Searching for the Novel Specific Predictors of Prostate Cancer in Urine: The Analysis of 84 miRNA Expression

Abstract

The aim of this study was to investigate miRNA profiles of clarified urine supernatant and combined urine vesicle fractions of healthy donors and patients with benign prostatic hyperplasia and prostate cancer (PCa). The comparative analysis of miRNA expression was conducted with a custom miRCURY LNA miRNA qPCR panel. Significant combinations of miRNA pairs were selected by the RandomForest-based feature selection algorithm Boruta; the difference of the medians between the groups and a 95% confidence interval was built using the bootstrap approach. The Asymptotic Wilcoxon-Mann-Whitney Test was performed for miRNA combinations to compare different groups of donors. Benjamini-Hochberg correction was used to adjust the statistical significance for multiple comparisons. The most diagnostically significant miRNAs pairs were miR-107-miR-26b.5p and miR-375.3p-miR-26b.5p in the urine supernatant fraction that discriminated the group of healthy patients and PCa patients, as well as miR-31.5p-miR-16.5p, miR-31.5p-miR-200b, miR-31.5p-miR-30e.3p and miR-31.5p-miR-660.5p in the fraction extracellular vesicles that were different between healthy men and benign prostate hyperplasia patients. Such statistical criteria as the occurrence of individual significant miRNA pairs in the total number of comparisons, median ΔCt difference, and confidence interval can be useful tools for determining reliable markers of PCa.

The Panel of 12 Cell-Free MicroRNAs as Potential Biomarkers in Prostate Neoplasms

“…Based on previous data obtained by profiling of miRNA expression using LNA-based RT-PCR arrays (miRCURY LNA miRNA qPCR, Exiqon, Denmark) in paired samples of urine EVs and cell-free urine supernatant, we identified 12 candidate miRNA biomarkers of PCa [3,18]. For all miRNAs, qRT-PCR assays with a working range of 24-38 threshold cycles (Ct) of PCR were designed.…”

“…Serum prostate-specific antigen (PSA), digital rectal examination (DRE), and transrectal ultrasound (TRUS) followed by ultrasound-guided biopsy of the prostate constitute the foundation of modern clinical diagnosis for PCa. However, the sensitivity and the specificity of these methods are insufficient for effective detection and monitoring of PCa [3]. Moreover, the United States Preventive Services Task Force (USPSTF) has repeatedly issued recommendations against widespread use of PSA as a screening marker due to overdiagnosis and uncertain impact on patients' survival.…”

“…Other reports also showed extracellular vesicles (EVs) and cell-free nucleoprotein complexes carry distinct populations of miRNA, and the content of these miRNA pools can be used to develop promising tools for PCa screening [16,17]. We recently analyzed the expression of 84 miRNAs in paired samples of urine EVs and cell-free urine supernatant from healthy donors as well as patients with benign and malignant prostate tumors and revealed sets of miRNAs differentially expressed between PCa and control groups [3]. Based on these results, we designed an algorithm comprising 17 analytical systems that allowed for PCa detection with 97.5% accuracy [18].…”

“…Here, we aim to validate candidate biomarker miRNAs selected from our previous data [3,18] in blood plasma, clarified urine, and urine EVs by quantitative reverse transcription PCR (qRT-PCR) in order to define the minimal set of miRNA markers and estimate the required sample size for subsequent large-scale validation study.…”

MicroRNA95 May Be Involved in Oligometastatic Prostate Cancer

“…Despite the limited data available, in our series it is likely to infer that there is a signature expression of miRNA in patients with oligometastatic prostate cancer, an aspect of great interest for future studies. However, advances in molecular biology techniques and the possibility of making determinations in urine [44]-or simple plasma - [45]-open new horizons for the future study of highly specific groups of patients with oligometastatic prostate cáncer.…”