RGS4 inhibits glioma cells sensitivity to radiotherapy and temozolomide by regulating ferroptosis

Chemoradiotherapy is the major means in the treatment of gliomas followed by surgery. Ferroptosis has been shown to play an important role in carcinogenesis by many studies. However, its underlying effect on chemoradiotherapy sensitivity in gliomas remains unclear. The genetic and clinical information and ferroptosis-related genes were downloaded from The Cancer Genome Atlas (TCGA) database. Gene Expression Profiling Interactive Analysis (GEPIA) was used to perform hub gene expression and survival analysis. Cell Counting Kit 8 (CCK-8), colony formation, 5-Ethynyl-2′-Deoxyuridine (EdU), Transwell and chemoradiotherapy sensitivity experiments were performed to confirm the biological function of RGS4 in glioma cells. The molecular mechanism of RGS4 on ferroptosis in gliomas was explored <i>in vitro.</i> 385 ferroptosis-related genes were identified <i>via</i> bioinformatics analysis. 16 differential expressed genes (DEGs) were identified as radiation-related genes. Among them, RGS4, HSPA5, and SLC40A1 had prognostic values in further analysis. The calculated risk score could significantly distinguish the high-risk population. Moreover, RGS4 expression was closely related with immune infiltration and regulators. RGS4 knockdown could inhibit the proliferation and migration of glioma cells. Down-regulation of RGS4 expression induced ferroptosis to promote cancer sensitivity to chemoradiotherapy. A three-gene signature was developed in a risk-score model, which could be used to predict the prognosis of glioma patients. RGS4 is dysregulated in many types of cancers, and is a candidate prognostic biomarker for many types of cancers. Moreover, RGS4 may be a target for predicting and enhancing the chemoradiotherapy sensitivity of gliomas.

手术是胶质瘤（gliomas）治疗的核心步骤，放化疗为其后的主要治疗手段。多项研究已证实，铁死亡（ferroptosis）在肿瘤发生发展中发挥关键作用。然而其对胶质瘤放化疗敏感性的潜在调控机制仍未明确。本研究从癌症基因组图谱（The Cancer Genome Atlas, TCGA）数据库中获取了胶质瘤患者的遗传与临床信息，以及铁死亡相关基因集。采用基因表达谱交互分析（Gene Expression Profiling Interactive Analysis, GEPIA）工具开展核心基因表达与生存分析。通过细胞计数试剂盒8（Cell Counting Kit 8, CCK-8）、集落形成实验、5-乙炔基-2'-脱氧尿苷（5-Ethynyl-2′-Deoxyuridine, EdU）、Transwell实验以及放化疗敏感性实验，验证了RGS4在胶质瘤细胞中的生物学功能，并通过体外（in vitro）实验探索了RGS4调控胶质瘤细胞铁死亡的分子机制。经生物信息学分析，共鉴定出385个铁死亡相关基因。进一步筛选得到16个差异表达基因（differential expressed genes, DEGs），均为辐射相关基因。其中，RGS4、HSPA5与SLC40A1在后续分析中展现出预后价值。所构建的风险评分模型可显著区分高风险人群。此外，RGS4的表达水平与肿瘤免疫浸润及免疫调控因子密切相关。敲低RGS4的表达可抑制胶质瘤细胞的增殖与迁移能力。下调RGS4的表达可诱导铁死亡，进而增强胶质瘤细胞对放化疗的敏感性。本研究构建了包含上述3个基因的风险评分模型，该模型可用于预测胶质瘤患者的预后情况。RGS4在多种癌症中均存在表达异常，可作为多种癌症的潜在预后生物标志物。此外，RGS4或可作为预测并增强胶质瘤放化疗敏感性的潜在靶点。