胶质瘤在靶向死亡因铁过载异质性显示。在胶质瘤中，环状RNA如何促进铁代谢和防御死亡因铁该问题尚未明确。本研究通过分析测序数据集获得了富集的环状RNA在胶质母细胞瘤（GBM）中的表达情况。利用定量实时PCR（qRT-PCR）确定了环状RNA circRNF10在胶质瘤和正常脑组织中的表达情况。利用体外和体内实验评估circRNF10对死亡因铁的影响，进行了正功能和负功能研究。采用生物信息学分析和功能实验建立了ZBTB48促进防御死亡因铁的假设。通过RNA pull-down和RNA免疫沉淀（RIP）实验检测了circRNF10与目标蛋白（包括ZBTB48、MKRN3和IGF2BP3）之间的相互作用。利用共免疫沉淀（co-IP）和泛素化实验验证了ZBTB48的转录后修饰机制。通过荧光素酶报告基因和染色质免疫沉淀（ChIP）实验确认了ZBTB48对HSPB1和IGF2BP3的转录激活作用。通过放线菌素D实验探讨了IGF2BP3对circRNF10的稳定作用。最后，进行了一系列体内实验，探究了circRNF10对胶质瘤进展的影响。一种新的环状RNA，hsa_circ_0028912（命名为circRNF10），在胶质母细胞瘤组织中显著上调，并与患者的不良预后相关。通过对环状RNA-蛋白互作数据集和测序结果的综合分析，我们发现ZBTB48是与circRNF10相结合的转录因子，显著促进HSPB1和IGF2BP3表达，重构铁代谢并促进GSCs中circRNF10/ZBTB48/IGF2BP3正反馈环的启动。此外，circRNF10可以竞争性地结合MKRN3，阻断E3泛素连接酶活性以增强ZBTB48的表达。因此，过表达circRNF10的胶质瘤干细胞（GSCs）显示较低的Fe2+积累，有选择地使肿瘤对死亡因铁避免形成。我们的研究揭示了异常环状RNA表达引起的胶质瘤的分子和代谢变化，该变化可用于发现靶向死亡因铁的可用于治疗的脆弱性。 © 2023. 意大利国家癌症研究所“Regina Elena”。

Glioma exhibit heterogeneous susceptibility for targeted ferroptosis. How circRNAs alterations in glioma promote iron metabolism and ferroptosis defense remains unclarified.The highly enriched circRNAs in glioblastoma (GBM) were obtained through analysis of sequencing datasets. Quantitative real-time PCR (qRT-PCR) was used to determine the expression of circRNF10 in glioma and normal brain tissue. Both gain-of-function and loss-of-function studies were used to assess the effects of circRNF10 on ferroptosis using in vitro and in vivo assays. The hypothesis that ZBTB48 promotes ferroptosis defense was established using bioinformatics analysis and functional assays. RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to examine the interaction between circRNF10 and target proteins including ZBTB48, MKRN3 and IGF2BP3. The posttranslational modification mechanism of ZBTB48 was verified using coimmunoprecipitation (co-IP) and ubiquitination assays. The transcription activation of HSPB1 and IGF2BP3 by ZBTB48 was confirmed through luciferase reporter gene and chromatin immunoprecipitation (ChIP) assays. The stabilizing effect of IGF2BP3 on circRNF10 was explored by actinomycin D assay. Finally, a series of in vivo experiments were performed to explore the influences of circRNF10 on the glioma progression.A novel circular RNA, hsa_circ_0028912 (named circRNF10), which is significantly upregulated in glioblastoma tissues and correlated with patients' poor prognosis. Through integrated analysis of the circRNA-proteins interaction datasets and sequencing results, we reveal ZBTB48 as a transcriptional factor binding with circRNF10, notably promoting upregulation of HSPB1 and IGF2BP3 expression to remodel iron metabolism and facilitates the launch of a circRNF10/ZBTB48/IGF2BP3 positive feedback loop in GSCs. Additionally, circRNF10 can competitively bind to MKRN3 and block E3 ubiquitin ligase activity to enhance ZBTB48 expression. Consequently, circRNF10-overexpressed glioma stem cells (GSCs) display lower Fe2+ accumulation, selectively priming tumors for ferroptosis evading.Our research presents abnormal circRNAs expression causing a molecular and metabolic change of glioma, which we leverage to discover a therapeutically exploitable vulnerability to target ferroptosis.© 2023. Italian National Cancer Institute ‘Regina Elena’.