MicroRNA (miRNA) found in seminal fluid (SF) may be a diagnostically useful maker of prostate cancer, according to a proof-of-principle study published online ahead of print May 23 in Endocrine-Related Cancer. If, with further validation, these biomarkers continue to show that they that can accurately identify prostate cancer at an early stage and identify aggressive disease subtypes, it would be an important step in improving patient management, the authors say. Using small RNA sequencing (Illumina’s TruSeq Small RNA work-flow) and quantitative real-time polymerase chain reaction, the Australian researchers analyzed the RNA population in the nonsperm cellular portion of SF. In the discovery phase, comparisons were made between RNA men with low- or intermediate-risk cancer and men without cancer. All had elevated prostate-specific antigen (PSA) levels. Identified miRNA biomarkers were then validated in a subsequent cohort of 26 men with biopsy-proven, low-high risk tumors and 22 men with elevated PSA, but no detectable cancer on biopsy. The researchers found that the RNA of the nonsperm SF cellular fraction consisted primarily of transfer RNA (tRNA) and miRNA, with a higher ratio of tRNA to miRNA among men with cancer compared to controls. A filtering strategy applied to robustly expressed miRNA identified 82 […]