MAGEA3基因表达对亚洲胃癌患者免疫微环境的影响

The effect of MAGEA3 gene expression on the immune microenvironment of Asian patients with gastric cancer

目的:通过对亚洲肿瘤研究组(ACRG)中的胃癌数据集进行生物信息学分析并收集临床胃癌患者血清进行验证,揭示MAGEA3基因对亚洲胃癌患者免疫微环境的影响。方法:从GEO下载GSE52254/ACRG数据集,根据MAGEA3基因表达值的中位数,将300例胃癌患者分为MAGEA3高表达组和低表达组。然后应用ESTIMATE和CIBERSORT计算方法计算两组胃癌组织免疫和基质成分的数量以及22种浸润淋巴细胞的比例,通过比较两组间免疫微环境及免疫细胞浸润的差异,利用GSEA进一步分析相关通路的变化以确定MAGEA3对胃癌免疫微环境的影响。收集2022年1月至2022年4月在温州医科大学附属第一医院胃肠外科住院的86例胃癌患者血清,通过ELISA法检测血清中MAGEA3表达量,并使用流式细胞技术检测血清中不同淋巴细胞亚群的数量,分析MAGEA3蛋白与外周血淋巴细胞亚群的相关性。结果:ESTIMATE结果显示MAGEA3高表达组的免疫评分、基质评分均显著低于MAGEA3低表达组(P<0.001),并通过Spearman分析发现MAGEA3表达与免疫评分(r=-0.244,P<0.001)、基质评分(r=-0.266,P<0.001)呈负相关。GSEA分析进一步提示MAGEA3低表达组存在T细胞活化、增殖、巨噬细胞活化以及免疫细胞调节的相关通路富集。CIBERSORT结果提示在MAGEA3低表达组中,幼稚B细胞、浆细胞、CD8^(+)T细胞、γδT细胞、激活的NK细胞浸润更多,而巨噬细胞M0浸润更少。通过临床胃癌血清样本MAGEA3蛋白ELISA检测以及流式细胞检测血清中各淋巴细胞亚群发现,MAGEA3表达与CD8^(+)T细胞数量呈显著负相关(r=-0.310,P=0.004),结果与ACRG数据分析一致。结论:MAGEA3的表达水平可能通过影响胃癌免疫微环境的免疫细胞发挥作用,同时也提示了MAGEA3可能是胃癌免疫治疗的潜在靶点和生物标志物。

Objective:To reveal the impact of MAGEA3 on the immune microenvironment of Asian gastric cancer patients through bioinformatic analysis of the gastric cancer dataset from The Asian Cancer Research Group(ACRG)for validation with clinical serum samples collected from gastric cancer patients.Methods:Altogether 300 gastric cancer patients in the ACRG GSE52254 dataset were divided as MAGEA3 high expression group and low expression group based on the median expression value.The ESTIMATE and CIBERSORT methods were then used to calculate the immune and stromal components as well as the proportions of 22 infiltrating lymphocyte subsets in both groups.The differences in immune microenvironment and immune cells between the two groups were compared,and further GSEA analysis was conducted to determine the changes in related pathways by MAGEA3.Serum samples of 86 gastric cancer patients admitted to the First Affiliated Hospital of Wenzhou Medical University from January to April 2022 were collected to detect the expression levels of MAGEA3 protein and the correlation between MAGEA3 protein and subpopulations of peripheral blood lymphocytes was verified through ELISA and flow cytometry.Results:The ESTIMATE results showed that theimmune scores and stromal scores of the MAGEA3 high expression group were significantly lower than those of the MAGEA3 low expression group(P<0.001),and Spearman analysis revealed a negative correlation between MAGEA3 expression and immune scores(r=-0.244,P<0.001)and stromal scores(r=-0.266,P<0.001).Further GSEA analysis suggested that there were pathways related to T cell activation,proliferation,macrophage activation,and immune cell regulation enriched in the MAGEA3 low expression group.The CIBERSORT results showed that in the MAGEA3 low expression group,there was more infiltration of naive B cells,plasma cells,CD8^(+)T cells,γδT cells,and activated NK cells,and less infiltration of macrophages M0.Clinical serum samples showed that MAGEA3 expression had significant negative correlation with CD8^(+)T cells(r=-0.310,P=0.004),which was consistent with the ACRG data analysis.Conclusion:The expression level of MAGEA3 may affect the immune components of the immune microenvironment of gastric cancer,revealing its potential as a target for immunotherapy and a biological marker。