缓了转基因小鼠模型中神经母细胞瘤的发展。代谢组学分析表明，M606调节葡萄糖代谢，这与缺氧反应和铁剥夺一致。M606的生化特性不仅证实了其铁螯合特性，还揭示了其下调启动子活性的能力，这种能力可通过添加铁来挽救。荧光素酶测定确定了M606反应所需的最小启动子区域，该区域包含重叠的E2F转录因子结合位点。进一步评估确定了E2F3在M606介导的反应中的关键作用。发现一种有效的细胞可渗透铁螯合剂，它可以螯合铁以通过E2F3介导的反应直接下调转录，这代表了一种在治疗过表达Myc癌蛋白的癌症中潜在有价值的治疗方法。
