Gilmartin Aidan G, Groy Arthur, Gore Elizabeth R, Atkins Charity, Long Edward R, Montoute Monica N, Wu Zining, Halsey Wendy, McNulty Dean E, Ennulat Daniela, Rueda Lourdes, Pappalardi Melissa, Kruger Ryan G, McCabe Michael T, Raoof Ali, Butlin Roger, Stowell Alexandra, Cockerill Mark, Waddell Ian, Ogilvie Donald, Luengo Juan, Jordan Allan, Benowitz Andrew B
GlaxoSmithKline, Collegeville, Pennsylvania, USA.
Drug Discovery Unit, Cancer Research UK Manchester Institute, University of Manchester, UK.
Haematologica. 2021 Jul 1;106(7):1979-1987. doi: 10.3324/haematol.2020.248658.
Pharmacological induction of fetal hemoglobin (HbF) expression is an effective therapeutic strategy for the management of beta-hemoglobinopathies such as sickle cell disease. DNA methyltransferase (DNMT) inhibitors 5-azacytidine (5-aza) and 5-aza-2'-deoxycytidine (decitabine) have been shown to induce fetal hemoglobin expression in both preclinical models and clinical studies, but are not currently approved for the management of hemoglobinopathies. We report here the discovery of a novel class of orally bioavailable DNMT1-selective inhibitors as exemplified by GSK3482364. This molecule potently inhibits the methyltransferase activity of DNMT1, but not DNMT family members DNMT3A or DNMT3B. In contrast with cytidine analog DNMT inhibitors, the DNMT1 inhibitory mechanism of GSK3482364 does not require DNA incorporation and is reversible. In cultured human erythroid progenitor cells (EPCs), GSK3482364 decreased overall DNA methylation resulting in de-repression of the gamma globin genes HBG1 and HBG2 and increased HbF expression. In a transgenic mouse model of sickle cell disease, orally administered GSK3482364 caused significant increases in both HbF levels and in the percentage HbF-expressing erythrocytes, with good overall tolerability. We conclude that in these preclinical models, selective, reversible inhibition of DNMT1 is sufficient for the induction of HbF, and is well-tolerated. We anticipate that GSK3482364 will be a useful tool molecule for the further study of selective DNMT1 inhibition both in vitro and in vivo.
药理学诱导胎儿血红蛋白（HbF）表达是治疗β-血红蛋白病（如镰状细胞病）的有效策略。DNA甲基转移酶（DNMT）抑制剂5-氮杂胞苷（5-aza）和5-氮杂-2'-脱氧胞苷（地西他滨）在临床前模型和临床研究中均已显示可诱导胎儿血红蛋白表达，但目前尚未获批用于血红蛋白病的治疗。我们在此报告发现了一类新型的口服生物可利用的DNMT1选择性抑制剂，以GSK3482364为例。该分子可有效抑制DNMT1的甲基转移酶活性，但对DNMT家族成员DNMT3A或DNMT3B无抑制作用。与胞苷类似物DNMT抑制剂不同，GSK3482364的DNMT1抑制机制不需要DNA掺入且是可逆的。在培养的人类红系祖细胞（EPC）中，GSK3482364降低了总体DNA甲基化，导致γ珠蛋白基因HBG1和HBG2去抑制并增加了HbF表达。在镰状细胞病的转基因小鼠模型中，口服GSK3482364可使HbF水平及表达HbF的红细胞百分比显著增加，且总体耐受性良好。我们得出结论，在这些临床前模型中，选择性、可逆性抑制DNMT1足以诱导HbF，且耐受性良好。我们预计GSK3482364将成为体外和体内进一步研究选择性DNMT1抑制作用的有用工具分子。
