Vesicle-related microRNAs in plasma of nonsmall cell lung cancer patients and correlation with survival

The Clinical Utility of miR-21 and let-7 in Non-small Cell Lung Cancer (NSCLC). A Systematic Review and Meta-Analysis

Non-small cell lung cancer (NSCLC) remains a problem worldwide due to its rapid progression and low rate of response to treatment. The heterogeneity of these tumors observed in histopathology exam but also in the mutational status and gene expression pattern makes this malignancy difficult to treat in clinic. The present study investigated the effect of miR-21 and let-7 family members as prognostic biomarkers in NSCLC patients based on the results published in different studies regarding this subject until March 2019. The analysis revealed that these two transcripts are steady biomarkers for prediction of patient outcome or survival. Upregulated expression of miR-21 is associated with poor outcome of patients with NSCLC [HR = 1.87, 95% CI = (1.41, 2.47), p < 0.001]. The analysis regarding let-7 family, specifically let-7a/b/e/f, revealed that downregulated expression of these transcripts predicts poor outcome for NSCLC patients [HR = 2.61, 95% CI = (1.58, 4.30), p < 0.001]. Besides, the reliability of these microRNAs is reflected in the fact that their prognostic significance is constant given the different sample types (tissue, FFPE tissue, serum, serum/plasma or exosomes) used in the selected studies.

Exosomal microRNAs: novel players in cervical cancer

Cervical cancer ranks fourth for both mortality and morbidity in women globally. Exosomes are considered as extracellular vesicles, secreted continuously by many cells with a size range from 30 to 150 nm. Exosomes can encapsulate microRNAs (miRNAs) and release them for cellular communications. This exosome-induced miRNA transfer is a novel strategy for genetic exchange among cells. This trafficking modality affects many pathological as well as physiological conditions. Moreover, exosomes can protect the miRNAs against harsh environments and keep them very stable. Given that a variety of exosomal miRNAs derived from cervical cancer cells can be targeted to recipient cells and contribute to tumorgenesis, it has been documented that exosomal miRNAs could be applied as diagnostic and therapeutic biomarkers in the treatment of cervical cancer. Herein, we summarize the pathologic and diagnostic roles of exosomal miRNAs in the cervical cancer. Moreover, we highlight the roles of exosomal miRNAs in other cancers.

Therapeutically Significant MicroRNAs in Primary and Metastatic Brain Malignancies

Simple Summary

The overall survival of brain cancer patients remains grim, with conventional therapies such as chemotherapy and radiotherapy only providing marginal benefits to patient survival. Cancers are complex, with multiple pathways being dysregulated simultaneously. Non-coding RNAs such as microRNA (miRNAs) are gaining importance due to their potential in regulating a variety of targets implicated in the pathology of cancers. This could be leveraged for the development of targeted and personalized therapies for cancers. Since miRNAs can upregulate and/or downregulate proteins, this review aims to understand the role of these miRNAs in primary and metastatic brain cancers. Here, we discuss the regulatory mechanisms of ten miRNAs that are highly dysregulated in glioblastoma and metastatic brain tumors. This will enable researchers to develop miRNA-based targeted cancer therapies and identify potential prognostic biomarkers.

Abstract

Brain cancer is one among the rare cancers with high mortality rate that affects both children and adults. The most aggressive form of primary brain tumor is glioblastoma. Secondary brain tumors most commonly metastasize from primary cancers of lung, breast, or melanoma. The five-year survival of primary and secondary brain tumors is 34% and 2.4%, respectively. Owing to poor prognosis, tumor heterogeneity, increased tumor relapse, and resistance to therapies, brain cancers have high mortality and poor survival rates compared to other cancers. Early diagnosis, effective targeted treatments, and improved prognosis have the potential to increase the survival rate of patients with primary and secondary brain malignancies. MicroRNAs (miRNAs) are short noncoding RNAs of approximately 18–22 nucleotides that play a significant role in the regulation of multiple genes. With growing interest in the development of miRNA-based therapeutics, it is crucial to understand the differential role of these miRNAs in the given cancer scenario. This review focuses on the differential expression of ten miRNAs (miR-145, miR-31, miR-451, miR-19a, miR-143, miR-125b, miR-328, miR-210, miR-146a, and miR-126) in glioblastoma and brain metastasis. These miRNAs are highly dysregulated in both primary and metastatic brain tumors, which necessitates a better understanding of their role in these cancers. In the context of the tumor microenvironment and the expression of different genes, these miRNAs possess both oncogenic and/or tumor-suppressive roles within the same cancer.

A three-miRNA panel in serum as a noninvasive biomarker for colorectal cancer detection

BACKGROUND

Circulating miRNAs have been proved to be promising biomarkers for disease detection in recent years. The present study aimed at exploring available serum miRNA biomarkers for the detection of colorectal cancer.

METHODS

A three-phase study was performed to select and validate candidate miRNAs with significant dysregulation in colorectal cancer using quantitative reverse transcription-polymerase chain reaction. This study recruited 137 colorectal cancer patients and 145 healthy controls. The diagnostic values of miRNAs were evaluated by receiver operating characteristic analysis. Bioinformatics analyses were utilized to predict target genes of miRNAs, and to conduct functional annotation and enrichment.

RESULTS

miR-30e-3p, miR-31-5p, miR-34b-3p and miR-146a-5p, miR-148a-3p and miR-192-5p were significantly dysregulated in colorectal cancer serum when compared with healthy controls. The panel composed of miR-30e-3p, miR-146a-5p, and miR-148a-3p exhibited strong diagnostic ability. The area under the receiver operating characteristic curve of the three-miRNA panel was 0.883, with a sensitivity of 0.800 and specificity of 0.787.

CONCLUSION

The present study identified a three-miRNA panel in serum with a strong diagnostic ability of colorectal cancer, which may be able to serve as a novel noninvasive biomarker for colorectal cancer detection.

Critical Roles of Tumor Extracellular Vesicles in the Microenvironment of Thoracic Cancers

Extracellular vesicles (EVs), such as exosomes, are critical mediators of intercellular communication between tumor cells and other cells located in the microenvironment but also in more distant sites. Exosomes are small EVs that can carry a variety of molecules, such as lipids, proteins, and non-coding RNA, especially microRNAs (miRNAs). In thoracic cancers, including lung cancers and malignant pleural mesothelioma, EVs contribute to the immune-suppressive tumor microenvironment and to tumor growth and metastasis. In this review, we discuss the recent understanding of how exosomes behave in thoracic cancers and how and why they are promising liquid biomarkers for diagnosis, prognosis, and therapy, with a special focus on exosomal miRNAs.

Exosome: An Emerging Source of Biomarkers for Human Diseases

Exosomes are 30-120nm long endocytic membrane-derived vesicles, which are secreted by various types of cells and stably present in body fluids, such as plasma, urine, saliva and breast milk. Exosomes participate in intercellular communication. Recently accumulative studies have suggested that exosomes may serve as novel biomarkers for disease diagnosis and prognosis. Herein, we reviewed the biological features of exosomes, technologies for exosome isolation and identification, as well as progress in exosomal biomarker identification, highlighting the relevance of exosome to human diseases and significance and great potential in translational medicine.

Exosomics

Extracellular vesicles have been the focus of a large number of studies in the past five years. Exosomes, a subgroup of extracellular vesicles, are of particularly high interest because they partake in a wide number of biological pathways. Produced by a variety of cells, exosomes have an important role in both physiological and pathological conditions. Exosome cargo heavily defines the vesicles’ unique characteristics, and the cargo with the most intriguing prospects in its’ biomedical applications is the non-coding RNAs. Non-coding RNAs, and specifically microRNAs are implicated in the regulation of many biological processes and have been associated with numerous diseases. Exosomes containing such important cargo can be used as biomarkers, therapeutic biomaterials, or even drug carriers. The potential media use of exosomes seems promising. However, some obstacles should be overcome before their clinical application. Synthetic exosome-like biomolecules may be a solution, but their production is still in their beginning stages. This review provides concise information regarding the current trends in exosome studies.

Exosomes: Multiple-targeted multifunctional biological nanoparticles in the diagnosis, drug delivery, and imaging of cancer cells

Exosomes are biological nanoparticles (30-150 nm) secreted in the extracellular area from all of cells, that mediate intercellular message. Exosomes act as the carriers for numerous proteins, DNAs, RNAs and cell-signaling molecules. Therefore, exosomes secreted by the tumor cells are useful for diagnostic purposes because of their persistent presence in the blood and their provision of genetic cargo similar to those in tumor. Due to the risks of aggressive activity and ambiguity of biological activity in other tissues, the use of exosomes in drug delivery and imaging has been limited. However, their high loading, stability and longer circulation time, excellent targeting, high cell penetration performance, and optimal biodegradability have made them potential agents in targeted cancer treatment. Therefore, in addition to examining methods for isolating and loading exosomes, this paper discusses the applications of exosomes in biological measurement, imaging, and therapeutic activities. Also, this review describes the challenges of using exosomes compared to conventional methods and shows that it is very useful to use them due to less aggressive activities. Finally, this review attempts to provide an appropriate incentive by showing the performance of exosomes in cancer therapy through targeted drug delivery, gene therapy, imaging and diagnosis.

Methods for the Determination of the Purity of Exosomes

BACKGROUND

Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance.

METHODS

Articles describing the isolation and purification of exosomes were retrieved from the PubMed database.

RESULTS

Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols.

CONCLUSION

Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Exosomes in intercellular communication and implications for osteoarthritis

Osteoarthritis (OA) is the most prevalent of the musculoskeletal conditions and represents a significant public health burden. While degeneration of articular cartilage is a key feature, it is now increasingly recognized as a complex condition affecting the whole joint, with synovial inflammation present in a significant proportion of patients. As a secretory tissue, the OA synovium is a rich source of both soluble inflammatory mediators and extracellular vesicles, including exosomes, which have been implicated in cell-cell communication. Exosome cargo has been found to include proteins, lipids and various RNA subtypes such as mRNA and miRNA, potentially capable of regulating gene expression in target cells and tissues. Profiling of exosome cargo and understanding effects on cartilage could elucidate novel regulatory mechanisms within the joint, providing insight for targeted treatment. The aim of this article is to review current literature on exosome biology, highlighting the relevance and application for OA pathogenesis.

Tumor-associated exosomal miRNA biomarkers to differentiate metastatic vs. nonmetastatic non-small cell lung cancer

Background

Exosomal microRNAs (miRNAs) are proposed to be excellent candidate biomarkers for clinical applications. However, little is known about their potential value as diagnostic biomarkers for metastatic non-small cell lung cancer (NSCLC).

Methods

In this study, microarrays were used to determine distinct miRNA profiles of plasma exosomes in a discovery cohort of healthy donors, metastatic NSCLC and nonmetastatic NSCLC patients. Three potential candidate miRNAs were selected based on the differential expression profiles. The discovery set data were validated by quantitative real-time polymerase chain reaction using a validation cohort.

Results

NSCLC patients (n = 80) and healthy controls (n = 30) had different exosome-related miRNA profiles in plasma. Results demonstrated that the level of let-7f-5p was decreased in plasma exosomes of NSCLC patients (p < 0.0001). Further analysis of three differentially expressed miRNAs revealed that miR-320a, miR-622 and let-7f-5p levels could significantly segregate patients with metastatic NSCLC from patients with nonmetastatic NSCLC (p < 0.0001, p < 0.0001 and p = 0.023, respectively). In addition, the combination of let-7f-5p, CEA and Cyfra21-1 generated an area under the curve (AUC) of 0.981 for the diagnosis of NSCLC patients, and the combination of miR-320a, miR-622, CEA and Cyfra21-1 had an AUC of 0.900 for the diagnosis of patients with metastatic NSCLC.

Conclusions

This novel study demonstrated that plasma exosomal miRNAs are promising noninvasive diagnostic biomarkers for metastatic NSCLC.

Exosomal miR-125a-5p derived from silica-exposed macrophages induces fibroblast transdifferentiation

Silica particles can cause a systemic disease in workers termed lung silicosis, characterized by diffuse fibrosis. The development of lung silicosis involves various signaling pathway networks comprising numerous cell types and cytokines. As an important medium for communication between cells, exosomes have emerged as a hot research topic; however, the role of exosomal microRNAs (miRNAs) in silicosis remains unclear. In this study, we conducted high-throughput sequencing to generate exosomal miRNAs profiles from macrophages that were either exposed to silica or not. A total of 298 miRNAs were differentially expressed, with 155 up-regulated and 143 down-regulated. Highly conserved differentially expressed miRNAs were functionally annotated and analyzed to predict target genes. Among target interactions associated with the TGF-β signaling pathway, miR-125a-5p and its putative target gene, Smurf1, were subjected to further research. As expected, levels of miR-125a-5p were upregulated in human serous exosomes and vitro, and inhibit the exosomal miR-125a-5p suppressed the expression of the fibrosis hallmarks. Besides, high levels of the miRNA led to upregulation of smooth muscle actin alpha and repression of Smurf1 in NIH-3T3 and MRC-5 cells. ID1 and SMAD1, downstream of TGF-β signaling, were upregulated, indicating potential activation of this signaling pathway. These results contribute to understanding of the intercellular communication mediated by exosomal miRNAs and its critical role in fibroblast to myofibroblast transition and silicosis.

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.

miR‑20b promotes growth of non‑small cell lung cancer through a positive feedback loop of the Wnt/β‑catenin signaling pathway

microRNAs (miRNAs or miRs) are endogenous noncoding single‑stranded RNA molecules that can regulate gene expression by targeting the 3'‑untranslated region and play an important role in many biological and pathological processes, such as inflammation and cancer. In this study, we found that miR‑20b was significantly increased in human non‑small cell lung cancer (NSCLC) cell lines and patient tissues, suggesting that it may possess a carcinogenic role in lung cancer. This miRNA promoted the proliferation, migration and invasion of NSCLC cells by targeting and downregulating the expression of adenomatous polyposis coli (APC), which is a negative regulator of the canonical Wnt signaling pathway. Wnt signaling activation may increase transcription of miR‑20b. Therefore, miR‑20b and canonical Wnt signaling were coupled through a feed‑forward positive feedback loop, forming a biological regulatory circuit. Finally, an in vivo investigation further demonstrated that an increase in miR‑20b promoted the growth of cancer cells. Overall, our findings offer evidence that miR‑20b may contribute to the development of NSCLC by inhibiting APC via the canonical Wnt signaling pathway.

MicroRNA-20b Promotes Cardiac Hypertrophy by the Inhibition of Mitofusin 2-Mediated Inter-organelle Ca2+ Cross-Talk

MicroRNA (miRNA) and mitofusin-2 (Mfn2) are important in the development of cardiac hypertrophy, but the target relationship and mechanism associated with Ca²⁺ handling between SR and mitochondria under hypertrophic condition is not established. Mfn2 expression, Mfn2-mediated interorganelle Ca²⁺ cross-talk, and target regulation by miRNA-20b (miR-20b) were evaluated using animal/cellular hypertrophic models with state-of-the-art techniques. The results demonstrated that Mfn2 was downregulated and miR-20b was upregulated upon the target binding profile under hypertrophic condition. Our data showed that miR-20b induced cardiac hypertrophy that was reversed by recombinant adeno-associated virus vector 9 (rAAV9)-anti-miR-20b or miR-20b antisense inhibitor (AMO-20b). The deleterious action of miR-20b on Mfn2 expression/function and mitochondrial ATP synthesis was observed and reversed by rAAV9-anti-miR-20b or AMO-20b. The targeted regulation of miR-20b on Mfn2 was confirmed by luciferase reporter and miRNA-masking. Importantly, the facts that mitochondrial calcium uniporter (MCU) activation by Spermine increased the cytosolic Ca²⁺ into mitochondria, manifested as enhanced histamine-mediated Ca²⁺ release from mitochondrial, suggesting that Ca²⁺ reuptake/buffering capability of mitochondria to cytosolic Ca²⁺ is injured by miR-20b-mediated Mfn2 signaling, by which leads cytosolic Ca²⁺ overload and cardiac hypertrophy through Ca²⁺ signaling pathway. In conclusion, pro-hypertonic miR-20b plays crucial roles in cardiac hypertrophy through downregulation of Mfn2 and cytosolic Ca²⁺ overload by weakening the buffering capability of mitochondria.

Extracellular Vesicles in Non-Small-Cell Lung Cancer: Functional Role and Involvement in Resistance to Targeted Treatment and Immunotherapy

Targeted and immunological therapies have become the gold standard for a large portion of non-small cell lung cancer (NSCLC) patients by improving significantly clinical prognosis. However, resistance mechanisms inevitably develop after a first response, and almost all patients undergo progression. The knowledge of such a resistance mechanism is crucial to improving the efficacy of therapies. So far, monitoring therapy responses through liquid biopsy has been carried out mainly in terms of circulating tumor (ctDNA) analysis. However, other particles of tumor origin, such as extracellular vehicles (EVs) represent an emerging tool for the studying and monitoring of resistance mechanisms. EVs are now considered to be ubiquitous mediators of cell-to-cell communication, allowing cells to exchange biologically active cargoes that vary in response to the microenvironment and include proteins, metabolites, RNA species, and nucleic acids. Novel findings on the biogenesis and fate of these vesicles reveal their fundamental role in cancer progression, with foreseeable and not-far-to-come clinical applications in NSCLC.

Circulating exosomal miRNAs: clinical significance in human cancers

Introduction: The identification of novel noninvasive biomarkers to ameliorate early-diagnosis, and disease prognosis, as well as to support personalized treatment and monitoring decisions is of first clinical priority for cancer patients' care. Exosomes are natural endosome-derived extracellular vesicles that have emerged as crucial mediators of intercellular communication and tumor progression. Considering that deregulated miRNA levels have been described in numerous human malignancies and that tumor-derived exosomes reflect miRNA expression of donor tumor cells, the evaluation of exosome-derived circulating miRNAs (exomiRs) may offer a new promising class of noninvasive molecular markers to improve patients' management and quality-of-life. Areas covered: In the current review we have summarized the existing knowledge on the clinical relevance of circulating exosomal miRNAs in improving cancer diagnosis and prognosis, and thus supporting personalized patients' management Expert commentary: Cancer research has highlighted the abundance of exomiRs in patients' plasma and serum samples, as well as their biomarker capabilities in the vast majority of human malignancies studied so far. Their analytical stability constitutes exomiRs ideal molecular markers to overcome numerous limitations of cancer clinical management, while future large-scale studies should unveil exomiRs translational utility in modern cancer molecular diagnostics.

Deregulated miRNAs in osteoporosis: effects in bone metastasis

Starting from their role exerted on osteoblast and osteoclast differentiation and activity pathways, microRNAs (miRNAs) have been recently identified as regulators of different processes in bone homeostasis. For this purpose, in a recent review, we highlighted, as deregulated miRNAs could be involved in different bone diseases such as osteoporosis. In addition, recent studies supported the concept that osteoporosis-induced bone alterations might offer a receptive site for cancer cells to form bone metastases, However, to date, no data on specific-shared miRNAs between osteoporosis and bone metastases have been considered and described to clarify the evidence of this link. The main goal of this review is to underline as deregulated miRNAs in osteoporosis may have specific roles in the development of bone metastases. The review showed that several circulating osteoporotic miRNAs could facilitate tumor progression and bone-metastasis formation in several tumor types, i.e., breast cancer, prostate cancer, non-small-cell lung cancer, esophageal squamous cell carcinoma, and multiple myeloma. In detail, serum up-regulation of pro-osteoporotic miRNAs, as well as serum down-regulation of anti-osteoporotic miRNAs are common features of all these tumors and are able to promote bone metastasis. These results are of key importance and could help researcher and clinicians to establish new therapeutic strategies connected with deregulation of circulating miRNAs and able to interfere with pathogenic processes of osteoporosis, tumor progressions, and bone-metastasis formation.

Plasma extracellular vesicle microRNAs for pulmonary ground-glass nodules

In this study, we evaluated the diagnostic value and molecular characteristics of plasma extracellular vesicles (EVs)-derived miRNAs for patients with solitary pulmonary nodules (SPNs), particularly ground-glass nodules (GGNs). This study was registered at www.clinicaltrials.gov under registration number NCT03230019. Small RNA sequencing was performed to assess plasma EVs miRNAs in 59 patients, including 12 patients with benign nodules (2017, training set). MiRNA profiles of 40 an additional individuals were sequenced (2018, validation set). Overall, 16 pure GGNs, 21 mixed GGNs, and 42 solid nodules were included, with paired post-operative plasma samples available for 20 patients. The target miRNA/reference miRNA ratio was used to construct a support vector machine (SVM) model. The SVM model with the best specificity showed 100% specificity in both the training and validation sets independently. The model with the best sensitivity showed 100% and 96.9% sensitivity in the training and validation sets, respectively. Principal component analysis revealed that pure GGN distributions were distinct from those of solid nodules, and mixed GGNs had a diffuse distribution. Among differentially expressed miRNAs, miR-500a-3p, miR-501-3p, and miR-502-3p were upregulated in tumor tissues and enhanced overall survival. The SVM classifier accurately distinguished malignant GGNs and benign nodules. The distinct profile characteristics of miRNAs provided insights into the feasibility of EVs miRNAs as prognostic factors in lung cancer.

Let-7 as biomarker, prognostic indicator, and therapy for precision medicine in cancer

Abnormal regulation and expression of microRNAs (miRNAs) has been documented in various diseases including cancer. The miRNA let-7 (MIRLET7) family controls developmental timing and differentiation. Let-7 loss contributes to carcinogenesis via an increase in its target oncogenes and stemness factors. Let-7 targets include genes regulating the cell cycle, cell signaling, and maintenance of differentiation. It is categorized as a tumor suppressor because it reduces cancer aggressiveness, chemoresistance, and radioresistance. However, in rare situations let-7 acts as an oncogene, increasing cancer migration, invasion, chemoresistance, and expression of genes associated with progression and metastasis. Here, we review let-7 function as tumor suppressor and oncogene, considering let-7 as a potential diagnostic and prognostic marker, and a therapeutic target for cancer treatment. We explain the complex regulation and function of different let-7 family members, pointing to abnormal processes involved in carcinogenesis. Let-7 is a promising option to complement conventional cancer therapy, but requires a tumor specific delivery method to avoid toxicity. While let-7 therapy is not yet established, we make the case that assessing its tumor presence is crucial when choosing therapy. Clinical data demonstrate that let-7 can be used as a biomarker for rational precision medicine decisions, resulting in improved patient survival.

Circulating MicroRNAs in Cancer: Potential and Challenge

MicroRNAs (miRNAs) are endogenous non-coding small RNA molecules that can be secreted into the circulation and exist in remarkably stable forms. Like intercellular miRNAs, circulating miRNAs participate in numerous regulations of biological process and expressed aberrantly under abnormal or pathological status. The quality and quantity changes of circulating miRNAs are associated with the initiation and progression of cancer and can be easily detected by basic molecular biology techniques. Consequently, considerable effort has been devoted to identify suitable extracellular miRNAs for noninvasive biomarkers in cancer. However, several challenges need to be overcome before the practical application. In this review, we discuss several issues of circulating miRNAs: biological function and basic transport carriers; extracellular cell communication process; roles as reliable cancer biomarkers and usage in targeted cancer therapy; and challenges for clinical application.

Recent advances in microfluidic methods in cancer liquid biopsy

Early cancer detection, its monitoring, and therapeutical prediction are highly valuable, though extremely challenging targets in oncology. Significant progress has been made recently, resulting in a group of devices and techniques that are now capable of successfully detecting, interpreting, and monitoring cancer biomarkers in body fluids. Precise information about malignancies can be obtained from liquid biopsies by isolating and analyzing circulating tumor cells (CTCs) or nucleic acids, tumor-derived vesicles or proteins, and metabolites. The current work provides a general overview of the latest on-chip technological developments for cancer liquid biopsy. Current challenges for their translation and their application in various clinical settings are discussed. Microfluidic solutions for each set of biomarkers are compared, and a global overview of the major trends and ongoing research challenges is given. A detailed analysis of the microfluidic isolation of CTCs with recent efforts that aimed at increasing purity and capture efficiency is provided as well. Although CTCs have been the focus of a vast microfluidic research effort as the key element for obtaining relevant information, important clinical insights can also be achieved from alternative biomarkers, such as classical protein biomarkers, exosomes, or circulating-free nucleic acids. Finally, while most work has been devoted to the analysis of blood-based biomarkers, we highlight the less explored potential of urine as an ideal source of molecular cancer biomarkers for point-of-care lab-on-chip devices.

Exo-miRNAs as a New Tool for Liquid Biopsy in Lung Cancer

Lung cancer is the predominant cause of cancer-related deaths. The high mortality rates are mainly due to the lack of diagnosis before the cancer is at a late stage. Liquid biopsy is a promising technique that could allow early diagnosis of lung cancer and better treatment selection for patients. Cell-free microRNAs have been detected in biological fluids, such as serum and plasma, and are considered interesting biomarkers for lung cancer screening and detection. Exosomes are nanovesicles of 30-150 nm and can be released by different cell types within the tumor microenvironment. Their exosomal composition reflects that of their parental cells and could be potentially useful as a biomarker for lung cancer diagnosis. This review summarizes the state-of-the-art of circulating microRNAs (miRNAs) in lung cancer, focusing on their potential use in clinical practice. Moreover, we describe the importance of exosomal miRNA cargo in lung cancer detection and their potential role during lung carcinogenesis. Finally, we discuss our experience with the analysis of circulating exosomal miRNAs in the bioMILD screening trial.

Microfluidic Technology for Clinical Applications of Exosomes

Exosomes, a type of nanovesicle, are distinct cellular entities specifically capable of carrying various cargos between cells. It has been hypothesized that exosomes, as an enriched source of biomolecules, may serve as biomarkers for various diseases. This review introduces general aspects of exosomes, presents the challenges in exosome research, discusses the potential of exosomes as biomarkers, and describes the contribution of microfluidic technology to enable their isolation and analysis for diagnostic and disease monitoring. Additionally, clinical applications of exosomes for diagnostic purposes are also summarized.

Relationship between cellular and exosomal miRNAs targeting NOD-like receptors in bladder cancer: preliminary results

BACKGROUND

Exosomes are membrane vesicles secreted by both cancerous and normal cells which play important roles during intercellular communications and oncogenic transformation. Many reports highlight the importance of exosomal microRNAs (miRNAs) as pro-tumorigenic mediators during carcinogenesis, since they regulate all these pathways at the post-transcriptional level. Since bladder cancer cells have a high immunogenic potential, from one hand, and inflammation process is intimately connected to carcinogenesis, from the other, the interest in analyzing inflammasome-related exo-miRNAs is apparent. The modulation of miRNAs targeting NOD-like receptor mRNAs in patients harboring bladder cancer has been assessed in our previous studies.

METHODS

In the present report, we characterized the previously selected miRNAs in the soluble fraction of the same bladder cancer patient cohort, stratified according to the risk of recurrence and progression. Exosome precipitation and isolation were performed; the expression levels of exosomal miRNAs were compared with their cellular counterparts.

RESULTS

An up-regulation of exosomal miR-141-3p and miR-19a-3p with respect to urine sediment was reported. Linear regression analysis showed a significant negative correlation for the same miRNAs. Moreover, exosomal miRNAs increased in low risk compared to high risk patients, which was opposite to that observed for urine sediment.

CONCLUSIONS

Our work demonstrated the inverse correlation between exosomal and cellular miRNAs in patients with bladder cancer. The fact that these miRNAs were higher in exosomal than cellular fraction allowed us to hypothesize their active compartmentalization during cancer progression, suggesting their potential role as cancer messengers.

Comprehensive analysis of circulating microRNAs in plasma of patients with pituitary adenomas

BACKGROUND

Circulating miRNAs in pituitary adenoma would help patient care especially in non-functioning adenoma cases as minimally invasive biomarkers of tumor recurrence and progression.

AIM

Our aim was to investigate plasma miRNA profile in patients with pituitary adenoma.

MATERIALS AND METHODS

149 plasma and extracellular vesicle (preoperative, early- and late postoperative) samples were collected from 45 pituitary adenoma patients. Adenomas were characterized based on anterior pituitary hormones and transcription factors by immunostaining. MiRNA next generation sequencing was performed on 36 samples (discovery set). Individual TaqMan assay was used for validation on extended sample set. PA tissue miRNAs were evaluated by TaqMan array and literature data.

RESULTS

Global downregulation of miRNA expression was observed in plasma samples of pituitary adenoma patients compared to normal samples. Expression of 29 miRNAs and isomiR variants were able to distinguish preoperative plasma samples and normal controls. MiRNAs with altered expression in both plasma and different adenoma tissues were identified. 3, 7 and 66 miRNAs expressed differentially between preoperative and postoperative plasma samples in growth hormone secreting, FSH/LH+ and hormone-immunonegative groups, respectively. MiR-143-3p was downregulated in late- but not in early postoperative plasma samples compared to preoperative ones exclusively in FSH/LH+ adenomas. Plasma level of miR-143-3p discriminated these samples with 81.8% sensitivity and 72.3% specificity (AUC=0.79; p=0.02).

CONCLUSIONS

Differentially expressed miRNAs in pituitary adenoma tissues have low abundance in plasma minimizing their role as biomarkers. Plasma miR-143-3p decreases in patients with FSH/LH+ adenoma indicated successful surgery, but its application for evaluating tumor recurrence needs further investigation.

Emerging Function and Clinical Values of Exosomal MicroRNAs in Cancer

Exosomes are a subset of membrane-bound extracellular vesicles with diameters ranging from 30 to 100 nm. Exosomes enclose a variety of molecules, such as lipids, proteins, and non-coding RNAs. In the past decades, microRNAs (miRNAs) have attracted great attention in cancer research, as they play an important role in the occurrence and development of cancer. Increasing evidence indicates that tumor cells communicate with not only other tumor cells but also cells present in the tumor microenvironment via secretion and transfer of exosomal miRNAs. More importantly, exosomal miRNAs are found to serve as signaling molecules to regulate tumor growth, angiogenesis, metastasis, sensitivity to chemotherapy, and immune evasion. Deregulated expression of exosomal miRNAs is an early event in carcinogenesis and may reflect the malignant characteristics of cancer. Owing to the wide existence and high stability of exosomal miRNAs in body fluids, they may represent a novel class of non-invasive biomarkers for cancer. In this review, we highlight the recent advances on the functional role of exosomal miRNAs in cancer pathogenesis. We also discuss the potential clinical utility of exosome-shuttled miRNAs as biomarkers for the diagnosis and treatment of cancer.

Extracellular Vesicles and Carried miRNAs in the Progression of Renal Cell Carcinoma

The formation and maintenance of renal cell carcinomas (RCC) involve many cell types, such as cancer stem and differentiated cells, endothelial cells, fibroblasts and immune cells. These all contribute to the creation of a favorable tumor microenvironment to promote tumor growth and metastasis. Extracellular vesicles (EVs) are considered to be efficient messengers that facilitate the exchange of information within the different tumor cell types. Indeed, tumor EVs display features of their originating cells and force recipient cells towards a pro-tumorigenic phenotype. This review summarizes the recent knowledge related to the biological role of EVs, shed by renal tumor cells and renal cancer stem cells in different aspects of RCC progression, such as angiogenesis, immune escape and tumor growth. Moreover, a specific role for renal cancer stem cell derived EVs is described in the formation of the pre-metastatic niche. We also highlight the tumor EV cargo, especially the oncogenic miRNAs, which are involved in these processes. Finally, the circulating miRNAs appear to be a promising source of biomarkers in RCC.

Review of the Isolation, Characterization, Biological Function, and Multifarious Therapeutic Approaches of Exosomes

Exosomes are extracellular vesicles that contain a specific composition of proteins, lipids, RNA, and DNA. They are derived from endocytic membranes and can transfer signals to recipient cells, thus mediating a novel mechanism of cell-to-cell communication. They are also thought to be involved in cellular waste disposal. Exosomes play significant roles in various biological functions, including the transfer of biomolecules such as RNA, proteins, enzymes, and lipids and the regulation of numerous physiological and pathological processes in various diseases. Because of these properties, they are considered to be promising biomarkers for the diagnosis and prognosis of various diseases and may contribute to the development of minimally invasive diagnostics and next generation therapies. The biocompatible nature of exosomes could enhance the stability and efficacy of imaging probes and therapeutics. Due to their potential use in clinical applications, exosomes have attracted much research attention on their roles in health and disease. To explore the use of exosomes in the biomedical arena, it is essential that the basic molecular mechanisms behind the transport and function of these vesicles are well-understood. Herein, we discuss the history, biogenesis, release, isolation, characterization, and biological functions of exosomes, as well as the factors influencing their biogenesis and their technical and biological challenges. We conclude this review with a discussion on the future perspectives of exosomes.

Extracellular vesicle‑delivered miR‑505‑5p, as a diagnostic biomarker of early lung adenocarcinoma, inhibits cell apoptosis by targeting TP53AIP1

Lung adenocarcinoma (LA) is the most commonly occurring histological type of non‑small cell lung cancer. Diagnosis and treatment of LA remain a major clinical challenge. In the present study, to identify early LA biomarkers, extracellular vesicles (EVs) were separated from the plasma samples from 153 patients with LA and 75 healthy controls. microRNA (miRNA) expression profiling was performed at the screening stage (5 patients with LA vs. 5 controls), followed by verification at the validation stage (40 patients with LA vs. 20 controls) using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). The four disordered miRNAs (miR‑505‑5p, miR‑486‑3p, miR‑486‑3p and miR‑382‑3p) identified in the plasma EVs were further evaluated at the testing stage (108 patients with LA vs. 50 controls) by RT‑qPCR. It was revealed that miR‑505‑5p was upregulated, whereas miR‑382‑3p was downregulated, in the EVs from patients with LA. Furthermore, miR‑505‑5p was also upregulated in tumor tissues, compared with adjacent non‑tumor control tissues. Subsequently, the direct targets of miR‑505‑5p were predicted using bioinformatics analyses, and verified by luciferase assay and immunoblotting. The present study determined that miR‑505‑5p functions as an oncogene, promoting lung cancer cell proliferation and inhibiting cancer cell apoptosis via the targeting of tumor protein P53‑regulated apoptosis‑inducing protein 1 (TP53AIP1). Finally, it was confirmed that miR‑505‑5p in plasma EVs could be delivered to lung cancer cells, inhibiting cell apoptosis and promoting cell proliferation by targeting TP53AIP1. In conclusion, the present study indicated that miRNA‑505‑5p functions as an oncogene that may be used as a novel biomarker for the diagnosis and treatment of LA.

Development of a miRNA-seq based prognostic signature in lung adenocarcinoma

Background

We utilized miRNAs expression and clinical data to develop a prognostic signature for patients with lung adenocarcinoma, with respect to their overall survival, to identify high-risk subjects based on their miRNA genomic profile.

Methods

MiRNA expressions based on miRNA sequencing and clinical data of lung adenocarcinoma patients (n = 479) from the Cancer Genome Atlas were randomly partitioned into non-overlapping Model (n = 320) and Test (n = 159) sets, respectively, for model estimation and validation.

Results

Among the ten miRNAs identified using the univariate Cox analysis, six from miR-8, miR-181, miR-326, miR-375, miR-99a, and miR-10, families showed improvement of the overall survival chance, while two miRNAs from miR-582 and miR-584 families showed a worsening of survival chances. The final prognostic signature was developed with five miRNAs—miR-375, miR-582-3p, miR-326, miR-181c-5p, and miR-99a-5p—utilizing a stepwise variable selection procedure. Using the KEGG pathway analysis, we found potential evidence supporting their significance in multiple cancer pathways, including non-small cell lung cancer. We defined two risk groups with a score calculated using the Cox regression coefficients. The five-year survival rates for the low-risk group was approximately 48.76% (95% CI = (36.15, 63.93)); however, it was as low as 7.50% (95% CI = (2.34, 24.01)) for the high-risk group. Furthermore, we demonstrated the effect of the genomic profile using the miRNA signature, quantifying survival rates for hypothetical subjects in different pathological stages of cancer.

Conclusions

The proposed prognostic signature can be used as a reliable tool for identifying high-risk subjects regarding survival based on their miRNA genomic profile.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5206-8) contains supplementary material, which is available to authorized users.

Exosomes at a glance - common nominators for cancer hallmarks and novel diagnosis tools

Cancer represents a heterogeneous disease with multiple levels of regulation and a dynamic environment that sustains the evolution of the malignant mass. This dynamic is in part sustained by a class of extracellular vesicles termed exosomes that are able to imprint the pathological state by incorporating differential cargos in order to facilitate cell-to-cell communication. Exosomes are stable within the extracellular medium and function as shuttles secreted by healthy or pathological cells, being further taken by the accepting cell with direct effects on its phenotype. The exosomal trafficking is deeply involved in multiple levels of cancer development with roles in all cancer hallmarks. Nowadays, studies are constantly exploring the ability of exosomes to sustain the malignant progression in order to attack this pathological trafficking and impair the ability of the tumor mass to expand within the organisms. As important, the circulatory characteristics of exosomes represent a steady advantage regarding the possibility of using them as minimally invasive diagnosis tools, where cancer patients' present modified exosomal profiles compared to the healthy ones. This last characteristic, as novel diagnosis tools, has the advantage of a possible rapid transition within the clinic, compared to the studies that evaluate the therapeutic meaning.

Differential Expression of Keratinocyte-Derived Extracellular Vesicle Mirnas Discriminate Exosomes From Apoptotic Bodies and Microvesicles

Extracellular vesicles (EVs) are mammalian cell-derived nano-scale structures enclosed by a lipid bilayer that were previously considered to be cell debris with little biological value. However, EVs are now recognized to possess biological function, acting as a packaging, transport and delivery mechanisms by which functional molecules (i.e., miRNAs) can be transferred to target cells over some distance. To examine the miRNA from keratinocyte-derived EVs, we isolated three distinct populations of EVs from both HaCaT and primary human keratinocytes (PKCs) and characterized their biophysical, biochemical and functional features by using microscopy, immunoblotting, nanoparticle tracking, and next generation sequencing. We identified 1,048; 906; and 704 miRNAs, respectively, in apoptotic bodies (APs), microvesicles (MVs) and exosomes (EXs) released from HaCaT, and 608; 506; and 622 miRNAs in APs, MVs and EXs released from PKCs. In which, there were 623 and 437 identified miRNAs common to three HaCaT-derived EVs and PKC-derived EVs, respectively. In addition, we found hundreds of exosomal miRNAs that were previously un-reported. Differences in the abundance levels of the identified EV miRNAs could discriminate between the three EV populations. These data contribute substantially to knowledge within the EV-identified miRNA database, especially with regard to keratinocyte-derived EV miRNA content.

Genome-scale analysis to identify prognostic microRNA biomarkers in patients with early stage pancreatic ductal adenocarcinoma after pancreaticoduodenectomy

Background

The aim of the study was to investigate potential prognostic microRNA (miRNA) biomarkers for patients with early stage pancreatic ductal adenocarcinoma (PDAC) after pancreaticoduodenectomy using a miRNA-sequencing (miRNA-seq) data set from The Cancer Genome Atlas (TCGA). A miRNA expression-based prognostic signature was generated, and the potential role of target genes in overall survival (OS) in patients with PDAC was examined.

Methods

A miRNA-seq data set of 112 PDAC patients who underwent pancreaticoduodenectomy was obtained from TCGA. Survival analysis was performed to identify potential prognostic biomarkers.

Results

Eleven miRNAs (hsa-mir-501, hsa-mir-4521, hsa-mir-5091, hsa-mir-24-1, hsa-mir-126, hsa-mir-30e, hsa-mir-3157, hsa-let-7a-3, hsa-mir-133a-1, hsa-mir-4709, and hsa-mir-421) were used to construct a prognostic signature using the step function. The 11-miRNA prognostic signature showed good performance for prognosis prediction (adjusted P<0.0001, adjusted hazard ratio =4.285, 95% confidence interval =2.146–8.554), and the time-dependent receiver operating characteristic analysis showed an area under the curve of 0.864, 0.877, and 0.787 for 1-, 2-, and 3-year PDAC OS predictions, respectively. Comprehensive survival analysis suggested that the prognostic signature could serve as an independent prognostic factor for PDAC OS and performs better in prognosis prediction than other traditional clinical indicators. Functional assessment of the target genes of the miRNAs indicated that they were significantly enriched in multiple biological processes and pathways, including cell proliferation, cell cycle biological processes, the forkhead box O, mitogen-activated protein kinase, Janus kinase/signal transducers and activators of transcription signaling pathways, pathways in cancer, and the ErbB signaling pathway. Several target genes of these miRNAs were also associated with PDAC OS.

Conclusion

The present study identified a novel miRNA expression signature that showed potential as a prognostic biomarker for PDAC after pancreaticoduodenectomy.

Extracellular vesicles and their nucleic acids for biomarker discovery

Extracellular vesicles (EVs) are a heterogenous population of vesicles originate from cells. EVs are found in different biofluids and carry different macromolecules, including proteins, lipids, and nucleic acids, providing a snap shot of the parental cells at the time of release. EVs have the ability to transfer molecular cargoes to other cells and can initiate different physiological and pathological processes. Mounting lines of evidence demonstrated that EVs' cargo and machinery is affected in disease states, positioning EVs as potential sources for the discovery of novel biomarkers. In this review, we demonstrate a conceptual overview of the EV field with particular focus on their nucleic acid cargoes. Current knowledge of EV subtypes, nucleic acid cargo and pathophysiological roles are outlined, with emphasis placed on advantages against competing analytes. We review the utility of EVs and their nucleic acid cargoes as biomarkers and critically assess the newly available advances in the field of EV biomarkers and high throughput technologies. Challenges to achieving the diagnostic potential of EVs, including sample handling, EV isolation, methodological considerations, and bioassay reproducibility are discussed. Future implementation of 'omics-based technologies and integration of systems biology approaches for the development of EV-based biomarkers and personalized medicine are also considered.

Exosomes and their implications in central nervous system tumor biology

Exosomes are 20-100 nm cellular derived vesicles that upon discovery, were thought to be a form of cellular recycling of intracellular contents. More recently, these vesicles are under investigation for their purported significant roles in intercellular communication in both healthy and diseased states. Herein, we focus on the secretion of exosomes associated with glioblastoma, as most exosome studies on brain tumors have been performed in this tumor type. However, we included exosomes secreted from other forms of brain tumors for comparison as available. Exosomes contain intracellular content that can be transferred to other cells in the tumor or to cells of the immune system and endothelial cells. These recipient cells may subsequently take on oncogenic properties, including therapeutic resistance, cancer progression, and angiogenesis. Genetic components (DNA, RNA and miRNA) of the cell of origin may be included in the secreted exosomes. The presence of genetic material in the exosomes could serve as a biomarker for mutations in tumors, potentially leading to novel treatment strategies. In the last decade, exosomes have been identified as having a major impact on multiple aspects of medicine and tumor biology, and appear to be primed for a critical position in cancer diagnosis, prognosis, and treatment.

Exosomes in lung cancer diagnosis and treatment. From the translating research into future clinical practice

Lung cancer is one of the main causes of cancer-related death worldwide. Despite advances in lung cancer pathophysiology, diagnosis and prognosis, a better understanding of the disease is strongly needed in order to establish novel diagnostic and therapeutic approaches that should improve treatment outcomes. Exosomes are a type of cell-secreted extracellular vesicles, which transfer a wide variety of biomolecules, such as proteins, mRNAs, microRNAs, and lipids, are implicated in intercellular communication and modulate tumor-host interactions. The potential value of exosomes and their contents in lung cancer diagnosis, prognosis and prediction of treatment outcome is supported by ample literature. Growing attention has been drawn specifically to the critical role of exosomal miRNAs in lung cancer pathogenesis and their potential clinical utility, especially due to their ability to modulate gene expression post-transcriptionally. Owing to their universal presence in the blood and other bodily fluids, exosomes are considered candidate biomarkers. Furthermore, their ability to deliver biomolecules and drugs to recipient cells renders them possible drug delivery vehicles in lung cancer. Here we review the pathological functions of exosomes in cancer and discuss their possible clinical utility as biomarkers and therapeutic agents in the management of lung cancer.

Clinical significance of blood-based miRNAs as biomarkers of non-small cell lung cancer

Non-small-cell lung cancer (NSCLC) accounts for 85% of all cases of lung cancer. However, the predicted 5-year survival rate of patients with NSCLC is only 15.9%. microRNAs (miRNAs) are single-stranded, noncoding RNA molecules that are easily detectable in blood in a non-invasive manner, with features of stability, reproducibility and consistency in blood. Therefore, miRNAs derived from blood are able to have a significant impact on NSCLC diagnosis, metastasis and targeted therapies. Compared with the clinical protein markers carcinoembryonic antigen, cytokeratin fragment 21-1 and cancer antigen-125, blood-based miRNAs also display a higher diagnostic efficacy in NSCLC. Exosomal miRNAs are identified to be easily measured and have the potential to be used as diagnostic biomarkers in NSCLC, therefore providing an alternative method of biopsy profiling. The miRNA profile in exosomes is similar to the profile in primary tumor, meaning that this feature may be a powerful tool for NSCLC clinical diagnosis and targeted therapies. The focus of the present review was the clinical significance of blood-based exosomal miRNAs in diagnosis, prognosis, metastasis and targeted therapies of NSCLC.

Blood-based tumor biomarkers in lung cancer for detection and treatment

The therapeutic landscape of lung cancer has expanded significantly over the past decade. Advancements in molecularly targeted therapies, strategies to discover and treat resistance mutations, and development of personalized cancer treatments in the context of tumor heterogeneity and dynamic tumor biology have made it imperative to obtain tumor samples on several different occasions through the course of patient treatment. While this approach is critical to the delivery of optimal cancer treatment, it is fraught with a number of barriers including the need for invasive procedures with associated complications, access to limited amount of tissue, logistical delays in obtaining the biopsy, high healthcare cost, and in many cases inability to obtain tissue because of technically difficult location of the tumor. Given multiple limitations of obtaining tissue samples, the use of blood-based biomarkers ("liquid biopsies") may enable earlier diagnosis of cancer, lower costs by avoiding complex invasive procedures, tailoring molecular targeted treatments, improving patient convenience, and ultimately supplement clinical oncologic decision-making. In this paper, we review various blood-based biomarkers including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), tumor derived exosomes, tumor educated platelets (TEPs), and microRNA; and highlight current evidence for their use in detection and treatment of lung cancer.

Blood-based biomarkers in lung cancer: prognosis and treatment decisions

Despite recent advances, non-small cell lung cancer (NSCLC) remains a devastating disease with overall poor prognosis. Major contributing factors include obstacles to diagnosing the disease early in its course during the asymptomatic stage as well as diversity and complexity of its biology underlying tumorigenesis and tumor progression. Advances in molecularly targeted therapies which drives the development of personalized cancer care require precise and comprehensive understanding of tumor biology, not only at the time of diagnosis but also during treatment course and surveillance. As lung tumor tissue can be difficult to obtain without invasive and potentially risky procedures, it is difficult to monitor treatment response with serial tissue biopsies. Development of non-invasive but reliable blood based tumor markers has become an important research area. In this review, we focus on the following circulating biomarkers that have been identified in recent years: circulating tumor cells (CTCs); circulating cell-free nucleic acids, such as circulating tumor DNA (ctDNA) and microRNA (miR); and other biomarkers such as genomic and proteomic features. These biomarkers not only have prognostic values, but also can help guild treatment decisions by monitoring tumor burden, detecting minimal residual disease and/or recurrent disease, as well as monitoring evolution of genetic alterations throughout the treatment course.

Identification of differential expressed PE exosomal miRNA in lung adenocarcinoma, tuberculosis, and other benign lesions

Pleural effusion (PE) is a common clinical complication of many pulmonary and systemic diseases, including lung cancer and tuberculosis. Nevertheless, there is no clinical effective biomarker to identify the cause of PE. We attempted to investigate differential expressed exosomal miRNAs in PEs of lung adenocarcinoma (APE), tuberculous (TPE), and other benign lesions (NPE) by using deep sequencing and quantitative polymerase chain reaction (qRT-PCR). As a result, 171 differentiated miRNAs were observed in 3 groups of PEs, and 11 significantly differentiated exosomal miRNAs were validated by qRT-PCR. We identified 9 miRNAs, including miR-205-5p, miR-483-5p, miR-375, miR-200c-3p, miR-429, miR-200b-3p, miR-200a-3p, miR-203a-3p, and miR-141-3p which were preferentially represented in exosomes derived from APE when compared with TPE or NPE, while 3 miRNAs, including miR-148a-3p, miR-451a, and miR-150-5p, were differentially expressed between TPE and NPE. These different miRNAs profiles may hold promise as biomarkers for differential diagnosis of PEs with more validation based on larger cohorts.

Novel nanosensing technologies for exosome detection and profiling

Exosomes have recently emerged as highly promising cancer biomarkers because they are abundant in biofluids, carry proteins and RNA reflecting their originating cells and are stable over weeks. Beyond abundance and stability, detailed exosome analyses could be clinically useful for diagnosing and profiling cancers. Despite their clinical potential, simple, reliable and sensitive approaches for rapidly quantifying exosomes and their molecular information has been challenging. Therefore, there is a clear need to develop next-generation sensing technologies for exosome detection and analysis. In this critical review, we will describe three nanotechnology sensing platforms developed for analysis of exosomal proteins and RNAs directly from clinical specimens and discuss future development to facilitate their translation into routine clinical use.

Identifying the miRNA signature associated with survival time in patients with lung adenocarcinoma using miRNA expression profiles

Lung adenocarcinoma is a multifactorial disease. MicroRNA (miRNA) expression profiles are extensively used for discovering potential theranostic biomarkers of lung cancer. This work proposes an optimized support vector regression (SVR) method called SVR-LUAD to simultaneously identify a set of miRNAs referred to the miRNA signature for estimating the survival time of lung adenocarcinoma patients using their miRNA expression profiles. SVR-LUAD uses an inheritable bi-objective combinatorial genetic algorithm to identify a small set of informative miRNAs cooperating with SVR by maximizing estimation accuracy. SVR-LUAD identified 18 out of 332 miRNAs using 10-fold cross-validation and achieved a correlation coefficient of 0.88 ± 0.01 and mean absolute error of 0.56 ± 0.03 year between real and estimated survival time. SVR-LUAD performs well compared to some well-recognized regression methods. The miRNA signature consists of the 18 miRNAs which strongly correlates with lung adenocarcinoma: hsa-let-7f-1, hsa-miR-16-1, hsa-miR-152, hsa-miR-217, hsa-miR-18a, hsa-miR-193b, hsa-miR-3136, hsa-let-7g, hsa-miR-155, hsa-miR-3199-1, hsa-miR-219-2, hsa-miR-1254, hsa-miR-1291, hsa-miR-192, hsa-miR-3653, hsa-miR-3934, hsa-miR-342, and hsa-miR-141. Gene ontology annotation and pathway analysis of the miRNA signature revealed its biological significance in cancer and cellular pathways. This miRNA signature could aid in the development of novel therapeutic approaches to the treatment of lung adenocarcinoma.

Diagnostic and Therapeutic Potential of Exosomes in Cancer: The Beginning of a New Tale?

Exosomes have emerged as one of the main players in intercellular communication. These small nano-sized particles have many roles in various physiological pathways in normal and abnormal cells. Exosomes can carry various cargos such as proteins, mRNAs, and miRNAs to recipient cells. Uptake of exosomes and their cargo can induce and/or inhibit different cellular and molecular pathways that lead to the alteration of cell behavior. Multiple lines of evidence have indicated that exosomes released from cancer cells can effect development of cancer in different stages. These particles and their cargo could regulate different processes such as tumor growth, metastasis, drug resistance, angiogenesis, and immune system functioning. It has been observed that exosomes can be used as potential diagnostic biomarkers in various cancer types. Moreover, some studies have used these particles as biological vehicles for delivery of various drugs such as doxorubicin, siRNAs, and miRNAs. Here, we summarized the findings on the role of exosomes in different pathological processes involved in cancer. Moreover, application of these particles as diagnostic and therapeutic biomarkers in different types of cancers is discussed. J. Cell. Physiol. 232: 3251-3260, 2017. © 2016 Wiley Periodicals, Inc.

Effect of MicroRNA-30e on the Behavior of Vascular Smooth Muscle Cells via Targeting Ubiquitin-Conjugating Enzyme E2I

BACKGROUND

Many microRNAs (miRNAs) have recently been shown to demonstrate critical roles in differentiation, proliferation and migration of vascular smooth muscle cells (VSMCs).

METHODS AND RESULTS

In this study, a certain amount of miRNA expression in VSMCs was evaluated by real-time polymerase chain reaction, and it was found that microRNA-30e (miR-30e) was expressed more strongly than other common vascular well-expressed miRNAs in vitro. Subsequently, both a gain and loss of function study was performed in vitro and in vivo. It was found that miR-30e in VSMCs was strongly downregulated concomitantly with stimulation, and miR-30e inhibited VSMCs proliferation and migration both in vitro and in vivo. Furthermore, ubiquitin-conjugating enzyme E2I (Ube2i) was identified as the target gene of endogenous miR-30e by luciferase reporter assay, and it was confirmed that overexpression of miR-30e significantly reduced Ube2i and inhibited the phenotypic switch of VSMCs. Knockdown of Ube2i had an influence over the proliferation and migration of cultured VSMCs, as same as the miR-30e mimic did. Overexpression of miR-30e induced the apoptosis of VSMCs and deregulated the protein expression of IkBα, which is crucial for the NFκB signal pathway.

CONCLUSIONS

The results of this study indicated that miR-30e in VSMCs exerted an anti-atherosclerosis effect via inhibiting proliferation and migration, and promoting apoptosis of VSMCs. More specifically, it was demonstrated that miR-30e exhibited these effects on VSMCs partially through targeting Ube2i and downregulating the IκBα/NFκB signaling pathway.

Exosomes: a new horizon in lung cancer

Circulating exosomes are the major mediators of cell-cell communication. They have been found in various body fluids of healthy individuals and patients with malignancies as cargos of several molecules including miRNAs. Several studies have underlined the role of exosome miRNAs in different tumor types, including lung cancer, suggesting their potential use as biomarkers and therapeutic agents. An overview of the biology and function of exosomes and exosome miRNAs as indicators of diagnosis and treatment response in lung cancer is presented. In addition, preliminary data on exosomes as potential therapeutic agents are reported.