Long non-coding RNA profile study identifies an immune-related lncRNA prognostic signature for prostate adenocarcinoma

Prostate adenocarcinoma (PRAD) is the highest incidence rate of male urogenital morbidity worldwide. Long non-coding RNAs (lncRNAs), as a significant class of gene expression regulators, play a critical role in immune regulation. The purpose of this study is to explore a new immune related lncRNA signature to exactly predict the prognosis of PRAD patients. In this study, we conducted a genome-wide comparative analysis of lncRNA expression profiles in 532 patients with PRAD from the Cancer Genome Atlas (TCGA) database. The immune-related lncRNAs were identified by Cox regression model, and then a new five immune-related lncRNAs signature (FRMD6-AS2, AC008770.3, AC109460.3, AC011899.2, and AC008063.1) were constructed, which could predict the prognosis of PRAD patients. Univariate and multivariate Cox regression analysis showed that the signature could be an independent prognostic indicator of overall survival (OS). Through further study of different clinic-pathological parameters, we found that PRAD samples can be divided into high-risk groups with shorter OS and low-risk groups with longer OS by the signature. Principal component analysis showed that five immune-related lncRNA signature could distinguish the high-risk group from low-risk group in view of the immune-related lncRNAs. The difference of immune status between the two groups was observed by gene set enrichment analysis and the ESTIMATE algorithm. Except FRMD6-AS2, the expression of the other 4 lncRNAs were remarkably up-regulated in tumor tissues. In conclusion, the identified five immune-related lncRNAs signature had important clinical significance in prognosis prediction, and can be used as potential immunotherapy targets for PRAD patients.