ABSTRACT

Children with ependymoma have high mortality rates because ependymoma is resistant to conventional therapy. Genomic and transcriptomic studies have identified potential targets as significantly altered genes in ependymoma patients. Although several candidate oncogenes in ependymoma were recently reported, the detailed mechanisms for the roles of these candidate oncogenes in ependymoma progression remain unclear. Here, we report an oncogenic role of the nucleoporin TPR (translocated promoter region, nuclear basket protein) in regulating HSF1 (heat shock transcription factor 1) mRNA trafficking, maintaining MTORC1 activity to phosphorylate ULK1, and preventing macroautophagy/autophagy induction in ependymoma. High expression of TPR were associated with increased HSF1 and HSPA/HSP70 expression in ependymoma patients. In an ependymoma mouse xenograft model, MTOR inhibition by rapamycin therapeutically suppressed TPR expression and reduced tumor size in vivo. Together, these results suggest that TPR may act as a biomarker for ependymoma, and pharmacological interventions targeting TPR-HSF1-MTOR may have therapeutic potential for ependymoma treatment.

Abbreviations: ATG: autophagy related; BECN1: beclin 1; BSA: bovine serum albumin; CQ: chloroquine; DMSO: dimethyl sulfoxide; GEO: gene expression omnibus; GFP: green fluorescence protein; HSF1: heat shock transcription factor 1; HSPA/HSP70: heat shock protein family A (Hsp70); LMNB1: lamin B1; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAPK: mitogen-activated protein kinase; MAPK8/JNK: mitogen-activated protein kinase 8; MTORC1: mechanistic target of rapamycin kinase complex 1; NPC: nuclear pore complex; NUP: nucleoporin; PBS: phosphate-buffered saline; q-PCR: quantitative real time PCR; SDS: sodium dodecyl sulfate; SQSTM1: sequestosome 1; STED: stimulated emission depletion microscopy; STX17: syntaxin 17; TCGA: the cancer genome atlas; TPR: translocated promoter region, nuclear basket protein; ULK1: unc-51 like autophagy activating kinase 1.

摘要

患有室管膜瘤的儿童死亡率很高，因为室管膜瘤对常规治疗有抵抗力。基因组学和转录组学研究已将潜在靶标确定为室管膜瘤患者中显着改变的基因。尽管最近报道了室管膜瘤中的几个候选癌基因，但这些候选癌基因在室管膜瘤进展中的作用的详细机制仍不清楚。在这里，我们报告了核孔蛋白 TPR（易位启动子区域，核篮蛋白）在调节HSF1（热休克转录因子 1）mRNA 运输、维持 MTORC1 活性以磷酸化 ULK1 和防止室管膜瘤中的巨自噬/自噬诱导方面的致癌作用。TPR 的高表达与HSF1和HSPA/HSP70在室管膜瘤患者中的表达。在室管膜瘤小鼠异种移植模型中，雷帕霉素对 MTOR 的抑制在治疗上抑制了 TPR 表达并减小了体内肿瘤大小。总之，这些结果表明 TPR 可能作为室管膜瘤的生物标志物，针对 TPR-HSF1-MTOR 的药物干预可能具有治疗室管膜瘤的潜力。

缩写：ATG：自噬相关；BECN1: beclin 1; BSA：牛血清白蛋白；CQ：氯喹；DMSO：二甲亚砜；GEO：基因表达综合；GFP：绿色荧光蛋白；HSF1：热休克转录因子1；HSPA/HSP70：热休克蛋白家族 A（Hsp70）；LMNB1：核纤层蛋白 B1；MAP1LC3B/LC3B：微管相关蛋白 1 轻链 3 β；MAPK：丝裂原活化蛋白激酶；MAPK8/JNK：丝裂原活化蛋白激酶 8；MTORC1：雷帕霉素激酶复合物 1 的机制靶点；NPC：核孔复合体；NUP：核孔蛋白；PBS：磷酸盐缓冲盐水；q-PCR：定量实时PCR；SDS：十二烷基硫酸钠；SQSTM1：螯合体 1；STED：受激发射损耗显微镜；STX17：syntaxin 17；TCGA：癌症基因组图谱；TPR：易位启动子区，核篮蛋白；ULK1：