Transcriptome Analysis of Adipocytokines and Their-related LncRNAs in Lung Adenocarcinoma Revealing the Association with Prognosis, Immune Infiltration, and Metabolic Characteristics

Lung adenocarcinoma (LUAD) is amongst the major contributors to cancer-related deaths on a global scale. Adipocytokines have an impact on immune and metabolism. Long non-coding RNAs (lncRNAs) are indispensable participants in cancer. We performed a pan-cancer analysis of the mRNA expression, single nucleotide variation, copy number variation, and prognostic value of adipocytokines, and displayed the results in heat maps. LUAD samples were obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Simultaneously, train, internal and external cohorts were grouped. After a stepwise screening of optimized genes through least absolute shrinkage and selection operator regression analysis, univariate Cox regression analysis, random forest, and multivariate Cox regression analysis, an adipocytokine-related prognostic signature (ARPS) with superior performance compared with four additional well-established signatures for survival prediction was constructed. After determination of risk levels, the discrepancy of immune microenvironment, immune checkpoint gene expression, immune subtypes, and immune response in low- and high-risk cohorts were explored through multiple bioinformatics methods such as ESTIMATE, EPIC, CIBERSORT, XCELL, CIBERSORT-ABS, MCPCOUNTER, QUANTISEQ, and TIMER algorithms. Abnormal pathways underlying high- and low-risk subgroups were identified through gene set enrichment analysis (GSEA). Immune-related pathways together with metabolism-related pathways that were correlated with risk score were selected with the aid of a single sample gene set enrichment analysis (ssGSEA). Finally, a nomogram was plotted with satisfied predictive survival probability which was verified by calibration curves. In summary, this study offers meaningful information that will be used to assist and guide clinical treatment and scientific investigation.