Background: Long non-coding RNA (lncRNA), as an important regulator of gene expression, can affect a variety of physiological processes. Recent studies have shown that immune-related lncRNA play an important role in the tumor immune microenvironment and may have potential application value in the treatment and prognosis prediction of tumor patients. Epithelial ovarian cancer (EOC) is characterized by high incidence and poor prognosis. However, there are few studies on immune-related lncRNAs in EOC. In this study, we focused on the immune-related lncRNAs associated with survival in EOC.
Methods: We downloaded mRNA data for EOC patients from The Cancer Genome Atlas (TCGA) database, and mRNA data for normal ovarian tissue from the Genotype-Tissue Expression (GTEx) database, and identified differential genes through differential Expression analysis. Immune-related lncRNAs were obtained through taking intersection and co-expression analysis of differential genes and immune-related genes from the Immunology Database and Analysis Portal (ImmPort). Samples in the TCGA EOC cohort were randomly divided into training set, validation set and combination set. In the training set, Cox regression analysis and LASSO regression were used to construct an immune-related lncRNA signature. Kaplan-Meier survival analysis, time-dependent ROC curve analysis, Cox regression analysis and principal component analysis were applied to verification in the training set, training set, validation set and combination set. Further studies of pathways and immune cell infiltration were conducted through Gene Set Enrichment Analysis (GESA) and the Timer data portal.
Results: An immune-related lncRNA signature was identified in EOC, which was composed of six immune-related lncRNAs (KRT7-AS, USP30-AS1, AC011445.1, AP005205.2, DNM3OS and AC027348.1). The signature divided patients into high-risk and low-risk groups. The overall survival of the high-risk group was lower than that of the low-risk group, and was verified to be robust in both the training set and the combination set. This signature was identified as an independent prognostic biomarker. The signature was confirmed to be an independent prognostic biomarker. Principal component analysis showed the different distribution patterns of high-risk and low-risk groups. This signature may be related to immune cell infiltration (mainly macrophages) and differential expression of immune checkpoint-related molecules (PD-1, PDL1, etc.).
Conclusions: we identified and established a prognostic signature of immune-related lncRNA in EOC, which is of great value in predicting the prognosis of clinical patients and may provide a new perspective for the immunological research and individualized treatment in EOC.