Comprehensive analysis of a novel lncRNA profile reveals potential prognostic biomarkers in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the main subtype of malignant kidney cancer. Long non­coding RNA (lncRNA) serves a key role in predicting survival in patients with cancer. The present study aimed to develop an lncRNA­related signature of prognostic values for patients with ccRCC. RNA sequencing data of 454 patients were analyzed from The Cancer Genome Atlas (TCGA). To identify the differentially expressed lncRNAs, the patients from four groups classified by tumor stages were compared. The association between survival outcome and lncRNA expression profile was assessed by the univariate and multivariate Cox proportional hazards model. Survival was analyzed using the log­rank test, and functions of target lncRNAs were investigated through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Finally, 19 lncRNAs were identified as significantly associated with overall survival (OS) time. These lncRNAs were gathered as a signal prognostic signature, which may be a potential biomarker for the prognosis of ccRCC. The risk score was built to evaluate the predictive value of the lncRNA signature. There was a significant positive correlation between ccRCC patients with the low­risk score and OS time (P<0.001). Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was used to verify the result in 17 pairs of ccRCC and adjacent non­tumor tissues. Functional enrichment analysis revealed that these lncRNAs were associated with several molecular pathways of the tumor. The RT­qPCR validation was consistent with the TCGA bioinformatics results. In conclusion, a tumor­specific lncRNA signature of 19 lncRNAs was identified and the joint prognostic power was evaluated in the present study, and this signature was determined to be a potential biomarker for the prognosis of ccRCC.