Cell-free lncRNA expression signatures in urine serve as novel noninvasive biomarkers for diagnosis and recurrence prediction of bladder cancer

To identify lncRNAs dysregulated in BC, we assessed the lncRNA expression profile in pooled urine samples of 10 BC patients and 10 controls by microarray. A total of 3093 lncRNAs determined differential expression (fold change>=2.0) between BC patients and controls. Among them, 1680 lncRNAs were up-regulated and 1413 lncRNAs were down-regulated in BC. Of all the differentially expressed lncRNAs indicated by lncRNA expression profiling, 26 lncRNAs (fold change>25) were firstly selected for further evaluation, in which 16 lncRNAs were up-regulated and 10 lncRNAs were down-regulated in BC. Recent studies have demonstrated that cell-free long non-coding RNAs (lncRNAs) were stably present in urine and could serve as novel noninvasive biomarkers for cancer detection. This study was designed to identify unique lncRNA expression signatures in urine for diagnosis and prognosis of bladder cancer (BC). Pooled urine samples from 10 patients with BC and 10 healthy controls were labled as normal group and cancer group, respectively. Initial screening of lncRNAs by microarray analysis was respectively performed on urine sample of normal group and cancer group. Differential expression of candidate lncRNAs would be selected from the microarray results.