The translational potential of microRNAs as biofluid markers of urological tumours

Molecular characterization and functional roles of circulating cell-free extrachromosomal circular DNA

Circular DNA segments isolated from chromosomes are known as extrachromosomal circular DNA (eccDNA). Its distinct structure and characteristics, along with the variations observed in different disease states, makes it a promising biomarker. Recent studies have revealed the presence of eccDNAs in body fluids, indicating their involvement in various biological functions. This finding opens up avenues for utilizing eccDNAs as convenient and real-time biomarkers for disease diagnosis, treatment monitoring, and prognosis assessment through noninvasive analysis of body fluids. In this comprehensive review, we focused on elucidating the size profiles, potential mechanisms of formation and clearance, detection methods, and potential clinical applications of eccDNAs. We aimed to provide a valuable reference resource for future research in this field.

Urinary markers for bladder cancer diagnosis: A review of current status and future challenges

Bladder cancer is a common urological cancer with a high recurrence rate that requires long-term follow-up, and early detection positively affects prognosis. To date, the initial diagnosis and follow-up for bladder cancer rely on cystoscopy, which is an invasive and expensive procedure. Therefore, urinary markers for the detection of bladder cancer have attracted research attention for decades to reduce unnecessary cystoscopies. Urine, which is in continuous contact with bladder cancer, is considered a suitable fluid for providing tumor information. Urinary cytology is the only widely used urinary marker in clinical practice; however, it has poor sensitivity for low-grade tumors; indicating the need for novel urinary markers. Considerable research has been conducted on this topic over the years, resulting in a complex landscape with a wide range of urinary markers, including protein-, exfoliated cell-, RNA-, DNA-, and extracellular vesicle-based markers. Although some of these markers have been approved by the U.S. Food and Drug Administration and are commercially available, their use in clinical practice is limited. To facilitate clinical application, potential urinary markers must withstand prospective clinical trials and be easy for patients and clinicians to understand and utilize in a clinical context. This review provides a comprehensive overview of currently available and recently reported promising urinary markers for bladder cancer. Additionally, the challenges and the prospects of these urinary markers for clinical implementation in bladder cancer treatment were discussed.

MicroRNAs for detecting occult genitourinary cancer

PURPOSE OF REVIEW

Genitourinary (GU) malignancies are a real burden in global health worldwide. Each model has its own clinical challenges, and the early screening and/or detection of occult cancer in follow-up is transversal to all of them. MicroRNAs (miRNAs) have been proposed as minimally invasive liquid biopsy cancer biomarkers, due to their stability and low degradation.

RECENT FINDINGS

The different GU tumor models are in different stages concerning miRNAs as biomarkers for cancer detection. Testicular germ cell tumors (TGCTs) already have a specific defined target, miR-371a-3p, that has shown high sensitivity and specificity in different clinical settings, and is now in final stages of preanalytical testing before entering the clinic. The other GU malignancies are in a different stage, with many liquid biopsy studies (both in urine and plasma/serum) being currently performed, but there is not an agreeable miRNA or set of miRNAs that is ready to follow the footsteps of miR-371a-3p in TGCTs.

SUMMARY

Further studies with proper molecular characterization of miRNA profiles of GU malignancies and standardization of sampling, biobanking and formal analysis may aid in the advance and choosing of specific target sets to be used for occult cancer detection.

A serum miRNAs signature for early diagnosis of bladder cancer

BACKGROUND

Bladder cancer accounts for the most common type of urologic malignancy and presents high recurrence rate after surgical resection and adjuvant intravesical therapy. We aim to search for an early diagnostic biomarker in serum for bladder cancer in this study.

METHODS

The expression profiles of miRNAs in serum samples of 112 bladder cancer patients and 112 healthy controls were detected with real-time polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROC) curve and area under curve (AUC) analysis were performed to assess the diagnostic efficiency of miRNAs. Stepwise logic regression analysis was used to construct a diagnostic signature with highest sensitivity and specificity. Bioinformatics analysis was applied to explore the potential biological functions and mechanisms of candidate miRNAs.

RESULTS

Five miRNAs including miR-451a, miR-381-3p, miR-223-3p, miR-142-5p and miR-27b-3p were found differentially expressed in serum samples of bladder patients and healthy subjects. The diagnostic signature was constructed with miR-27b-3p, miR-381-3p and miR-451a. AUC of the three-miRNA signature was 0.894 (0.837-0.936, p < 0.001). The sensitivity and specificity of this signature were 86.90% and 77.38%, respectively, indicating that this signature has a good ability to diagnose bladder cancer.

CONCLUSION

The three-miRNA signature we constructed has favorable diagnostic capacity and may be a promising non-invasive biomarker in the early diagnosis of bladder cancer.KEY MESSAGESThere is still no clinical utilization of serum miRNAs in the early detection of bladder cancer.We screened and constructed a three-miRNA signature with the sensitivity of 86.90% and specificity of 77.38% which may be a promising non-invasive biomarker in the early diagnosis of bladder cancer.

Urine biomarkers in bladder cancer - current status and future perspectives

Urine markers to detect bladder cancer have been the subject of research for decades. The idea that urine - being in continuous contact with tumour tissue - should provide a vector of tumour information remains an attractive concept. Research on this topic has resulted in a complex landscape of many different urine markers with varying degrees of clinical validation. These markers range from cell-based assays to proteins, transcriptomic markers and genomic signatures, with a clear trend towards multiplex assays. Unfortunately, the number of different urine markers and the efforts in research and development of clinical grade assays are not reflected in the use of these markers in clinical practice, which is currently limited. Numerous prospective trials are in progress with the aim of increasing the quality of evidence about urinary biomarkers in bladder cancer to achieve guideline implementation. The current research landscape suggests a division of testing approaches. Some efforts are directed towards addressing the limitations of current assays to improve the performance of urine markers for a straightforward detection of bladder cancer. Additionally, comprehensive genetic analyses are emerging based on advances in next-generation sequencing and are expected to substantially affect the potential application of urine markers in bladder cancer.

Potential plasma microRNAs signature miR-190b-5p, miR-215-5p and miR-527 as non-invasive biomarkers for prostate cancer

BackgroundProstate cancer (PCa) is the most prevalent (20%) pathological cancer among males globally. MicroRNAs (miRNAs) are short (19-22 nucleotide), conserved, noncoding molecules that regulate post-transcriptional processes either by repressing or degrading mRNA or by translation inhibition binding to complementary sites on mRNA. The goal of this study was to find out whether differentially expressed microRNA (DEM) could be used as a potential marker in the prognosis and diagnosis of PCa.MethodologyThe miRNAs profiling was done both from plasma and tissue samples of the same PCa patient (n = 3) by real-time quantitative PCR (qRT-PCR) and compared with BPH (benign prostatic hyperplasia) patients (n = 3) as controls and further validation of selected miRNAs.ResultsWe found 55 significant overexpressed DEMs, 44 significant underexpressed DEMs in plasma and 6 significant overexpressed DEMs, 27 significant underexpressed DEMs in tissue compared between PCa and BPH. Furthermore, there were eight miRNAs namely miR-190b, miR-215, miR-300, miR-329, miR-504, miR-525-3p, miR-527, miR-548a-3p found to be significantly differentially expressed in plasma and tissue samples via profiling, however only three showed concordant expression. After validation, miR-190b-5p were shown to be significantly downexpressed with fold changes of 0.4177 (p value - 0.0072) and 0.7264 (p value - 0.0143) in plasma and tissue samples, respectively. The expression of miR-215-5p was shown to be significantly overexpressed with fold change of 1.820 (p - 0.0016) and 1.476 (p - 0.0407) in plasma and tissue samples, respectively. Furthermore, miR-527 was shown to be significantly downexpressed with fold changes of 0.6018 (p - 0.0095) and 0.6917 (p - 0.0155) in plasma and tissue samples, respectively.ConclusionAccording to our findings, plasma miR-190b-5p, miR-215-5p, miR-527 levels alteration is consistently linked with PCa tissue. For establishing significant miRNAs as biomarkers, additional research of a larger population is needed.

Circulating microRNAs as Reliable Tumor Biomarkers: Opportunities and Challenges Facing Clinical Application

MicroRNAs (miRNAs) are involved in the development of human malignancies, and cells have the ability to secrete these molecules into extracellular compartments. Thus, cell-free miRNAs (circulating miRNAs) can potentially be used as biomarkers to evaluate pathophysiological changes. Although circulating miRNAs have been proposed as potential noninvasive tumor biomarkers for diagnosis, prognosis, and response to therapy, their routine application in the clinic is far from being achieved. This review focuses on the recent progress regarding the value of circulating miRNAs as noninvasive biomarkers, with specific consideration of their relevant clinical applications. In addition, we provide an in-depth analysis of the technical challenges that impact the assessment of circulating miRNAs. We also highlight the significance of integrating circulating miRNAs with the standard laboratory biomarkers to boost sensitivity and specificity. The current status of circulating miRNAs in clinical trials as tumor biomarkers is also covered. These insights and general guidelines will assist researchers in experimental practice to ensure quality standards and repeatability, thus improving future studies on circulating miRNAs. SIGNIFICANCE STATEMENT: Our review will boost the knowledge behind the inconsistencies and contradictory results observed among studies investigating circulating miRNAs. It will also provide a solid platform for better-planned strategies and standardized techniques to optimize the assessment of circulating cell-free miRNAs.

The Role of Long Noncoding RNA (lncRNAs) Biomarkers in Renal Cell Carcinoma

Renal cell carcinoma is one of the common cancers whose incidence and mortality are continuously growing worldwide. Initially, this type of tumour is usually asymptomatic. Due to the lack of reliable diagnostic markers, one-third of ccRCC patients already have distant metastases at the time of diagnosis. This underlines the importance of establishing biomarkers that would enable the prediction of the disease's course and the risk of metastasis. LncRNA, which modulates genes at the epigenetic, transcriptional, and post-transcriptional levels, appears promising. The actions of lncRNA involve sponging and sequestering target miRNAs, thus affecting numerous biological processes. Studies have confirmed the involvement of RNAs in various diseases, including RCC. In this review, we focused on MALAT1 (a marker of serious pathological changes and a factor in the promotion of tumorigenesis), RCAT1 (tumour promoter in RCC), DUXAP9 (a plausible marker of localized ccRCC), TCL6 (exerting tumour-suppressive effects in renal cancer), LINC00342 (acting as an oncogene), AGAP2 Antisense1 (plausible predictor of RCC progression), DLEU2 (factor promoting tumours growth via the regulation of epithelial-mesenchymal transition), NNT-AS1 (sponge of miR-22 contributing to tumour progression), LINC00460 (favouring ccRCC development and progression) and Lnc-LSG1 (a factor that may stimulate ccRCC metastasis).

METTL1 drives tumor progression of bladder cancer via degrading ATF3 mRNA in an m7G-modified miR-760-dependent manner

7-methylguanosine (m⁷G) modification is recently found to conservatively exist in RNA internal position besides mRNA caps and mediates the various RNA metabolisms. As the core confirmed transmethylase of m⁷G modification, METTL1 has been reported in certain human cancers. However, the role of internal m⁷G at miRNAs and its core writer METTL1 in bladder cancer (BCa) remains to be elucidated. Here, we demonstrated that METTL1 was indispensable for BCa proliferation and metastasis in vitro and in vivo. By combining miRNA sequencing, m⁷G methylated RNA immunoprecipitation (MeRIP) and RIP, we identified METTL1 promoted the processing of miR-760 in an m⁷G-dependent manner. Transcription sequencing suggested that METTL1 indirectly degrades tumor suppressor ATF3 mRNA mediated by miR-760. Together, we concluded a regulatory axis composed of METTL1/m⁷G/miR-760/ATF3 in regulating BCa progression and provided potential therapeutic targets for BCa.

Bladder cancer diagnosis with a four-miRNA panel in serum

Background: Bladder cancer is one of the most prevalent malignancies. Due to the disadvantage of existing bladder cancer diagnostic tools, miRNAs hold promise as new diagnostic markers. Materials & methods: A total of 224 participants were involved in this three-cohort trial. A total of 15 candidate miRNAs were selected, and miRNAs with diagnostic ability were screened out with quantitative reverse transcription PCR. Diagnostic capability was ascertained by the receiver operating characteristic curve and area under the curve. Bioinformatics analysis was constructed for target gene prediction and functional annotation. Results: Six candidate miRNAs showed significantly different expression between bladder cancer patients and normal controls, and the final diagnostic panel comprised miR-181b-5p, miR-183-5p, miR-199-5p and miR-221-3p. Conclusion: This four-miRNA panel could represent a stable biomarker for bladder cancer diagnosis.

MiRNA biomarkers in cancers of the male reproductive system: are we approaching clinical application?

BACKGROUND

Specific cancer types face specific clinical management challenges. Owing to their stability, robustness and fast, easy, and cost-effective detection, microRNAs (miRNAs) are attractive candidate biomarkers to the clinic.

OBJECTIVES

Based on a comprehensive review of the relevant literature in the field, we explore the potential of miRNAs as biomarkers to answer relevant clinical dilemmas inherent to cancers of the male reproductive tract (prostate (PCa), testis (TGCTs) and penis (PeCa)) and identify some of the challenges/limitations hampering their widely application.

RESULTS AND DISCUSSION

We conclude that the use of miRNAs as biomarkers is at different stages for these distinct cancer types. While for TGCTs, miRNA-371a-3p is universally accepted to fill in important clinicals gaps and is moving fast towards clinical implementation, for PCa almost no overlap of miRNAs exists between studies, denoting the absence of a consistent miRNA biomarker, and for PeCa the field of miRNAs has just recently started, with only a few studies attempting to explore their clinical usefulness.

CONCLUSION

Technological advances influencing miRNA detection and quantification will be instrumental to continue to move forward with implementation of miRNAs in the clinic as biomarkers for non-invasive diagnosis, risk stratification, treatment monitoring and follow-up. This article is protected by copyright. All rights reserved.

Urinary microRNAome in healthy cats and cats with pyelonephritis or other urological conditions

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression at the post-transcriptional level. miRNAs have been found in urine and have shown diagnostic potential in human nephropathies. Here, we aimed to characterize, for the first time, the feline urinary miRNAome and explore the use of urinary miRNA profiles as non-invasive biomarkers for feline pyelonephritis (PN). Thirty-eight cats were included in a prospective case-control study and classified in five groups: healthy Control cats (n = 11), cats with PN (n = 10), cats with subclinical bacteriuria or cystitis (SB/C, n = 5), cats with ureteral obstruction (n = 7) and cats with chronic kidney disease (n = 5). By small RNA sequencing we identified 212 miRNAs in cat urine, including annotated (n = 137) and putative novel (n = 75) miRNAs. The 15 most highly abundant urinary miRNAs accounted for nearly 71% of all detected miRNAs, most of which were previously identified in feline kidney. Ninety-nine differentially abundant (DA) miRNAs were identified when comparing Control cats to cats with urological conditions and 102 DA miRNAs when comparing PN to other urological conditions. Tissue clustering analysis revealed that the majority of urine samples clustered close to kidney, which confirm the likely cellular origin of the secreted urinary miRNAs. Relevant DA miRNAs were verified by quantitative real-time PCR (qPCR). Eighteen miRNAs discriminated Control cats from cats with a urological condition. Of those, seven miRNAs were DA by both RNAseq and qPCR methods between Control and PN cats (miR-125b-5p, miR-27a-3p, miR-21-5p, miR-27b-3p, miR-125a-5p, miR-17-5p and miR-23a-3p) or DA between Control and SB/C cats (miR-125b-5p). Six additional miRNAs (miR-30b-5p, miR-30c, miR-30e-5p, miR-27a-3p, miR-27b-39 and miR-222) relevant for discriminating PN from other urological conditions were identified by qPCR alone (n = 4) or by both methods (n = 2) (P<0.05). This panel of 13 miRNAs has potential as non-invasive urinary biomarkers for diagnostic of PN and other urological conditions in cats.

MicroRNA-99b-5p targets mTOR/AR axis, induces autophagy and inhibits prostate cancer cell proliferation

OBJECTIVES: MicroRNAs (miRNAs) are the small non-coding regulatory RNA molecules involved in gene regulation via base-pairing with complementary sequences in mRNAs. The dysregulation of specific miRNAs, such as miR-99b-5p (miR-99b), is associated with prostate cancer (PCa) progression. However, the mechanistic role of miR-99b in PCa remains to be determined. In this study, we aimed to investigate the functional and clinical significance of miR-99b in PCa. STUDY DESIGN: The expression of miR-99b and its downstream targets mTOR/AR in the PCa samples were analyzed by RT/qPCR. The effects of miR-99b overexpression/inhibition on PCa cell survival/proliferation, spheroid formation, and cell migration were examined by specific assays. Luciferase reporter assays were performed to determine the binding of miR-99b to 3′ untranslated region (UTR) of the mTOR gene. The effects of miR-99b on the expression of mTOR, AR, and PSA proteins, as well as on AKT/mTOR signaling, autophagy, and neuroendocrine differentiation markers were analyzed by western blotting. The expression of miR-99b, mTOR, AR, PSA in AR-negative PC3 and AR-positive LNCaP cells was analyzed by RT/qPCR. The effect of miR-99b on global gene expression in PC3 cells was analyzed by RNA-seq. RESULTS: The expression of miR-99b was downregulated in tumor samples from PCa patients, whereas the expression of mTOR and AR was upregulated. In PCa cell lines, overexpression of miR-99b inhibited cell proliferation and cell colony/spheroid formation; induced apoptosis, and increased sensitivity towards docetaxel (DTX). In contrast, inhibition of miR-99b by miR-99b inhibitor resulted in increased cell growth in PCa cells. Mechanistically, miR-99b inhibited the expression of the mammalian target of the rapamycin (mTOR) gene by binding to its 3′ UTR and induced autophagy. Furthermore, miR-99b inhibited androgen receptor (AR) activity in LNCaP cells and induced apoptosis. Activation of AR signaling by dihydrotestosterone (DHT) downregulated miR-99b expression and promoted cell PCa cell growth/survival, whereas inactivation of mTOR by rapamycin or AR by enzalutamide decreased miR-99b mediated PCa cell growth. CONCLUSION: Our data suggest that miR-99b functions as a tumor suppressor by targeting the mTOR/AR axis in PCa cells, implicating miR-99b as a novel biomarker and therapeutic target for PCa management.

Urinary microRNAs and Their Significance in Prostate Cancer Diagnosis: A 5-Year Update

Simple Summary

Current diagnostics of prostate cancer often show unsatisfactory results, leading to delayed detection or overtreatment. Urinary microRNAs are a class of promising non-invasive biomarkers. Although many studies have been conducted on this topic in the last five years, there is little agreement on the data obtained. This review aims to discuss new knowledge but also focuses on technical aspects affecting urinary miRNA analysis.

Abstract

Current routine screening methods for the diagnosis of prostate cancer (PCa) have significantly increased early detection of the disease but often show unsatisfactory analytical parameters. A class of promising markers represents urinary microRNAs (miRNAs). In the last five years, there has been an extensive increase in the number of studies on this topic. Thus, this review aims to update knowledge and point out technical aspects affecting urinary miRNA analysis. The review of relevant literature was carried out by searching the PubMed database for the keywords: microRNA, miRNA, urine, urinary, prostate cancer, and diagnosis. Papers discussed in this review were retrieved using PubMed, and the search strategy was as follows: (urine OR urinary) WITH (microRNA OR miRNA) AND prostate cancer. The search was limited to the last 5 years, January 2017 to December 2021. Based on the defined search strategy, 31 original publications corresponding to the research topic were identified, read and reviewed to present the latest findings and to assess possible translation of urinary miRNAs into clinical practice. Reviews or older publications were read and cited if they valuably extended the context and contributed to a better understanding. Urinary miRNAs are potentially valuable markers for the diagnosis of prostate cancer. Despite promising results, there is still a need for independent validation of exploratory data, which follows a strict widely accepted methodology taking into account the shortcomings and factors influencing the analysis.

Identification of a three-miRNA panel in serum for bladder cancer diagnosis by a diagnostic test

BACKGROUND

Bladder cancer (BC) is the tenth most common cancer in the world. Serum microRNA (miRNA) profiles previously have been reported as non-invasive biomarkers in cancer screening. The non-invasive and reliable diagnostic biomarkers are urgently needed for detecting BC, while cystoscopy is invasive. Our study aimed to identify candidate miRNAs in serum as potential diagnostic biomarkers for BC detection.

METHODS

This study was including the screening stage, training stage, and validation stage with 137 BC patients and 127 healthy controls (HCs). We identified the expression of 28 serum miRNAs from 5 BC pools and 3 HC pools in the initial screening stage. The other 112 BC patients and 112 HCs were randomly divided into training stage with 30 BC patients and 30 HCs and validation stages with 82 BC patients and 82 HCs. These HCs matched BC patients based on age and gender with P value >0.05. Identified dysregulated miRNAs were further confirmed in the training stage, and validation stages by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The diagnostic value of miRNAs was assessed by receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC). Target genes of 3 candidate miRNAs were predicted by bioinformatic analysis.

RESULTS

Five miRNAs (miR-106a-5p, miR-145-5p, miR-132-3p, miR-7-5p and miR-148b-3p) in serum were obviously dysregulated in BC patients compared to HCs. The ability to diagnose BC of 3 candidate miRNAs was estimated by AUC, with miR-132-3p (AUC =0.781; sensitivity =68.29%, specificity =81.71%), miR-7-5p (AUC =0.778; sensitivity =59.76%, specificity =84.15%) and miR-148b-3p (AUC =0.837; sensitivity =81.71%, specificity =71.95%). Combined application of these candidate miRNAs with parallel test could improve the diagnostic value (AUC =0.922; sensitivity =90.24%, specificity =81.71%). BNC2, GAS7, and NTRK2, considered as target genes of the three-miRNA panel, may play an important role in the process of BC development.

CONCLUSIONS

A three-miRNA panel in serum was identified for BC diagnosis in our study, which HCs were used for differential diagnosis. The three-miRNA panel (miR-132-3p, miR-7-5p, and miR-148b-3p) might be performed as a non-invasive and convenient diagnostic tool for BC screening and diagnosis.

Circle-Seq reveals genomic and disease-specific hallmarks in urinary cell-free extrachromosomal circular DNAs

BACKGROUND

Extrachromosomal circular deoxyribonucleic acid (eccDNA) is evolving as a valuable biomarker, while little is known about its presence in urine.

METHODS

Here, we report the discovery and analysis of urinary cell-free eccDNAs (ucf-eccDNAs) in healthy controls and patients with advanced chronic kidney disease (CKD) by Circle-Seq.

RESULTS

Millions of unique ucf-eccDNAs were identified and comprehensively characterised. The ucf-eccDNAs are GC-rich. Most ucf-eccDNAs are less than 1000 bp and are enriched in four pronounced peaks at 207, 358, 553 and 732 bp. Analysis of the genomic distribution of ucf-eccDNAs shows that eccDNAs are found on all chromosomes but enriched on chromosomes 17, 19 and 20 with a high density of protein-coding genes, CpG islands, short interspersed transposable elements (SINEs) and simple repeat elements. Analysis of eccDNA junction sequences further suggests that microhomology and palindromic repeats might be involved in eccDNA formation. The ucf-eccDNAs in CKD patients are significantly higher than those in healthy controls. Moreover, eccDNA with miRNA genes is highly enriched in CKD ucf-eccDNA.

CONCLUSIONS

This work discovers and provides the first deep characterisation of ucf-eccDNAs and suggests ucf-eccDNA as a valuable noninnvasive biomarker for urogenital disorder diagnosis and monitoring.

Diagnostic Value of microRNA-375 as Future Biomarker for Prostate Cancer Detection: A Meta-Analysis

Background and Objectives: Responding to the need for additional biomarkers for the diagnosis of prostate cancer (PCa), mounting studies show that microRNAs (miRNAs/miRs) possess great potential as future promising diagnostic tools. However, the usefulness of these miRNAs is still highly debated, as the degree of inconsistency between study designs and results is still elevated. Herein, we present a meta-analysis evaluating the diagnostic value and accuracy of circulating miR-375, as it is one of the most studied types of miRs in PCa. Materials and Methods: The diagnostic accuracy of miR-375 was evaluated using the QUADAS-2 tool, analyzing different statistical parameters. The seven studies (from six articles) that matched our selection included 422 PCa patients and 212 controls (70 healthy volunteers + 142 with benign prostate diseases). Results and Conclusion: We obtained a p-value of 0.76 for sensitivity, 0.83 for specificity, 16 for DOR, 4.6 for LR+, 0.29 for LR−, and 0.87 for AUC (95% CI 0.83–0.89). Our results confirm that miRNA-375 has high diagnostic potential for PCa, suggesting its usefulness as a powerful biomarker. More comprehensive studies are warranted to better assess its true value as a diagnostic biomarker for this urologic disease.

Diverse Roles and Targets of miRNA in the Pathogenesis of Testicular Germ Cell Tumour

Testicular germ cell tumour (TGCT) is the most common cancer type among young adults in many parts of the world. Although the pathogenesis of TGCT is not well understood, the involvement of heritable components is evident, and the risk is polygenic. Genome-wide association studies have so far found 78 susceptibility loci for TGCT, and many of the loci are in non-coding regions indicating the involvement of non-coding RNAs in TGCT pathogenesis. MicroRNAs (miRNAs), a class of non-coding RNAs, have emerged as important gene regulators at the post-transcriptional level. They are crucial in controlling many cellular processes, such as proliferation, differentiation, and apoptosis, and an aberrant miRNA expression may contribute to the pathogenesis of several cancers, including TGCT. In support of this notion, several studies reported differential expression of miRNAs in TGCTs. We previously demonstrated that miRNAs were the most common group of small non-coding RNAs in TGCTs, and several functional studies of miRNAs in TGCTs suggest that they may act as either oncogene or tumour suppressors. Moreover, individual miRNA targets and downstream pathways in the context of TGCT development have been explored. In this review, we will focus on the diverse roles and targets of miRNAs in TGCT pathogenesis.

AGAP2-AS1 as a prognostic biomarker in low-risk clear cell renal cell carcinoma patients with progressing disease

Background

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer and one of the most common cancers. While survival for localized ccRCC is good, the survival of metastatic disease is not, and thirty percent of patients with ccRCC develop metastases during follow-up. Although current scoring methods accurately identify patients at low progression risk, a small subgroup of those patients still experience metastasis. We therefore aimed to identify ccRCC progression biomarkers in “low-risk” patients who were potentially eligible for adjuvant treatments or more intensive follow-up.

Methods

We assembled a cohort of ccRCC patients (n  = 443) and identified all “low-risk” patients who later developed progressing tumors (n  = 8). Subsequently, we performed genome-wide expression profiling from formalin-fixed samples obtained at initial surgery from these “low-risk” patients and 16 matched patients not progressing to recurrence with metastasis. The patients were matched for Leibovich sore, creatinine, age, sex, tumor size and tumor stage. Key results were confirmed with qPCR and external data from The Cancer Genome Atlas.

Results

Principal component analysis indicated that systematic transcriptomic differences were already detectable at the time of initial surgery. One thousand one hundred sixty-seven genes, mainly associated with cancer and immune-related pathways, were differentially expressed between progressors and nonprogressors. A search for a classifier revealed that overexpression of AGAP2-AS1, an antisense long noncoding RNA, correctly classified 23 of 24 samples, years (4.5 years average) in advance of the discovery of metastasis and without requiring larger gene panels. Subsequently, we confirmed AGAP2-AS1 gene overexpression by qPCR in the same samples (p  < 0.05). Additionally, in external data from The Cancer Genome Atlas, overexpression of AGAP2-AS1 is correlated with overall unfavorable survival outcome in ccRCC, irrespective of other prognostic predictors (p  = 2.44E−7).

Conclusion

AGAP2-AS1 may represent a novel biomarker identifying high-risk ccRCC patients currently classified as “low risk” at the time of surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02395-9.

Circular RNAs in prostate cancer: Biogenesis,biological functions, and clinical significance

Circular RNAs (circRNAs) are covalently closed RNA molecules that play important regulatory roles in various tumors. Prostate cancer (PCa) is one of the most common malignant tumors in the world, with high morbidity and mortality. In recent years, more and more circRNAs have been found to be abnormally expressed and involved in the occurrence and development of PCa, including cell proliferation, apoptosis, invasion, migration, metastasis, chemotherapy resistance, and radiotherapy resistance. Most of the circRNAs regulate biological behaviors of cancer through a competitive endogenous RNA (ceRNA) regulatory mechanism, and some can exert their functions by binding to proteins. circRNAs are also associated with many clinicopathological features of PCa, including tumor grade, lymph node metastasis, and distant metastasis. In addition, circRNAs are potential diagnostic and prognostic biomarkers for PCa. Considering their critical regulatory roles in the progression of PCa, circRNAs would be the potential therapeutic targets. In this paper, the current research status of circRNAs in PCa is briefly reviewed.

Exploratory Profiling of Extracellular MicroRNAs in Cerebrospinal Fluid Comparing Leptomeningeal Metastasis with Other Central Nervous System Tumor Statuses

The diagnosis of leptomeningeal metastasis (LM) is often difficult due to the paucity of cancer cells in cerebrospinal fluid (CSF) and nonspecific findings on neuroimaging. Investigations of extracellular microRNAs (miRNAs) in CSF could be used for both the diagnosis and study of LM pathogenesis because they reflect the activity of disseminating cancer cells. We isolated CSF extracellular miRNAs from patients (n = 65) of different central nervous system tumor statuses, including cancer control, healthy control, LM, brain metastasis (BM), and primary brain tumor (BT) groups, and performed miRNA microarrays. In unsupervised clustering analyses, all LM and two BM samples showed unique profiles. Among 30 miRNAs identified for LM-specific biomarkers via a Prediction Analysis of Microarrays, miR-335-5p and miR-34b-3p were confirmed in both the discovery and validation samples (n = 23). Next, we performed a significance analysis of the microarray (SAM) to extract discriminative miRNA profiles of two selected CSF groups, with LM samples revealing a greater number of discriminative miRNAs than BM and BT samples compared to controls. Using SAM comparisons between LM and BM samples, we identified 30 upregulated and 6 downregulated LM miRNAs. To reduce bias from different primary cancers, we performed a subset analysis with primary non-small cell lung cancer, and 12 of 13 upregulated miRNAs in LM vs. BM belonged to the upregulated miRNAs in LM. We identified possible target genes and their biological processes that could be affected by LM discriminative miRNAs in NSCLC using the gene ontology database. In conclusion, we identified a unique extracellular miRNA profile in LM CSF that was different from BM, suggesting the use of miRNAs as LM biomarkers in studies of LM pathogenesis.

The MicroRNA Prediction Models as Ancillary Diagnosis Biomarkers for Urothelial Carcinoma in Patients With Chronic Kidney Disease

Urothelial carcinoma is a common urological cancer in chronic kidney disease patients. Cystoscopy and urine cytology are the clinical diagnostic tools for UC. However, cystoscopy is an invasive procedure, while urine cytology showed low sensitivity for low-grade urothelial tumors. High accuracy with non-invasive tools for UC is needed for CKD patients. Our study collected a total of 272 urine and 138 plasma samples to detect the miRNA expression levels for establishing UC signatures from CKD patients. Seventeen candidate miRNAs of biofluids were selected and confirmed by qRT-PCR. Our results showed that urinary miR-1274a and miR-30a-5p expression levels were significantly lower but miR-19a-5p expression levels were higher in UC when compared with CKD. In plasma samples, miR-155-5p, miR-19b-1-5p, miR-378, and miR-636 showed significantly lower expression in UC compared to those with CKD. The Kaplan-Meier curve showed that lower expression of miR-19a, miR-19b, miR-636 and miR-378, and higher expression of miR-708-5p were associated with poor prognosis in patients with bladder cancer. In addition, we produced classifiers for predicting UC by multiple logistic regression. The urine signature was developed with four miRNAs, and the AUC was 0.8211. Eight miRNA expression levels from both urine and plasma samples were examined, and the AUC was 0.8595. Two miRNA classifiers and the nomograms could improve the drawbacks of current UC biomarker screenings for patients with CKD.

PDE11A gene polymorphism in testicular cancer: sperm parameters and hormonal profile

PURPOSE

Testicular germ cell tumours (TGCTs) is the most common malignancy among young adult males. The etiology is multifactorial and both environmental and genetic factors play an important role in the origin and development of TGCT. Genetic susceptibility may result from the interaction of multiple common and low-penetrance genetic variants and one of the main candidate genes is PDE11A. Many PDE11A polymorphisms were found responsible for a reduced PDE activity in TGCT patients, who often also display impaired hormone and sperm profile. The aim of this study was to investigate testicular function and PDE11A sequence in testicular cancer cases.

METHODS

Semen analysis was performed in 116 patients with unilateral and bilateral sporadic TGCTs and in 120 cancer-free controls. We also investigated hormone profile and PDE11A polymorphisms using peripheral blood samples.

RESULTS

Our data revealed that TGCT patients showed lower testosterone levels, higher gonadotropins levels and worse semen quality than controls, although the mean and the medians of sperm parameters are within the reference limits. PDE11A sequencing detected ten polymorphisms not yet associated with TGCTs before. Among these, G223A in homozygosity and A288G in heterozygosity were significantly associated with a lower risk of testicular tumour and they displayed a positive correlation with total sperm number.

CONCLUSIONS

Our findings highlight the key role of PDE11A in testis and suggest the presence of an underlying complex and fine molecular mechanism which controls testis-specific gene expression and susceptibility to testicular cancer.

MiR-622 acts as a tumor suppressor to induce cell apoptosis and inhibit metastasis in human prostate cancer

Growing evidence indicating the critical modulator roles of microRNAs (miRNAs) involved in prostate cancer (PCa) metastasis that holds great promise as therapeutic targets. Herein, we transfected the miR-622 mimic into PC3 cells and evaluated the effects of this interference on these tumour cells' growth and the expression of specific metastatic genes. Transfecting of miR-622 mimic and inhibitor, negative control (NC) inhibitor and NC was established using Lipofectamine 2000. The mRNA levels of miR-622 and metastatic genes were evaluated using the qRT-PCR and Western blot. Cytotoxic effects of miR-622 were assessed by MTT. Apoptosis was detected using an ELISA cell death assay kit. miR-622 is down-regulated in PC3 cells. As expected, cell viability effects after transfection were described as miR-622 inhibitor >NC and NC inhibitor >miR-622 mimic (p < .01). Importantly, we showed that transfected miR-622 mimic could enhance the apoptosis of PC3 cells, while transfected miR-622 inhibitor could decrease cell apoptosis (p < .01). Furthermore, miR-622 overexpression could increase significantly down-regulated the MMP2, MMP9, CXCR-4, c-Myc and K-Ras expression levels. Findings demonstrate a novel mechanism by which miR-622 modulates PCa cells' metastasis by targeting metastatic genes. These data confirm the tumour-suppressive function of miR-622 in PCa cells by enhancing apoptosis and reducing metastasis.

Epigenetic Biomarkers of Renal Cell Carcinoma for Liquid Biopsy Tests

Renal cell carcinomas (RCC) account for 2–3% of the global cancer burden and are characterized by the highest mortality rate among all genitourinary cancers. However, excluding conventional imagining approaches, there are no reliable diagnostic and prognostic tools available for clinical use at present. Liquid biopsies, such as urine, serum, and plasma, contain a significant amount of tumor-derived nucleic acids, which may serve as non-invasive biomarkers that are particularly useful for early cancer detection, follow-up, and personalization of treatment. Changes in epigenetic phenomena, such as DNA methylation level, expression of microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), are observed early during cancer development and are easily detectable in biofluids when morphological changes are still undetermined by conventional diagnostic tools. Here, we reviewed recent advances made in the development of liquid biopsy-derived DNA methylation-, miRNAs- and lncRNAs-based biomarkers for RCC, with an emphasis on the performance characteristics. In the last two decades, a mass of circulating epigenetic biomarkers of RCC were suggested, however, most of the studies done thus far analyzed biomarkers selected from the literature, used relatively miniature, local, and heterogeneous cohorts, and suffered from a lack of sufficient validations. In summary, for improved translation into the clinical setting, there is considerable demand for the validation of the existing pool of RCC biomarkers and the discovery of novel ones with better performance and clinical utility.

Identification of miR-20a-5p as Robust Normalizer for Urine microRNA Studies in Renal Cell Carcinoma and a Profile of Dysregulated microRNAs

Renal cell carcinoma (RCC) is the third most frequent urinary malignancy and one of the most lethal. Current diagnostic and follow-up techniques are harmful and unspecific in low-grade tumors. Novel minimally invasive markers such as urine microRNAs (miRNAs) are under study. However, discrepancies arise among studies in part due to lack of consent regarding normalization. We aimed to identify the best miRNA normalizer for RCC studies performed in urine samples together with a miRNA profile with diagnostic value and another for follow-up. We evaluated the performance of 120 candidate miRNAs in the urine of 16 RCC patients and 16 healthy controls by RT-qPCR followed by a stability analysis with RefFinder. In this screening stage, miR-20a-5p arose as the most stably expressed miRNA in RCC and controls, with a good expression level. Its stability was validated in an independent cohort of 51 RCC patients and 32 controls. Using miR-20a-5p as normalizer, we adjusted and validated a diagnostic model for RCC with three miRNAs (miR-200a-3p, miR-34a-5p and miR-365a-3p) (AUC = 0.65; Confidence Interval 95% [0.51, 0.79], p = 0.043). let-7d-5p and miR-205-5p were also upregulated in patients compared to controls. Comparing RCC samples before surgery and fourteen weeks after, we identified let-7d-5p, miR-152-3p, miR-30c-5p, miR-362-3p and miR-30e-3p as potential follow-up profile for RCC. We identified validated targets of most miRNAs in the renal cell carcinoma pathway. This is the first study that identifies a robust normalizer for urine RCC miRNA studies, miR-20a-5p, which may allow the comparison of future studies among laboratories. Once confirmed in a larger independent cohort, the miRNAs profiles identified may improve the non-invasive diagnosis and follow-up of RCC.

Size-Exclusion Chromatography Separation Reveals That Vesicular and Non-Vesicular Small RNA Profiles Differ in Cell Free Urine

Urinary extracellular vesicles (EVs) and their RNA cargo are a novel source of biomarkers for various diseases. We aimed to identify the optimal method for isolating small (<200 nm) EVs from human urine prior to small RNA analysis. EVs from filtered healthy volunteer urine were concentrated using three methods: ultracentrifugation (UC); a precipitation-based kit (PR); and ultrafiltration (UF). EVs were further purified by size-exclusion chromatography (SEC). EV preparations were analysed with transmission electron microscopy (TEM), Western blotting, nanoparticle tracking analysis (NTA) and an Agilent Bioanalyzer Small RNA kit. UF yielded the highest number of particles both before and after SEC. Small RNA analysis from UF-concentrated urine identified two major peaks at 10–40 nucleotides (nt) and 40–80 nt. In contrast, EV preparations obtained after UC, PR or SEC combined with any concentrating method, contained predominantly 40–80 nt sized small RNA. Protein fractions from UF+SEC contained small RNA of 10–40 nt in size (consistent with miRNAs). These data indicate that most of the microRNA-sized RNAs in filtered urine are not associated with small-sized EVs, and highlights the importance of removing non-vesicular proteins and RNA from urine EV preparations prior to small RNA analysis.

The discriminative ability of Prostate Health Index to detect prostate cancer is enhanced in combination with miR-222-3p

BACKGROUND

There is an urgent need for better prostate cancer (PCa) biomarkers due to the low specificity of prostate specific antigen (PSA).

OBJECTIVE

Prostate Health Index (PHI) is an advanced PSA-based test for early detection of PCa. The present study aim was to investigate the potential improvement of diagnostic accuracy of PHI by its combination with suitable discriminative microRNAs (miRNAs).

METHODS

A two-phase study was performed. In a discovery phase, a panel of 177 miRNAs was measured in ten men with biopsy proven PCa and ten men with histologically no evidence of malignancy (NEM). These results were validated in a second phase including 25 patients in each group. The patients of all groups were matched regarding their PSA values and PHI were measured.

RESULTS

Based on data in the discovery phase, four elevated miRNAs were selected as potential miRNA candidates for further validation. A combination of miR-222-3p as the best discriminative miRNA with PHI extended the diagnostic accuracy of PHI from an AUC value of 0.690 to 0.787 and resulted in a sensitivity of 72.0% and a specificity of 84.0%.

CONCLUSION

Circulating microRNAs show useful diagnostic potential in combination with common used biomarkers to enhance their diagnostic power.

Pre-Implementation Assessment of the Acceptability of Using Circulating microRNAs for Follow-Up of Malignant Germ-Cell Tumors

BACKGROUND

MicroRNAs from the miR-371~373 and miR-302/367 clusters, particularly miR-371a-3p, are promising biomarkers for blood-based diagnosis and disease monitoring of malignant germ cell tumors (GCTs) and are nearing clinical implementation. These biomarkers have superior sensitivity and specificity compared with current markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG). We explored patient acceptability of using circulating microRNAs to replace multiple serial computed tomography (CT) scans in malignant GCT follow-up.

PATIENTS AND METHODS

Two workshops involved interactive presentations and focus groups. Discussions were digitally recorded and transcribed verbatim. Qualitative thematic analysis of transcripts identified the key themes.

RESULTS

Prior to the workshops, potential participants expressed concern about the adoption of new blood tests due to personal experiences of the limitations of existing (AFP/HCG) markers. Twelve males (22-57 years of age; currently, 26-59 years of age) with a malignant GCT diagnosis participated; all were in follow-up. Three had experienced recurrence. Participants had cumulative exposure of between 1 and 15 CT scans. Data saturation was reached at the second workshop; five themes emerged underpinning preference for microRNA testing versus CT scans: (1) increased sensitivity and safety, (2) reduced financial costs, (3) reduced time for testing and results, (4) practicalities, and (5) reduced anxiety. However, some participants perceived an increased diagnostic capacity of CT scans versus blood testing.

CONCLUSION

This first user consultation of circulating microRNA testing for future malignant GCT follow-up suggests high acceptability with potential patient and healthcare system benefits.

A preliminary study of micro-RNAs as minimally invasive biomarkers for the diagnosis of prostate cancer patients

Background

A prostate cancer diagnosis is based on biopsy sampling that is an invasive, expensive procedure, and doesn’t accurately represent multifocal disease.

Methods

To establish a model using plasma miRs to distinguish Prostate cancer patients from non-cancer controls, we enrolled 600 patients histologically diagnosed as having or not prostate cancer at biopsy. Two hundred ninety patients were eligible for the analysis. Samples were randomly divided into discovery and validation cohorts.

Results

NGS-miR-expression profiling revealed a miRs signature able to distinguish prostate cancer from non-cancer plasma samples. Of 51 miRs selected in the discovery cohort, we successfully validated 5 miRs (4732-3p, 98-5p, let-7a-5p, 26b-5p, and 21-5p) deregulated in prostate cancer samples compared to controls (p ≤ 0.05). Multivariate and ROC analyses show miR-26b-5p as a strong predictor of PCa, with an AUC of 0.89 (CI = 0.83–0.95;p < 0.001). Combining miRs 26b-5p and 98-5p, we developed a model that has the best predictive power in discriminating prostate cancer from non-cancer (AUC = 0.94; CI: 0,835-0,954).

To distinguish between low and high-grade prostate cancer, we found that miR-4732-3p levels were significantly higher; instead, miR-26b-5p and miR-98-5p levels were lower in low-grade compared to the high-grade group (p ≤ 0.05).

Combining miR-26b-5p and miR-4732-3p we have the highest diagnostic accuracy for high-grade prostate cancer patients, (AUC = 0.80; CI 0,69-0,873).

Conclusions

Noninvasive diagnostic tests may reduce the number of unnecessary prostate biopsies.

The 2-miRs-diagnostic model (miR-26b-5p and miR-98-5p) and the 2-miRs-grade model (miR-26b-5p and miR-4732-3p) are promising minimally invasive tools in prostate cancer clinical management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01875-0.

MicroRNAs: Their Role in Metastasis, Angiogenesis, and the Potential for Biomarker Utility in Bladder Carcinomas

Angiogenesis is the process of generating new capillaries from pre-existing blood vessels with a vital role in tumor growth and metastasis. MicroRNAs (miRNAs) are noncoding RNAs that exert post-transcriptional control of protein regulation. They participate in the development and progression of several cancers including bladder cancer (BLCA). In cancer tissue, changes in microRNA expression exhibit tissue specificity with high levels of stability and detectability. miRNAs are less vulnerable to degradation, making them novel targets for therapeutic approaches. A suitable means of targeting aberrant activated signal transduction pathways in carcinogenesis of BLCA is possibly through altering the expression of key miRNAs that regulate them, exerting a strong effect on signal transduction. Precaution must be taken, as the complexity of miRNA regulation might result in targeting several downstream tumor suppressors or oncogenes, enhancing the effect further. Since exosomes contain both mRNA and miRNA, they could therefore possibly be more effective in targeting a recipient cell if they deliver a specific miRNA to modify the recipient cell protein production and gene expression. In this review, we discuss the molecules that have been shown to play a significant role in BLCA tumor development. We also discuss the roles of various miRNAs in BLCA angiogenesis and metastasis. Advances in the management of metastatic BLCA have been limited; miRNA mimics and molecules targeted at miRNAs (anti-miRs) as well as exosomes could serve as therapeutic modalities or as diagnostic biomarkers.

Evaluation of Serum miR-17-92 Cluster as Noninvasive Biomarkers for Bladder Cancer Diagnosis

Previous studies have shown that the miR-17-92 cluster is involved in the occurrence and development of bladder cancer. However, the role of serum miR-17-92 cluster in the diagnosis of bladder cancer has not been studied. In the present study, we evaluated the expression of miR-17-92 cluster members in bladder cancer tissues by analyzing 428 cases from TCGA database. Next, we collected the sera of 74 bladder cancer patients and 90 controls, and used qRT-PCR to detect the relative expression of the cluster. The results showed that the expression of the cluster members in the sera of patients were significantly higher than that of the controls, and they were positively correlated with the clinical stage and pathological grade of the patients. We evaluated their ability to diagnose bladder cancer using ROC, of which miR-92a-3p (AUC = 0.902), miR-17-5p (AUC = 0.845) and miR-20a-5p (AUC = 0.806) were the most prominent. Finally, we established a diagnostic model by logistic regression (AUC = 0.969). We further validated the results of the study using another dataset from the GEO database. Moreover, we evaluated the prognostic value of the cluster. The results revealed that miR-20a-5p was correlated with recurrence of bladder cancer. In summary, the present study validated the overexpression of serum miR-17-92 cluster in bladder cancer. The model composed of the three cluster members were confirmed to be a promising noninvasive biomarker for bladder cancer diagnosis.

A Circulating MicroRNA Panel for Malignant Germ Cell Tumor Diagnosis and Monitoring

Reverse transcription (RT) based quantitative PCR (qPCR) for quantifying microRNAs (miRNAs) in in the circulation presents specific challenges. Here, we describe an optimized research protocol to assess serum sample quality and quantify levels of a panel of four test miRNAs (miR-371a-3p, miR-372-3p, miR-373-3p, and miR-367-3p) that enables highly sensitive and specific malignant germ cell tumor (GCT) diagnosis and monitoring. This protocol utilizes a multiplex RT step using Taqman miRNA stem-loop primers. A multiplexed preamplification stage is then employed to increase the sensitivity of the final quantification step, which is performed using standard singleplex Taqman qPCR methodology.

Adipose tissue from metabolic syndrome mice induces an aberrant miRNA signature highly relevant in prostate cancer development

Prostate cancer (PCa) remains an important public health concern in Western countries. Metabolic syndrome (MeS) is a cluster of pathophysiological disorders with increasing prevalence in the general population that is a risk factor for PCa. Several studies have determined that a crosstalk between white adipose tissue (WAT) and solid tumors favors cancer aggressiveness. In this work, our main goal was to investigate the interaction between WAT and PCa cells through microRNAs (miRNAs), in MeS mice. We developed a MeS‐like disease model using C57BL/6J mice chronically fed with high‐fat diet (HFD) that were inoculated with TRAMP‐C1 PCa cells. A group of five miRNAs (mmu‐miR‐221‐3p, 27a‐3p, 34a‐5p, 138‐5p, and 146a‐5p) were increased in gonadal WAT (gWAT), tumors, and plasma of MeS mice compared to control animals. Three of these five miRNAs were detected in the media from gWAT and TRAMP‐C1 cell cocultures, and significantly increased in MeS context. More importantly, hsa‐miR‐221‐3p, 146a‐5p, and 27a‐3p were increased in bloodstream of PCa patients compared to healthy donors. Using miRNA microarrays, we found that 121 miRNAs were differentially released to the coculture media between HFD‐gWAT and tumor cells compared to control diet‐gWAT and tumor cells. Target genes for the 66 most deregulated miRNAs were involved in common pathways, mainly related to fatty acid metabolism, ER protein processing, amino acid degradation, PI3K AKT signaling, and PCa. Our findings show for the first time a signature of five miRNAs as important players involved in the interaction between WAT and PCa in MeS mice. Further research will be necessary to track these miRNAs in the interaction between these tissues as well as their role in PCa patients with MeS.

Urinary biomarkers in bladder cancer: A review of the current landscape and future directions

AIM

This narrative review aims to describe established and emerging urinary biomarkers in the diagnosis and surveillance of non-muscle invasive bladder cancer. It provides a comprehensive account of classical, FDA-approved protein biomarkers and discusses their limitations. Further, we discuss the role that epigenetic, genetic, and exosomal markers can play to enhance sensitivity and specificity of the available tests.

BACKGROUND

The initial diagnosis and surveillance of bladder cancer involves a combination of cystoscopy, upper urinary tract imaging, and urine cytology. Despite high specificity, cytology is limited by low sensitivity. There are currently 6 urinary assays approved by the FDA to enhance diagnosis and surveillance of bladder cancer. While these have improved diagnosis and surveillance when combined with cytology, these tests are still not sufficiently sensitive and false positives often occur in benign conditions which result in inflammation of the urinary tract. Advancements in laboratory techniques have produced significant advancements in epigenetic and genetic markers, as well as extracellular vesicles, with DNA- and RNA-based markers dominating the research in this area in recent years.

METHODS

We identified relevant published data, using the PubMed/ Medline search engines as well as Google Scholar. We performed an online search using the terms "bladder cancer", "non-muscle invasive bladder cancer" in combination with "urine biomarkers" and limited articles in English published up to February 2020. This review consolidated on all available narrative and systematic reviews published in the 5 years in this field, while also reviewing the original data of each clinical trial or observational study which led to the development of the biomarkers.

CONCLUSION

The development of laboratory techniques and understanding urine-based biomarkers in BC has fuelled the use of noninvasive liquid-based biomarkers to complement urine cytology. Nonetheless, none are sufficiently effective when used in isolation, and cytology remains the gold standard in many practices. Future efforts will be focused on using these markers in combination as a predictive signature, and moving on to validating them for use in everyday clinical practice.

Identification of plasma hsa_circ_0008673 expression as a potential biomarker and tumor regulator of breast cancer

OBJECTIVE

Cell-free circular RNAs (circRNAs) are stable and abundantly exist in body fluids. In this study, we aimed to investigate plasma cell-free circRNAs as a novel class of biomarkers for the diagnosis of breast cancer (BC).

METHODS

Differentially expressed circRNAs from 6 normal and 6 BC plasma samples were detected by microarray. Hsa_circ_0008673 was then screened and validated in the plasma of 102 normal and 378 BC samples. A receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value. The correlations between hsa_circ_0008673 expression and demographic characteristics, tumor features, and prognosis were analyzed. The effects of hsa_circ_0008673 on BC cell proliferation and metastasis were also measured.

RESULTS

Of the top ten up-regulated (hsa_circ_0008673, hsa_circ_0008500, hsa_circ_0005260, hsa_circ_0003423, hsa_circ_0119881, hsa_circ_0000987, hsa_circ_0007386, hsa_circ_0000091, hsa_circ_0016601, and hsa_circ_0008549) and top ten down-regulated (hsa_circ_0000826, hsa_circ_0072697, hsa_circ_0004587, hsa_circ_0000471, hsa_circ_0007786, hsa_circ_0001417, hsa_circ_0005982, hsa_circ_0001566, hsa_circ_0003823, and hsa_circ_0003823) circRNAs from microarray, hsa_circ_0008673 was the most significantly up-regulated circRNA in BC, and represented a good diagnostic value. Hsa_circ_0008673 was remarkably down-regulated after breast mastectomy. Hsa_circ_0008673 expression was associated with larger tumor size, distant metastasis, positive estrogen receptor (ER) status, and positive progesterone receptor (PR) status. Additionally, hsa_circ_0008673 could serve as a prognostic predicator of overall survival (OS) and disease-specific survival (DSS). Cell assays proved that hsa_circ_0008673 knockdown contributed to inhibition of tumor cell proliferation and migration.

CONCLUSION

Plasma cell-free hsa_circ_0008673 was up-regulated in BC, which was associated with poorer prognosis and promoted tumor proliferation and metastasis. Hsa_circ_0008673 is a promising biomarker for tumor diagnosis and prognostic assessment of BC patients.

Emerging role of secreted miR-210-3p as potential biomarker for clear cell Renal Cell Carcinoma metastasis

BACKGROUND

MicroRNAs (miRNAs) are emerging as promising molecules in the diagnosis, prognosis and treatment of urological tumours. Recently, our group performed two independent studies highlighting that miR-210-3p may be a useful biomarker not only for diagnosis but also for post-surgery clear cell Renal Cell Carcinoma (ccRCC) management.

OBJECTIVE

The aim of this study is to further explore the effectiveness of miRNA as non-invasive biomarker for clinical outcomes and ccRCC response to the treatment.

METHODS

We analyzed miR-210-3p levels in neoplastic and healthy tissue and in urine specimens collected at surgery and during follow-up of 21 ccRCC patients by RTqPCR.

RESULTS

Firstly, we confirmed that the expression of miR-210-3p was upregulated in tumor tissues and in urine samples of analyzed cohort. Of note is that miR-210-3p expression was significantly reduced in urine samples from disease-free patients during follow-up (from 3 to 12 months) compared to the baseline levels observed at the time of surgery. In a small subgroup of patients presenting metastatic progression (such as bone, intestinal or lung metastasis), the urine levels of miR-210-3p correlated with responsiveness to the therapy.

CONCLUSIONS

This pilot study highlights the relevance of secreted miR-210-3p as powerful non-invasive prognostic and predictive biomarker for the evaluation of clinical outcomes and treatment response during ccRCC follow up.

Small nucleolar RNAs signature (SNORS) identified clinical outcome and prognosis of bladder cancer (BLCA)

Background

Small nucleolar RNAs (snoRNAs) are a new non-coding RNAs (ncRNAs), which have not been widely investigated and are identified to be involved in tumorigenesis. But the function of snoRNAs in BLCA has not been reported yet.

Methods

SnoRNAs signature (SNORS) was constructed through LASSO cox regression analysis. Integrated analysis of candidate snoRNAs was performed to detect the correlation between copy number variation (CNV)/DNA methylation/protein/mRNA/alternative splicing (AS). Then we built a nomogram integrating independent prognostic factors to assist the clinical utility.

Results

We have screened out 15 prognostic differentially expressed snoRNAs (DESs) and constructed SNORS consisting of 5 candidate snoRNAs which could appropriately stratify patients into low or high SNORS groups with distinct prognosis. Then we found 5 candidate snoRNAs might be regulated by their own CNV and DNA methylation. Moreover, 5 candidate snoRNAs were significantly correlated mRNA and alternative splicing (AS), which might regulate diverse biological process in tumorigenesis, such as "extracellular matrix", "epithelial-mesenchymal transition (EMT)", etc. signaling pathways. Furthermore, SNORS was an independent prognostic factor, which was strikingly correlated with clinical outcome. Through inporating with other variables, we have established a predictive nomogram, which was more effectively to predict prognosis than any other variables alone.

Conclusion

Our findings first highlighted an important role of snoRNAs in BLCA and established a potential prognostic model which could serve as a biomarker for BLCA.

Identification of miR-21-5p and miR-210-3p serum levels as biomarkers for patients with papillary renal cell carcinoma: a multicenter analysis

Background

Expression of circulating serum microRNAs has not been studied in a cohort of patients with papillary renal cell carcinoma (pRCC) so far. We hypothesized that miRNA deregulation in malignant tissue is reflected in serum and could be used for non-invasive diagnosis of pRCC as well as differentiation between type 1 and type 2 pRCC.

Methods

We selected 11 differentially regulated miRNAs from the Cancer Genome Atlas (TCGA) pRCC data set as potential serum validation candidates. Serum miRNA expression was determined by qRT-PCR in a total of 34 pRCC type 1, 33 pRCC type 2 and 33 control subjects of three german high-volume medical centers.

Results

Heatmap and principal component analysis showed that miRNA expression did not cluster the samples into distinct sample groups and that miRNA levels did not significantly discriminate healthy individuals from patients with pRCC, nor between patients with type 1 and type 2 pRCC. However, miR-21-5p levels were significantly increased in patients with advanced pRCC (>pT3, and/or pN+ and/or pM+) in comparison to localized pRCC. Moreover, adding the expression of miR-210-3p, which was significantly down-regulated in localized pRCC sera in comparison to healthy sera, additionally increased diagnostic accuracy in our study cohort.

Conclusions

In our multicenter cohort, we were not able to identify a single miRNA serum marker for pRCC including its subclasses. However, our study revealed that miR-21-5p levels were elevated in advanced disease (with added diagnostic accuracy via addition of miR-210-3p expression), proposing these two miRs as potential biomarkers in pRCC.

Urinary expression of let-7c cluster as non-invasive tool to assess the risk of disease progression in patients with high grade non-muscle invasive bladder Cancer: a pilot study

BACKGROUND

High grade non-muscle-invasive bladder cancer (HG-NMIBC) is a heterogeneous disease with variable risk of progression. Urinary microRNAs are promising biomarkers for BC detection and surveillance. Let-7c-5p miRNA, clustered with miR-99a-5p and -125b-5p, is deregulated in cancer, including BC. The aim of this study is to evaluate urinary let-7c cluster expression in Ta/T1 HG-NMIBC patients and its impact on progression-free survival (PFS).

METHODS

Quantitative Real-Time-Polymerase-Chain-Reaction (qRT-PCR) was used to analyze the let-7c cluster expression in 57 urine and 49 neoplastic paired tissue samples prospectively collected from transurethral resection (TUR) HG-NMIBC patients. Twenty urine and 10 bladder tissue samples were collected and analyzed as normal controls. QRT-PCR was also used to detect intra-/extra-cellular let-7c cluster in BC cells. Receiver Operating Characteristic (ROC) curves were used to identify urinary miRNAs cut-off values predicting T-stage and PFS. Uni/multivariable Cox regression was performed to identify predictors of PFS. A nomogram predicting progression risk and a decision curve analysis (DCA) were performed.

RESULTS

Urinary let-7c was significantly up-regulated in patients compared with controls, while the whole cluster was down-regulated in tumor tissues. Supporting these findings, in vitro comparison of extra-/intra-cellular ratios of cluster levels between BC cells, showed a higher ratio for let-7c in HG-NMIBC versus low-grade cells. Urinary let-7c cluster expression was increased in higher T-stage and was an independent predictor of progression. Lower EORTC-score and downregulation of urinary cluster were predictors of higher PFS on univariable Cox regression, while on multivariable analysis only cluster expression was an independent progression predictor. On DCA, a benefit was evident for patients with a PFS probability > 20%.

CONCLUSIONS

Urinary let-7c cluster evaluation may improve prognosis, identifying patients at risk of progression and addressing early radical treatment.

Integrated RNA and metabolite profiling of urine liquid biopsies for prostate cancer biomarker discovery

Sensitive and specific diagnostic and prognostic biomarkers for prostate cancer (PCa) are urgently needed. Urine samples are a non-invasive means to obtain abundant and readily accessible “liquid biopsies”. Herein we used urine liquid biopsies to identify and characterize a novel group of urine-enriched RNAs and metabolites in patients with PCa and normal individuals with or without benign prostatic disease. Differentially expressed RNAs were identified in urine samples by deep sequencing and metabolites in urine were measured by mass spectrometry. mRNA and metabolite profiles were distinct in patients with benign and malignant disease. Integrated analysis of urinary gene expression and metabolite signatures unveiled an aberrant glutamate metabolism and tricarboxylic acid (TCA) cycle node in prostate cancer-derived cells. Functional validation supported a role for glutamate metabolism and glutamate oxaloacetate transaminase 1 (GOT1)-dependent redox balance in PCa, which could be exploited for novel biomarkers and therapies. In this study, we discovered cancer-specific changes in urinary RNAs and metabolites, paving the way for the development of sensitive and specific urinary PCa diagnostic biomarkers either alone or in combination. Our methodology was based on single void urine samples (i.e., without prostatic massage). The integrated analysis of metabolomic and transcriptomic data from these liquid biopsies revealed a glutamate metabolism and tricarboxylic acid cycle node that was specific to prostate-derived cancer cells and cancer-specific metabolic changes in urine.

Radiogenomics in Clear Cell Renal Cell Carcinoma: Correlations Between Advanced CT Imaging (Texture Analysis) and MicroRNAs Expression

PURPOSE

A relevant challenge for the improvement of clear cell renal cell carcinoma management could derive from the identification of novel molecular biomarkers that could greatly improve the diagnosis, prognosis, and treatment choice of these neoplasms. In this study, we investigate whether quantitative parameters obtained from computed tomography texture analysis may correlate with the expression of selected oncogenic microRNAs.

METHODS

In a retrospective single-center study, multiphasic computed tomography examination (with arterial, portal, and urographic phases) was performed on 20 patients with clear cell renal cell carcinoma and computed tomography texture analysis parameters such as entropy, kurtosis, skewness, mean, and standard deviation of pixel distribution were measured using multiple filter settings. These quantitative data were correlated with the expression of selected microRNAs (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both the evaluations (microRNAs and computed tomography texture analysis) were performed on matched tumor and normal corticomedullar tissues of the same patients cohort.

RESULTS

In this pilot study, we evidenced that computed tomography texture analysis has robust parameters (eg, entropy, mean, standard deviation) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression was evidenced in tumor versus normal tissue. Interestingly, entropy and miR-21-5p show promising correlation in clear cell renal cell carcinoma opening to a radiogenomic strategy to improve clear cell renal cell carcinoma management.

CONCLUSION

In this pilot study, a promising correlation between microRNAs and computed tomography texture analysis has been found in clear cell renal cell carcinoma. A clear cell renal cell carcinoma can benefit from noninvasive evaluation of texture parameters in adjunction to biopsy results. In particular, a promising correlation between entropy and miR-21-5p was found.

LncRNA00518 promotes cell proliferation through regulating miR-101 in bladder cancer

The purpose of our study is to elucidate the expression of lncRNA00518 (lnc00518) in the bladder cancer, and its potential mechanism in regulating the development of bladder cancer. The expression of lnc00518 in bladder cancer tissues and cells was examined by qRT-PCR. Correlation between lnc00518 expression with clinicopathologic characteristics and prognosis of bladder cancer patients was analyzed. In vitro effects of lnc00518 on the cellular behaviors of bladder cancer cells were explored. Moreover, in vivo effect of lnc00518 was evaluated by subcutaneous tumorigenesis in nude mice. The possible miRNA targets of lnc00518 were predicted by bioinformatics and further confirmed by dual-luciferase reporter gene assay, RIP and rescue experiments. Lnc00518 was highly expressed in bladder cancer tissues and cells. Lnc00518 expression was correlated with TNM staging and histological grade of bladder cancer. Besides, the overall survival was lower in bladder cancer patients with high expression of lnc00518 relative to those with low expression. Overexpression of lnc00518 enhanced proliferative, invasive, migratory potentials and clonality, but shortened G0/G1 phase of bladder cancer cells. Lnc00518 knockdown obtained the opposite trends. In vivo experiments revealed that lnc00518 knockdown inhibited subcutaneous tumorigenesis in nude mice. QRT-PCR results indicated that lnc00518 expression was negatively correlated with miRNA-101 expression in bladder cancer cells. Through dual-luciferase reporter gene assay and RIP, we confirmed the binding between lnc00518 and miRNA-101. Furthermore, EZH2 was verified to be the target of miRNA-101. MiRNA-101 knockdown reversed the inhibitory roles of lnc00518 knockdown in proliferative, migratory and invasive potentials of bladder cancer cells. Lnc00518 is highly expressed in bladder cancer and can be served as a predictor of poor prognosis. Lnc00518 promotes the proliferative, invasive and migratory potentials of bladder cancer by upregulating EZH2 via competitively binding to miRNA-101.

The Extracellular RNA Communication Consortium: Establishing Foundational Knowledge and Technologies for Extracellular RNA Research

The Extracellular RNA Communication Consortium (ERCC) was launched to accelerate progress in the new field of extracellular RNA (exRNA) biology and to establish whether exRNAs and their carriers, including extracellular vesicles (EVs), can mediate intercellular communication and be utilized for clinical applications. Phase 1 of the ERCC focused on exRNA/EV biogenesis and function, discovery of exRNA biomarkers, development of exRNA/EV-based therapeutics, and construction of a robust set of reference exRNA profiles for a variety of biofluids. Here, we present progress by ERCC investigators in these areas, and we discuss collaborative projects directed at development of robust methods for EV/exRNA isolation and analysis and tools for sharing and computational analysis of exRNA profiling data.

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

Prostate cancer is a global biological, medical, and social issue aggravated by the lack of reliable, highly specific, and sensitive non-invasive tests for diagnosis and staging of prostate cancer. One prospective source of biomarkers are the cell-free miRNAs present in various biological fluids. In the present study, we validated the diagnostic potential of cell-free miRNAs: miR-19b, miR-22, miR-92a, miR-378, miR-425, miR-30e, miR-31, miR-125b, miR-200b, miR-205, miR-375, and miR-660; we estimated the required sample size and the minimal miRNA set for a subsequent large-scale validation study. Relative expression of 12 miRNA combined in 31 ratios was investigated in three fractions of biological fluids (urine extracellular vesicles, clarified urine, and plasma) obtained from patients with prostate cancer (n = 10), benign prostate hyperplasia (n = 8), and healthy volunteers (n = 11). Eight of the miRNAs found in urine vesicles (miR-19b, miR-30e, miR-31, miR-92a, miR-125, miR-200, miR-205, and miR-660) showed great promise and when combined into six ratios (miR-125b/miR-30e, miR-200/miR-30e, miR-205/miR-30e, miR-31/miR-30e, miR-660/miR-30e, and miR-19b/miR-92a) could classify patients with prostate cancer, benign prostate hyperplasia, and healthy donors with 100% specificity, 100% sensitivity, and with a high degree of reliability for most donors.

Glycan Analysis as Biomarkers for Testicular Cancer

The U.S. Preventive Services Task Force does not recommend routine screening for testicular cancer (TC) in asymptomatic men, essentially because serological testicular cancer (TC) biomarkers are not reliable. The main reason is that two of the most important TC biomarkers, α-fetoprotein (AFP) and human chorionic gonadotropin (hCG), are not produced solely due to TC. Moreover, up to 40% of patients with TC do not have elevated serological biomarkers, which is why serial imaging with CT is the chief means of monitoring progress. On the other hand, exposure to radiation can lead to an increased risk of secondary malignancies. This review provides the first comprehensive account of the applicability of protein glycoprofiling as a promising biomarker for TC with applications in disease diagnostics, monitoring and recurrence evaluation. The review first deals with the description and classification of TC. Secondly, the limitations of current TC biomarkers such as hCG, AFP and lactate dehydrogenase are provided together with an extensive overview of the glycosylation of hCG and AFP related to TC. The final part of the review summarises the potential of glycan changes on either hCG and AFP as TC biomarkers for diagnostics and prognostics purposes, and for disease recurrence evaluation. Finally, an analysis of glycans in serum and tissues as TC biomarkers is also provided.

Liquid biopsy in the clinical management of bladder cancer: current status and future developments

Introduction: The use of liquid biopsy on the blood from solid malignancies provides a convenient way of detecting actionable mutations, monitoring treatment response, detecting early recurrence and prognosticating outcomes. The aim of this review is to discuss the current status and future direction of serum biomarkers in the clinical management of urinary bladder cancer.Areas covered: This review provides an overview of blood liquid biopsy and bladder cancer using methods of circulating tumors cells, circulating RNA, serum metabolites and cell-free DNA. Recent clinical studies and advances in methodology are emphasized. We performed a literature search using PMC/PubMed with keywords including 'liquid biopsy', 'circulating tumor DNA', 'cell-free DNA', 'biomarkers', 'bladder cancer' 'precision medicine'. Additional articles were obtained from the cited references of key articles. An emphasis was placed on recent studies published since 2018.Expert opinion: Liquid biopsies represent a potential biomarker using cell-free DNA, metabolomic profiles of altered cellular metabolism, circulating cancer cells and RNA. Despite displaying tremendous clinical promise, the current status of the blood liquid biopsies has not reached fruition. However, future investigations should lead the evolution of liquid biomarker into clinical utility for the management of bladder cancer.