Background Colon cancer is the third most common malignant tumor in the world. Although immunotherapy has been used in cancer treatment, there is still no first-line immunotherapy method for colon cancer. Therefore, it is essential to search for potential immunotherapy targets and molecular biomarkers for early diagnosis and prognosis. Methods In this study, we downloaded transcriptome data from The Cancer Genome Atlas (TCGA) and immune-related genes from the ImmPort database. Then we filtered genes with prognostic value and constructed an immune-related signature. Patients were classified into low- and high-risk groups, and we exerted a series of analysis between the signature and clinical phenotypes. Additionally, we used protein-protein interaction networks, gene set enrichment analysis (GSEA) and single-sample gene-set enrichment analysis (ssGSEA) to explore the underlying mechanism of this signature. Furthermore, the accuracy of this signature was verified, using two data sets from Gene Expression Omnibus (GEO). Results We selected 12 immune-related genes to construct the immune-related signature. Low-risk group had a higher level of immunity compared to high-risk group. The expression level of HLA genes and checkpoint-related genes were statistically different in low- and high-risk groups. This signature showed its prognostic value in TCGA cohort and 2 GEO data sets. The signature also had strong correlation with TNM classification, stage, survival state and lymphatic invasion. The mechanism of the signature may be related to several transcription factors and CD8+ T cell in the tumor microenvironment. Conclusion In conclusion, this immune-related signature is of great prognosis value for colon cancer and its biofunction might be correlated with HLA genes, checkpoint-related genes and high-infiltrating T cells in tumor tissues.

中文翻译：

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构建对结肠癌具有预后价值的免疫相关特征

背景结肠癌是世界上第三大常见的恶性肿瘤。尽管免疫疗法已用于癌症治疗，但结肠癌仍没有一线免疫治疗方法。因此，寻找潜在的免疫治疗靶点和分子生物标志物对于早期诊断和预后至关重要。方法在本研究中，我们从癌症基因组图谱 (TCGA) 中下载了转录组数据，并从 ImmPort 数据库中下载了免疫相关基因。然后我们过滤了具有预后价值的基因并构建了免疫相关的特征。患者被分为低风险组和高风险组，我们对特征和临床表型进行了一系列分析。此外，我们使用蛋白质-蛋白质相互作用网络、基因集富集分析（GSEA）和单样本基因集富集分析（ssGSEA）来探索该特征的潜在机制。此外，使用基因表达综合 (GEO) 的两个数据集验证了该签名的准确性。结果我们选择了 12 个免疫相关基因来构建免疫相关特征。与高危人群相比，低危人群的免疫力较高。低危组和高危组的HLA基因和检查点相关基因的表达水平有统计学差异。该特征在 TCGA 队列和 2 个 GEO 数据集中显示了其预后价值。该特征还与TNM分类、分期、生存状态和淋巴侵犯有很强的相关性。该特征的机制可能与肿瘤微环境中的多种转录因子和CD8+T细胞有关。结论 总之，这种免疫相关特征对结肠癌具有重要的预后价值，其生物功能可能与肿瘤组织中的HLA基因、检查点相关基因和高浸润T细胞有关。