miR-186, miR-3651 and miR-494: Potential biomarkers for oral squamous cell carcinoma extracted from whole blood

Extracellular vesicles as tools and targets in therapy for diseases

Extracellular vesicles (EVs) are nano-sized, membranous structures secreted into the extracellular space. They exhibit diverse sizes, contents, and surface markers and are ubiquitously released from cells under normal and pathological conditions. Human serum is a rich source of these EVs, though their isolation from serum proteins and non-EV lipid particles poses challenges. These vesicles transport various cellular components such as proteins, mRNAs, miRNAs, DNA, and lipids across distances, influencing numerous physiological and pathological events, including those within the tumor microenvironment (TME). Their pivotal roles in cellular communication make EVs promising candidates for therapeutic agents, drug delivery systems, and disease biomarkers. Especially in cancer diagnostics, EV detection can pave the way for early identification and offers potential as diagnostic biomarkers. Moreover, various EV subtypes are emerging as targeted drug delivery tools, highlighting their potential clinical significance. The need for non-invasive biomarkers to monitor biological processes for diagnostic and therapeutic purposes remains unfulfilled. Tapping into the unique composition of EVs could unlock advanced diagnostic and therapeutic avenues in the future. In this review, we discuss in detail the roles of EVs across various conditions, including cancers (encompassing head and neck, lung, gastric, breast, and hepatocellular carcinoma), neurodegenerative disorders, diabetes, viral infections, autoimmune and renal diseases, emphasizing the potential advancements in molecular diagnostics and drug delivery.

Emerging cell cycle related non-coding RNA biomarkers from saliva and blood for oral squamous cell carcinoma

The unnotified or undifferentiable early stages of oral squamous cell carcinoma (OSCC) progression are the prime reasons for late-stage detection and poor survival outcomes of oral cancer. This review summarizes the prior research and recent advancements on the influence of dysregulated non-coding RNA (ncRNA) on cell cycle and their employability as diagnostic and prognostic biomarkers of oral cancer. The literature search was performed using the following keywords: 'serum/saliva non-coding RNAs' and 'serum/saliva non-coding RNAs and cell cycle', 'serum/saliva dysregulated ncRNAs and cell cycle', 'Cdk/CKI and ncRNAs', 'tissue ncRNAs' concerning 'oral cancer''. The compiled data focuses mainly on the diagnostic and prognostic significance of MicroRNAs (miRNAs), Circular RNAs (circRNAs), and Long noncoding RNAs (lncRNAs) on oral cancer and all other cancers as well as subject-relevant articles published in languages other than English are beyond the scope of this review and excluded from the study. Moreover, articles focusing on DNA, protein, and metabolite markers are eliminated from the study. While there exist various potential biomolecules such as DNA, RNA, proteins, metabolites, and specific antigens representing predictive biomarkers in body fluids for oral cancer, this review completely focuses on non-coding RNAs restricted to saliva and blood, picking out a few of the reliable ones amongst the recent investigations based on the sophisticated techniques, cohort, and sensitivity as well as specificity, i.e., salivary miR-1307-5p, miR-3928, hsa_circ_0001874 and ENST00000412740, NR_131012, ENST00000588803, NR_038323, miR-21 in circulation. Thus, further studies are required to clinically confirm the usage of these non-invasive biomarkers in oral cancer.

Non-Coding RNAs in Oral Cancer: Emerging Roles and Clinical Applications

Oral cancer (OC) is among the most prevalent cancers in the world. Certain geographical areas are disproportionately affected by OC cases due to the regional differences in dietary habits, tobacco and alcohol consumption. However, conventional therapeutic methods do not yield satisfying treatment outcomes. Thus, there is an urgent need to understand the disease process and to develop diagnostic and therapeutic strategies for OC. In this review, we discuss the role of various types of ncRNAs in OC, and their promising clinical implications as prognostic or diagnostic markers and therapeutic targets. MicroRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), and small nucleolar RNA (snoRNA) are the major ncRNA types whose involvement in OC are emerging. Dysregulated expression of ncRNAs, particularly miRNAs, lncRNAs, and circRNAs, are linked with the initiation, progression, as well as therapy resistance of OC via modulation in a series of cellular pathways through epigenetic, transcriptional, post-transcriptional, and translational modifications. Differential expressions of miRNAs and lncRNAs in blood, saliva or extracellular vesicles have indicated potential diagnostic and prognostic importance. In this review, we have summarized all the promising aspects of ncRNAs in the management of OC.

The paradigm of miRNA and siRNA influence in Oral-biome

Short nucleotide sequences like miRNA and siRNA have attracted a lot of interest in Oral-biome investigations. miRNA is a small class of non-coding RNA that regulates gene expression to provide effective regulation of post-transcription. On contrary, siRNA is 21-25 nucleotide dsRNA impairing gene function post-transcriptionally through inhibition of mRNA for homologous dependent gene silencing. This review highlights the application of miRNA in oral biome including oral cancer, dental implants, periodontal diseases, gingival fibroblasts, oral submucous fibrosis, radiation-induced oral mucositis, dental Pulp, and oral lichenoid disease. Moreover, we have also discussed the application of siRNA against the aforementioned disease along with the impact of miRNA and siRNA to the various pathways and molecular effectors pertaining to the dental diseases. The influence of upregulation and downregulation of molecular effector post-treatment with miRNA and siRNA and their impact on the clinical setting has been elucidated. Thus, the mentioned details on application of miRNA and siRNA will provide a novel gateway to the scholars to not only mitigate the long-lasting issue in dentistry but also develop new theragnostic approaches.

SNHG1/miR-186/FUT8 regulates cell migration and invasion in oral squamous cell carcinoma

Recently, lncRNAs are associated with the progression and development of various cancers. We aimed to explore the effects of lncRNA SNHG1 on the proliferation, apoptosis, migration, and invasion of oral squamous cell carcinoma (OSCC) cells. Quantitative real-time PCR (RT-qPCR) was used for measurement of SNHG1 in OSCC cells. Cell proliferation, apoptosis, migration, and invasion were detected by CCK-8 assay, flow cytometry, Cell Death Detection ELISA PLUS kit, and transwell assays. Dual-luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) assay were used to clarify the relationship between SNHG1 and miR-186. SNHG1 was overexpressed in OSCC cells. SNHG1 silencing prevented cell proliferation and increased the incidence of apoptosis, DNA fragments, cleaved-caspase 3, and Bax protein levels. Cell migration and invasion were reduced after SNHG1 deletion, and MMP2 and MMP9 protein levels were decreased. SNHG1 overexpression promoted cell survival, migration, and invasion, reduced DNA fragments formation. Mechanistically, we demonstrated that SNHG1 could directly bind to miR-186 and positively regulated α1, 6-fucosyltransferase (FUT8) level. Functional investigation showed that miR-186 depletion reversed the roles of SNHG1 silencing in cell proliferation, apoptosis, and migration. Taken together, our findings illuminated that SNHG1 regulated cell proliferation, migration, and invasion by sponging miR-186 to depress FUT8 expression.

The clinical implications of circulating microRNAs as potential biomarkers in screening oral squamous cell carcinoma

Background

Recent studies have highlighted the biomarker role of circulating miRNAs in oral squamous cell carcinoma (OSCC), indicating their potential application as early diagnostic markers for OSCC. However, the diagnostic results have proven inconclusive. This study was conducted to evaluate the diagnostic value of circulating miRNAs for OSCC diagnosis.

Methods

Eligible published studies were identified by a literature search carried out in several databases by using combinations of keywords associated with OSCC, circulating miRNAs, and diagnosis. The bivariate meta-analysis model was adopted to summarize the pooled parameters. Afterwards, we thoroughly explored the sources of heterogeneity after evaluating the risk of bias.

Results

A total of 60 studies focusing on 41 circulating miRNAs were included. The pooled sensitivity, specificity, and AUC were 0.75 (95%CI: 0.69-0.80), 0.76 (0.70-0.81), 0.82 (0.79-0.85), respectively. Subgroup analyses showed that miRNA combinations were more accurate than single miRNAs. Additionally, plasma may be a better matrix for miRNAs assays in OSCC diagnosis as the plasma-based miRNA assay had a higher level of diagnostic accuracy than serum-based miRNA assay. Subgroup analyses also suggested that using circulating miRNAs for OSCC diagnosis is more effective in Caucasians than in Asian ethnic groups. Finally, circulating miRNA assays based on large sample sizes have superior diagnostic accuracy than small sample sizes.

Conclusion

Circulating miRNAs might be applied as effective surrogate biomarkers for early diagnosis of OSCC. Nevertheless, future larger-scale prospective studies should be performed to enhance the diagnostic efficiency and investigate the miRNA combinations with more pronounced accuracy.

miR-3651 Participates in the Growth Cycle of Hepatocellular Carcinoma Cells and Promotes the Malignant Metastasis via the PI3K/AKT/mTOR Signalling Pathway

Objective

Hepatocellular carcinoma (HCC) shows a growing incidence over the past few years, and clinical efforts are made to search for more effective novel diagnosis and therapy regimen for it to improve its outcome. This study probed into the association of miR-3651 with the PI3K/AKT/mTOR pathway to offer a more detailed reference to the follow-up exploration of novel diagnosis and therapy methods of HCC.

Methods

Totally, 83 patients with HCC treated in our hospital between Apr. 2017 and Aug. 2018, 100 patients with simple liver cirrhosis (LC), and 94 normal persons over the same time span were enrolled, and serum miR-3651 in them was quantified to understand the predictive and prognostic significance of miR-3651 for HCC. In addition, with purchased human HCC cell strains (HepG2), the impacts of miR-3651 on the invasion as well as proliferation of HepG2 were determined using the MTT and Transwell assays, and the PI3K/AKT/mTOR pathway and autophagy-associated proteins in HepG2 were quantified via WT.

Results

Serum miR-3651 was found to be higher in HCC patients than in LC patients and normal persons, and it presented a sensitivity and specificity of 57.14% and 94.00%, respectively, in forecasting the occurrence of HCC in LC patients. The decrease of miR-3651 in HCC patients after therapy was strongly bound up with patients' prognosis, and its increase implied an increased risk of death. In in vitro assays, HepG2 presented higher miR-3651 expression than HL-7702, and upregulated miR-3651 intensified the invasion and proliferation of HepG2, while silencing miR-3651 gave rise to opposite results. Additionally, the PI3K/Akt/mTOR pathway in HepG2 presented an obvious activation state, and its activation was further intensified after increase of miR-3651, while its activation was suppressed after silence of miR-3651. Moreover, HepG2 presented notably downregulated autophagy-associated proteins, and the increase of miR-3651 further suppressed the autophagy process, but with the intervention of BEZ235, the impacts of miR-3651 were completely reversed.

Conclusion

miR-3651 intensifies the growth and invasion of HCC cells through activating the PI3K/AKT/mTOR signalling pathway, which is probably a breakthrough in the future diagnosis and therapy of HCC.

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.

miRNA-Gene Interaction Network Construction Strategy to Discern Promising Traditional Chinese Medicine against Osteoporosis

Osteoporosis is a widespread bone disease that affects million cases annually. The underlying mechanisms behind the progress of osteoporosis remain enigmatic, which limits detections of biomarkers and therapeutic targets. Hence, this study was aimed at exploring hub molecules to better understand the mechanism of osteoporosis development and discover the traditional Chinese medicine potential drugs for osteoporosis. miRNA and gene expression profiles were downloaded from Gene Expression Omnibus (GEO). Weighted correlation network analysis (WGCNA) was used to identify the key modules for osteoporosis. DIANA Tools was applied to perform pathway enrichment. A miRNA-gene interaction network was constructed, and hub miRNAs and genes were distinguished using Cytoscape software. Receiver operating characteristic (ROC) curves of hub miRNAs and genes were plotted, and correlations with hub genes and osteoporosis-associated factors were evaluated. Potential drugs for osteoporosis in Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) were screened, and molecular docking models between these drugs and target genes were showed by AutoDock tools. Two hub modules, 1 miRNA module and 1 gene module, were identified to be the most strongly correlated with osteoporosis by using WGCNA. Then, 3 KEGG pathways including focal adhesion, PI3K-Akt signaling pathway, and gap junction were shared pathways enriched with the miRNAs and genes screened out by WGCNA and differential expression analyses. Finally, after constructing a miRNA-gene interaction network, 6 hub miRNAs (hsa-miR-18b-3p, hsa-miR-361-3p, hsa-miR-484, hsa-miR-519e-5p, hsa-miR-940, and hsa-miR-1275) and 6 hub genes (THBS1, IFNAR2, ARHGAP5, TUBB2B, FLNC, and NTF3) were detected. ROC curves showed good performances of miRNAs and genes for osteoporosis. Correlations with hub genes and osteoporosis-associated factors suggested implicational roles of them for osteoporosis. Based on these hub genes, 3 natural compounds (kainic acid, uridine, and quercetin), which were the active ingredients of 192 herbs, were screened out, and a target-compound-herb network was extracted using TCMSP. Molecular docking models of kainic acid-NTF3, uridine-IFNAR2, and quercetin-THBS1 were exhibited with AutoDock tools. Our study sheds light on the pathogenesis of osteoporosis and provides promising therapeutic targets and traditional Chinese medicine drugs for osteoporosis.

miR-186-5p inhibits the progression of oral squamous cell carcinoma by targeting ITGA6 to impair the activity of the PI3K/AKT pathway

BACKGROUND

microRNAs (miRNAs) are pivotal regulators of multiple biological processes. miR-186-5p functions as a tumor suppressor in a variety of cancers and promotes the malignant proliferation of oral squamous cell carcinoma (OSCC). This study aimed to clarify the role and regulatory mechanism of miR-186-5p in OSCC.

METHODS

The levels of miR-186-5p and integrin subunit alpha 6 (ITGA6) were investigated in clinical specimens and OSCC cell lines by reverse transcription-quantitative polymerase chain reaction. The effects of miR-186-5p and ITGA6 on the cell migration, proliferation, and phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway activity were evaluated by transwell assay, cell counting kit 8 assay, and western blotting, respectively. A xenograft model was used to analyze the effect of miR-186-5p on tumor growth. Bioinformatic analyses were conducted to identify the putative targets of miR-186-5p in OSCC.

RESULTS

Decreased miR-186-5p expression levels were observed in OSCC tumor tissues and cell lines. The overexpression of miR-186-5p suppressed the proliferation and migration of OSCC cells, and weakened the phosphorylation of PI3K and AKT. Moreover, the overexpression of miR-186-5p in xenograft tumor models impedes tumor growth. miR-186-5p is bound to ITGA6 and negatively related to ITGA6 expression in tumor tissues. The forced expression of ITGA6 promoted OSCC cell proliferation and migration and enhanced the phosphorylation levels of PI3K and AKT, while additional miR-186-5p enrichment partly abolished these effects.

CONCLUSION

miR-186-5p binds to ITGA6 to impair the activity of the PI3K/AKT signaling pathway, thereby blocking the development of OSCC. This study provides insight to understand the pathogenesis of OSCC.

Hsa-miR-3651 could serve as a novel predictor for in-breast recurrence via FRMD3

Background

MicroRNAs are small non-coding RNAs with pivotal regulatory functions in multiple cellular processes. Their significance as molecular predictors for breast cancer was demonstrated in the past 15 years. The aim of this study was to elucidate the role of hsa-miR-3651 for predicting of local control (LC) in early breast cancer.

Results

By means of high-throughput technology, hsa-miR-3651 was found to be differentially expressed between patients who experienced local relapse compared to those without (N  =  23; p  =  0.0035). This result could be validated in an independent cohort of 87 patients using RT-qPCR (p  <  0.0005). In a second analysis step with a chip-based microarray containing 70,523 probes of potential target molecules, FERM domain protein 3 (FRMD3) was found to be the most down-regulated protein (N  =  21; p  =  0.0016). Computational analysis employing different prediction algorithms revealed FRMD3 as a likely downstream target of hsa-miR-3651 with an 8mer binding site between the two molecules. This could be validated in an independent patient set (N  =  20, p  =  0.134).

Conclusion

The current study revealed that hsa-miR-3651 is a predictor of LC in early breast cancer via its putative target protein FRMD3. Since microRNAs interfere in multiple pathways, the results of this hypothesis generating study may contribute to the development of tailored therapies for breast cancer in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12282-021-01308-y.

Deregulation of hsa_circ_0001971/miR-186 and hsa_circ_0001874/miR-296 signaling pathways promotes the proliferation of oral squamous carcinoma cells by synergistically activating SHP2/PLK1 signals

It has been demonstrated that circ_0001874 and circ_0001971 are potential biomarkers for the diagnosis of oral squamous carcinoma (OSCC). MiR-186 was reported to serve as a tumor suppressor in OSCC, and the down-regulation of miR-186 was reported to lead to higher expression of oncogenic factor SHP2 and the activation of growth promoting signaling. In this study, we aimed to explore the possible molecular role of circ_0001874 and circ_0001971 signaling in the pathogenesis of OSCC. RT-qPCR, Western blot, online bioinformatics tools and luciferase assay were utilized to study the molecular signaling pathways of circ_0001874 and circ_0001971. MTT assay and FCM assay were performed to investigate the synergistic effect of circ_0001971 and circ_0001874 on cell proliferation and apoptosis. By observing the effect of different miRNAs on the levels of circ_0001847 and circ_0001971, it was identified that circ_0001847 and circ_0001971 respectively sponged the expression of miR-296 and miR-186 via binding to these miRNAs. Also, SHP2 mRNA and PLK1 mRNA were respectively targeted by miR-186 and miR-296-5p. We also established two signaling pathways, i.e., circ_0001971/miR-186/SHP2 and circ_0001874/miR-296-5p/PLK1, and validated the synergistic effect of circ_0001971 and circ_0001874 via observing their positive effect on cell proliferation and negative effect on cell apoptosis. The expression of miR-186 and miR-296-5p was generally lower in saliva of OSCC patients compared with that in OLK patients, while the expression of miR-186 and miR-296-5p was specifically up-regulated in saliva of OSCC patients. In conclusion, the finding of this study demonstrated that the relative level of hsa_circ_0001971 and hsa_circ_0001874 were different in the saliva of OSCC patients and could be used as predictive biomarkers for the development of OSCC. Furthermore, oncogenic effects of hsa_circ_0001971 and hsa_circ_0001874 in the development of OSCC might be, at least partially, mediated by its downstream signaling pathways including hsa_circ_0001971/microRNA-186/SHP2 and hsa_circ_0001874/microRNA-297/PLK1.

Extracellular Vesicles as a Novel Liquid Biopsy-Based Diagnosis for the Central Nervous System, Head and Neck, Lung, and Gastrointestinal Cancers: Current and Future Perspectives

Simple Summary

To improve clinical outcomes, early diagnosis is mandatory in cancer patients. Several diagnostic approaches have been proposed, however, the main drawback relies on the invasive procedures required. Extracellular vesicles (EVs) are bilayer lipid membrane structures released by almost all cells and transferred to remote sites via the bloodstream. The observation that their cargo reflects the cell of origin has opened a new frontier for non-invasive biomarker discovery in oncology. Moreover, since EVs can be recovered from different body fluids, their impact as a Correctdiagnostic tool has gained particular interest. Hence, in the last decade, several studies using different biological fluids have been performed, showing the valuable contributions of EVs as tumour biomarkers, and their improved diagnostic power when combined with currently available tumour markers. In this review, the most relevant data on the diagnostic relevance of EVs, alone or in combination with the well-established tumour markers, are discussed.

Abstract

Early diagnosis, along with innovative treatment options, are crucial to increase the overall survival of cancer patients. In the last decade, extracellular vesicles (EVs) have gained great interest in biomarker discovery. EVs are bilayer lipid membrane limited structures, released by almost all cell types, including cancer cells. The EV cargo, which consists of RNAs, proteins, DNA, and lipids, directly mirrors the cells of origin. EVs can be recovered from several body fluids, including blood, cerebral spinal fluid (CSF), saliva, and Broncho-Alveolar Lavage Fluid (BALF), by non-invasive or minimally invasive approaches, and are therefore proposed as feasible cancer diagnostic tools. In this review, methodologies for EV isolation and characterization and their impact as diagnostics for the central nervous system, head and neck, lung, and gastrointestinal cancers are outlined. For each of these tumours, recent data on the potential clinical applications of the EV’s unique cargo, alone or in combination with currently available tumour biomarkers, have been deeply discussed.

MicroRNAs as Modulators of Oral Tumorigenesis-A Focused Review

Oral cancers constitute the majority of head and neck tumors, with a relatively high incidence and poor survival rate in developing countries. While the five-year survival rates of the oral cancer patients have increased to 65%, the overall survival for advanced stages has been at 27% for the past ten years, emphasizing the necessity for further understanding the etiology of the disease, diagnosis, and formulating possible novel treatment regimens. MicroRNAs (miRNAs), a family of small non-coding RNA, have emerged as master modulators of gene expression in various cellular and biological process. Aberrant expression of these dynamic molecules has been associated with many human diseases, including oral cancers. The deregulated miRNAs have been shown to control various oncogenic processes, including sustaining proliferative signaling, evading growth suppressors, resisting cell death activating invasion and metastasis, and inducing angiogenesis. Hence, the aberrant expression of miRNAs associated with oral cancers, makes them potential candidates for the investigation of functional markers, which will aid in the differential diagnosis, prognosis, and development of novel therapeutic regimens. This review presents a holistic insight into our understanding of the role of miRNAs in regulating various hallmarks of oral tumorigenesis.

The roles of extracellular vesicles in the development, microenvironment, anticancer drug resistance, and therapy of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the main malignant tumours affecting human health, mainly due to delayed diagnosis and high invasiveness. Extracellular vehicles (EVs) are membranous vesicles released by cells into the extracellular matrix that carry important signalling molecules and stably and widely exist in various body fluids, such as plasma, saliva, cerebrospinal fluid, breast milk, urine, semen, lymphatic fluid, synovial fluid, amniotic fluid, and sputum. EVs transport almost all types of bioactive molecules (DNA, mRNAs, microRNAs (miRNAs), proteins, metabolites, and even pharmacological compounds). These "cargoes" can act on recipient cells, reshaping the surrounding microenvironment and altering distant targets, ultimately affecting their biological behaviour. The extensive exploration of EVs has deepened our comprehensive understanding of HNSCC biology. In this review, we not only summarized the effect of HNSCC-derived EVs on the tumour microenvironment but also described the role of microenvironment-derived EVs in HNSCC and discussed how the "mutual dialogue" between the tumour and microenvironment mediates the growth, metastasis, angiogenesis, immune escape, and drug resistance of tumours. Finally, the clinical application of EVS in HNSCC was assessed.

Alteration of Pituitary Tumor Transforming Gene 1 by MicroRNA-186 and 655 Regulates Invasion Ability of Human Oral Squamous Cell Carcinoma

Background: Pituitary tumor-transforming gene 1 (PTTG1) was recently shown to be involved in the progression as well as the metastasis of cancers. However, their expression and function in the invasion of oral squamous cell carcinoma (SCC) remain unclear. Methods: The expressions of PTTG1 and PTTG1-targeted miRNA in oral SCC cell lines and their invasion capability depended on PTTG1 expression were analyzed by quantitative RT-PCR, Western blots, the transwell insert system and Zymography. Results: Invasion abilities were decreased in oral SCC cells treated with siRNA-PTTG1. When PTTG1 were downregulated in oral SCC cells treated with microRNA-186 and -655 inhibited their invasion abilities via MMP-9 activity. Conclusions: These results indicate that alteration of expression of PTTG1 in oral SCC cells by newly identified microRNA-186 and -655 can regulate invasion activity. Therefore, these data offer new insights into further understanding PTTG1 function in oral SCC and should provide new strategies for diagnostic markers for oral SCC.

Blood and Salivary MicroRNAs for Diagnosis of Oral Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

PURPOSE

This meta-analysis aimed to compare and evaluate the diagnostic accuracy of blood and salivary microRNAs (miRNAs) in discriminating oral squamous cell carcinoma (OSCC).

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library were searched (updated to February 2020) to identify all articles describing the diagnostic value of blood and salivary miRNAs for OSCC. The pooled parameters were calculated using Revman (v.5.3) and STATA (v.14.0).

RESULTS

Twenty articles involving 1,106 patients and 732 controls were included in this meta-analysis. The pooled sensitivity and specificity of salivary miRNAs were 0.70 (95% CI: 0.63-0.77) and 0.82 (95% CI: 0.72-0.90). For blood miRNAs, they were 0.79 (95% CI: 0.73-0.84) and 0.82 (95% CI: 0.77-0.86). The areas under receiver operating characteristic curve in saliva, blood, and body fluid miRNAs were 0.80 (95% CI: 0.77-0.84), 0.88 (95% CI: 0.84-0.90), and 0.87 (95% CI: 0.84-0.90), respectively.

CONCLUSIONS

The results of this meta-analysis indicate a moderate diagnostic accuracy of blood and salivary miRNAs presented for OSCC. These findings may provide less invasive and relatively reliable diagnostic tools for OSCC detection.

Application of salivary noncoding microRNAs for the diagnosis of oral cancers

Oral cancer is on the rise globally and survival rates, despite improvements in clinical care, have not significantly improved. Early detection followed by immediate intervention is key to improving patient outcomes. The use of biomarkers has changed the diagnostic landscape for many cancers. For oral cancers, visual inspection followed by a tissue biopsy is standard practice. The discovery of microRNAs as potential biomarkers has attracted clinical interest but several challenges remain. These microRNAs can be found in bodily fluids such as blood and saliva which have been investigated as potential sources of biomarker discovery. As oral cancer is localized within the oral cavity, saliva may contain clinically relevant molecular markers for disease detection. Our review provides an outline of the current advances for the application of salivary microRNAs in oral cancer. We also provide a technical guide for the processing of salivary RNAs to ensure accurate clinical measurement and validation.

Functional Landscape of Dysregulated MicroRNAs in Oral Squamous Cell Carcinoma: Clinical Implications

MicroRNA (miRNA) dysregulation is associated with the pathogenesis of oral squamous cell carcinoma (OSCC), and its elucidation could potentially provide information on patient outcome. A growing body of translational research on miRNA biology is focusing on precision oncology, aiming to decode the miRNA regulatory network in the development and progression of cancer. Tissue-specific expression and stable presence in all body fluids are unique features of miRNAs, which could be potentially exploited in the clinical setting. Recent understanding of miRNA properties has led them to be useful, attractive, and potential tools either as biomarkers (distinct miRNA expression signature) for diagnosis and prognostic outcomes or as targets for novel therapeutic entities, enabling personalized treatment for OSCC. In this review, we discuss recent research on different aspects of alterations in miRNA profiles along with their clinical significance and strive to identify probable potential miRNA biomarkers for diagnosis and prognosis of OSCC. We also discuss the current understanding and scope of development of miRNA-based therapeutics against OSCC.

MicroRNA‑3651 promotes colorectal cancer cell proliferation through directly repressing T‑box transcription factor 1

Colorectal cancer is a commonly diagnosed gastrointestinal malignancy worldwide with a high mortality rate. Accumulating evidence has indicated that the expression of a number of microRNAs (miRNAs) is associated with the development of colorectal cancer. However, the precise molecular mechanism of these miRNAs in regulating cancer progression is yet to be determined. In the present study, miR‑3651 was demonstrated to be overexpressed in colorectal cancer tissues compared with normal tissues, and to be associated with the tumor‑node‑metastasis stage. The downregulation of miR‑3651 was found to induce growth arrest and apoptosis in colorectal cancer cells. In addition, western blot analysis demonstrated that the downregulation of miR‑3651 inactivated PI3K/AKT and MAPK/ERK signaling in colorectal cancer cells. Bioinformatics analysis predicted T‑box transcription factor 1 (TBX1) as a potential target gene of miR‑3651, and a dual‑luciferase reporter assay confirmed that TBX1 was directly repressed by miR‑3651. The results of the current study also indicated that TBX1 was associated with the miR‑3651 mediated activation of oncogenic signaling and colorectal cancer cell proliferation. In conclusion, the results of the current study revealed the oncogenic potential of miR‑3651 in colorectal cancer.

MicroRNA-3651 promotes the growth and invasion of hepatocellular carcinoma cells by targeting PTEN

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in human worldwide. Evidence indicated that upregulation of microRNA-3651 (miR-3651) was observed in human HCC tissues. In this study, we explored the mechanisms by which miR-3651 regulated the proliferation, apoptosis and invasion of HCC.

Methods

The levels of miR-3651 in human HCC tissues were detected using qRT-PCR assay. In addition, transwell invasion and Western blot assay were conducted to detect cell invasion and apoptosis, respectively. Meanwhile, the dual-luciferase reporter assay was used to explore the interaction of miR-3651 and phosphate and tension homology deleted on chromsome ten (PTEN) in HCC.

Results

The levels of miR-3651 were upregulated in HCC tissues in comparison with the matched normal tissues. Overexpression of miR-3651 significantly promoted the proliferation and invasion of Huh-7 cells. In contrast, inhibition of miR-3651 markedly inhibited the proliferation and invasion of Huh-7 cells via promoting apoptosis. Moreover, downregulation of miR-3651 markedly inhibited tumor growth in vivo. Furthermore, bioinformatics analysis and luciferase reporter assay identified that PTEN was the directly binding target of miR-3651 in Huh-7 cells. Meanwhile, overexpression of miR-3651 obviously decreased the level of PTEN, and increased the expressions of p-p85 and p-Akt in Huh-7 cells.

Conclusion

These results indicated that miR-3651 might act as a potential oncogene in HCC by targeting PTEN. Therefore, miR-3651 might be a novel therapeutic target for the treatment of HCC.

Extracellular miRNAs as Biomarkers of Head and Neck Cancer Progression and Metastasis

Head and neck squamous cell carcinomas (HNSCCs) contribute to over 300,000 deaths every year worldwide. Although the survival rates have improved in some groups of patients, mostly due to new treatment options and the increasing percentage of human papillomavirus (HPV)-related cancers, local recurrences and second primary tumors remain a great challenge for the clinicians. Presently, there is no biomarker for patient surveillance that could help identify patients with HNSCC that are more likely to experience a relapse or early progression, potentially requiring closer follow-up or salvage treatment. MicoRNAs (miRNAs) are non-coding RNA molecules that posttranscriptionally modulate gene expression. They are highly stable and their level can be measured in biofluids including serum, plasma, and saliva, enabling quick results and allowing for repeated analysis during and after the completion of therapy. This has cemented the role of miRNAs as biomarkers with a huge potential in oncology. Since altered miRNA expression was described in HNSCC and many miRNAs play a role in radio- and chemotherapy resistance, cancer progression, and metastasis, they can be utilized as biomarkers of these phenomena. This review outlines recent discoveries in the field of extracellular miRNA-based biomarkers of HNSCC progression and metastasis, with a special focus on HPV-related cancers and radioresistance.

miR-21 Expression Determines the Early Vaccine Immunity Induced by LdCen -/- Immunization

No vaccine exists against visceral leishmaniasis. Toward developing vaccines against VL, we have reported previously on the immunogenicity of live attenuated LdCen ^-/- parasites in animal models. Immunization with LdCen ^-/- parasites has been shown to induce durable protective immunity in pre-clinical animal models. Although the innate immune responses favoring a Th1 type immunity are produced following LdCen ^-/- immunization, the molecular determinants of such responses remain unknown. To identify early biomarkers of immunogenicity associated with live attenuated parasitic vaccines, we infected macrophages derived from healthy human blood donors with LdCen ^-/- or LdWT parasites ex vivo and compared the early gene expression profiles. In addition to altered expression of immune related genes, we identified several microRNAs that regulate important cytokine genes, significantly altered in LdCen ^-/- infection compared to LdWT infection. Importantly, we found that LdCen ^-/- infection suppresses the expression of microRNA-21 (miR-21) in human macrophages, which negatively regulates IL12, compared to LdWT infection. In murine DC experiments, LdCen ^-/- infection showed a reduced miR-21 expression with a concomitant induction of IL12. Silencing of miR-21 using specific inhibitors resulted in an augmented induction of IL12 in LdWT infected BMDCs, illustrating the role of miR-21 in LdWT mediated suppression of IL12. Further, exosomes isolated from LdCen ^-/- infected DCs contained significantly reduced levels of miR-21 compared to LdWT infection, that promoted proliferation of CD4⁺ T cells in vitro. Similar miR-21 mediated IL12 regulation was also observed in ex vivo human macrophage infection experiments indicating that miR-21 plays a role in early IL12 mediated immunity. Our studies demonstrate that LdCen ^-/- infection suppresses miR-21 expression, enables IL12 mediated induction of adaptive immunity including proliferation of antigen experienced CD4⁺ T cells and development of a Th1 immunity, and suggest that miR-21 could be an important biomarker for LdCen ^-/- vaccine immunity in human clinical trials.

One Sentence Summary

Role of miR-21 in vaccine induced immunity.

Functions and mechanisms of miR-186 in human cancer

MicroRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the post-transcriptional level. Mounting evidence suggests the involvement of miRNAs in carcinogenesis and the development of human cancer. Among the miRNAs, miR-186 has been extensively studied in various cancers. The expression of miR-186 in tissues varies depending on the type of cancer and miR-186 in tissues and body fluids may serve as a marker for the diagnosis and prognosis of cancers. Various biological processes in human cancer are affected by miR-186. Additionally, miR-186 itself is regulated by several factors. Thus, this evidence highlights the potential value of miR-186 in the diagnosis, prognosis and treatment of human cancer.

Overexpression of hsa-miR-186 induces chromosomal instability in arsenic-exposed human keratinocytes

The mechanism of arsenic-induced skin carcinogenesis is not yet fully understood. Chromosomal instability contributes to aneuploidy and is a driving force in carcinogenesis. Arsenic causes mitotic arrest and induces aneuploidy. hsa-miR-186 overexpression is associated with metastatic cancers as well as arsenic-induced squamous cell carcinoma and is reported to target several mitotic regulators. Decreased levels of these proteins can dysregulate chromatid segregation contributing to aneuploidy. This work investigates the potential aneuploidogenic role of hsa-miR-186 in arsenic carcinogenesis. Clones of immortalized human keratinocytes (HaCaT) stably transfected with a hsa-miR-186 expression or empty vector were isolated. Three clones with high and low hsa-miR-186 expression determined by RT-qPCR were selected for further analysis and cultured with 0 or 100 nM NaAsO2 for 8 weeks. Analysis of mitoses revealed that chromosome number and structural abnormalities increased in cells overexpressing hsa-miR-186 and were further increased by arsenite exposure. Double minutes were the dominant structural aberrations. The peak number of chromosomes also increased. Cells with >220 to >270 chromosomes appeared after 2 months in hsa-miR-186 overexpressing cells, indicating multiple rounds of endomitosis had occurred. The fraction of cells with increased chromosome number or structural abnormalities did not increase in passage matched control cells. Levels of selected target proteins were determined by western blot. Expression of BUB1, a predicted hsa-miR-186 target was suppressed in hsa-miR-186 overexpressing clones, but increased with arsenite exposure. CDC27 remained constant under all conditions. These results suggest that overexpression of miR-186 in arsenic exposed tissues likely induces aneuploidy contributing to arsenic-induced carcinogenesis.

Circulating miR-21 as a prognostic and predictive biomarker in oral squamous cell carcinoma

Background & Objective:

The high-throughput analysis of circulating microRNAs (miRNAs) is an active area of biomarker research. The oral cancer remains a common cancer among Pakistani males that continues to present at an advance stage, thus exhibiting poor survival. MiRNA 21 (miR-21) is the most consistently over-expressed miRNA in different types of tumor tissues. However, information regarding expression of miR-21 in plasma remains to be resolved. Therefore, present study was designed to investigate if miR-21 was expressed in plasma of patients with oral cancer, and further explore its diagnostic and prognostic potential.

Methods:

Present study was conducted at Ziauddin University and Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN). Histologically confirmed cases of oral squamous cell carcinoma were recruited from Oncology Department of Ziauddin Hospital between 2013 and 2017. Controls were carefully selected after considering age, gender and socioeconomic condition. MiRNA was extracted and immediately reverse transcribed to cDNA. MiR-21 expression was evaluated using probes specifically designed for Real time quantitative polymerase chain reaction.

Results:

A significant over expression of miRNA 21 was observed in histologically confirmed cases as compared to controls. The increased expression of miRNA 21 was also reported to be associated with tumor size, metastasis and local invasion (p<0.05).

Conclusion:

The expression of circulating miR-21 in plasma samples of oral cancer patients makes it a promising diagnostic and prognostic marker.

Overexpression of microRNA-186 inhibits angiogenesis in retinoblastoma via the Hedgehog signaling pathway by targeting ATAD2

Retinoblastoma (RB) represents an aggressive malignancy in the eye during the period of infancy and childhood. We delineated the ability of microRNA-186 (miR-186) to influence viability, invasion, migration, angiogenesis, and apoptosis of RB via the Hedgehog signaling pathway by targeting AAA domain-containing protein 2 (ATAD2). The microarray-based analysis was adopted to identify differentially expressed genes (DEGs) related to RB. Subsequently, RB cells were treated with miR-186 mimic, miR-186 inhibitor, or si-ATAD2. The expression of miR-186, ATAD2, Hedgehog signaling pathway-related genes were evaluated, and the target relationship between miR-186 and ATAD2 was verified. Finally, cell proliferation, invasion, migration, apoptosis, and angiogenesis were assessed. ATAD2 was identified as a DEG and modulated by miR-186. Moreover, we revealed that ATAD2 was highly expressed, whereas miR-186 was lowly expressed, and the Hedgehog signaling pathway was activated in RB. Then, ATAD2 as a putative target of miR-186 was validated using a luciferase assay. miR-186 mimic or siRNA-ATAD2 in RB cells reduced cell viability, invasion, and migration coordinating with elevated apoptosis via impairing the Hedgehog signaling pathway, where repressed angiogenesis was observed. Overexpression of miR-186 attenuates RB via the inactivation of the Hedgehog signaling pathway by downregulating ATAD2.

Circulating microRNAs in head and neck cancer: a scoping review of methods

Circulating microRNAs have been described as head and neck cancer biomarkers in multiple anatomical subsites including the oral cavity, nasopharynx, larynx, salivary glands and the skin. While there is an expanding volume of published literature showing the significance of individual or panels of microRNAs, the clinical validation of candidate biomarkers is lacking. The various methods used to collect, store, process and interpret these microRNAs are likely introducing bias and contributing to the inconsistent results. A systematic scoping review was conducted using PRISMA standards to identify published English literature between 2007 and 2018. Pubmed and EMBASE databases were searched using specific keyword combinations related to head and neck cancer, circulating samples (whole blood, plasma or serum) and microRNA. Following the title and abstract review, two primary authors appraised the articles for their suitability to include in the review based on the detail of methodological descriptions. Thirty suitable articles were identified relating to nasopharyngeal carcinoma, oral cavity, oropharyngeal and laryngeal squamous cell carcinoma as well as primary salivary gland malignancies. Comprehensive methodological analysis identified poor reporting of detailed methodology, variations in collection, storage, pre-processing, RNA isolation and relative quantification including normalisation method. We recommend standardising the pre-processing, RNA isolation, normalisation and relative quantitation steps at biomarker discovery phase. Such standardisation would allow for bias minimisation and effective progression into clinical validation phases.

Liquid biopsy: miRNA as a potential biomarker in oral cancer

Oral cancer is one of the leading cancers in South-Asian countries. Despite the easy access of the oral cavity, the detection and five year survival rates of OSCC patients are dismal. Identification of non-invasive biomarkers to determine the progression and recurrence of OSCC could be of immense help to patients. Recent studies on oral cancer suggest the importance of non-invasive biomarker development. Micro-RNAs (miRNAs) are one of the important components of the cell-free nucleic acids available in different body fluids. Here, we have reviewed the current understanding of circulating miRNAs as non-invasive biomarkers in different body fluids of oral cancer patients. A number of circulating miRNAs are found to be common in the body fluids of OSCC patients, while many of these are study specific, the possible sources of this variability could be due to differences in sample processing, assay procedure, clinical stage of the disease, oral habit and environmental factors. The prognostic and therapeutic significance of these circulating miRNAs are suggested by several studies. Mir-371, mir-150, mir-21 and mir-7d were found to be potential prognostic markers, while mir-134, mir-146a, mir-338 and mir-371 were associated with metastases. The prognostic markers, mir-21 and mir-7d were also found to be significantly correlated with resistance to chemotherapy, while mir-375, mir-196 and mir-125b were significantly correlated with sensitivity to radiotherapy. Despite the promising roles of circulating miRNAs, challenges still remain in unravelling the exact regulation of these miRNAs before using them for targeted therapy.

Plasma-Derived Inflammatory Proteins Predict Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a major concern with high morbidity and mortality worldwide, even with the current knowledge and the advancement in treatment. OSCCs diagnosed at late-stage often require wide-excision with or without neck dissection, radiotherapy, or chemotherapy. When deemed successful, treatment often results in diminished quality of life, impaired function, and disfigurement. Strategies for early detection are urgently needed for patients afflicted with this disease. Inflammatory protein plasma biomarkers have shown to be potential tests for early detection and disease monitoring in several cancers. There has been no study on inflammation-related plasma biomarkers in OSCC. The objectives of the study were to use a multiplex approach to screen plasma-derived biomarkers and to examine the association of measurable proteins with OSCC. A total of 260 plasma samples (210 OSCC and 50 normal controls) were collected to measure for concentration of inflammatory related biomarkers using electrochemiluminescence multiplex assay. After screening of 82 potential biomarkers of the first 160 OSCC, 16 cytokines, chemokines, and growth factors were identified and verified in the second set of samples containing 50 OSCC and 50 normal. After adjustment of age and batch effects, the adjusted differential expression analysis showed that the OSCCs were markedly lower in 14 biomarkers and significantly higher level of interleukin 1 receptor antagonist (IL1Ra). By performing unsupervised clustering analysis, we observed distinctive groups of normal and two subgroups of OSCC. Linear regression of IL2, IL1Ra, and macrophage inhibitory factor (MIF) showed high accuracy in classifying OSCC with sensitivity of 0.96 and specificity of 0.92. In conclusion, this is the first paper to identify potential inflammatory plasma protein biomarkers of patients with OSCC. With further validation, the set of biomarkers can potentially be used to assist in early detection of OSCC when the disease is localized and in more treatable stage.

miR-16-5p inhibits chordoma cell proliferation, invasion and metastasis by targeting Smad3

Aberrantly expressed miRNAs play a crucial role in the development of multiple cancer types, including chordoma. However, the detailed molecular mechanisms are unclear and need to be elucidated. In this study, miRNAs were screened by miRNA array analysis and then confirmed by real-time PCR analysis. We found that miR-16-5p was significantly downregulated in chordoma, and overexpression of miR-16-5p suppressed chordoma cell proliferation, invasion and migration in vitro and in vivo and correlated with the upregulated expression of E-cadherin and downregulated expression of N-cadherin and vimentin. Furthermore, Smad3 was identified as a target of miR-16-5p, and Smad3 was highly expressed in chordoma tissues. Further research showed that knockdown of Smad3 had an effect similar to that of overexpression of miR-16-5p in chordoma cells. Our findings demonstrate that miR-16-5p plays a tumor suppressor role in chordoma progression by targeting Smad3, which could provide a promising prognostic and therapeutic strategy for chordoma treatment.

Salivary extracellular vesicle-associated miRNAs as potential biomarkers in oral squamous cell carcinoma

BACKGROUND

Several studies in the past have investigated the expression of micro RNAs (miRNAs) in saliva as potential biomarkers. Since miRNAs associated with extracellular vesicles (EVs) are known to be protected from enzymatic degradation, we evaluated whether salivary EVs from patients with oral squamous cell carcinoma (OSCC) were enriched with specific subsets of miRNAs.

METHODS

OSCC patients and controls were matched with regards to age, gender and risk factors. Total RNA was extracted from salivary EVs and the differential expression of miRNAs was evaluated by qRT-PCR array and qRT-PCR. The discrimination power of up-regulated miRNAs as biomarkers in OSCC patients versus controls was evaluated by the Receiver Operating Characteristic (ROC) curves.

RESULTS

A preliminary qRT-PCR array was performed on samples from 5 OSCC patients and 5 healthy controls whereby a subset of miRNAs were identified that were differentially expressed. On the basis of these results, a cohort of additional 16 patients and 6 controls were analyzed to further confirm the miRNAs that were up-regulated or selectively expressed in the previous pilot study. The following miRNAs: miR-302b-3p and miR-517b-3p were expressed only in EVs from OSCC patients and miR-512-3p and miR-412-3p were up-regulated in salivary EVs from OSCC patients compared to controls with the ROC curve showing a good discrimination power for OSCC diagnosis. The Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis suggested the possible involvement of the miRNAs identified in pathways activated in OSCC.

CONCLUSIONS

In this work, we suggest that salivary EVs isolated by a simple charge-based precipitation technique can be exploited as a non-invasive source of miRNAs for OSCC diagnosis. Moreover, we have identified a subset of miRNAs selectively enriched in EVs of OSCC patients that could be potential biomarkers.

Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Background

Dysregulation of microRNA (miRNA) expression is associated with hallmarks of aggressive tumor phenotypes, e.g., enhanced cell growth, proliferation, invasion, and anchorage independent growth in prostate cancer (PCa).

Methods

Serum-based miRNA profiling involved 15 men diagnosed with non-metastatic (stage I, III) and metastatic (stage IV) PCa and five age-matched disease-free men using miRNA arrays with select targets confirmed by quantitative real-time PCR (qRT-PCR). The effect of miR-186-5p inhibition or ectopic expression on cellular behavior of PCa cells (i.e., PC-3, MDA-PCa-2b, and LNCaP) involved the use bromodeoxyuridine (BrdU) incorporation, invasion, and colony formation assays. Assessment of the impact of miR-186-5p inhibition or overexpression on selected targets entailed microarray analysis, qRT-PCR, and/or western blots. Statistical evaluation used the modified t-test and ANOVA analysis.

Results

MiR-186-5p was upregulated in serum from PCa patients and metastatic PCa cell lines (i.e., PC-3, MDA-PCa-2b, LNCaP) compared to serum from disease-free individuals or a normal prostate epithelial cell line (RWPE1), respectively. Inhibition of miR-186-5p reduced cell proliferation, invasion, and anchorage-independent growth of PC-3 and/or MDA-PCa-2b PCa cells. AKAP12, a tumor suppressor target of miR-186-5p, was upregulated in PC-3 and MDA-PCa-2b cells transfected with a miR-186-5p inhibitor. Conversely, ectopic miR-186-5p expression in HEK 293 T cells decreased AKAP12 expression by 30%. Both pAKT and β-catenin levels were down-regulated in miR-186-5p inhibited PCa cells.

Conclusions

Our findings suggest miR-186-5p plays an oncogenic role in PCa. Inhibition of miR-186-5p reduced PCa cell proliferation and invasion as well as increased AKAP12 expression. Future studies should explore whether miR-186-5p may serve as a candidate prognostic indicator and a therapeutic target for the treatment of aggressive prostate cancer.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4258-0) contains supplementary material, which is available to authorized users.

Tumor-derived extracellular vesicles in angiogenesis

Angiogenesis is crucial for tumor growth and metastasis. Recent studies revealed that tumor cells promote angiogenesis by secreting extracellular vesicles, which can be captured by endothelial cells. These tumor-derived extracellular vesicles carry microRNAs, long non-coding RNAs, and proteins, which activate pro-angiogenic signaling in endothelial cells. In this review, we will summarize the roles of tumor-derived extracellular vesicles in angiogenesis and the underlying molecular mechanisms.

MiR-21 as prognostic biomarker in head and neck squamous cell carcinoma patients undergoing an organ preservation protocol

Despite progress in the treatment of head and neck squamous cell carcinoma (HNSCC) in recent decades, including new surgical techniques, radiotherapy advances and chemotherapy schedules, the prognosis for the affected patients has not improved at the same pace, and still, most HNSCC patients are diagnosed in advanced stages. To increase their survival, the development of better screening methods for early detection is required and appropriate tailored therapeutic interventions are desired. The aim of the present study was to evaluate miRNAs as prognostic biomarkers in patients undergoing organ preservation protocol for locally advanced HNSCC. For this purpose, we assessed the global miRNA expression profile of 15 HNSCC patients (‘screening set’) to identify miRNAs differentially expressed in responders and non-responders to therapy. Four miRNAs differentially expressed in HNSCC samples from the ‘screening set’ were validated in a different cohort of patients (47 samples - ‘validation set’). The results from the ‘validation set’ showed that the higher expression of one of these miRNAs, miR-21, was negatively associated with the treatment response to the organ preservation protocol (p=0.029). A multivariate analysis showed that, in a model adjusted for age, tumor site, p16 immunoexpression and tumor resectability, high expression of miR-21 remained an independent predictor of poor response to the organ preservation protocol (OR=5.69; 95%CI 1.27-25.58; p=0.023), together with clinical stage IV (OR=5.05; 95%CI 1.22-20.88; p=0.025). Furthermore, considering the entire cohort, patients with high expression of miR-21 had worse survival. A multivariate Cox regression analysis also showed miR-21 (HR=2.05; 95%CI 1.05-4.02; p=0.036) and clinical stage IV (HR=3.17; 95%CI 1.49-6.77; p=0.003) as independent prognostic factors (model adjusted for age, tumor site, tumor resectability, and sets ‘screening’ or ‘validation’).

In conclusion, the results of this study suggest that the evaluation of miR-21 expression could be an important tool for treatment planning and a prognosis predictior for HNSCC patients undergoing organ preservation protocols.

Cell-free nucleic acids in body fluids as biomarkers for the prediction and early detection of recurrent head and neck cancer: A systematic review of the literature

Liquid biopsy is a minimally invasive detection method for molecular biomarkers in body fluids which may serve as a novel tool in management of head and neck cancer. The purpose of this systematic review is to outline the current status of liquid biopsy in head and neck squamous cell carcinoma (HNSCC) patients by systematically identifying and qualifying all published studies on the diagnostic or prognostic value of cell-free nucleic acids detection for posttreatment disease monitoring and/or disease outcome. A search was performed in PubMed, EMBASE, and Cochrane Library. Thirty articles met the inclusion criteria for further analysis. Study and patient characteristics, molecular analysis method and treatment or prognostic outcomes were extracted. Seventeen studies investigated circulating miRNAs in blood. Of these studies, 16 found statistically significant results for a total of 24 different candidate miRNAs for prognostication or treatment monitoring. The remaining studies investigated circulating tumor DNA by targeting somatic mutations, allelic imbalances, hypermethylation, or HPV-DNA. Of these studies, 2 found a statistically significant association between nucleic acid levels (tumor DNA targeted by allelic imbalances and HPV-DNA) in blood and/or saliva and prognostic outcome. One study found significantly different pre- and posttreatment levels of mitochondrial DNA in serum. Despite large differences among these studies in both design and results, individual results are promising and provide ground for more large-scale studies with standardized serial assessment of patient samples in the future.

TNFα-induced downregulation of microRNA-186 contributes to apoptosis in rat primary cardiomyocytes

Progressive loss of cardiac cardiomyocytes is involved in pathogenesis of heart failure. Inflammation is considered as a major risk factor that triggers cardiomyocytes apoptosis or induces cellular damage. Proinflammatory cytokines such as TNFα can directly activate cell apoptosis or promote oxidant production that damages cellular structure eventually. We investigated TNFα mediated apoptosis in cultured rat primary cardiomyocytes. Annexin V/PI staining and apoptosis biomarker expression were used to examine cardiomyocytes cell apoptosis response. We also identified key microRNA that plays a regulatory role in this pathway with genetic and biochemical approaches. Apoptosis Inducing Factor (AIF) expression was found to be upregulated with 10μg/ml or 50μg/ml TNFα stimulation for 24h, which was associated with apoptotic index. Subsequently, miR-186 was identified as direct regulator of AIF in TNFα mediated cardiomyocytes apoptosis from microRNA expression profiling. miR-186 level was downregulated with TNFα treatment that was correlated with AIF induction. Last, in the rescue experiment, miR-186 mimic protected cardiomyocytes against TNFα mediated apoptosis. Collectively, the results suggest TNFα-induced AIF upregulation contributes to apoptosis in rat primary cardiomyocytes through regulating miR-186 expression, which implies miR-186 could be a potential therapeutic target for preventing inflammation associated cardiac damage.

Serum miR-92a-3p as a New Potential Biomarker for Diagnosis of Kawasaki Disease with Coronary Artery Lesions

Recent studies have suggested that serum microRNAs (miRNAs) are novel biomarkers for many cardiovascular diseases, but their role in Kawasaki disease (KD) is still unclear. We demonstrated that serum miR-92a-3p levels were significantly higher in children with KD compared with children with fever and controls (both P < 0.05). When the disease recovered, miR-92a-3p levels returned to those of controls. Clinical and pathological data showed that high levels of miR-92a-3p were significantly associated with coronary artery lesions (CALs). Analysis of the receiver operating characteristic (ROC) curve showed that serum miR-92a-3p had a sensitivity of 81.8% and a specificity of 66.7% for distinguishing KD with CALs from KD without CALs. The area under the curve was 0.816 (P < 0.05, 95% CI 0.669-0.962). Therefore, the miRNA miR-92a-3p may be used as a potential biomarker for diagnosis of KD and KD with coronary artery lesions.

Circulating miRNAs from blood, plasma or serum as promising clinical biomarkers in oral squamous cell carcinoma: A systematic review of current findings

The purpose of this systematic review was to summarize current findings on the use of circulating miRNAs from blood, serum and plasma as cancer biomarkers in patients with oral squamous cell carcinoma. Studies were gathered after searching four different electronic databases: PUBMED, SCOPUS, Cochrane Library and Web of Science. Additional search was carried out through cross check on bibliography of selected articles. After the selection process made by two of the authors, 16 articles met the inclusion criteria and were included in the review. Results showed that circulating miRNAs from blood, serum or plasma represent promising candidates as cancer biomarkers in patients suffering from oral cancer. The possibility to predict recurrences and metastases through follow-up quantification of candidate miRNAs represents another potential feature to be addressed in future studies. However, methodological standardization and uniform sampling is needed to increase the power and accuracy of results.

miR-219-5p inhibits proliferation and clonogenicity in chordoma cells and is associated with tumor recurrence

Chordoma is a rare malignant bone tumor that is usually localized to the skull base, vertebral column and sacrum. The transcription factor brachyury, which is encoded by the T gene, has a critical role in the development and progression of chordoma, although the mechanisms underlying brachyury regulation remain unclear. The aim of the current study was to identify and characterize microRNAs (miRs) that regulate brachyury expression in chordoma. MicroRNAs that target brachyury were predicted using miRanda and TargetScan. Using reverse transcription-quantitative polymerase chain reaction, miR-219-5p was shown to be significantly downregulated in chordoma tissues and the U-CH2 chordoma cell lines. A dual-luciferase reporter assay was used to validate the inhibitory effect of miR-219-5p on brachyury mRNA expression. The expression level of brachyury was downregulated in U-CH2 cells following transfection with miR-219-5p mimics and upregulated following transfection with the miR-219-5p inhibitor. The effects of miR-219-5p on the proliferation and clonogenicity of chordoma cells were assessed using cell counting kit-8, EdU and clone formation assays. These in vitro results indicated that miR-219-5p may have an important role in regulating the cell proliferation and clonogenicity of human chordoma cells, potentially by targeting brachyury. Furthermore, the associations between the expression levels of miR-219-5p and various clinicopathological factors were analyzed, and miR-219-5p expression was shown to correlate with tumor extent and recurrence. These results suggested that miR-219-5p functions as a tumor suppressor in chordoma and, therefore, that miR-219-50 may be a potential target for therapeutic intervention.

miR-186 suppressed CYLD expression and promoted cell proliferation in human melanoma

Previous studies have shown that microRNA-186 (miR-186) is overexpressed in various human cancers and is associated with the regulation of the carcinogenic processes. However, the underlying mechanisms of this microRNA in melanoma remain largely unknown. In the present study, the overexpression of miR-186 was identified in melanoma tissues and melanoma cells compared to the expression of miR-186 in the matched tumor adjacent tissues and normal human epidermal melanocytes. Overexpression of miR-186 promoted the proliferation and anchorage-independent growth of melanoma cells, whereas inhibition of miR-186 reduced this effect. Bioinformatics analysis also revealed cylindromatosis (CYLD), a putative tumor suppressor, to be a potential target of miR-186. Luciferase reporter assays showed that miR-186 directly targeted the 3′-untranslated regions of CYLD messenger RNA. Additional experiments showed that overexpression of miR-186 promoted the proliferation of melanoma cells, which was consistent with the inhibitory effects induced by knockdown of CYLD. In summary, the present study indicated that miRNA-186 plays a crucial role in melanoma growth and its oncogenic effect is mediated chiefly through the direct suppression of CYLD expression.

Circulating miR-223 in Oral Cancer: Its Potential as a Novel Diagnostic Biomarker and Therapeutic Target

Circulating microRNAs (miRNAs) have been detected in various types of cancer and have been proposed as novel biomarkers for diagnosis and treatment. Until recently, however, no studies had comprehensively examined circulating miRNAs in oral cancer. The current study used an ultra-sensitive genome-wide miRNA array to investigate changes in circulating miRNAs in plasma from five patients with oral cancer and ten healthy individuals. Results indicated that there were only a few circulating miRNAs, including miR-223, miR-26a, miR-126, and miR-21, that were up-regulated in patients with oral cancer. A subsequent validation test indicated that circulating miR-223 levels were significantly higher (~2-fold, P< 0.05) in patients with oral cancer (n = 31) than in those without cancer (n = 31). Moreover, miR-223 was found to be up-regulated in tumor-adjacent normal tissue compared to tumor tissue from patients with oral cancer. A gain-of-function assay was performed to explore the potential roles of circulating miR-223 in the development of oral cancer. Results revealed that miR-223 functions as a tumor suppressor by inhibiting cell proliferation and inducing apoptosis. In conclusion, this study suggested that circulating miR-223 may serve as a potential biomarker for diagnosis and that it may represent a novel therapeutic target for treatment of oral cancer.

Insights into the potential use of microRNAs as a novel class of biomarkers in esophageal cancer

MicroRNAs (abbreviated miRNAs) have been demonstrated to be involved in tumorigenesis and cancer development and proposed as promising biomarkers in cancer diagnosis. Numerous studies have observed the aberrant expression of miRNAs in esophageal cancer. However, there are some discrepant results. Thus, we conducted this meta-analysis to identify the overall accuracy of miRNAs in the diagnosis of esophageal cancer. A comprehensive literature search was conducted in PubMed and other databases using combinations of key words. The summary receiver operator characteristic curves were plotted to assess the overall diagnostic performance of miRNAs. Chi-squared and I(2) tests were used to assess the heterogeneity between studies. Additionally, we conducted subgroup and sensitivity analyses to analyze the potential sources of heterogeneity. In total, 33 studies from 12 articles were available in this meta-analysis. The pooled sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR) diagnostic odds ratio, and area under the curve were 0.80, 0.80, 4.0, 0.25, 16, and 0.87, respectively. Subgroup analyses based on the sample types (saliva-, serum- and plasma-based) showed no differences in the diagnostic accuracy of each subgroup. An independent meta-analysis of eight articles was conducted to evaluate the diagnostic accuracy of miRNAs in patients with esophageal squamous cell carcinoma, with a pooled sensitivity of 0.77, specificity of 0.83, PLR of 4.4, NLR of 0.27, diagnostic odds ratio of 16, and area under the curve of 0.87. In conclusion, this meta-analysis demonstrates the feasibility of using miRNAs as non-invasive biomarkers to discriminate esophageal cancer from healthy controls. However, further high-quality studies on more clearly defined esophageal cancer patient are needed to confirm our conclusion.

miR-494 inhibits ovarian cancer cell proliferation and promotes apoptosis by targeting FGFR2

MicroRNAs (miRs) have been reported to be key regulators in numerous types of cancer. The aim of the present study was to investigate the role of miR-494 in ovarian cancer. Expression of miR-494 was analyzed in ovarian cancer tissues and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). miR-494 mimic or negative control was transiently transfected into A2780 and SKOV3 cell lines. A cell counting kit-8 assay was performed to assess the effects of miR-494 on cell proliferation, and flow cytometry was used to evaluate the apoptotic rate. The target gene of miR-494 was detected by luciferase assay. Expression of fibroblast growth factor receptor 2 (FGFR2) was identified using RT-qPCR and western blotting. In the present study, decreased expression of miR-494 was observed in ovarian cancer samples and cell lines. Overexpression of miR-494 inhibited ovarian cancer cell proliferation by inducing apoptosis. Additional investigation indicated that FGFR2 was a direct target of miR-494. Taken together, the results of the present study suggested that miR-494 suppressed ovarian cancer cell proliferation by inducing apoptosis via targeting FGFR2.