Department of Oncology, Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
Research Center for Genetic Medicine, Children's National Hospital, Washington, DC, USA.
Neuro Oncol. 2022 Sep 1;24(9):1438-1451. doi: 10.1093/neuonc/noac041.
Pediatric diffuse midline gliomas (DMGs) are incurable childhood cancers. The imipridone ONC201 has shown early clinical efficacy in a subset of DMGs. However, the anticancer mechanisms of ONC201 and its derivative ONC206 have not been fully described in DMGs.
DMG models including primary human in vitro (n = 18) and in vivo (murine and zebrafish) models, and patient (n = 20) frozen and FFPE specimens were used. Drug-target engagement was evaluated using in silico ChemPLP and in vitro thermal shift assay. Drug toxicity and neurotoxicity were assessed in zebrafish models. Seahorse XF Cell Mito Stress Test, MitoSOX and TMRM assays, and electron microscopy imaging were used to assess metabolic signatures. Cell lineage differentiation and drug-altered pathways were defined using bulk and single-cell RNA-seq.
ONC201 and ONC206 reduce viability of DMG cells in nM concentrations and extend survival of DMG PDX models (ONC201: 117 days, P = .01; ONC206: 113 days, P = .001). ONC206 is 10X more potent than ONC201 in vitro and combination treatment was the most efficacious at prolonging survival in vivo (125 days, P = .02). Thermal shift assay confirmed that both drugs bind to ClpP, with ONC206 exhibiting a higher binding affinity as assessed by in silico ChemPLP. ClpP activation by both drugs results in impaired tumor cell metabolism, mitochondrial damage, ROS production, activation of integrative stress response (ISR), and apoptosis in vitro and in vivo. Strikingly, imipridone treatment triggered a lineage shift from a proliferative, oligodendrocyte precursor-like state to a mature, astrocyte-like state.
Targeting mitochondrial metabolism and ISR activation effectively impairs DMG tumorigenicity. These results supported the initiation of two pediatric clinical trials (NCT05009992, NCT04732065).
儿科弥漫性中线脑胶质瘤（DMG）是一种无法治愈的儿童癌症。Imipridone 药物 ONC201 在一部分 DMG 患者中表现出早期临床疗效。然而，ONC201 及其衍生物 ONC206 的抗癌机制在 DMG 中尚未得到充分描述。
使用了包括原代人体外（n=18）和体内（鼠和斑马鱼）模型以及 20 名患者的冷冻和 FFPE 标本的 DMG 模型。使用计算机 ChemPLP 和体外热位移测定评估药物靶标结合。在斑马鱼模型中评估药物毒性和神经毒性。使用 Seahorse XF 细胞线粒体应激测试、MitoSOX 和 TMRM 测定以及电子显微镜成像来评估代谢特征。使用批量和单细胞 RNA-seq 定义细胞谱系分化和药物改变的途径。
ONC201 和 ONC206 以 nM 浓度降低 DMG 细胞的活力并延长 DMG PDX 模型的存活时间（ONC201：117 天，P=0.01；ONC206：113 天，P=0.001）。ONC206 在体外比 ONC201 强 10 倍，联合治疗在体内延长存活时间最有效（125 天，P=0.02）。热位移测定证实两种药物均与 ClpP 结合，通过计算机 ChemPLP 评估，ONC206 表现出更高的结合亲和力。两种药物对 ClpP 的激活导致肿瘤细胞代谢受损、线粒体损伤、ROS 产生、整合应激反应（ISR）激活和体外及体内凋亡。引人注目的是，Imipridone 治疗引发了从增殖性、少突胶质细胞前体细胞样状态到成熟、星形胶质细胞样状态的谱系转变。
靶向线粒体代谢和 ISR 激活可有效损害 DMG 的致瘤性。这些结果支持启动两项儿科临床试验（NCT05009992、NCT04732065）。
