A panel of five circulating microRNAs as potential biomarkers for prostate cancer.

Background: Circulating microRNA (miRNAs) have been shown to have the potential as noninvasive diagnosis markers in several types of cancers. In this study, we investigated whether circulating miRNAs could be used in the diagnosis of prostate cancer (CaP) in a Chinese patient population.

Methods: Illumina's Human v2 miRNA microarray was used to analyze miRNAs levels in a small set of patients [25 CaP, 17 benign prostatic hyperplasia (BPH)] in an effort to identify CaP-specific miRNAs. The identified miRNAs were further examined by quantitative real-time PCR (qRT-PCR) in the same small set of patients. After the training phase of screening and selecting, the candidate miRNAs were validated in a larger independent cohort (80 CaP, 44 BPH, and 54 healthy controls) with qRT-PCR in the verification phase.

Results: Five miRNAs were confirmed by qRT-PCR analysis in validation sets. Receiver operating characteristic (ROC) curve analysis showed all 5 miRNAs had diagnostic value. More importantly, further principal component analysis indicated component 1 extracted from expression data of the 5 miRNAs could differentiate CaP from BPH and healthy controls with high diagnosis performance, with an AUC of 0.924 and 0.860, respectively.

Conclusions: Our data suggested that circulating miRNAs could serve as biomarkers for CaP, and compared to single miRNA, the 5 miRNAs panel can accurately discriminate CaP from BPH and healthy controls with high sensitivity and specificity, and therefore, combined with routine PSA test, these 5 CaP-specific miRNAs may help improve CaP diagnosis in clinical application.