MicroRNA molecular profiling from matched tumor and bio-fluids in bladder cancer

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.

Role of Exosomal miRNA in Bladder Cancer: A Promising Liquid Biopsy Biomarker

Bladder cancer (BCa) is the most prevalent neoplasia of the urinary tract. Unfortunately, limited improvements in effective BCa management have meant that it remains a challenging disease. Cystoscopy has been the gold standard for BCa diagnosis and surveillance for over two centuries but is an invasive and expensive approach. Recently, liquid biopsy has been identified as a promising field of cancer research, due to its noninvasiveness and ease of sampling. Liquid biopsy samples could provide comprehensive information regarding the genetic landscape of cancer and could track genomic evolution of the disease over time. Exosomes, which contain RNAs, DNAs, and proteins, are a potential source of tumor biomarkers in liquid biopsy samples. In particular, exosomal miRNAs (exomiRs) hold great promise as biomarkers for tumor development and progression. In this review, we provide an overview of liquid biopsy biomarkers, with a particular focus on the use of exomiRs as biomarkers of cancer, and summarize their clinical implications for BCa. Finally, we discuss the future perspectives of these biomarkers in cancer research.

Exosomal hsa-miR-129-2 and hsa-miR-889 from a 6-microRNA signature might be a potential biomarker for predicting prognosis of papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is a subtype of thyroid cancer with increasing incidence over time.

OBJECTIVE

This study aimed to build a risk score (RS) system for PTC patients.

METHODS

PTC microRNA (miRNA) and messenger RNA (mRNA) expression data were extracted from The Cancer Genome Atlas (TCGA) database. The 491 PTC samples were randomly divided into training and validation sets. Using the limma software package, differentially expressed mRNAs (DEGs) and miRNAs (DEMs) between the tumor and control groups were screened. In order to construct an RS system, a survival package was used to select independent miRNAs related to prognosis. Enrichment analysis was performed, and a miRNA-mRNA co-expression network was constructed. High-throughput sequencing was also used to verify the prognostic miRNAs in exosomes.

RESULTS

We found 1363 DEGs and 171 DEMs between the tumor and control groups. After identifying 26 DEMs that were significantly related to prognosis, 6 independent prognosis-associated miRNAs were selected to build an RS system. The areas under the curves of the overall survival rates of the training, validation, and entire sets were 0.847, 0.772, and 0.819, respectively. By conducting pathway analysis using the miRNA-mRNA co-expression network, one overlapping factor and five overlapping pathways were obtained. In addition, high-throughput sequencing revealed that the hsa-miR-129-2, hsa-miR-548j, hsa-miR-6734, and hsa-miR-889 expression levels in TCGA tumor tissues and exosomes were consistent, and those of hsa-miR-129-2 and hsa-miR-889 between patients and controls were significantly different in exosomes.

CONCLUSION

The six-miRNA RS system in exosomes may comprise independent signatures for predicting PTC patient prognosis.

Influence of Obesity in the miRNome: miR-4454, a Key Regulator of Insulin Response Via Splicing Modulation in Prostate

CONTEXT

Obesity is a major health problem associated with severe comorbidities, including type 2 diabetes and cancer, wherein microRNAs (miRNAs) might be useful as diagnostic/prognostic tools or therapeutic targets.

OBJECTIVE

To explore the differential expression pattern of miRNAs in obesity and their putative role in obesity-related comorbidities such as insulin resistance.

METHODS

An Affymetrix-miRNA array was performed in plasma samples from normoweight (n = 4/body mass index < 25) and obese subjects (n = 4/body mass index > 30). The main changes were validated in 2 independent cohorts (n = 221/n = 18). Additionally, in silico approaches were performed and in vitro assays applied in tissue samples and prostate (RWPE-1) and liver (HepG2) cell-lines.

RESULTS

A total of 26 microRNAs were altered (P < 0.01) in plasma of obese subjects compared to controls using the Affymetrix-miRNA array. Validation in ampler cohorts revealed that miR-4454 levels were consistently higher in obesity, associated with insulin-resistance (Homeostatic Model Assessment of Insulin Resistance/insulin) and modulated by medical (metformin/statins) and surgical (bariatric surgery) strategies. miR-4454 was highly expressed in prostate and liver tissues and its expression was increased in prostate and liver cells by insulin. In vitro, overexpression of miR-4454 in prostate cells resulted in decreased expression levels of INSR, GLUT4, and phosphorylation of AMPK/AKT/ERK, as well as in altered expression of key spliceosome components (ESRP1/ESRP2/RBM45/RNU2) and insulin-receptor splicing variants.

CONCLUSIONS

Obesity was associated to an alteration of the plasmatic miRNA landscape, wherein miR-4454 levels were higher, associated with insulin-resistance and modulated by obesity-controlling interventions. Insulin regulated miR-4454, which, in turn may impair the cellular response to insulin, in a cell type-dependent manner (i.e., prostate gland), by modulating the splicing process.

Tumor heterogeneity and the potential role of liquid biopsy in bladder cancer

Bladder cancer (BC) is a heterogeneous disease that characterized by genomic instability and a high mutation rate. Heterogeneity in tumor may partially explain the diversity of responses to targeted therapies and the various clinical outcomes. A combination of cytology and cystoscopy is the standard methodology for BC diagnosis, prognosis, and disease surveillance. However, genomics analyses of single tumor‐biopsy specimens may underestimate the mutational burden of heterogeneous tumors. Liquid biopsy, as a promising technology, enables analysis of tumor components in the bodily fluids, such as blood and urine, at multiple time points and provides a minimally invasive approach that can track the evolutionary dynamics and monitor tumor heterogeneity. In this review, we describe the multiple faces of BC heterogeneity at the genomic and transcriptional levels and how they affect clinical care and outcomes. We also summarize the outcomes of liquid biopsy in BC, which plays a potential role in revealing tumor heterogeneity. Finally, we discuss the challenges that must be addressed before liquid biopsy can be widely used in clinical treatment.

miR-4454 up-regulated by HPV16 E6/E7 promotes invasion and migration by targeting ABHD2/NUDT21 in cervical cancer

The abnormal expression of HPV16 E6/E7 activates oncogenes and/or inactivates tumor suppressor genes, resulting in the selective growth and malignant transformation of cancer cells. miR-4454 was selected by sequencing due to its abnormal high expression in HPV16 E6/E7 positive CaSki cell compared with HPV16 E6/E7 negative C33A cell. Overexpression of miR-4454 enhances cervical cancer cell invasion and migration. ABHD2 and NUDT21 are identified as a target gene of miR-4454.The effects of ABHD2 and NUDT21 on migration and invasion of CaSki and C33A cells were determined. The dual luciferase and RT-qPCR assays confirmed that miR-4454 might regulate its targets ABHD2 and NUDT21 to promote the proliferation, invasion and migration, whereas, inhibit the apoptosis in CaSki and C33A cells.

Evaluation of miR-130 family members as circulating biomarkers for the diagnosis of bladder cancer

OBJECTIVE

Previous research has shown that the miR-130 family is closely related to the occurrence and development of bladder cancer. We hope to use the miR-130 family members as new, non-invasive, and easily detectable biomarkers for bladder cancer.

METHODS

We analyzed 428 cases in The Cancer Genome Atlas-Bladder Urothelial Carcinoma database and verified that the miR-130 family members were significantly overexpressed in bladder cancer. A total of 74 bladder cancer patients and 90 controls were enrolled. The relative expression of the miR-130 family in serum was detected using quantitative reverse transcription-polymerase chain reaction. The diagnostic efficacy of the miR-130 family members was determined using the receiver operating characteristic method (ROC), and a diagnostic panel was built using logistic regression. The results of the study were further confirmed in an external validation set of 492 samples from the Gene Expression Omnibus database.

RESULTS

The expression of the miR-130 family members (except for miR-301b-3p) in the serum of bladder cancer patients was higher than that in the controls. The diagnostic capabilities for bladder cancer were 0.847 (miR-130a-3p), 0.762 (miR-130b-3p), and 0.892 (miR-301a-3p). We established a three-miRNA panel with an area under the ROC curve as high as 0.961, indicating that it is a promising clinical diagnostic biomarker of bladder cancer with high sensitivity and specificity.

CONCLUSION

The expression levels of miR-130 family members in serum can effectively distinguish the bladder cancer patients from healthy controls. This finding will facilitate the clinical diagnosis of bladder cancer.

Multifunctional role of microRNAs in mesenchymal stem cell-derived exosomes in treatment of diseases

Mesenchymal stem cells can be replaced by exosomes for the treatment of inflammatory diseases, injury repair, degenerative diseases, and tumors. Exosomes are small vesicles rich in a variety of nucleic acids [including messenger RNA, Long non-coding RNA, microRNA (miRNA), and circular RNA], proteins, and lipids. Exosomes can be secreted by most cells in the human body and are known to play a key role in the communication of information and material transport between cells. Like exosomes, miRNAs were neglected before their role in various activities of organisms was discovered. Several studies have confirmed that miRNAs play a vital role within exosomes. This review focuses on the specific role of miRNAs in MSC-derived exosomes (MSC-exosomes) and the methods commonly used by researchers to study miRNAs in exosomes. Taken together, miRNAs from MSC-exosomes display immense potential and practical value, both in basic medicine and future clinical applications, in treating several diseases.

Identification of miR-29c-3p as a Robust Normalizer for Urine microRNA Studies in Bladder Cancer

Bladder cancer (BC) is among the most frequent malignancies worldwide, being the most expensive cancer to treat and monitor and the most lethal urological cancer. Urine microRNAs (miRNAs) have been proposed as novel non-invasive biomarkers to early diagnose and monitor BC patients in order to avoid the performance of current aggressive diagnostic techniques. However, huge discrepancies arise among studies mainly due to the lack of standardization in the normalization, a crucial step in all miRNA studies. Our aim was to identify the best miRNA normalizer for miRNA studies in urine of BC patients. We evaluated the performance of 110 candidate miRNAs in urine of 35 BC patients and 15 healthy controls by Real Time quantitative Polymerase Chain Reaction (RT-qPCR) followed by a stability analysis with RefFinder. In this screening stage, miR-29c-3p arose as the most stably expressed miRNA in BC and controls, with a good expression level. Stability of miR-29c-3p expression was validated in an independent cohort of 153 BC patients and 57 controls. Finally, we evaluated the robustness of miR-29c-3p as normalizer in the expression study of miR-200c-3p, a potential diagnostic marker for BC. We propose miR-29c-3p as a normalizer for miRNA studies in BC urine. This is the first study that characterizes a reliable normalizer that may allow the comparison of future urine miRNA studies as non-invasive biomarkers for BC diagnosis and monitoring.

Circulatory miRNA as a Biomarker for Therapy Response and Disease-Free Survival in Hepatocellular Carcinoma

The clinical outcome of hepatocellular carcinoma (HCC) treatment remains unsatisfactory, contributing to the high mortality of HCC worldwide. Circulating miRNAs have the potential to be a predictor of therapy response. Microarray profiling was performed in serum samples of 20 HCC patients before treatment. Circulating miRNAs associated with treatment response were validated in 86 serum HCC samples using the qRT-PCR system. Patients were treated either with curative treatments (resection or radiofrequency) or trans-arterial chemoembolization (TACE), and grouped according to therapy response in complete responders (CR) and partial responders or progressive disease (PRPD), following mRECIST criteria. Four miRNA candidates from the discovery phase (miR-4443, miR-4454, miR-4492, and miR-4530) were validated. Before therapy, miR-4454 and miR-4530 were up-regulated in CR to curative treatments (2.83 fold, p = 0.02 and 2.33 fold, p = 0.008, respectively) and were able to differentiate CR from PRPD (area under the curve (AUC) = 0.74, sens/spec 79/63% and AUC = 0.77, sens/spec 72/73%). On the contrary, miR-4443 was 1.95 times down-regulated in CR (p = 0.05) with an AUC of 0.72 (sens = 70%, spec = 60%) in distinguishing CR vs. PRPD). The combination of the three miRNAs was able to predict the response to curative treatment with an AUC of 0.84 (sens = 72%, spec = 75%). The higher levels of miR-4454 and miR-4530 in were associated to longer overall survival (HR = 2.79, p = 0.029 and HR = 2.97, p = 0.011, respectively). Before TACE, miR-4492 was significantly up-regulated in CR patients (FC = 2.67, p = 0.01) and able to differentiate CR from PRPD (AUC = 0.84, sens/spec 84.6/71%). We demonstrated that different miRNAs predictors can be used as potential prognostic circulating biomarkers according to the selected treatment for HCC.

MiR-486-5p enhances cisplatin sensitivity of human muscle-invasive bladder cancer cells by induction of apoptosis and down-regulation of metastatic genes

OBJECTIVES

Cisplatin is one of the common chemotherapy drugs for bladder cancer, and resistance to this drug is one of the major obstacles to effective chemotherapy. MicroRNAs (miRNAs) are a category of small noncoding RNAs that can regulate the expression of numerous genes. Recent studies showed that miRNAs can act as a powerful regulator of chemo-sensitivity in cancer cells. Hence, this study aimed to investigate the effects of miRNA-486-5p on cisplatin-sensitivity of different bladder cancer cells.

MATERIAL AND METHODS

The 5637 and EJ138 cancer cells were treated with miRNA-486-5p and cisplatin, individually or in combination.

RESULTS

Afterward, the cytotoxicity effects of these treatments were determined by MTT assay and the increased cisplatin-sensitivity observed in both cell lines, especially, 5637 cells. Moreover, subG1 phase cell cycle arrest, changes in the expression of caspase-9, caspase-3, P53, SIRT1, OLFM4, SMAD2, and Bcl-2 genes and nuclear fragmentation also revealed the induction of apoptosis in all treatments, which increased in combination groups. Also, the combination of miRNA-486-5p with cisplatin significantly down-regulated the expression of migration associated genes including ROCK, CD44, and MMP-9 as compared with cisplatin alone.

CONCLUSION

Altogether, these results indicated that the miRNA-486-5p could induce apoptosis and inhibit cell migration ability of the cells. It seems that pre-electroporation of cells with miRNA-486-5p has useful results in the enhancement of cisplatin sensitivity of 5637 and EJ138 cancer cells and this combination may be a promising treatment strategy for bladder cancer therapy.

Application of exosomes as liquid biopsy in clinical diagnosis

Liquid biopsy refers to the sampling and molecular analysis of the biofluids of circulating tumor cells, extracellular vesicles, nucleic acids, and so forth. Exosomes are small extracellular vesicles with sizes between 30–150 nm. They are secreted by multivesicular bodies through exocytosis in live cells and can participate in intercellular communication due to their contents, including nucleic acids, proteins, and lipids. Herein, we investigate publication frequencies on exosomes over the past 10 years, and review recent clinical studies on liquid biopsy of exosomes in the fields of oncology, pregnancy disorders, cardiovascular diseases, and organ transplantation. We also describe the advantages of exosomes as an effective liquid biopsy tool and the progression of exosome extraction methods. Finally, we depict the commercial development of exosome research and discuss the future role of exosomes in liquid biopsy.

Signals from the Metastatic Niche Regulate Early and Advanced Ovarian Cancer Metastasis through miR-4454 Downregulation

Treatment of ovarian cancer is limited by extensive metastasis and yet it remains poorly understood. We have studied the critical step of metastatic colonization in the context of the productive interactions with the metastatic microenvironment with a goal of identifying key regulators. By combining miRNA expression analysis using an organotypic 3D culture model of early ovarian cancer metastasis with that of matched primary and metastatic tumors from 42 patients with ovarian cancer, we identified miR-4454 as a key regulator of both early colonization and advanced metastasis in patients with ovarian cancer. miR-4454 was downregulated in the metastasizing ovarian cancer cells through paracrine signals from microenvironmental fibroblasts, which promoted migration, invasion, proliferation, and clonogenic growth in ovarian cancer cells as well as their ability to penetrate through the outer layers of the omentum. Stable overexpression of miR-4454 decreased metastasis in ovarian cancer xenografts. Its mechanism of action was through the upregulation of its targets, secreted protein acidic and cysteine rich (SPARC) and BCL2 associated athanogene 5 (BAG5), which activated focal adhesion kinase (FAK) signaling, promoted mutant p53 gain of function by its stabilization, and inhibited apoptosis. Because microenvironment-induced downregulation of miR-4454 is essential for early and advanced metastasis, targeting it could be a promising therapeutic approach. IMPLICATIONS: This study identifies a miRNA, miR-4454, which is downregulated by signals from the microenvironment and promotes early and advanced ovarian cancer metastasis through its effects on FAK activation, mutant p53 stabilization, and apoptosis inhibition.

Peripheral circulation miRNA expression of pediatric brain tumors and its relation to tumor miRNA expression levels

OBJECTIVE

Micro RNAs (miRNAs) in peripheral biofluids (e.g., blood, saliva, urine) have been investigated as potential sources of diagnostic and prognostic information for a variety of tumor types, including pediatric brain tumors. While significant predictive associations have been identified between unique serum miRNA concentrations and some pediatric brain tumors, it is unclear whether serum miRNA abnormalities in pediatric brain tumor patients are representative of miRNA alterations in the tumor tissue compartment or whether they represent host tissue reactions to the presence of a brain tumor. The authors sought to identify whether serum miRNA changes in pediatric brain tumor patient sera could be explained by miRNA alterations within their tumors.

METHODS

Matched serum and tissue samples were taken from a cohort of pediatric brain tumor patients (juvenile pilocytic astrocytoma [JPA] = 3, medulloblastoma = 4, ependymoma = 3), and unmatched control samples (n = 5) were acquired from control pediatric patients without oncological diagnoses. Extracted RNAs were tested within an array of 84 miRNAs previously noted to be relevant in a variety of brain tumors.

RESULTS

miR-26a-5p correlated strongly in JPA patients within both the serum and tumor tissue samples (R2 = 0.951, p = 0.046), and serum levels were highly predictive of JPA (area under the curve = 0.751, p = 0.027). No other miRNAs that were significantly correlated between biological compartments were significantly associated with brain tumor type. In total, 15 of 84 tested miRNAs in JPA patients, 14 of 84 tested miRNAs in ependymoma patients, and 4 of 84 tested miRNAs in medulloblastoma patients were significantly, positively correlated between serum and tumor tissue compartments (R2 > 0.950, p < 0.05).

CONCLUSIONS

The majority of miRNA changes in pediatric brain tumor patient sera that are significantly associated with the presence of a brain tumor do not correlate with brain tumor miRNA expression levels. This suggests that peripheral miRNA changes within pediatric brain tumor patients likely derive from tissues other than the tumors themselves.

Tumor-derived extracellular vesicles: Regulators of tumor microenvironment and the enlightenment in tumor therapy

In recent decades, extracellular vesicles (EVs) have been proven to establish an important bridge of communication between cells or cells and their microenvironment. It is well known that EVs play crucial roles in many human diseases, especially in tumors. Tumor-derived EVs (TEVs) are not only involved in epithelial-mesenchymal transition and extracellular matrix remodeling to promote the invasion and metastasis, but also contribute to the suppression of antitumor immune responses by carrying different inhibitory molecules. In this review, we mainly discuss the effects of TEVs on the remodeling of tumor microenvironment through immune and non-immune associated mechanisms. We summarize the latest studies about utilizing EVs in clinical diagnosis and therapeutic drug delivery as well. In addition, the perspective of tumor therapy by targeting EVs is discussed in this review.

Technologies and Standardization in Research on Extracellular Vesicles

Extracellular vesicles (EVs) are phospholipid bilayer membrane-enclosed structures containing RNAs, proteins, lipids, metabolites, and other molecules, secreted by various cells into physiological fluids. EV-mediated transfer of biomolecules is a critical component of a variety of physiological and pathological processes. Potential applications of EVs in novel diagnostic and therapeutic strategies have brought increasing attention. However, EV research remains highly challenging due to the inherently complex biogenesis of EVs and their vast heterogeneity in size, composition, and origin. There is a need for the establishment of standardized methods that address EV heterogeneity and sources of pre-analytical and analytical variability in EV studies. Here, we review technologies developed for EV isolation and characterization and discuss paths toward standardization in EV research.

Small Non-Coding RNA Profiling in Plasma Extracellular Vesicles of Bladder Cancer Patients by Next-Generation Sequencing: Expression Levels of miR-126-3p and piR-5936 Increase with Higher Histologic Grades

Bladder cancer (BC) is the tenth most frequent cancer worldwide. Due to the need for recurrent cystoscopies and the lack of non-invasive biomarkers, BC is associated with a high management burden. In this respect, small non-coding RNAs (sncRNAs) have been investigated in urine as possible biomarkers for BC, but in plasma their potential has not yet been defined. The expression levels of sncRNAs contained in plasma extracellular vesicles (EVs) from 47 men with BC and 46 healthy controls were assessed by next-generation sequencing. The sncRNA profiles were compared with urinary profiles from the same subjects. miR-4508 resulted downregulated in plasma EVs of muscle-invasive BC patients, compared to controls (adj-p = 0.04). In World Health Organization (WHO) grade 3 (G3) BC, miR-126-3p was upregulated both in plasma EVs and urine, when compared to controls (for both, adj-p < 0.05). Interestingly, two sncRNAs were associated with the risk class: miR-4508 with a downward trend going from controls to high risk BC, and piR-hsa-5936 with an upward trend (adj-p = 0.04 and adj-p = 0.05, respectively). Additionally, BC cases with low expression of miR-185-5p and miR-106a-5p or high expression of miR-10b-5p showed shorter survival (adj-p = 0.0013, adj-p = 0.039 and adj-p = 0.047, respectively). SncRNAs from plasma EVs could be diagnostic biomarkers for BC, especially in advanced grade.

Evaluating prognostic utility of preoperative Neutrophil to Lymphocyte Ratio and hsa-let-7g/c up-regulation in patients with urinary bladder cancer

BACKGROUND

Stratification and risk-evaluation of bladder cancer (BCa) patients are far-reached issues, especially for those with non muscle invasive disease. Thus, setting-up biomarkers, especially after resection of the primary tumor, is crucial. Specifically, Neutrophil to lymphocyte ratio NLR and let-7 deregulation which have been preliminarily but not consistently described to be associated to unfavorable prognosis.

OBJECTIVE

To explore the clinical value of pre-treatment Neutrophil to Lymphocyte Ratio (NLR), let-7c and let-7g's deregulation.

METHODS

Data were extracted from ninety BCa samples. Pre-treatment NLR was estimated as the absolute neutrophil count divided by the absolute lymphocyte count. Expression patterns of let-7c and let-7g were assessed by qRT-PCR. Correlation with clinical characteristics was performed by descriptive statistics.

RESULTS

Both let-7 miRs were upregulated. Interestingly, let-7g was associated to pathological stage (p= 0.001) and tumor multiplicity (p= 0.003). NLR was associated to histological grade (p= 0.005) and clinical stage (p= 0.006). They were both associated to more aggressive phenotype and their worth as potential stratification biomarkers was confirmed by ROC curve.

CONCLUSIONS

Our data demonstrated the potential clinical value of all markers, especially pretreatment NLR and let-7g. Further studies are recommended to confirm their utility in improving the clinical decision-making regarding treatment and follow-up scheduling.

Serum MicroRNA Signatures in Recovery From Acute and Chronic Liver Injury and Selection for Liver Transplantation

We previously demonstrated a distinct hepatic microRNA (miRNA) signature (down-regulation of miRNA-23a, -150, - 200b, -503, and -663 and up-regulation of miRNA-20a) is associated with successful regeneration in auxiliary liver transplantation (ALT). This study aimed to evaluate whether the serum expression of this regeneration-linked miRNA signature is associated with clinical outcomes in acute and chronic liver disease. These were represented by patients with acetaminophen-induced acute liver failure (ALF; n = 18) and patients with hepatitis C virus (HCV) undergoing treatment with direct-acting antivirals (n = 56), respectively. Patients were grouped depending on their clinical outcome. Global serum miRNA expression was analyzed using polymerase chain reaction (PCR) arrays and selected miRNA expression using targeted PCR. We demonstrate that specific regeneration-linked miRNAs discriminate outcomes in both clinical scenarios. We further show that miRNA-20a, -23a, -150, -200b, -503, and -663 undergo concordant changes in expression in 3 distinct clinical settings: liver regeneration accompanying successful ALT, clinical recovery after ALF, and clinical recompensation after cure of HCV. This miRNA signature represents a potentially novel biomarker to predict outcome and optimize patient selection for liver transplantation in both acute and chronic liver disease.

Urinary Biomarkers in Bladder Cancer: Where Do We Stand and Potential Role of Extracellular Vesicles

Extracellular vesicles (EVs) are small membrane vesicles released by all cells and involved in intercellular communication. Importantly, EVs cargo includes nucleic acids, lipids, and proteins constantly transferred between different cell types, contributing to autocrine and paracrine signaling. In recent years, they have been shown to play vital roles, not only in normal biological functions, but also in pathological conditions, such as cancer. In the multistep process of cancer progression, EVs act at different levels, from stimulation of neoplastic transformation, proliferation, promotion of angiogenesis, migration, invasion, and formation of metastatic niches in distant organs, to immune escape and therapy resistance. Moreover, as products of their parental cells, reflecting their genetic signatures and phenotypes, EVs hold great promise as diagnostic and prognostic biomarkers. Importantly, their potential to overcome the current limitations or the present diagnostic procedures has created interest in bladder cancer (BCa). Indeed, cystoscopy is an invasive and costly technique, whereas cytology has poor sensitivity for early staged and low-grade disease. Several urine-based biomarkers for BCa were found to overcome these limitations. Here, we review their potential advantages and downfalls. In addition, recent literature on the potential of EVs to improve BCa management was reviewed and discussed.

Crosstalk among colon cancer-derived exosomes, fibroblast-derived exosomes, and macrophage phenotypes in colon cancer metastasis

Cellular crosstalk is an important mechanism in the pathogenesis of inflammatory disorders and cancers. One significant means by which cells communicate with each other is through the release of exosomes. Exosomes are extracellular vesicles formed by the outward budding of plasma membranes, which are then released from cells into the extracellular space. Many studies have suggested that microvesicles released by colon cancer cells initiate crosstalk and modulate the fibroblast activities and macrophage phenotypes. Interestingly, crosstalk among colon cancer cells, macrophages and cancer-associated fibroblasts maximizes the mechanical composition of the stromal extracellular matrix (ECM). Exosomes contribute to cancer cell migration and invasion, which are critical for colon cancer progression to metastasis. The majority of the studies on colorectal cancers (CRCs) have focused on developing exosomal biomarkers for the early detection and prediction of CRC prognosis. This study highlights the crosstalk among colon cancer-derived exosomes, macrophage phenotypes and fibroblasts during colon cancer metastasis.

tRNA-derived fragments and microRNAs in the maternal-fetal interface of a mouse maternal-immune-activation autism model

tRNA-derived small fragments (tRFs) and tRNA halves have emerging functions in different biological pathways, such as regulating gene expression, protein translation, retrotransposon activity, transgenerational epigenetic changes and response to environmental stress. However, small RNAs like tRFs and microRNAs in the maternal-fetal interface during gestation have not been studied extensively. Here we investigated the small RNA composition of mouse placenta/decidua, which represents the interface where the mother communicates with the foetus, to determine whether there are specific differences in tRFs and microRNAs during fetal development and in response to maternal immune activation (MIA). Global tRF expression pattern, just like microRNAs, can distinguish tissue types among placenta/decidua, fetal brain and fetal liver. In particular, 5' tRNA halves from tRNA^Gly, tRNA^Glu, tRNA^Val and tRNA^Lys are abundantly expressed in the normal mouse placenta/decidua. Moreover, tRF and microRNA levels in the maternal-fetal interface change dynamically over the course of embryonic development. To see if stress alters non-coding RNA expression at the maternal-fetal interface, we treated pregnant mice with a viral infection mimetic, which has been shown to promote autism-related phenotypes in the offspring. Acute changes in the levels of specific tRFs and microRNAs were observed 3-6 h after MIA and are suppressed thereafter. A group of 5' tRNA halves is down-regulated by MIA, whereas a group of 18-nucleotide tRF-3a is up-regulated. In conclusion, tRFs show tissue-specificity, developmental changes and acute response to environmental stress, opening the possibility of them having a role in the fetal response to MIA.

Urinary MicroRNAs as Emerging Class of Noninvasive Biomarkers

MicroRNAs (miRNAs) are endogenous noncoding RNAs, which regulate gene expression on the post-transcriptional level. Since miRNAs are involved in the regulation of apoptosis, cellular proliferation, differentiation, and other important cellular processes, their deregulation is important for the development of a wide range of diseases including cancer. Apart from tissue, specific disease-related miRNA signatures can be found in body fluids as well. Especially for urologic diseases or injuries, urine miRNAs represent a promising group of biomarkers. Despite a large number of studies describing the importance of urinary miRNAs, there is a lack of recommendations for urine management and subsequent miRNA analysis. Thus, in this chapter, we aim to describe the origin and functions of urinary miRNAs and discuss the technical aspects of their detection including the pre-analytical phase principles and new directions in quantification, which could forward urine miRNA into clinical practice.

Extracellular vesicles in urological malignancies: an update

Extracellular vesicles (EVs) have an essential functional role in local tumour progression, metastatic spread and the emergence of drug resistance in bladder, kidney and prostate cancer. Thus, EVs could be diagnostic, prognostic and predictive biomarkers for these malignancies. Virtually all biomolecules (including DNA, mRNA, microRNA, long non-coding RNA, proteins and lipids) packaged into EVs have been tested as biomarkers in blood and urine samples. The results are very heterogeneous, but promising biomarker candidates have been identified. Differing methods of EV isolation, characterization and analysis of their content have been used owing to a lack of international consensus; hence, comparing study results is challenging. Furthermore, validation of potential biomarkers in independent cohorts or prospective trials has rarely been performed. Future efforts to establish EV-derived biomarkers need to adequately address these points. In addition, emerging technologies such as mass spectroscopy and chip-based approaches can identify surface markers specific for cancer-associated EVs and will enable specific separation from blood and urine EVs, which probably will improve their performance as biomarkers. Moreover, EVs could be harnessed as therapeutic drug delivery vehicles for precise and effective anticancer therapy.

Bladder cancer cell‑secreted exosomal miR‑21 activates the PI3K/AKT pathway in macrophages to promote cancer progression

Tumour-associated macrophages (TAMs) compose a major component of the tumour microenvironment and form in this microenvironment prior to cancer metastasis. However, the detailed mechanisms of TAM remodelling in the context of bladder cancer have not been clearly defined. The present study collected exosomes from the conditioned medium of human bladder T24 cancer cells. The effects of macrophages treated with exosomes derived from T24 cells on bladder cancer cell migration and invasion were analysed by Transwell assays. The expression levels of endogenous and exosomal microRNA-21 (miR-21) were examined by reverse transcription-quantitative PCR, while the expression level of the target protein was analysed by western blot analysis. Luciferase reporter plasmids and mutants were used to confirm direct targeting. The effects of miR-21 on bladder cancer cell migration and invasion were analysed by Transwell and Matrigel assays following miR-21 transfection. It was identified that exosomes derived from bladder cancer cells polarized THP-1 cell-derived macrophages into the M2 phenotype, and TAM-mediated pro-migratory and pro-invasive activity was determined. Moreover, it was found that miR-21 was highly expressed in exosomes derived from bladder cancer cells as well as in macrophages treated with exosomes. In addition, macrophages transfected with miR-21 exhibited M2 polarization and promoted T24 cell migratory and invasive ability. Mechanistically, exosomal miR-21 derived from bladder cancer cells inhibited phosphatase and tensin homolog activation of the PI3K/AKT signalling pathway in macrophages and enhanced STAT3 expression to promote M2 phenotypic polarization. The present results suggest that exosomal miR-21 can promote cancer progression by polarizing TAMs.

Urinary micro-RNA expressions and protein concentrations may differentiate bladder cancer patients from healthy controls

PURPOSE

To determine expression differences of urine exosomal miR-19b1-5p, 21-5p, 136-3p, 139-5p, 210-3p and concentration differences of urinary BLCA-4, NMP22, APE1/Ref1, CRK, VIM between bladder cancer, follow-up patients, and control samples, to evaluate diagnostic importance of these differences and establish a diagnostic panel for bladder cancer.

METHODS

Urine samples of 59 bladder cancer patients, 34 healthy controls, and 12 follow-up patients without recurrence were enrolled to this study. Real-time PCR and ELISA were performed to determine urine exosomal miR-19b1-5p, 21-5p, 136-3p, 139-5p, 210-3p expressions and urinary BLCA-4, NMP22, APE1/Ref1, CRK, VIM, creatinine concentrations. Logistic regression analyses were performed to determine the diagnostic panel, the sensitivity, and specificity of the panel assessed by the ROC curve analysis. p values < 0.05 were considered statistically significant.

RESULTS

In bladder cancer risk groups, mir-139, -136, -19 and 210 expressions or positivity were found to be different and concentrations of urinary Ape1/Ref1, BLCA4, CRK, and VIM increased by twofold on average compared to healthy controls. Logistic regression and ROC analyses revealed that panel could differentiate bladder cancer patients from healthy controls with 80% sensitivity and 88% specificity (AUC = 0.899), low-risk patients from controls with 93% sensitivity and 95.5% specificity (AUC = 0.976). Despite the low number of samples, our findings suggest that urine exosomal miR-19b1-5p, 136-3p, 139-5p expression, and urinary APE1/Ref1, BLCA-4, CRK concentrations are promising candidates in terms of bladder cancer diagnosis.

CONCLUSIONS

Although our panel has great sensitivity for early detection of BC, it needs to be validated in larger populations.

Extracellular vesicles in urologic malignancies-Implementations for future cancer care

Extracellular vesicles (EVs), a heterogeneous group of vesicles differing in size and shape, cargo content and function, are membrane-bound and nano-sized vesicles that could be released by nearly all variations of cells. EVs have gained considerable attention in the past decades for their functions in modulating intercellular signalling and roles as potential pools for the novel diagnostic and prognostic biomarkers, as well as therapeutic targets in several cancers including urological neoplasms. In general, human and animal cells both can release distinct types of EVs, including exosomes, microvesicles, oncosomes and large oncosomes, and apoptotic bodies, while the content of EVs can be divided into proteins, lipids and nucleic acids. However, the lack of standard methods for isolation and detection platforms rein the widespread usage in clinical applications warranted furthermore investigations in the development of reliable, specific and sensitive isolation techniques. Whether and how the EVs work has become pertinent issues. With the aid of high-throughput proteomics or genomics methods, a fully understanding of contents contained in EVs from urogenital tumours, beyond all doubt, will improve our ability to identify the complex genomic alterations in the process of cancer and, in turn, contribute to detect potential therapeutic target and then provide personalization strategy for patient.

Connecting the dots between different networks: miRNAs associated with bladder cancer risk and progression

BACKGROUND

Bladder cancer (BC) is a common urothelial malignancy, characterized by a high recurrence rate. The biology of bladder cancer is complex and needs to be deciphered. The latest evidence reveals the critical role of the non-coding RNAs, particularly microRNAs (miRNAs), as vital regulatory elements in cancer.

METHOD

We performed a miRNAs microarray using paired tissues (tumor and adjacent normal bladder tissue), followed by the validation with qRT-PCR of five selected transcripts. Additional next-generation sequencing investigation established the interconnection among the altered miRNAs and mutated genes. Based on the overlapping between TCGA data and data obtained in the study, we focused on the systematic identification of altered miRNAs and genes mutated involved in bladder cancer tumorigenesis and progression.

RESULTS

By overlapping the miRNAs expression data, the two patient cohorts, we identified 18 miRNAs downregulated and, 187 miRNAs upregulated. qRT-PCR validation was completed using a selected panel of two downregulated (miR-139-5p and miR-143-5p) and three up-regulated miRNAs (miR-141b, miR-200 s or miR-205). Altered miRNAs patterns are interrelated to bladder tumorigenesis, allowing them to be used for the development of novel diagnostic and prognostic biomarkers. Three EMT-related upregulated miRNAs have an essential role in the molecular mechanisms, specifically key processes underlying tumorigenesis, invasion and metastasis. Using the Ampliseq Cancer Panel kit and Ion Torrent PGM Next-Generation Sequencing an increased mutation rate for TP53, FGFR3, KDR, PIK3CA and ATM were observed, but the mutational status for only TP53 was correlated to the survival rate. The miRNAs pattern, along with the gene mutation pattern attained, can assist for better patient diagnosis.

CONCLUSION

This study thereby incorporates miRNAs as critical players in bladder cancer prognosis, where their altered gene expression profiles have a critical biological function in relationship with tumor molecular phenotype. The miRNA-mRNA regulatory networks identified in BC are ripe for exploitation as biomarkers or targeted therapeutic strategies.

MicroRNAs Which Can Prognosticate Aggressiveness of Bladder Cancer

Bladder cancer (BC) is still characterized by a very high death rate in patients with this disease. One of the reasons for this is the lack of adequate markers which could help determine the biological potential of the tumor to develop into its invasive stage. It has been found that some microRNAs (miRNAs) correlate with disease progression. The purpose of this study was to identify which miRNAs can accurately predict the presence of BC and can differentiate low grade (LG) tumors from high grade (HG) tumors. The study included 55 patients with diagnosed bladder cancer and 30 persons belonging to the control group. The expression of seven selected miRNAs was estimated with the real-time PCR technique according to miR-103-5p (for the normalization of the results). Receiver operating characteristics (ROC) curves and the area under the curve (AUC) were used to evaluate the feasibility of using selected markers as biomarkers for detecting BC and discriminating non-muscle invasive BC (NMIBC) from muscle invasive BC (MIBC). For HG tumors, the relevant classifiers are miR-205-5p and miR-20a-5p, whereas miR-205-5p and miR-182-5p are for LG (AUC = 0.964 and AUC = 0.992, respectively). NMIBC patients with LG disease are characterized by significantly higher miR-130b-3p expression values compared to patients in HG tumors.

BCDIN3D regulates tRNAHis 3' fragment processing

5' ends are important for determining the fate of RNA molecules. BCDIN3D is an RNA phospho-methyltransferase that methylates the 5' monophosphate of specific RNAs. In order to gain new insights into the molecular function of BCDIN3D, we performed an unbiased analysis of its interacting RNAs by Thermostable Group II Intron Reverse Transcriptase coupled to next generation sequencing (TGIRT-seq). Our analyses showed that BCDIN3D interacts with full-length phospho-methylated tRNAHis and miR-4454. Interestingly, we found that miR-4454 is not synthesized from its annotated genomic locus, which is a primer-binding site for an endogenous retrovirus, but rather by Dicer cleavage of mature tRNAHis. Sequence analysis revealed that miR-4454 is identical to the 3' end of tRNAHis. Moreover, we were able to generate this 'miRNA' in vitro through incubation of mature tRNAHis with Dicer. As found previously for several pre-miRNAs, a 5'P-tRNAHis appears to be a better substrate for Dicer cleavage than a phospho-methylated tRNAHis. Moreover, tRNAHis 3'-fragment/'miR-4454' levels increase in cells depleted for BCDIN3D. Altogether, our results show that in addition to microRNAs, BCDIN3D regulates tRNAHis 3'-fragment processing without negatively affecting tRNAHis's canonical function of aminoacylation.

Tumor-derived extracellular vesicles: reliable tools for Cancer diagnosis and clinical applications

BACKGROUND

Studies have recently revealed that almost every type of cells including tumor cells abundantly release small vesicles known as extracellular vesicles (EVs) into the extracellular milieu. EVs carry a repertoire of biological molecules including nucleic acids, proteins, lipids, and carbohydrates and transport their cargo between cells in the vicinity as well as distantly located cells and hence act as messengers of intercellular communication. In this review, we aimed to discuss the tumor-derived exosome biology and the pivotal roles of exosomes in cancer diagnosis and treatment.

METHODS

In the present review study, the authors studied several articles over the past two decades published on the kinetics of EVs in tumor environment as well as on the application of these vesicles in cancer diagnosis and therapy.

RESULTS

A growing body of evidence indicates that nucleic acids such as microRNAs (miRNAs) transferring by EVs participate to create a conducive tumor environment. As EV-associated miRNAs are tissue-specific and present in most biological fluids, they hold great potential for clinical application in cancer early diagnosis, prognosis, and treatment response. Furthermore, exosomes can serve as drug delivery vehicles transferring miRNAs as well as therapeutic agents to target cells. These nano-vesicles exhibit ideal properties in comparison with the synthetic carriers that attracted scientist's attention in the field of nanotechnology medicine. Scientists have employed different strategies to build exosomes-based drug delivery system. In general, two methods (direct engineering and indirect engineering) are being utilized to produce artificial exosomes. Para-clinical data have confirmed the beneficial effects of engineering exosomes in cancer therapy.

CONCLUSION

Exosomal miRNAs hold great promise for clinical application in early diagnosis and treatment of cancers. In addition, in spite of enthusiastic results obtained by engineered exosomes, however, there is an increasing concern over the use of optimal methods for engineering exosomes and the safety of engineered exosomes in clinical trials is still unclear.

miR-3622a promotes proliferation and invasion of bladder cancer cells by downregulating LASS2

As a tumor metastasis suppressor gene, LASS2 has been found to be negatively associated with the stage of bladder cancer and overall survival of patients. However, the mechanisms regulating LASS2 in bladder cancer remain poorly understood. Here, we aim to identify a miRNA that targets LASS2 from bladder cancer-associated miRNAs and to reveal its potential functions in bladder cancer cells. Through miRNA microarray and bioinformatics analyses, we identified miR-3622a as a negative regulator of LASS2. The expression levels of miR-3622a in bladder cancer tissues were negatively correlated with the overall survival of patients. Overexpression of miR-3622a significantly increased the proliferation and invasion abilities of bladder cancer cells. In conclusion, our results indicate that miR-3622a promotes the proliferation and invasion of bladder cancer cells by downregulating LASS2.

The research advances of exosomes in esophageal cancer

Esophageal carcinoma (EC) is one of the most common human digestive tract tumors, with high morbidity and mortality. It is necessary to elucidate the mechanism of cancer progression and seek early EC diagnostic markers for prompt detection and intervention. Exosomes are membrane nanovesicles secreted from many nucleated cells, 30-100 nm in diameter, containing various proteins, lipids and nucleic acids. They exist in peripheral blood, urine, ascites and other body fluids, widely engaged with intercellular material exchange and signal communication. Exosomes secreted from EC cells or tissues conduct important functions in tumor growth and progression. The detection and analysis of tumor-derived or tumor-associated exosomes has potential for EC early diagnosis and prognosis assessment. In the present paper, the exosomes' biological behaviors, isolation, detection and functions in EC progression - using as potential biomarkers for EC diagnosis or prognosis - are reviewed.

Urinary microRNA in kidney disease: utility and roles

MicroRNAs (miRNAs) are small, noncoding single-stranded RNA oligonucleotides that modulate physiological and pathological processes by modulating target gene expression. Many miRNAs display tissue-specific expression patterns, the dysregulation of which has been associated with various disease states, including kidney disease. Mounting evidence implicates miRNAs in various biological processes, such as cell proliferation and differentiation and cancer. Because miRNAs are relatively stable in tissue and biological fluids, particularly when carried by extracellular vesicles, changes in their levels may reflect the development of human disease. Urinary miRNAs originate from primary kidney and urinary tract cells, cells infiltrating the renal tissue and shed in the urine, or the systemic circulation. Although their validity as biomarkers for kidney disease has not been fully established, studies have been applying analysis of miRNAs in the urine in an attempt to detect and monitor acute and chronic renal diseases. Because appreciation of the significance of miRNAs in the renal field is on the rise, an understanding of miRNA pathways that regulate renal physiology and pathophysiology is becoming critically important. This review aims to summarize new data obtained in this field of research. It is hoped that new developments in the use of miRNAs as biomarkers and/or therapy will help manage and contain kidney disease in affected subjects.

MMP23B expression and protein levels in blood and urine are associated with bladder cancer

Urothelial bladder cancer (UBC) represents a public health problem because of its high incidence/relapse rates. At present, there are no suitable biomarkers for early diagnosis or relapse/progression prognosis. To improve diagnostic accuracy and overcome the disadvantages of current diagnostic strategies, the detection of UBC biomarkers in easily accessible biofluids, such as urine, represents a promising approach compared with painful biopsies. We investigated the levels of MMP23 genes (microarray and qPCR) and protein (western blot and enzyme-linked immunosorbent assay) in a set of samples (blood, plasma and urine) from patients with UBC and controls as biomarkers for this cancer. MMP23B and its pseudogene MMP23A resulted downregulated in blood cells from UBC compared with controls (66 cases, 70 controls; adjusted P-value = 0.02 and 0.03, respectively). In contrast, MMP23B protein levels in plasma (53 UBC, 49 controls) and urine (59 UBC, 57 controls) increased in cases, being statistically significant in urine. MMP23B dosage observed in urine samples was related to both tumor risk classification and grading. As the lack of correlation between mRNA and protein levels could be due to a posttranscriptional regulation mediated by microRNAs (miRNAs), we investigated the expression of urinary miRNAs targeting MMP23B. Five miRNAs resulted differentially expressed between cases and controls. We reported the first evidence of MMP23B secretion in plasma and urine, suggesting a role of this poorly characterized metalloproteinase in UBC as a potential non-invasive biomarker for this cancer. Further analyses are needed to elucidate the mechanism of regulation of MMP23B expression by miRNAs.

Exosomes: The Indispensable Messenger in Tumor Pathogenesis and the Rising Star in Antitumor Applications

As natural secreted nanovesicles through the endolysosomal pathway, exosomes have attracted increasing attention over the past decades. An overwhelming number of studies have provided evidence for the intriguing roles that exosomes play in intercellular communication. They are widely involved in the transmission of biomolecule cargos between original cells and neighboring/distant cells in normal physiological processes. In addition, it has also been demonstrated that exosomes play vital roles in multiple biological pathways in the development of numerous diseases including cancer. Moreover, both natural and modified exosomes showed promising potential in serving as a versatile nanoplatform for cancer diagnosis and cancer therapy. This review aims to present a comprehensive and critical overview on the recent advances in exosome nanoscience and nanotechnology, ranging from their biogenesis, secretion, isolation, and biological function in tumor pathogenesis to their extensive antitumor applications.

Bladder Cancer Diagnosis and Follow-Up: The Current Status and Possible Role of Extracellular Vesicles

Diagnostic methods currently used for bladder cancer are cystoscopy and urine cytology. Cystoscopy is an invasive tool and has low sensitivity for carcinoma in situ. Urine cytology is non-invasive, is a low-cost method, and has a high specificity but low sensitivity for low-grade urothelial tumors. Despite the search for urinary biomarkers for the early and non-invasive detection of bladder cancer, no biomarkers are used at the present in daily clinical practice. Extracellular vesicles (EVs) have been recently studied as a promising source of biomarkers because of their role in intercellular communication and tumor progression. In this review, we give an overview of Food and Drug Administration (FDA)-approved urine tests to detect bladder cancer and why their use is not widespread in clinical practice. We also include non-FDA approved urinary biomarkers in this review. We describe the role of EVs in bladder cancer and their possible role as biomarkers for the diagnosis and follow-up of bladder cancer patients. We review recently discovered EV-derived biomarkers for the diagnosis of bladder cancer.

MicroRNA Dysregulation and Non-Muscle-Invasive Bladder Cancer Prognosis

BACKGROUND

The high rate of non-muscle-invasive bladder cancer recurrence is a major challenge in patient management. miRNAs functionally regulate tumor cell proliferation and invasion, and have strong potential as biomarkers because they are robust to degradation. The objective of this project was to identify reproducible prognostic miRNAs in resected non-muscle-invasive bladder tumor tissue that are predictive of the recurrent tumor phenotype.

METHODS

We utilized patients diagnosed with primary non-muscle-invasive bladder cancer in three independent cohorts for a biomarker discovery/validation approach. Baseline tumor tissue from patients with the clinically challenging, non-muscle-invasive primary low stage (Ta), high grade, and T1 tumors (tumors extending into the lamina propria) comprised the discovery cohort (n = 38). We isolated the tumor tissue RNA and assessed a panel of approximately 800 miRNAs.

RESULTS

miR-26b-5p was the top-ranking prognostic tumor tissue miRNA, with a time-to-recurrence HR 0.043 for levels above versus below median, (P _adj = 0.0003). miR-26b-5p was related to a dose-response reduction in tumor recurrence, and levels above the median were also associated with reduced time-to-progression (P _adj = 0.02). We used two independent longitudinal cohorts that included both low-grade and high-grade Ta and T1 tumors for validation and found a consistent relationship between miR-26b-5p and recurrence and progression.

CONCLUSIONS

Our results suggest that miR-26b-5p levels may be prognostic for non-muscle-invasive bladder cancer recurrence, and can feasibly be assessed in baseline tumor tissue from a wide variety of clinical settings.

IMPACT

Early identification of those non-muscle-invasive bladder tumor patients with refractory phenotypes would enable individualized treatment and surveillance.

Current Progresses of Exosomes as Cancer Diagnostic and Prognostic Biomarkers

Cancer related exosomes are nano-size membrane vesicles that play important roles in tumor microenvironment. Emerging evidence indicates that exosomes can load unique cargoes, including proteins and nucleic acids that reflect the condition of tumor. Therefore, exosomes are being used as diagnostic and prognostic biomarkers for various cancers. In this review, we describe the current progresses of cancer related exosomes, including their biogenesis, molecular contents, biological functions, sources where they are derived from, and methods for their detection. We will also discuss the current exosomal biomarkers and the utilization of them for early diagnosis and prognostics in cancer.

Exosomes: fighting cancer with cancer

Exosomes are nanovesicles secreted by many cells, including cancer cells. Extensive research has been carried out to validate potential applications of exosomes and to evaluate their efficiency in a wide range of diseases, including cancer. The current knowledge on the origin, biogenesis and composition of exosomes is described. This review then focuses on the use of exosomes in cancer diagnostics and therapeutics.

Exosomes: Isolation, Analysis, and Applications in Cancer Detection and Therapy

Exosomes are cell-derived small extracellular vesicles that are naturally secreted by all types of cells and widely distributed in various biofluids. They carry a variety of key bioactive molecules (e.g., nucleic acids, proteins, growth factors, cytokines) from their parent cells and convey them to neighboring or even distant cells through circulation. In recent years, tumor-derived exosomes have attracted great interest from investigators because they actively participate in nearly all aspects of tumor development and facilitate both tumor growth and metastasis through exosome-mediated intercellular communication. The vesicular contents are increasingly considered potential biomarkers for tumor diagnoses and prognosis. With the progress made in isolation and analytical technologies, the functions of exosomes and their contents in tumor development are also becoming clearer. In this review article we describe the recent developments in exosome isolation techniques and analysis of exosomal contents. We also address their applications in cancer detection and therapy.

Extracellular Vesicles in Bladder Cancer: Biomarkers and Beyond

Tumor-derived extracellular vesicles (TEVs) are membrane-bound, nanosized vesicles released by cancer cells and taken up by cells in the tumor microenvironment to modulate the molecular makeup and behavior of recipient cells. In this report, we summarize the pivotal roles of TEVs involved in bladder cancer (BC) development, progression and treatment resistance through transferring their bioactive cargos, including proteins and nucleic acids. We also report on the molecular profiling of TEV cargos derived from urine and blood of BC patients as non-invasive disease biomarkers. The current hurdles in EV research and plausible solutions are discussed.

Urinary Markers in Bladder Cancer: An Update

Bladder cancer (BC) is ones of the most common cancer worldwide. It is classified in muscle invasive (MIBC) and muscle non-invasive (NMIBC) BC. NMIBCs frequently recur and progress to MIBCs with a reduced survival rate and frequent distant metastasis. BC detection require unpleasant and expensive cystoscopy and biopsy, which are often accompanied by several adverse effects. Thus, there is an urgent need to develop novel diagnostic methods for initial detection and surveillance in both MIBCs and NMIBCs. Multiple urine-based tests approved by FDA for BC detection and surveillance are commercially available. However, at present, sensitivity, specificity and diagnostic accuracy of these urine-based assays are still suboptimal and, in the attend to improve them, novel molecular markers as well as multiple-assays must to be translated in clinic. Now there are growing evidence toward the use of minimally invasive “liquid biopsy” to identify biomarkers in urologic malignancy. DNA- and RNA-based markers in body fluids such as blood and urine are promising potential markers in diagnostic, prognostic, predictive and monitoring urological malignancies. Thus, circulating cell-free DNA, DNA methylation and mutations, circulating tumor cells, miRNA, IncRNA and mRNAs, cell-free proteins and peptides, and exosomes have been assessed in urine specimens. However, proteomic and genomic data must to be validated in well-designed multicenter clinical studies, before to be employed in clinic oncology.