ATRX loss promotes immunosuppressive mechanisms in IDH1 mutant glioma
ATRX loss promotes immunosuppressive mechanisms in IDH1 mutant glioma
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DOI：
10.1093/neuonc/noab292
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发表时间：
2022-01-17
期刊：
影响因子：
15.9
通讯作者：
Li, Yunqing
中科院分区：
文献类型：
--
作者：
Hu, Chengchen;Wang, Kimberly;Li, Yunqing
背景ATRX失活发生在超过80%的II/III级星形细胞瘤中，伴有IDH 1（R132 H）和p53突变。据信，ATRX损失有助于通过失调表观遗传和端粒机制的肿瘤发生，但对抗神经胶质瘤免疫的影响尚未探讨。本文研究了ATRX丢失如何导致IDH 1（R132 H）/p53（mut）胶质瘤细胞和异种移植物的恶性和免疫抑制表型。方法使用编码多西环素诱导的IDH 1（R132 H）、ATRX shRNA或Lenti-CRISPR/Cas9 ATRX的慢病毒在p53 mut星形细胞瘤细胞系中建立同基因星形细胞瘤细胞（+/-IDH 1（R132 H）/+/-ATRX（丢失））。通过克隆生长、transwell和划痕试验、MTT、免疫荧光和免疫印迹试验以及异种移植物生长评价IDH 1（R132 H）+/-ATRX（缺失）对细胞迁移、生长、DNA修复和致瘤性的影响。通过qRT-PCR、免疫印迹、T细胞功能、巨噬细胞极化和流式细胞术测定来定量对免疫微环境调节剂的表达和功能的影响。使用药理学抑制剂来检查IDH 1（R132 H）/p53（mut）/ATRX（loss）细胞的免疫抑制转录组的表观遗传驱动因子。将ATRX损失添加到IDH 1（R132 H）/p53（mut）背景中促进星形细胞瘤细胞侵袭性，诱导BET蛋白BRD 3/4和由上调的免疫检查点组成的免疫抑制转录组（例如，PD-L1、PD-L2）和改变的细胞因子/趋化因子谱（例如，IL33、CXCL8、CSF 2、IL6、CXCL9）。ATRX损失增强了IDH 1（R132 H）/p53（mut）细胞诱导T细胞凋亡、致瘤/抗炎巨噬细胞极化和Treg浸润的能力。转录和生物免疫抑制反应ATRX损失增强替莫唑胺和辐射和废除药理BET抑制。结论ATRX缺失激活IDH 1（R132 H）/p53（mut）星形细胞瘤细胞中BRD依赖的免疫抑制转录组和免疫逃逸机制。
Background ATRX inactivation occurs with IDH1(R132H) and p53 mutations in over 80% of Grades II/III astrocytomas. It is believed that ATRX loss contributes to oncogenesis by dysregulating epigenetic and telomere mechanisms but effects on anti-glioma immunity have not been explored. This paper examines how ATRX loss contributes to the malignant and immunosuppressive phenotypes of IDH1(R132H)/p53(mut) glioma cells and xenografts. Methods Isogenic astrocytoma cells (+/-IDH1(R132H)/+/-ATRX(loss)) were established in p53mut astrocytoma cell lines using lentivirus encoding doxycycline-inducible IDH1(R132H), ATRX shRNA, or Lenti-CRISPR/Cas9 ATRX. Effects of IDH1(R132H)+/-ATRX(loss) on cell migration, growth, DNA repair, and tumorigenicity were evaluated by clonal growth, transwell and scratch assays, MTT, immunofluorence and immunoblotting assays, and xenograft growth. Effects on the expression and function of modulators of the immune microenvironment were quantified by qRT-PCR, immunoblot, T-cell function, macrophage polarization, and flow cytometry assays. Pharmacologic inhibitors were used to examine epigenetic drivers of the immunosuppressive transcriptome of IDH1(R132H)/p53(mut)/ATRX(loss) cells. Results Adding ATRX loss to the IDH1(R132H)/p53(mut) background promoted astrocytoma cell aggressiveness, induced expression of BET proteins BRD3/4 and an immune-suppressive transcriptome consisting of up-regulated immune checkpoints (e.g., PD-L1, PD-L2) and altered cytokine/chemokine profiles (e.g., IL33, CXCL8, CSF2, IL6, CXCL9). ATRX loss enhanced the capacity of IDH1(R132H)/p53(mut) cells to induce T-cell apoptosis, tumorigenic/anti-inflammatory macrophage polarization and Treg infiltration. The transcriptional and biological immune-suppressive responses to ATRX loss were enhanced by temozolomide and radiation and abrogated by pharmacologic BET inhibition. Conclusions ATRX loss activates a BRD-dependent immune-suppressive transcriptome and immune escape mechanism in IDH1(R132H)/p53(mut) astrocytoma cells.