AB003. Urinary microRNAs of prostate cancer

Background: MicroRNAs (miRNAs) may be potential cancer biomarkers as stable miRNAs have been detected in biological fluids such as serum, plasma, and urine. The aims of the study were to investigate whether expression of urinary cell-free miRNAs is different in prostate cancer (CaP) patients and patients with benign prostatic hyperplasia (BPH).

Methods: Total 750 urines, 150 serum and 269 prostate tissues from patients with CaP, BPH, and prostate biopsy were used in the study. After miRNA array analysis from urine to select candidate urinary miRNAs, these were validated in independent cohort. Finally matched samples from cases and control were used to evaluate correlation between candidate miRNA in prostate tissue, urine and serum.

Results: There were significant differences in the expression of five urinary miRNAs (hsa-miR-615-3p, ebv-miR-BART4, hsv1-miR-H18, hsv2-miR-H9-5p, and hsa-miR-4316) between BPH controls and CaP patients. In particular, hsv1-miR-H18 and hsv2-miR-H9-5p levels were higher in urine from prostate cancer patients. Moreover, hsv2-miR-H9-5p showed a better diagnostic performance than serum PSA for patients in the PSA gray zone. There was a significant correlation between hsv1-miR-H18 and hsv2-miR-H9-5p in tissue and urine samples, and two miRNAs were highly expressed in cancer tissues and surrounding non-cancer tissues than BPH tissues. Finally, urinary hsv2-miR-H9-5prevealed comparable diagnostic power to serum PSA even in transrectal biopsy patients, and combined with serum PSA could reduce unnecessary biopsy.

Conclusions: Virus-encoded miRNAs were strongly associated with CaP, and hsv1-miR-H18 and hsv2-miR-H9-5p may be important urinary diagnostic markers for CaP even in patients with PSA gray zone.

Keywords: MicroRNAs (miRNAs); prostate; cancer