G3BP1通过稳定PD-L1 mRNA抑制肺腺癌细胞的免疫杀伤OA
G3BP1 inhibits immune killing of lung adenocarcinoma cells by stabilizing PD-L1 mRNA
目的 探究RNA结合蛋白(RNA-binding protein,RBP)Ras-GTP酶激活蛋白SH3结构域结合蛋白1(Ras-GTPase-activating protein SH3 domain-binding protein 1,G3BP1)在肺腺癌细胞免疫杀伤过程中的作用及其分子机制.方法 运用在线数据库癌症基因组图谱(The Cancer Genome Atlas,TCGA)分析肺腺癌样本中G3BP1 与程序性死亡受体配体 1(programmed death-ligand 1,PD-L1)的相关性.采用慢病毒转染构建G3BP1 过表达的肺腺癌A549 细胞和G3BP1 敲低的肺腺癌H1975 细胞模型.采用逆转录聚合酶链反应(reverse transcription polymerase chain reaction,RT-PCR)和蛋白质印迹法检测细胞中mRNA和蛋白表达水平.采用T细胞杀伤实验评估细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)对细胞的免疫杀伤能力.采用免疫荧光-荧光原位杂交实验、RNA免疫共沉淀实验和RNA稳定性实验探究G3BP1 对PD-L1 mRNA的调控机制.利用Kaplan-Meier plotter数据库分析G3BP1 和PD-L1 表达水平对肺腺癌患者预后的影响.结果 TCGA数据库分析显示,526 例肺腺癌样本中G3BP1 与PD-L1 的表达呈正相关(r=0.326,P<0.01).G3BP1 过表达可促进A549 细胞PD-L1 的mRNA和蛋白表达(均P<0.05),进而抑制CTL对肺腺癌细胞的免疫杀伤作用(P<0.01).敲低G3BP1 能抑制H1975 细胞PD-L1 mRNA和蛋白表达(均P<0.05),增强CTL的免疫杀伤效果(P<0.01).在A549 和H1975 细胞中G3BP1 可通过与PD-L1 mRNA结合,提高其稳定性,从而促进蛋白表达.Kaplan-Meier plotter数据库分析显示,G3BP1 和PD-L1 高表达的肺腺癌患者总生存期和初次进展期均较相应低表达患者缩短(均P<0.01).结论 G3BP1 通过稳定PD-L1 mRNA抑制肺腺癌细胞的免疫杀伤过程,且其高表达与患者不良预后相关.
Objective To explore the role and molecular mechanism of Ras-GTPase-activating protein SH3 domain-binding protein 1(G3BP1),an RNA-binding protein(RBP),in the immune killing process of lung adenocarcinoma cells.Methods The correlation between G3BP1 and programmed death-ligand 1(PD-L1)expressions in lung adenocarcinoma samples was analyzed using data from The Cancer Genome Atlas(TCGA)database.Lentiviral transfection was employed to establish G3BP1-overexpressing lung adenocarcinoma A549 cell model and G3BP1-knockdown lung adenocarcinoma H1975 cell models.Reverse transcription polymerase chain reaction(RT-PCR)and Western blot were performed to detect the mRNA and protein expression levels in the cells,respectively.T cell cytotoxicity assay was used to evaluate the immune killing ability of cytotoxic T lymphocytes(CTLs)against various cell lines.Immunofluorescence-fluorescence in situ hybridization,RNA binding protein immunoprecipitation,and RNA stability assay were conducted to investigate the regulatory mech-anism of G3BP1 on PD-L1 mRNA.The Kaplan-Meier plotter database was utilized to analyze the effect of G3BP1 and PD-L1 expression levels on the prognosis of patients with lung adenocarcinoma.Results TCGA database analysis showed that G3BP1 expression was posi-tively correlated with PD-L1 expression in 526 lung adenocarcinoma samples(r=0.326,P<0.01).The overexpression of G3BP1 promoted the mRNA and protein expressions of PD-L1 in A549 cells(both P<0.05),thereby inhibiting the immune killing effect of CTLs on lung adenocarcinoma cells(P<0.01).The knockdown of G3BP1 suppressed the mRNA and protein expressions of PD-L1 in H1975 cells(both P<0.05),and enhanced the immune killing effect of CTLs(P<0.01).In A549 and H1975 cells,G3BP1 could bind to PD-L1 mRNA and improve its stability,thus promoting PD-L1 protein expression.Kaplan-Meier plotter database analysis revealed that lung adenocarcinoma patients with high expression of either G3BP1 or PD-L1 had significantly shorter overall survival and time to first progression compared with those with low expression(both P<0.01).Conclusions G3BP1 inhibits the immune killing process of lung adenocarcinoma cells by stabilizing PD-L1 mRNA,and its high expression is associated with the poor prognosis of patients.
王雪妮;张兰慧;黄冬薇;钱云峰;董凤英;胡亚惠
中国人民解放军南部战区总医院干部病房三科,广东 广州 510010中国人民解放军南部战区总医院干部病房三科,广东 广州 510010中国人民解放军南部战区总医院干部病房三科,广东 广州 510010中国人民解放军南部战区总医院干部病房三科,广东 广州 510010中国人民解放军南部战区总医院干部病房三科,广东 广州 510010南方医科大学南方医院惠侨医疗中心,广东 广州 510515
肺腺癌程序性死亡受体配体1Ras-GTP酶激活蛋白SH3结构域结合蛋白1
lung adenocarcinomaprogrammed death-ligand 1Ras-GTPase-activating protein SH3 domain-binding protein 1
《实用肿瘤杂志》 2026 (2)
128-135,8
广东省医学科学技术研究基金项目(B2022230)
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