Current status of genetic urinary biomarkers for surveillance of non-muscle invasive bladder cancer: a systematic review.

BACKGROUND: Genetic biomarkers are a promising and growing field in the management of bladder cancer in all stages. The aim of this paper is to understand the role of genetic urinary biomarkers in the follow up of patients with non muscle invasive bladder cancer where there is increasing evidence that they can play a role in avoiding invasive techniques. METHODS: Following PRISMA criteria, we have performed a systematic review. The search yielded 164 unique articles, of which 21 articles were included involving a total of 7261 patients. Sixteen of the articles were DNA based biomarkers, analyzing different methylations, microsatellite aberrations and gene mutations. Five articles studied the role of RNA based biomarkers, based on measuring levels of different combinations of mRNA. QUADAS2 critical evaluation of each paper has been reported. RESULTS: There are not randomized control trials comparing any biomarker with the gold standard follow-up, and the level of evidence is 2B in almost all the studies. Negative predictive value varies between 55 and 98.5%, being superior in RNA based biomarkers. CONCLUSIONS: Although cystoscopy and cytology are the gold standard for non muscle invasive bladder cancer surveillance, genetic urinary biomarkers are a promising tool to avoid invasive explorations to the patients with a safe profile of similar sensitivity and negative predictive value. The accuracy that genetic biomarkers can offer should be taken into account to modify the paradigm of surveillance in non muscle invasive bladder cancer patients, especially in high-risk ones where many invasive explorations are recommended and biomarkers experiment better results.

Development of a 90-Minute Integrated Noninvasive Urinary Assay for Bladder Cancer Detection.

PURPOSE: Despite suboptimal sensitivity urine cytology is often performed as an adjunct to cystoscopy for bladder cancer diagnosis. We aimed to develop a noninvasive, fast molecular diagnostic test for bladder cancer detection with better sensitivity than urine cytology while maintaining adequate specificity. MATERIALS AND METHODS: Urine specimens were collected at 18 multinational sites from subjects prior to cystoscopy or tumor resection, and from healthy and other control subjects without evidence of bladder cancer. The levels of 10 urinary mRNAs were measured in a training cohort of 483 subjects and regression analysis was used to identify a 5-mRNA model to predict cancer status. The performance of the GeneXpert® Bladder Cancer Assay, an assay labeled for investigational use only to detect the 5 mRNAs ABL1, CRH, IGF2, ANXA10 and UPK1B, was evaluated in an independent test cohort of 450 participants. RESULTS: In the independent test cohort the assay ROC curve AUC was 0.87 (95% CI 0.81-0.92). At an example cutoff point of 0.4 overall sensitivity was 73% while specificity was 90% and 77% in the hematuria and surveillance patient populations, respectively. CONCLUSIONS: We developed a 90-minute, urine based test that is simple to perform for the detection of bladder cancer. The test can help guide physician decision making in the management of bladder cancer. Additional evaluation in a prospective study is needed to establish the clinical usefulness of this assay.

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

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.

Cell-free RNA content in urine as a possible molecular diagnostic tool for clear cell renal cell carcinoma.

There is limited research on cell-free RNA (cf-RNA) in the urine of cancer patients. The present study was performed to detect the cf-RNA in the urine of patients with clear cell renal cell carcinoma (ccRCC). Ninety-five urine samples from ccRCC patients and 50 urine samples from control subjects were analyzed. The cf-RNA integrity index was calculated by using quantitative real-time RT-PCR assays of the small-sized fragment (106 bp) and the big-sized fragment (416 bp) in GAPDH mRNA. The initial analysis showed that cf-RNA was stable and detectable in the urine. The mean cf-RNA integrity index was significantly lower in the urine of ccRCC patients (mean: 0.07, 95%CI: 0.05-0.10) when compared with the urine from control subjects (mean: 0.25, 95%CI: 0.16-0.33) (p < 0.001). The value of the area under the receiver-operating characteristic curve by using the cf-RNA integrity index for the diagnosis of ccRCC was 0.858 with a sensitivity of 68.0% and a specificity of 92.6%. Moreover, the small-sized VEGF mRNA fragment (98 bp) was detected in 31 of 50 urine samples of patients with ccRCC and in only 2 of 50 urine samples of control subjects (p < 0.001) while the detection of the big-sized (420 bp) VEGF mRNA fragment was an infrequent event. Our findings suggest that the small-sized cf-RNA in urine was more abundant in cancer patients. The tumor-related gene VEGF mRNA fragment was detectable in the urine of cancer patients. Our finding may provide a new molecular assay for the diagnosis of renal cell carcinoma.

miR-143, miR-222, and miR-452 are useful as tumor stratification and noninvasive diagnostic biomarkers for bladder cancer.

Altered microRNA (miRNA) expression may occur early in bladder cancer and may play a role in carcinogenesis and tumor behavior. We evaluated whether alterations in miRNA expression could improve disease stratification and outcome prognosis in bladder tumors and noninvasive diagnosis in urinary samples. miR-143, miR-222, and miR-452 expression levels were analyzed by quantitative RT-PCR (RT-qPCR) in paired urinary and matching tumors and in two independent prospective series of tumors and urinary specimens. Differential expression of miR-143, miR-222, and miR-452 in urine were verified by in situ hybridization in matching tumors. Tumor miRNA expression by RT-qPCR correlated with tumor grade, size, and presence of carcinoma in situ for miR-222, recurrence (miR-222 and miR-143), progression (miR-222 and miR-143), disease-specific survival (miR-222), and overall survival (miR-222). Protein expression patterns of potential miRNA targets, including vascular endothelial growth factor, BCL2, v-erb-b2 erythroblastic leukemia viral oncogene (ERBB) homolog 3, and ERBB4, were evaluated by IHC in tissue arrays containing tumors for which miRNAs were assessed by RT-qPCR. Target expression correlated with expression of their predicted regulatory miRNAs, recurrence (ERBB3), progression (ERBB4), disease-specific survival (ERBB3 and ERBB4), and overall survival (ERBB3 and ERBB4). Furthermore, RT-qPCR of miR-452 (area under the curve, 0.848) and miR-222 (area under the curve, 0.718) in urine provided high accuracies for bladder cancer diagnosis. Thus, bladder tumors were characterized by changes in miRNA expression that could aid in tumor stratification and clinical outcome prognosis, and miRNAs were detected in urinary specimens for noninvasive diagnosis.

Toward the detection of prostate cancer in urine: a critical analysis.

PURPOSE: Prostate specific antigen and digital rectal examination have low specificity for detecting prostate cancer and they poorly predict the presence of aggressive disease. Urine is readily available and noninvasive, and it represents a promising source of biomarkers for the early detection and prediction of prostate cancer prognosis. We identified promising biomarkers for urine based prostate cancer, examined trends and outlined potential pitfalls. MATERIALS AND METHODS: We performed PubMed® and Web of Science® database searches of the peer reviewed literature on urine based testing for prostate cancer. Original studies of this subject as well as a small number of reviews were analyzed, including the strengths and weaknesses. We provide a comprehensive review of urine based testing for prostate cancer that covers the technical aspects, including the methodology of urine collection, as well as recent developments in biomarkers spanning the fields of genomics, epigenetics, transcriptomics, proteomics and metabolomics. RESULTS: The process of urine collection is subject to variability, which may result in conflicting clinical results. Detecting prostate cancer in urine is technically feasible, as demonstrated by numerous proof of principle studies, but few markers have been validated in multiple large sample sets. Biomarker development using urine has been accelerating in recent years with numerous studies identifying DNA, RNA, protein and metabolite based biomarkers in urine. Advanced clinical studies have identified PCA3 and TMPRSS2:ERG fusion transcripts as promising RNA markers for cancer detection and possibly prognosis. DNA methylation analysis of multiple genes improves specificity and represents a promising platform for developing clinical grade assays. CONCLUSIONS: Urine based testing is noninvasive and represents a rich source of novel biomarkers for prostate cancer. Although urine shows promise for detecting cancer, the ability to identify aggressive subsets of prostate cancer needs further development.

A novel method for detection of exfoliated prostate cancer cells in urine by RNA in situ hybridization.

BACKGROUND: In the current study, we explore the feasibility of detecting exfoliated prostate cancer cells in urine using an RNA in situ hybridization (RISH) assay. We hypothesized that robust and specific labeling of prostate cancer cells could be achieved in post-digital rectal examination (DRE) urine samples using RISH. METHODS: We focused on method development, optimization, and analytical evaluation of RISH-based detection of prostate cancer in urine. We optimized a sample collection, processing, and target detection workflow for urine cytology specimens in conjunction with RNA target detection by RISH. We screened a panel of 11 prostate-specific RNA targets, and selected NKX3-1 and PRAC1 as markers for cells of prostate origin and PCA3 as a marker of prostate malignancy. Following analytical validation of a multiplexed NKX3-1/PRAC1/PCA3 assay, we evaluated whether prostate cancer cells can be detected in a pilot cohort of 19 post-DRE specimens obtained from men diagnosed with prostate cancer. RESULTS: Using cytology specimens prepared from spiked urine samples, we established the analytical validity of the RISH assay for detection and visualization of prostate cells in urine. Cells of prostate origin could be readily and specifically identified and separated into benign and malignant cell populations based on the multiplex test that consisted of markers specific for prostate cells (NKX3-1, PRAC1) and prostate cancer cells (PCA3). Upon evaluation of post-DRE urine from a pilot cohort of prostate cancer patients, we identified 11 samples in which prostate cells were present, 6 of which were also positive for prostate cancer cells. CONCLUSIONS: Multiplex RISH enables the direct visualization and molecular characterization of individual exfoliated prostate cells in urine. This proof-of-principle study provides evidence supporting the application of RISH as a potential noninvasive tool for prostate cancer detection.

A novel urinary mRNA signature using the droplet digital polymerase chain reaction platform improves discrimination between prostate cancer and benign prostatic hyperplasia within the prostate-specific antigen gray zone.

Purpose: The aim of this study was to identify a noninvasive urinary marker for prostate cancer (PCa) diagnosis and to validate the clinical performance of this novel urinary mRNA signature using the droplet digital polymerase chain reaction (ddPCR) approach. Materials and Methods: A gene expression microarray (HT-12, Illumina Inc., USA) was used to identify genes differentially expressed between 16 PCa and 8 benign prostatic hyperplasia (BPH) tissues; ddPCR (QX200; Bio-Rad Laboratories, USA) was carried out to quantify the expression of selected genes in urine. The urinary molecular PCa risk score (UMPCaRS) was calculated by using the sum of three upregulated genes as the numerator and the sum of three downregulated genes as the denominator. The diagnostic utility of the UMPCaRS was validated by using a screening set (10 PCa and 10 BPH samples) and a validation set (131 PCa and 105 BPH samples). Results: Three upregulated genes (PDLIM5, GDF-15, THBS4) and three downregulated genes (UPK1A, SSTR3, NPFFR2) were selected from the microarray and subjected to ddPCR. The UMPCaRS for PCa in the screening and validation sets was significantly higher than that for BPH. For the validation set, the diagnostic accuracy of the UMPCaRS was comparable with that of prostate-specific antigen (PSA). Importantly, in the "PSA gray zone" (3-10 ng/mL), the AUC for the UMPCaRS was 0.843 and that for PSA was 0.628 (p<0.001). Conclusions: The data demonstrate that the UMPCaRS is useful for discriminating between PCa and BPH in the "PSA gray zone".

The Research Progression and Clinical Significance of Circular RNAs in Head and Neck Cancers.

With rapid development of science technique and molecular research, a large number of circular RNAs (circRNAs) were discovered. CircRNAs that are a heterogeneous endogenous group of non-coding RNA not only are abundantly and diffusely expressed in mammals but also participate in many biological processes, such as in tumor ingenuity and progress. CircRNAs have rarely open reports in the head and neck cancers (HNC), which are an aggressive malignant tumor with unsatisfactory overall survival rates. The diagnostics and treatments continue to improve while the survival rate of HNC patients has no more obvious improvement. Recent studies that are aimed at exploring the molecular mechanisms of occurrence and progression of circRNAs in HNC provide a valuable insight into potential novel diagnostic and therapeutic approaches. In this review, we summarize the increasing number of published researches on the research progression of circRNAs in HNC, as well as their possible clinical implications on HNC.

Prediction of breast cancer by profiling of urinary RNA metabolites using Support Vector Machine-based feature selection.

BACKGROUND: Breast cancer belongs to the most frequent and severe cancer types in human. Since excretion of modified nucleosides from increased RNA metabolism has been proposed as a potential target in pathogenesis of breast cancer, the aim of the present study was to elucidate the predictability of breast cancer by means of urinary excreted nucleosides. METHODS: We analyzed urine samples from 85 breast cancer women and respective healthy controls to assess the metabolic profiles of nucleosides by a comprehensive bioinformatic approach. All included nucleosides/ribosylated metabolites were isolated by cis-diol specific affinity chromatography and measured with liquid chromatography ion trap mass spectrometry (LC-ITMS). A valid set of urinary metabolites was selected by exclusion of all candidates with poor linearity and/or reproducibility in the analytical setting. The bioinformatic tool of Oscillating Search Algorithm for Feature Selection (OSAF) was applied to iteratively improve features for training of Support Vector Machines (SVM) to better predict breast cancer. RESULTS: After identification of 51 nucleosides/ribosylated metabolites in the urine of breast cancer women and/or controls by LC- ITMS coupling, a valid set of 35 candidates was selected for subsequent computational analyses. OSAF resulted in 44 pairwise ratios of metabolite features by iterative optimization. Based on this approach ultimately estimates for sensitivity and specificity of 83.5% and 90.6% were obtained for best prediction of breast cancer. The classification performance was dominated by metabolite pairs with SAH which highlights its importance for RNA methylation in cancer pathogenesis. CONCLUSION: Extensive RNA-pathway analysis based on mass spectrometric analysis of metabolites and subsequent bioinformatic feature selection allowed for the identification of significant metabolic features related to breast cancer pathogenesis. The combination of mass spectrometric analysis and subsequent SVM-based feature selection represents a promising tool for the development of a non-invasive prediction system.

Development of a multiplex RNA urine test for the detection and stratification of transitional cell carcinoma of the bladder.

PURPOSE: New markers that enable the percentage of transitional cell carcinomas (TCC) of the bladder that are diagnosed before invasion of the bladder muscle layers to be increased would reduce the morbidity and mortality associated with this disease. The purpose of this study was to develop a simple, accurate urine test based on mRNA markers and simple gene signatures that (a) could detect TCC before muscle invasion while maintaining high specificity in patients with hematuria or urinary tract infections and (b) identify patients most likely to have grade 3 or stage > or =T1 disease. EXPERIMENTAL DESIGN: RNA markers with high overexpression in stage Ta tumors and/or T1 to T4 tumors but low expression in blood or inflammatory cells were characterized by quantitative reverse transcription-PCR using 2 mL of voided urine from 75 TCC patients and 77 control patients with other urological diseases. RESULTS: A combination of the RNAs CDC2, MDK, IGFBP5, and HOXA13 detected 48%, 90%, and 100% of stage Ta, T1, and >T1 TCCs, respectively, at a specificity of 85%. Detection of Ta tumors increased to 60% for primary (non-recurrent) Ta tumors and 76% for Ta tumors > or =1 cm in diameter. Test specificity was 80% for the 20 control patients with urinary tract infections. The combination of CDC2 and HOXA13 distinguished between grade 1 to 2 TCCs and grade 3 or stage > or =T1 TCCs with approximately 80% specificity and sensitivity. CONCLUSIONS: Simple gene expression signatures can be used as urine markers for the accurate detection and characterization of bladder cancer.

Detection of exosome miRNAs using molecular beacons for diagnosing prostate cancer.

Prostate cancer is the fifth leading cause of cancer-related deaths among males worldwide. However, the biomarker for diagnosing prostate cancer that is used currently has limitations that must be overcome. Recently, several studies have demonstrated that the cancer liquid biopsy can be implemented by using exosome miRNAs. However, the current methods for the detection of exosome miRNAs are time-consuming, expensive, and laborious. Thus, we investigated a novel method for diagnosing prostate cancer that involves the use of molecular beacons for the in situ detection of miRNAs in exosomes from prostate cancer cells. We chose miRNA-375 and miRNA-574-3p as the target miRNAs for prostate cancer, and these markers in exosomes produced by prostate cancer cells including DU145 and PC-3 were successfully detected using molecular beacons. High fluorescent signals were obtained from MB and miRNA hybridization in exosomes in a concentration-dependent manner. In addition, exosome miRNAs can be detected even in the presence of human urine, so this method can be applied directly using human urine to perform liquid biopsies for prostate cancer. Overall, the in situ detection of exosome miRNAs using molecular beacons can be developed as a simple, cost effective, and non-invasive liquid biopsy for diagnosing prostate cancer.

Detection of survivin mRNA in urine of patients with superficial urothelial cell carcinomas.

INTRODUCTION: The aim of the present study was to assess if the presence of survivin mRNA in exfoliated cells present in urine samples can be a reliable marker of the presence of bladder tumour and recurrence. MATERIALS AND METHODS: Urine samples from 30 patients with superficial urothelial cell carcinomas (UCC) were collected prior to transurethral resection (TUR) of the tumour and in the first routine follow-up, three months after TUR. Detection of survivin mRNA was performed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: No correlation was observed between survivin detection and the clinicopathological variables analysed, nevertheless, when patients were grouped into low-grade (G1) and high-grade (G2+G3) tumours, statistically significant differences were found between both groups (p=0.04). When we analysed the results of survivin detection and urinary cytology together, we observed that informative cases rose from 27.8% to 44.4%. Also, Kaplan-Meier curves for patients with negative cytology in the first followup, categorised according to survivin detection, revealed that survivin mRNA positive cases recurred earlier than negative ones. CONCLUSIONS: From our results we can conclude that detection of survivin expression can be a reliable tumour marker, but more studies are needed to clarify the potential of survivin to predict recurrences. These results showed that survivin detection in combination with conventional urinary cytology can be a useful tool to increase the sensitivity in detecting the presence of a recurrence after TUR.

A nanoplasmonic label-free surface-enhanced Raman scattering strategy for non-invasive cancer genetic subtyping in patient samples.

Simple nucleic acid detection methods could facilitate the progress of disease diagnostics for clinical uses. An attractive strategy is label-free surface-enhanced Raman scattering (SERS) due to its capability of providing structural fingerprinting of analytes that are close to or on nanomaterial surfaces. However, current label-free SERS approaches for DNA/RNA biomarker detection are limited to short and synthetic nucleic acid targets and have not been fully realized in clinical samples due to two possible reasons: (i) low target copies in limited patient samples and (ii) poor capability in identifying specific biomarkers from complex samples. To resolve these limitations and enable label-free SERS for clinical applications, we herein present a novel strategy based on multiplex reverse transcription-recombinase polymerase amplification (RT-RPA) to enrich multiple RNA biomarkers, followed by label-free SERS with multivariate statistical analysis to directly detect, identify and distinguish between these long amplicons (∼200 bp). As a proof-of-concept clinical demonstration, we employed this strategy for non-invasive subtyping of prostate cancer (PCa). In a training cohort of 43 patient urinary samples, we achieved 93.0% specificity, 95.3% sensitivity, and 94.2% accuracy. We believe that our proposed assay could pave the way for simple and direct label-free SERS detection of multiple long nucleic acid sequences in patient samples, and thus facilitate rapid cancer molecular subtyping for personalized therapies.

Urinary microRNAs for prostate cancer diagnosis, prognosis, and treatment response: are we there yet?

Prostate cancer (PCa) remains one of the leading causes of cancer-related deaths in men. Despite the tremendous progress in research over the years, a suitable minimally invasive PCa biomarker is yet to be discovered. The recent advances regarding the roles of microRNAs as biomarkers has allowed for their study in PCa as well, especially as blood-based markers. However, there are several studies that used urine as biological sample to evaluate microRNAs as biomarkers for PCa diagnosis, prognosis, and treatment response, which were reviewed herein. A high degree of inconsistency among reports has been observed, which could be due to several analytical aspects, starting with different urinary fractions used for analysis and continuing with the employment of various analytical platforms and methods of statistical analysis. However, a few microRNAs were found to be dysregulated in the urine of PCa patients, which alone or together with serum prostate-specific antigen seem to improve diagnostic power even in the gray zone of PCa. These results warrant further confirmation by larger prospective studies, preferably using a standardized protocol for analysis. WIREs RNA 2017, 8:e1438. doi: 10.1002/wrna.1438 For further resources related to this article, please visit the WIREs website.

Emerging Utility of Urinary Cell-free Nucleic Acid Biomarkers for Prostate, Bladder, and Renal Cancers.

CONTEXT: By 2020 the estimated incidence of genitourinary (GU) cancers (prostate, bladder, and kidney) will be over 2 million worldwide and responsible for ∼800 000 deaths. Current diagnosis and monitoring methods of GU cancer patients are often invasive and/or lack sensitivity and specificity. Given the utility of blood-based cell-free nucleic acid (cfNA) biomarkers, the development of urinary cfNA biomarkers may improve the sensitivity of urine assays utilizing urine sediment for GU cancers. This review of urinary cfNA in GU cancers identifies the current stage of research, potential clinical utility, and the next steps needed to enter clinical use. OBJECTIVE: To critically evaluate the literature of urinary cfNA in GU cancers for clinical utility in diagnosis, screening, and precision medicine. Furthermore, the strategy for future efforts to discover potential new urinary cfNA biomarkers will be described. EVIDENCE ACQUISITION: A PubMed database (2006 to current) search was performed according to Preferred Reporting Items for Systemic Review and Meta-analysis using key Medical Subject Headings terms. Additional studies were obtained by cross-referencing from the literature. EVIDENCE SYNTHESIS: The collective research publications in urinary cfNA of GU cancers present a promising alternative liquid biopsy approach compared with blood biopsies and urine sediment, particularly for early-stage GU diseases. CONCLUSIONS: Urinary cfNA as a liquid biopsy holds potential for a more sensitive alternative to blood biopsies and urine sediment-based tests for clinical use in GU cancers. Not only does urinary cfNA offer advantages including the potential for more frequent testing, monitoring, and home use, but also has applications in early-stage GU cancers. PATIENT SUMMARY: In this review, we evaluated the current status of urinary cell-free nucleic acid in genitourinary cancers. We identified the potential advantages of urinary cell-free nucleic acid over blood and urine sediment and its clinical use in genitourinary cancer.

Urinary miRNAs as Biomarkers for Noninvasive Evaluation of Radiation-Induced Renal Tubular Injury.

Radiation nephropathy is one of the common late effects in cancer survivors who received radiotherapy as well as in victims of radiation accidents. The clinical manifestations of radiation nephropathy occur months after exposure. To date, there are no known early biomarkers to predict the future development of radiation nephropathy. This study focuses on the development of urinary biomarkers providing readout of acute responses in renal tubular epithelial cells. An amplification-free hybridization-based nCounter assay was used to detect changes in mouse urinary miRNAs after irradiation. After a single LD50 of total-body irradiation (TBI) or clinically relevant fractionated doses (2 Gy twice daily for 3 days), changes in urinary levels of microRNAs followed either an early pattern, peaking at 6-8 h postirradiation and gradually declining, or later pattern, peaking from 24 h to 7 days. Of 600 miRNAs compared, 12 urinary miRNAs showed the acute response and seven showed the late response, common to both irradiation protocols. miR-1224 and miR-21 were of particular interest, since they were the most robust acute and late responders, respectively. The early responding miR-1224 also exhibited good dose response after 2, 4, 6 and 8 Gy TBI, indicating its potential use as a biomarker for radiation exposure. In situ hybridization of irradiated mouse kidney sections and cultured mouse primary renal tubular cells confirmed the tubular origin of miR-1224. A significant upregulation in hsa-miR-1224-3p expression was also observed in human proximal renal tubular cells after irradiation. Consistent with mouse urine data, a similar expression pattern of hsa-miR-1224-3p and hsa-miR-21 were observed in urine samples collected from human leukemia patients preconditioned with TBI. This proof-of-concept study shows the potential translational utility of urinary miRNA biomarkers for radiation damage in renal tubules with possible prediction of late effects.

Composition, associated tissue methyltransferase activity, and catabolic end products of transfer RNA from carcinogen-induced hepatoma and normal monkey livers.

This investigation was designed to explore transfer RNA (TRNA) methyltransferase activity, urinary excretion levels of tRNA degradation products, and tRNA base composition in normal monkeys and in those with hepatocellular carcinomas induced by N-nitrosodiethylamine. After the development of the tumor, 24-hr urine specimens were collected, the monkeys were sacrificed, and the livers were removed for tRNA isolation and methyltransferase activity studies. The tRNA methyltransferase activity and capacity and the urinary excretion levels for selected tRNA degradation products (pseudouridine, N2,N2-dimethylguanosine, 1-methylinosine, 7-methylguanine, and beta-aminoisobutyric acid) were elevated for the hepatoma-bearing monkeys when compared to those with normal liver. The isolated tRNA pools were analyzed by high-resolution liquid chromatography, and similar base compositions were found for the hepatoma-bearing and normal monkeys. With the use of methyl-deficient Escherichia coli tRNA as the methyl receptor and the analytical procedure for tRNA anlysis, the methylating ability of the tRNA methyltransferases in hepatoma and normal liver extracts was determined. The hepatoma methyltransferase homogenates were found to produce increased levels of 7-methylguanine, N2,N2-dimethylguanine, and thymine, while the normal liver extracts gave higher levels of N2-methylguanine. These differences were not apparent in the base composition of the tRNA pools. The increased urinary excretion and higher methyltransferase activity of the hepatoma-bearing monkeys without an apparent increase in the methylated base content of their tRNA suggest increased tRNA tf individual isoaccepting tRNA's would be missed by analyzing the tRNA pools. The variations in the individual tRNA methyltransferase activities of the hepatoma and normal liver homogenates indicate a difference in the methlation of their tRNA's.

Urine Exosomes for Non-Invasive Assessment of Gene Expression and Mutations of Prostate Cancer.

PURPOSE: The analysis of exosome/microvesicle (extracellular vesicles (EVs)) and the RNA packaged within them (exoRNA) has the potential to provide a non-invasive platform to detect and monitor disease related gene expression potentially in lieu of more invasive procedures such as biopsy. However, few studies have tested the diagnostic potential of EV analysis in humans. EXPERIMENTAL DESIGN: The ability of EV analysis to accurately reflect prostate tissue mRNA expression was examined by comparing urinary EV TMPRSS2:ERG exoRNA from pre-radical prostatectomy (RP) patients versus corresponding RP tissue in 21 patients. To examine the differential expression of TMPRSS2:ERG across patient groups a random urine sample was taken without prostate massage from a cohort of 207 men including prostate biopsy negative (Bx Neg, n = 39), prostate biopsy positive (Bx Pos, n = 47), post-radical prostatectomy (post-RP, n = 37), un-biopsied healthy age-matched men (No Bx, n = 44), and young male controls (Cont, n = 40). The use of EVs was also examined as a potential platform to non-invasively differentiate Bx Pos versus Bx Neg patients via the detection of known prostate cancer genes TMPRSS2:ERG, BIRC5, ERG, PCA3 and TMPRSS2. RESULTS: In this technical pilot study urinary EVs had a sensitivity: 81% (13/16), specificity: 80% (4/5) and an overall accuracy: 81% (17/21) for non-invasive detection of TMPRSS2:ERG versus RP tissue. The rate of TMPRSS2:ERG exoRNA detection was found to increase with age and the expression level correlated with Bx Pos status. Receiver operator characteristic analyses demonstrated that various cancer-related genes could differentiate Bx Pos from Bx Neg patients using exoRNA isolated from urinary EVs: BIRC5 (AUC 0.674 (CI:0.560-0.788), ERG (AUC 0.785 (CI:0.680-0.890), PCA3 (AUC 0.681 (CI:0.567-0.795), TMPRSS2:ERG (AUC 0.744 (CI:0.600-0.888), and TMPRSS2 (AUC 0.637 (CI:0.519-0.754). CONCLUSION: This pilot study suggests that urinary EVs have the potential to be used as a platform to non-invasively differentiate patients with prostate cancer with very good accuracy. Larger studies are needed to confirm the potential for clinical utility.

Comparative Study of Extracellular Vesicles from the Urine of Healthy Individuals and Prostate Cancer Patients.

Recent studies suggest that extracellular vesicles may be the key to timely diagnosis and monitoring of genito-urological malignancies. In this study we investigated the composition and content of extracellular vesicles found in the urine of healthy donors and prostate cancer patients. Urine of 14 PCa patients and 20 healthy volunteers was clarified by low-speed centrifugation and total extracellular vesicles fraction was obtain by high-speed centrifugation. The exosome-enriched fraction was obtained by filtration of total extracellular vesicles through a 0.1 µm pore filter. Transmission electron microscopy showed that cell-free urine in both groups contained vesicles from 20 to 230 nm. Immunogold staining after ultrafiltration demonstrated that 95% and 90% of extracellular vesicles in healthy individuals and cancer patients, respectively, were exosomes. Protein, DNA and RNA concentrations as well as size distribution of extracellular vesicles in both fractions were analyzed. Only 75% of the total protein content of extracellular vesicles was associated with exosomes which amounted to 90-95% of all vesicles. Median DNA concentrations in total extracellular vesicles and exosome-enriched fractions were 18 pg/ml and 2.6 pg/ml urine, correspondingly. Urine extracellular vesicles carried a population of RNA molecules 25 nt to 200 nt in concentration of no more than 290 pg/ml of urine. Additionally, concentrations of miR-19b, miR-25, miR-125b, and miR-205 were quantified by qRT-PCR. MiRNAs were shown to be differently distributed between different fractions of extracellular vesicles. Detection of miR-19b versus miR-16 in total vesicles and exosome-enriched fractions achieved 100%/93% and 95%/79% specificity/sensitivity in distinguishing cancer patients from healthy individuals, respectively, demonstrating the diagnostic value of urine extracellular vesicles.