Mining Of IncRNAs From RNA-Seq Data And Construction Of A Prognostic Signature In Bladder Cancer

Bladder cancer is the ninth most common malignancy worldwide.Bladder Urothelial Carcinoma(BLCA)is the most common pathological type of bladder cancer.Most BLCA patients were diagnosed at late stage and the five-year survival rate at only 50-60%.Therefore,identifying novel independent biomarkers has important implications for diagnosis,therapy and prognosis for BLCA patients.Recently,lots of studies have demonstrated that the critical roles of long non-coding RNA(lncRNA)in cancer development and progression.However,the expression-based IncRNA signature for predicting overall survival in patients with BLCA has not been investigated.In this study,we performed a comprehensive analysis for lncRNA expression profiles and corresponding clinical information of 234 BLCA patients from The Cancer Genome Atlas(TCGA).First,the entire dataset was randomly divided into a training dataset and a testing dataset.Four lncRNAs whose expression profiles were significantly associated with patients' survival were identified in the training dataset.Then we constructed a four-lncRNA signature that can effectively predict BLCA patients' survival.This prognostic four-lncRNA signature could significantly classify the BLCA patients into high-risk and low-risk groups,and the prognostic power of the four-lncRNA signature was further validated in the testing dataset and entire dataset.Multivariate Cox regression and stratified survival analyses demonstrated that the four-lncRNA signature was independent of other clinical variables including age,gender,tumor stage and subtype.Gene Ontology(GO)functional enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses suggested the four prognostic lncRNAs may be involved in known BLCA-related biological processes and pathways.In summary,our results demonstrated that the four-lncRNA signature could be novel independent biomarkers for predicting survival in patients with BLCA.