Identification of a novel signature related to the immune landscape and prognosis for human colonic adenocarcinoma based on lncRNA pairs

Background: Long noncoding RNAs have diverse functions in the immune response to cancer and determining the tumor microenvironment. In consideration of its poor prognosis, immunogenic analysis might be effectively used for predicting the clinical outcome and immunotherapeutic response of colon adenocarcinoma(COAD).Methods: This study collected expression profiles from 423 COAD cases archived in The Cancer Genome Atlas(TCGA) database,which were then split into four subtypes(C1–C4) according to immune-related long noncoding RNA pairs(IRLPs).Results: Among these four subtypes, samples of the C4 subtype were associated with the worst prognosis, whereas samples of the C2 subtype were associated with the best prognosis. The analysis of the immune characteristics from samples of different subtypes subsequently showed that the C1 subtype had a significantly higher immune score than the other subtypes, with a higher level of immune cel infiltration, expression of immune-related genes, and a better therapeutic response to programmed cel death 1(PD-1) inhibitors and cytotoxic T-lymphocyte–associated protein 4(CTLA4) inhibitors. In addition, a combination of univariate COX analysis, least absolute shrinkage and selection operator(LASSO), Cox regression, and shrinkage estimate was used to successful y construct a prognostic model comprising six IRLPs.Conclusion: Our research highlights the importance of the IRLP signature in predicting the prognosis and immune characteristics of COAD.