Abstract 1161: Detection and identification of a miRNA expression profile from cell-free urine: Potential utility in bladder cancer

Introduction/Objective: MicroRNAs are small, non-coding RNAs that have been shown to play an important role in tumorigenesis. There is differential expression of miRNA in cancer progression, and profiling of miRNA is promising for both diagnosis and treatment of malignant tumors. In this study we isolated RNA from cell-free urine in an attempt to characterize miRNA profiles indicating the presence of urothelial carcinoma and its potential use as a non-invasive assay to identify patients with cancer progression. Methods: Urine was collected from patients diagnosed with bladder cancer and control patients with no history of cancer under an IRB-approved protocol. Urine was centrifuged and total RNA was isolated from the supernatants using the mirVana Paris™ kit. A total of 178 samples were grouped according to grade and stage (healthy controls (35), TaG1 (19), T1G3 (16), ≥T2 (30), carcinoma in situ (CIS; 28) and no evidence of disease following therapy (50). Seven hundred and thirty miRNAs were profiled by qRT-PCR on pooled samples within each group. Validation of selected miRNAs was performed on individual samples using qRT-PCR. Results: Cell-free RNA was isolated from urine of 35 healthy controls and 143 patients with bladder cancer. Of the 730 miRNAs tested, 236 were detected in at least one of the pooled samples using a Ct cutoff of 35. The number of miRNAs detected in the pooled samples correlated with disease progression where the healthy control group and the ≥T2 group expressed 8 and 228 miRNAs, respectively. qRT-PCR of individual samples revealed a gradual increase of some miRNAs with disease progression. Statistical analysis adjusted for multiple comparisons demonstrated differences between groups based on miRNA expression levels. In addition, a panel of miRNAs was identified which discriminated between cancer and cancer-free patients. Conclusion: This study demonstrates the successful isolation of miRNAs from cell-free urine. Utilizing non-invasive urine based assays, we identified a miRNA panel that can discriminate between cancer-free patients and patients with urinary carcinoma of the bladder. These findings provide evidence that profiling of miRNAs from cell-free urine holds the promise for the development of valuable clinical tools. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2