Children's Cancer Research Center and Department of Pediatrics, Klinikum rechts der Isar, Technische Universität München, München, Germany.
German Cancer Research Center (DKFZ), Partner Site Munich, München, Germany.
J Exp Clin Cancer Res. 2021 Oct 15;40(1):322. doi: 10.1186/s13046-021-02125-z.
Histone acetylation and deacetylation seem processes involved in the pathogenesis of Ewing sarcoma (EwS). Here histone deacetylases (HDAC) class I were investigated.
Their role was determined using different inhibitors including TSA, Romidepsin, Entinostat and PCI-34051 as well as CRISPR/Cas9 class I HDAC knockouts and HDAC RNAi. To analyze resulting changes microarray analysis, qRT-PCR, western blotting, Co-IP, proliferation, apoptosis, differentiation, invasion assays and xenograft-mouse models were used.
Class I HDACs are constitutively expressed in EwS. Patients with high levels of individual class I HDAC expression show decreased overall survival. CRISPR/Cas9 class I HDAC knockout of individual HDACs such as HDAC1 and HDAC2 inhibited invasiveness, and blocked local tumor growth in xenograft mice. Microarray analysis demonstrated that treatment with individual HDAC inhibitors (HDACi) blocked an EWS-FLI1 specific expression profile, while Entinostat in addition suppressed metastasis relevant genes. EwS cells demonstrated increased susceptibility to treatment with chemotherapeutics including Doxorubicin in the presence of HDACi. Furthermore, HDACi treatment mimicked RNAi of EZH2 in EwS. Treated cells showed diminished growth capacity, but an increased endothelial as well as neuronal differentiation ability. HDACi synergizes with EED inhibitor (EEDi) in vitro and together inhibited tumor growth in xenograft mice. Co-IP experiments identified HDAC class I family members as part of a regulatory complex together with PRC2.
Class I HDAC proteins seem to be important mediators of the pathognomonic EWS-ETS-mediated transcription program in EwS and in combination therapy, co-treatment with HDACi is an interesting new treatment opportunity for this malignant disease.
组蛋白乙酰化和去乙酰化似乎是尤文肉瘤（EwS）发病机制中的相关过程。本研究旨在调查组蛋白去乙酰化酶（HDAC）I 类。
采用不同抑制剂（TSA、Romidepsin、Entinostat 和 PCI-34051）以及 CRISPR/Cas9 类 I HDAC 敲除和 HDAC RNAi 来确定它们的作用。通过微阵列分析、qRT-PCR、western blot、Co-IP、增殖、凋亡、分化、侵袭测定和异种移植小鼠模型来分析结果变化。
I 类 HDAC 在 EwS 中持续表达。个体 I 类 HDAC 表达水平高的患者总生存率降低。CRISPR/Cas9 类 I HDAC 敲除单个 HDAC（如 HDAC1 和 HDAC2）可抑制侵袭性，并阻断异种移植小鼠的局部肿瘤生长。微阵列分析表明，单独使用 HDAC 抑制剂（HDACi）可阻断 EWS-FLI1 特异性表达谱，而 Entinostat 除了抑制转移相关基因外，还能抑制转移相关基因。在存在 HDACi 的情况下，EwS 细胞对包括多柔比星在内的化疗药物的敏感性增加。此外，HDACi 处理可模拟 EwS 中的 EZH2 RNAi。处理后的细胞生长能力下降，但内皮和神经元分化能力增强。HDACi 在体外与 EED 抑制剂（EEDi）协同作用，共同抑制异种移植小鼠肿瘤生长。Co-IP 实验鉴定出 I 类 HDAC 家族成员与 PRC2 一起作为调节复合物的一部分。
I 类 HDAC 蛋白似乎是 EwS 中标志性 EWS-ETS 介导的转录程序的重要介质，联合治疗时，HDACi 联合治疗是治疗这种恶性疾病的一种新的治疗机会。
