Background Lung adenocarcinoma (LUAD) is the leading histological subtype of non-small cell lung cancer (NSCLC). Methods In the present study, the gene matrixes of LUAD were downloaded from The Cancer Genome Atlas to infer immune and stromal scores with the ‘Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data’ (ESTIMATE) algorithm and identified immune-related differentially expressed genes (DEGs) between the high- and low-stromal/immune score groups. Next, all DEGs were subjected to univariate Cox regression and survival analyses to screen out prognostic biomarkers in the tumor microenvironment (TME), and were validated in the Gene Expression Omnibus database. Single-sample gene set enrichment analysis (ssGSEA) was performed to assess the level of tumor-infiltrating immune cells (TIICs) and immune functions, and GSEA was used to identified pathways altered by prognostic biomarkers. Results Survival analysis showed that LUAD in the high-immune and stromal score group had a better clinical prognosis. A total of 303 immune-related DEGs were detected. Univariate Cox regression and survival analyses revealed that P2Y purinoceptor 13 (P2RY13) was a favorable factor for the prognosis of LUAD. ssGSEA and Spearman correlation analysis demonstrated that P2RY13 was highly correlated with various TIICs and immune functions. Several immune-associated pathways were enriched between the high- and low-expression P2RY13 groups. Conclusion P2RY13 may be a potential prognostic indicator and is highly associated with the TME in LUAD. However, further experimental studies are required to validate the present findings.

中文翻译：

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P2RY13作为肺腺癌免疫相关预后生物标志物的鉴定：一项基于公共数据库的回顾性研究

背景 肺腺癌 (LUAD) 是非小细胞肺癌 (NSCLC) 的主要组织学亚型。方法 在本研究中，从癌症基因组图谱下载 LUAD 的基因矩阵，以使用“使用表达数据估计恶性肿瘤组织中的基质和免疫细胞”（ESTIMATE）算法推断免疫和基质评分，并确定免疫相关高和低基质/免疫评分组之间的差异表达基因（DEG）。接下来，对所有 DEG 进行单变量 Cox 回归和生存分析，以筛选出肿瘤微环境 (TME) 中的预后生物标志物，并在 Gene Expression Omnibus 数据库中进行验证。进行单样本基因集富集分析 (ssGSEA) 以评估肿瘤浸润免疫细胞 (TIIC) 和免疫功能的水平，GSEA 用于识别被预后生物标志物改变的通路。结果生存分析显示，高免疫和间质评分组的LUAD临床预后较好。共检测到 303 个免疫相关的 DEG。单变量 Cox 回归和生存分析显示 P2Y 嘌呤受体 13 (P2RY13) 是 LUAD 预后的有利因素。ssGSEA 和 Spearman 相关分析表明 P2RY13 与各种 TIIC 和免疫功能高度相关。在高表达和低表达 P2RY13 组之间富集了几种免疫相关途径。结论 P2RY13 可能是一个潜在的预后指标，并且与 LUAD 中的 TME 高度相关。然而，需要进一步的实验研究来验证目前的发现。