Differential MicroRNA Expression of miR-21 and miR-155 within Oral Cancer Extracellular Vesicles in Response to Melatonin

Exploring miR-155-5p and miR-1246 as Diagnostic and Prognostic Markers in Oral Squamous cell carcinoma

INTRODUCTION

Oral Squamous Cell Carcinoma (OSCC) is one of the leading cancers worldwide, significantly impacting developing nations. This study aimed to explore the diagnostic and prognostic potential of miR-155-5p and miR-1246 in OSCC in the Indian population, as their comparative roles in this context remain unexplored.

MATERIAL AND METHODS

The present cross-sectional study comprised 50 histopathologically confirmed OSCC cases, with adjacent normal mucosa as controls. MiRNA expression was assessed via qRT-PCR and correlated with clinicopathological factors. MiRwalk and miRTargetlink were used for miRNA:mRNA interaction prediction, and gprofiler was employed to analyze validated targets for functional insights.

RESULTS

The expression analysis showed a significant upregulation of miR-155-5p and miR-1246 in OSCC tissues compared to adjacent controls. Receiver operating curve analysis revealed that miR-1246 exhibited excellent diagnostic accuracy (AUC = 0.94) compared to miR-155-5p (AUC = 0.69). Higher miRNA levels were associated with age and extracapsular extension while overexpression of miR-1246 was correlated significantly with increased tumor size, tumor grade, TNM staging, and depth of invasion. The analysis for target prediction unveiled a set of validated targets, among which were WNT5A, TP53INP1, STAT3, CTNNB1, PRKAR1A, and NFIB.

CONCLUSION

miR-155-5p and miR-1246 may be used as potential prognostic biomarkers in OSCC, with miR-1246 demonstrating superior diagnostic accuracy.

Melatonin affects the expression of microRNA-21: A mini-review of current evidence

Melatonin (MLT) is an endogenous hormone produced by pineal gland which possess promising anti-tumor effects. Anti-inflammatory and anti-oxidant properties of MLT, along with its immunomodulatory, proapoptotic, and anti-angiogenic properties, are often referred to the main mechanisms of its anti-tumor effects. Recent evidence has suggested that epigenetic alterations are also involved in the anti-tumor properties of MLT. Among these MLT-induced epigenetic alterations is modulation of the expression of several oncogenic and tumor suppressor microRNAs(miRNAs). MiRNAs are among the most promising and potential therapeutic and diagnostic tools in different diseases and enhanced the development of better therapeutic drugs. Suppression of oncomicroRNAs such as microRNA-21, - 20a, and - 27a as well as, up-regulation of microRNA-34 a/c are among the most important effects of MLT on microRNAs homeostasis. Recently, miR-21 has attracted the attention of scientists due to the its wide range of effects on different cancers and diseases. Regulation of this RNA may be a key to the development of better therapeutic targets. The present review will summarize the findings of in vitro and experimental studies of MLT-induced impacts on the expression of microRNAs which are involved in different models and numerous stages of tumor initiation, growth, metastasis, and chemo-resistance.

Understanding exosomes: Part 3-therapeutic + diagnostic potential in dentistry

Exosomes are the smallest subset of extracellular signaling vesicles secreted by most cells with the ability to communicate with other tissues and cell types over long distances. Their use in regenerative medicine has gained tremendous momentum recently due to their ability to be utilized as therapeutic options for a wide array of various diseases. Over 5000 publications are currently being published on this topic yearly, many of which in the dental space. This extensive review article is the first scoping review aimed at summarizing all therapeutic uses of exosomes in regenerative dentistry. A total of 944 articles were identified as using exosomes in the dental field for either their regenerative/therapeutic potential or for diagnostic purposes derived from the oral cavity. In total, 113 research articles were selected for their regenerative potential (102 in vitro, 60 in vivo, 50 studies included both). Therapeutic exosomes were most commonly derived from dental pulps, periodontal ligament cells, gingival fibroblasts, stem cells from exfoliated deciduous teeth, and the apical papilla which have all been shown to facilitate the regenerative potential of a number of tissues including bone, cementum, the periodontal ligament, nerves, aid in orthodontic tooth movement, and relieve temporomandibular joint disorders, among others. Results demonstrate that the use of exosomes led to positive outcomes in 100% of studies. In the bone field, exosomes were found to perform equally as well or better than rhBMP2 while significantly reducing inflammation. Periodontitis animal models were treated with simple gingival injections of exosomes and benefits were even observed when the exosomes were administered intravenously. Exosomes are much more stable than growth factors and were shown to be far more resistant against degradation by periodontal pathogens found routinely in a periodontitis environment. Comparative studies in the field of periodontal regeneration found better outcomes for exosomes even when compared to their native parent stem cells. In total 47 diagnostic studies revealed a role for salivary/crevicular fluid exosomes for the diagnosis of birth defects, cardiovascular disease, diabetes, gingival recession detection, gingivitis, irritable bowel syndrome, neurodegenerative disease, oral lichen planus, oral squamous cell carcinoma, oropharyngeal cancer detection, orthodontic root resorption, pancreatic cancer, periodontitis, peri-implantitis, Sjögren syndrome, and various systemic diseases. Hence, we characterize the exosomes as possessing "remarkable" potential, serving as a valuable tool for clinicians with significant advantages.

Emerging roles of exosomes in oral diseases progression

Oral diseases, such as periodontitis, salivary gland diseases, and oral cancers, significantly challenge health conditions due to their detrimental effects on patient's digestive functions, pronunciation, and esthetic demands. Delayed diagnosis and non-targeted treatment profoundly influence patients' prognosis and quality of life. The exploration of innovative approaches for early detection and precise treatment represents a promising frontier in oral medicine. Exosomes, which are characterized as nanometer-sized extracellular vesicles, are secreted by virtually all types of cells. As the research continues, the complex roles of these intracellular-derived extracellular vesicles in biological processes have gradually unfolded. Exosomes have attracted attention as valuable diagnostic and therapeutic tools for their ability to transfer abundant biological cargos and their intricate involvement in multiple cellular functions. In this review, we provide an overview of the recent applications of exosomes within the field of oral diseases, focusing on inflammation-related bone diseases and oral squamous cell carcinomas. We characterize the exosome alterations and demonstrate their potential applications as biomarkers for early diagnosis, highlighting their roles as indicators in multiple oral diseases. We also summarize the promising applications of exosomes in targeted therapy and proposed future directions for the use of exosomes in clinical treatment.

Potential of melatonin to reverse epigenetic aberrations in oral cancer: new findings

It is now an accepted principle that epigenetic alterations cause cellular dyshomeostasis and functional changes, both of which are essential for the initiation and completion of the tumor cycle. Oral carcinogenesis is no exception in this regard, as most of the tumors in the different subsites of the oral cavity arise from the cross-reaction between (epi)genetic inheritance and the huge challenge of environmental stressors. Currently, the biochemical machinery is put at the service of the tumor program, halting the cell cycle, triggering uncontrolled proliferation, driving angiogenesis and resistance to apoptosis, until the archetypes of the tumor phenotype are reached. Melatonin has the ability to dynamically affect the epigenetic code. It has become accepted that melatonin can reverse (epi)genetic aberrations present in oral and other cancers, suggesting the possibility of enhancing the oncostatic capacity of standard multimodal treatments by incorporating this indolamine as an adjuvant. First steps in this direction confirm the potential of melatonin as a countermeasure to mitigate the detrimental side effects of conventional first-line radiochemotherapy. This single effect could produce synergies of extraordinary clinical importance, allowing doses to be increased and treatments not to be interrupted, ultimately improving patients' quality of life and prognosis. Motivated by the urgency of improving the medical management of oral cancer, many authors advocate moving from in vitro and preclinical research, where the bulk of melatonin cancer research is concentrated, to systematic randomized clinical trials on large cohorts. Recognizing the challenge to improve the clinical management of cancer, our motivation is to encourage comprehensive and robust research to reveal the clinical potential of melatonin in oral cancer control. To improve the outcome and quality of life of patients with oral cancer, here we provide the latest evidence of the oncolytic activity that melatonin can achieve by manipulating epigenetic patterns in oronasopharyngeal tissue.

Cancer-associated immune cells and their modulation by melatonin

OBJECTIVES

Rapidly growing evidence suggests that immune cells play a key role in determining tumor progression. Tumor cells are surrounded by a microenvironment composed of different cell populations including immune cells. The cross talk between tumor cells and the neighboring microenvironment is an important factor to take into account while designing tumor therapies. Despite significant advances in immunotherapy strategies, a relatively small proportion of patients have successfully responded to them. Therefore, the search for safe and efficient drugs, which could be used alongside conventional therapies to boost the immune system against tumors, is an ongoing need. In the present work, the modulatory effects of melatonin on different components of tumor immune microenvironment are reviewed.

METHODS

A thorough literature review was performed in PubMed, Scopus, and Web of Science databases. All published papers in English on tumor immune microenvironment and the relevant modulatory effects of melatonin were scrutinized.

RESULTS

Melatonin modulates macrophage polarization and prevents M2 induction. Moreover, it prevents the conversion of fibroblasts into cancer-associated fibroblasts (CAFs) and prevents cancer cell stemness. In addition, it can affect the payload composition of tumor-derived exosomes (TEXs) and their secretion levels to favor a more effective anti-tumor immune response. Melatonin is a safe molecule that affects almost all components of the tumor immune microenvironment and prevents them from being negatively affected by the tumor.

CONCLUSION

Based on the effects of melatonin on normal cells, tumor cells and microenvironment components, it could be an efficient compound to be used in combination with conventional immune-targeted therapies to increase their efficacy.

Tumor microenvironment remodeling in oral cancer: Application of plant derived-natural products and nanomaterials

Oral cancers consist of squamous cell carcinoma (SCC) and other malignancies in the mouth with varying degrees of invasion and differentiation. For many years, different modalities such as surgery, radiation therapy, and classical chemotherapy drugs have been used to control the growth of oral tumors. Nowadays, studies have confirmed the remarkable effects of the tumor microenvironment (TME) on the development, invasion, and therapeutic resistance of tumors like oral cancers. Therefore, several studies have been conducted to modulate the TME in various types of tumors in favor of cancer suppression. Natural products are intriguing agents for targeting cancers and TME. Flavonoids, non-flavonoid herbal-derived molecules, and other natural products have shown promising effects on cancers and TME. These agents, such as curcumin, resveratrol, melatonin, quercetin and naringinin have demonstrated potency in suppressing oral cancers. In this paper, we will review and discuss about the potential efficacy of natural adjuvants on oral cancer cells. Furthermore, we will review the possible therapeutic effects of these agents on the TME and oral cancer cells. Moreover, the potential of nanoparticles-loaded natural products for targeting oral cancers and TME will be reviewed. The potentials, gaps, and future perspectives for targeting TME by nanoparticles-loaded natural products will also be discussed.

Melatonin targeting non-coding RNAs in cancer: Focus on mechanisms and potential therapeutic targets

Despite, melatonin is mainly known as a regulatory factor for circadian rhythm, its notable role in other fundamental biological processes, such as redox homeostasis and programmed cell death, has been found. In this line, a growing body of evidence indicated that melatonin could apply an inhibitory effect on the tumorigenic processes. Hence, melatonin might be considered an efficient adjuvant agent for cancer treatment. Besides, the physiological and pathological functions of non-coding RNAs (ncRNAs) in various disease, particularly cancers, have been expanded over the past two decades. It is well-established that ncRNAs can modulate the gene expression at various levels, thereby, ncRNAs. can regulate the numerous biological processes, including cell proliferation, cell metabolism, apoptosis, and cell cycle. Recently, targeting the ncRNAs expression provides a novel insight in the therapeutic approaches for cancer treatment. Moreover, accumulating investigations have revealed that melatonin could impact the expression of different ncRNAs in a multiple disorders, including cancer. Therefore, in the precent study, we discuss the potential roles of melatonin in modulating the expression of ncRNAs and the related molecular pathways in different types of cancer. Also, we highlighted its importance in therapeutic application and translational medicine in cancer treatment.

MEL regulates miR-21 and let-7b through the STAT3 cascade in the follicular granulosa cells of Tibetan sheep

Under physiological and pathological conditions, melatonin (MEL) can regulate microRNA (miRNA) expression. However, the mechanisms underlying the regulatory effects of MEL on miRNAs in ovaries are not understood. Firstly, by using fluorescence in situ hybridisation, we found that in ovaries and follicular granulosa cells (FGCs), MT1 co-located with miR-21 and let-7b. Additionally, immunofluorescence revealed that MT1, STAT3, c-MYC and LIN28 proteins co-located. The mRNA and protein levels of STAT3, c-MYC and LIN28 increased under treatment with 10^-7 M MEL. MEL induced an increase in miR-21 and a decrease in let-7b. The LIN28/let-7b and STAT3/miR-21 axes are related to cell differentiation, apoptosis and proliferation. We explored whether the STAT3/c-MYC/LIN28 pathway was involved in miRNA regulation by MEL to explore the putative mechanism of the above relationship. AG490, an inhibitor of the STAT3 pathway, was added before MEL treatment. AG490 inhibited the MEL-induced increases in STAT3, c-MYC, LIN28 and MT1 and changes in miRNA. Through live-cell detection, we discovered that MEL enhanced the proliferation of FGCs. However, the ki67 protein levels decreased when AG490 was added in advance. Furthermore, the dual-luciferase reporter assay verified that STAT3, LIN28 and MT1 were target genes of let-7b. Furthermore, STAT3 and SMAD7 were target genes of miR-21. In addition, the protein levels of the STAT3, c-MYC, LIN28 and MEL receptors decreased when let-7b was overexpressed in FGCs. Overall, MEL might regulate miRNA expression through the STAT3 pathway. In addition, a negative feedback loop between the STAT3 and miR-21 formed; MEL and let-7b antagonized each other in FGCs. These findings may provide a theoretical basis for improving the reproductive performance of Tibetan sheep through MEL and miRNAs.

Melatonin enhances anti-tumor immunity by targeting macrophages PD-L1 via exosomes derived from gastric cancer cells

Melatonin (MLT) is a hormone with potential anti-tumor properties, but the molecular mechanisms remain unclear. The present study aimed to explore the effect of MLT on exosomes derived from gastric cancer cells, with the goal of gaining insight into its anti-tumor activity. Results from in vitro experiments showed that MLT was able to enhance the anti-tumor activity of macrophages that had been suppressed by exosomes from gastric cancer cells. This effect was achieved through regulation of the levels of PD-L1 in macrophages via modulation of the associated microRNAs in the cancer-derived exosomes. Furthermore, MLT treatment increased the secretion of TNF-α and CXCL10 by the macrophages. Besides, MLT treatment of gastric cancer cells led to the production of exosomes that promoted the recruitment of CD8⁺ T cells to the tumor site, resulting in inhibition of tumor growth. Collectively, these results provide evidence for the modulation of the tumor immune microenvironment by MLT through regulation of exosomes derived from gastric cancer cells, suggesting a potential role for MLT in novel anti-tumor immunotherapies.

Chemotherapeutic Drug Resistance Associated with Differential miRNA Expression of miR-375 and miR-27 among Oral Cancer Cell Lines

Recent advances have suggested that non-coding miRNAs (such as miR-21, miR-27, miR-145, miR-155, miR-365, miR-375 and miR-494) may be involved in multiple aspects of oral cancer chemotherapeutic responsiveness. This study evaluated whether these specific miRNAs are correlated with oral cancer responsiveness to chemotherapies, including Paclitaxel, Cisplatin and Fluorouracil (5FU). Commercially available and well-characterized oral squamous cell carcinoma cell lines (SCC4, SCC9, SCC15, SCC25 and CAL27) revealed differing resistance and chemosensitivity to these agents-with SCC9 and SCC25 demonstrating the most resistance to all chemotherapeutic agents. SCC9 and SCC25 were also the only cell lines that expressed miR-375, and were the only cell lines that did not express miR-27. In addition, the expression of miR-375 was associated with the upregulation of Rearranged L-myc fusion (RLF) and the downregulation of Centriolar protein B (POC1), whereas lack of miR-27 expression was associated with Nucleophosmin 1 (NPM1) expression. These data have revealed important regulatory pathways and mechanisms associated with oral cancer proliferation and resistance that must be explored in future studies of potential therapeutic interventions.

Melatonin: Emerging Player in the Management of Oral Cancer

Oral cancer (OC) has emerged as a major medical and social issue in many industrialized nations due to the high death rate. It is becoming increasingly common in people under the age of 45, although the underlying causes and mechanisms of this increase remain unclear. Melatonin, as a pleiotropic hormone, plays a pivotal role in a wide variety of cellular and physiological functions. Mounting evidence supports melatonin's ability to modify/influence oral carcinogenesis, help in the reduction of the incidence of OC, and increase chemo- and radiosensitivity. Despite its potential anti-carcinogenic effects, the precise function of melatonin in the management of OC is not well understood. This review summarizes the current knowledge regarding melatonin function in anti-carcinogenesis mechanisms for OC. In addition, clinical assessment and the potential therapeutic utility of melatonin in OC are discussed. This review will provide a basis for researchers to create new melatonin-based personalized medicines for treating and preventing OC.

Melatonin Inhibits OGD/R-Induced H9c2 Cardiomyocyte Pyroptosis via Regulation of MT2/miR-155/FOXO3a/ARC Axis

Emerging literature suggests that pyroptosis plays a critical role in ischemia/hypoxia (I/R) -induced myocardial injury. Melatonin has been implicated in attenuating I/R-induced injury of cardiomyocytes. Nevertheless, whether melatonin inhibits I/R-induced pyroptosis of cardiomyocytes and the underlying molecular mechanisms remain unexploited.H9c2 cardiomyocytes were cultured under oxygen-glucose deprivation/reperfusion (OGD/R) condition to establish a myocardial pyroptosis model in vitro. OGD/R-induced pyroptosis was evaluated by CCK-8 assay, IL-1β and IL-18 release, and western blotting. Luciferase reporter assay was utilized to validate the association between miR-155 and Forkhead box O3a (FOXO3a).Melatonin could inhibit OGD/R-induced pyroptosis of H9c2 cells and upregulation of FOXO3a contributed to the antipyroptotic effect of melatonin. Melatonin reduced miR-155 expression, which led to FOXO3a upregulation and inhibition of pyroptosis in OGD/R-exposed H9c2 cells. miR-155 inhibitor enhanced the antipyroptotic effect of melatonin in OGD/R-exposed H9c2 cells. Melatonin-induced downregulation of miR-155 and upregulation of FOXO3a were reversed by melatonin receptor 2 (MT2) siRNA. Melatonin treatment also led to an increased level of apoptosis repressor with caspase recruitment domain (ARC), which was inhibited by FOXO3a siRNA. Moreover, silencing ARC by siRNA significantly blocked the antipyroptotic actions of melatonin, whereas ARC overexpression enhanced the antipyroptotic actions of melatonin in OGD/R-exposed H9c2 cells.Our findings demonstrated that melatonin prevented OGD/R-induced pyroptosis via regulating the MT2/miR-155/FOXO3a/ARC axis in cardiomyocytes.

Use of Melatonin in Cancer Treatment: Where Are We?

Cancer represents a large group of diseases accounting for nearly 10 million deaths each year. Various treatment strategies, including surgical resection combined with chemotherapy, radiotherapy, and immunotherapy, have been applied for cancer treatment. However, the outcomes remain largely unsatisfying. Melatonin, as an endogenous hormone, is associated with the circadian rhythm moderation. Many physiological functions of melatonin besides sleep–wake cycle control have been identified, such as antioxidant, immunomodulation, and anti-inflammation. In recent years, an increasing number of studies have described the anticancer effects of melatonin. This has drawn our attention to the potential usage of melatonin for cancer treatment in the clinical setting, although huge obstacles still exist before its wide clinical administration is accepted. The exact mechanisms behind its anticancer effects remain unclear, and the specific characters impede its in vivo investigation. In this review, we will summarize the latest advances in melatonin studies, including its chemical properties, the possible mechanisms for its anticancer effects, and the ongoing clinical trials. Importantly, challenges for the clinical application of melatonin will be discussed, accompanied with our perspectives on its future development. Finally, obstacles and perspectives of using melatonin for cancer treatment will be proposed. The present article will provide a comprehensive foundation for applying melatonin as a preventive and therapeutic agent for cancer treatment.

MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERKMAPK signaling pathways

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants and children. The present study aimed to investigate the effects of miR-146a on RSV replication and the related mechanisms. Material and methods: We pretreated A549 and HEp-2 cells and young rats with miR-146a mimic before infection with RSV. The expressions of miR-146a and RSV-F mRNA in cells and lung tissues were detected by RT-qPCR, and production of IL-1β, IL-6, IL-18, and TNF-α in bronchial alveolar lavage fluid (BALF) were determined by ELISA. The expression level of TRAF-6 and activation of the JNK/ERK/MAPK/NF-κB signaling pathway was detected by Western blotting. Results: RSV infection significantly reduced miR-146a levels in both A549 and HEp-2 cells and rat lung tissues. RSV infection resulted in accelerated growth, increased release of inflammatory cytokines, increased expression of TRAF-6, and activation of the JNK pathway in cells, and the lung inflammatory infiltration and the pathological score increased in rats. Overexpression of miR-146a targeted down-regulation of TRAF-6 expression and JNK/ERK/MAPK/NF-κB pathway induced by RSV infection, reduced the production of inflammatory cytokines IL-1β, IL-6 and TNF-α, and alleviate lung injury in young rats. We got similar results in both A549 and HEp-2 cell experiments. Conclusion: MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERK/MAPK signaling pathways.

Usefulness of Melatonin and Other Compounds as Antioxidants and Epidrugs in the Treatment of Head and Neck Cancer

Along with genetic mutations, aberrant epigenetic alterations are the initiators of head and neck cancer carcinogenesis. Currently, several drugs are being developed to correct these epigenetic alterations, known as epidrugs. Some compounds with an antioxidant effect have been shown to be effective in preventing these malignant lesions and in minimizing the complications derived from cytotoxic treatment. Furthermore, in vitro and in vivo studies show a promising role in the treatment of head and neck squamous cell carcinoma (HNSCC). This is the case of supplements with DNA methylation inhibitory function (DNMTi), such as epigallocatechin gallate, sulforaphane, and folic acid; histone deacetylase inhibitors (HDACi), such as sodium butyrate and melatonin or histone acetyltransferase inhibitors (HATi), such as curcumin. The objective of this review is to describe the role of some antioxidants and their epigenetic mechanism of action, with special emphasis on melatonin and butyric acid given their organic production, in the prevention and treatment of HNSCC.

Melatonin enhances cisplatin-induced cell death through inhibition of DERL1 in mesenchymal-like CD44high OSCC cells

BACKGROUND

Melatonin is a hormone that is primarily produced in the pineal gland and is involved in wide range of biological functions. However, the impact of melatonin on chemotherapy-induced cell death remains to be elucidated in oral squamous cell carcinoma (OSCC) cells. The objective of this study was to clarify the role of melatonin in cisplatin-induced cytotoxicity in CD44^high OSCC cells.

METHODS

CD44^high OSCC cells were cultured on fibronectin-coated hydrogel. A lactate dehydrogenase cytotoxicity assay was performed to evaluate cisplatin-induced cell death. The effect of melatonin on cisplatin-induced cell death and Derlin-1 (DERL1) endoplasmic reticulum membrane protein expression was investigated.

RESULTS

CD44^high OSCC cells exhibited mesenchymal-like features when cultured on fibronectin-coated hydrogel. Mesenchymal-like CD44^high OSCC cells demonstrated strong resistance to cisplatin-induced cell death compared with epithelial-like CD44^high OSCC cells. DERL1 mRNA and DERL1 protein expression levels were significantly higher in mesenchymal-like CD44^high cells compared with epithelial-like CD44^high cells. Cisplatin-induced cell death was significantly enhanced after DERL1 siRNA knockdown, suggesting that DERL1 is involved in resistance to cisplatin-induced cell death. Melatonin significantly inhibited DERL1 expression and enhanced cisplatin-induced cell death in mesenchymal-like CD44^high cells. miR-181c-5p expression was significantly upregulated in the presence of melatonin. Furthermore, melatonin-inhibited DERL1 expression was significantly recovered by miR-181c-5p inhibitor. In addition, melatoninenhanced cisplatin-induced cell death was attenuated by miR-181c-5p inhibitor. These results suggest that melatonin-induced miR-181c-5p enhances cisplatin-induced cell death through inhibition of DERL1 in mesenchymal-like CD44^high cells.

CONCLUSIONS

Melatonin plays a vital role in promoting cisplatin-induced cytotoxicity in mesenchymal-like CD44^high OSCC cells.

Human breast milk-derived exosomes may help maintain intestinal epithelial barrier integrity

BACKGROUND

This study explores the functions of exosomes derived from human breast milk (HBM) in vivo and in vitro.

METHODS

HBM-derived exosomes were collected from healthy lactating mothers. In vitro analysis were divided into five groups: (1) a control with no added agents, (2) exosomes added, (3) stimulated with lipopolysaccharide (LPS), (4) pretreated with exosomes and stimulated with LPS, and (5) pretreated with exosome-free HBM and stimulated with LPS. For in vivo analysis, mouse pups were randomly assigned to four groups: (1) a control group of breastfed pups, (2) necrotizing enterocolitis-induced (NEC) pups, (3) pups pretreated with HBM-derived exosomes 6 h before being induced by NEC, and (4) pups pretreated with exosome-free HBM 6 h before NEC induction.

RESULTS

Expression of zonula occludens-1 (ZO-1), claudin-1, and occludin were decreased in groups 3 and 5. In the animal model, mice pups in group 3 showed milder intestinal tissue injury than those in group 2 or 4 and had lower levels of the proinflammatory cytokines and higher levels of epithelial tight-junction proteins than groups 2 and 4.

CONCLUSIONS

HBM-derived exosomes exert beneficial effects in preventing NEC by reducing inflammation and injury to the intestinal epithelium as well as by restoring intestinal tight-junction proteins.

IMPACT

HBM-derived exosomes can help protect the epithelial tight-junction proteins ZO-1, claudin, and occludin from inflammatory attack. This study sought (1) to analyze whether there were differences in exosome levels between the human breast milk (HBM) of mothers who had delivered preterm or at term and (2) to investigate whether these exosomes could help sustain the intestinal epithelial tight-junction proteins ZO-1, claudin-1, and occludin in the presence of NEC in vitro and in vivo.

Potential Therapeutic Effects of Melatonin Mediate via miRNAs in Cancer

miRNAs are evolutionarily conserved non-coding ribonucleic acids with a length of between 19 and 25 nucleotides. Because of their ability to regulate gene expression, miRNAs have an important function in the controlling of various biological processes, such as cell cycle, differentiation, proliferation, and apoptosis. Owing to the long-standing regulative potential of miRNAs in tumor-suppressive pathways, scholars have recently paid closer attention to the expression profile of miRNAs in various types of cancer. Melatonin, an indolic compound secreted from pineal gland and some peripheral tissues, has been considered as an effective anti-tumor hormone in a wide spectrum of cancers. Furthermore, it induces apoptosis, inhibits tumor metastasis and invasion, and also angiogenesis. A growing body of evidence indicates the effects of melatonin on miRNAs expression in broad spectrum of diseases, including cancer. Due to the long-term effects of the regulation of miRNAs expression, melatonin could be a promising therapeutic factor in the treatment of cancers via the regulation of miRNAs. Therefore, in this review, we will discuss the effects of melatonin on miRNAs expression in various types of cancers.

Exosomes and Melatonin: Where Their Destinies Intersect

Cell-to-cell communication is a broad and complex process associated with regular stimuli to maintain healthy cell interactions. One of the agents capable of cellular communication is known as an exosome, a subset of extracellular vesicles (EVs) released by the cell membrane. The exosome contains a wide range of functional proteins, mRNAs and miRNAs, which have the potential to interact with healthy or diseased cells in the body. On the other hand, melatonin also acts as a cellular communicator, produced and released by the pineal gland in a circadian way and also, non-circadian melatonin is derived from the mitochondria of all normal cells. In addition to exhibiting antioxidant, anti-inflammatory, anti-tumor and anti-aging activities, melatonin has recently been studied by its influence on exosomes. This review summarizes the relationship between exosomes and melatonin in various pathological processes. There is robust evidence that their combination ameliorates inflammation, ischemia-reperfusion injury, hepatic metabolic disturbance, cancer immunosuppression status, degenerative processes like chronic kidney disease, vascular calcification, ageing, ischemic brain injury, neurodegenerative diseases, obesity, colitis, wound healing and even embryonic development. Association of exosomes and melatonin represent a promising therapeutic tool, capable of interfering with basic molecular processes, such as oxidative stress and the inflammatory cascade, which support many pathophysiological aspects of diseases.

An Examination of the Putative Role of Melatonin in Exosome Biogenesis

During the last two decades, melatonin has been found to have pleiotropic effects via different mechanisms on its target cells. Data are abundant for some aspects of the signaling pathways within cells while other casual mechanisms have not been adequately addressed. From an evolutionary perspective, eukaryotic cells are equipped with a set of interrelated endomembrane systems consisting of intracellular organelles and secretory vesicles. Of these, exosomes are touted as cargo-laden secretory vesicles that originate from the endosomal multivesicular machinery which participate in a mutual cross-talk at different cellular interfaces. It has been documented that cells transfer various biomolecules and genetic elements through exosomes to sites remote from the original cell in a paracrine manner. Findings related to the molecular mechanisms between melatonin and exosomal biogenesis and cargo sorting are the subject of the current review. The clarification of the interplay between melatonin and exosome biogenesis and cargo sorting at the molecular level will help to define a cell's secretion capacity. This review precisely addresses the role and potential significance of melatonin in determining the efflux capacity of cells via the exosomal pathway. Certain cells, for example, stem cells actively increase exosome efflux in response to melatonin treatment which accelerates tissue regeneration after transplantation into the injured sites.

Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.

Evaluation of exosome derivatives as bio-informational reprogramming therapy for cancer

Exosomes are nanoparticle sized (100 ± 50 nm) extracellular vesicles (ECVs) that play important roles in cell-to-cell communication. They do this by utilizing their natural ability to shuttle signaling molecules across the cellular microenvironment and promote paracrine signaling. Currently, exosomes are being explored for their potential as therapeutic agents for various degenerative diseases including cancer. The rationale behind their therapeutic ability is that they can transfer signaling biomolecules, and subsequently induce metabolic and physiological changes in diseased cells and tissues. In addition, exosomes can be used as a drug delivery system and may be very effective at reducing toxicity and increasing bioavailability of therapeutic molecules and drugs. Although exosomes were first believed to be a waste product of the cell, current research has demonstrated that these particles can serve as modulators of the immune system, act as cancer biomarkers, cause re-differentiation of cancer cells, and induce apoptosis in diseased cells. Extensive research has been performed specifically using amniotic fluid-derived extracellular vesicles, named "cytosomes". While the use of cytosomes in clinical application is still in the early stages, researchers have shown great potential for these EVs in regenerative medicine as immune modulators, in controlling microbial infection and by inducing tissue repair through the activation of endogenous, tissue-specific stem cells. This review emphasizes the capabilities of specific subsets of extracellular vesicles that can potentially be used for cancer therapy, principally as a source of bi-informational reprogramming for malignant cells.

Melatonin and regulation of miRNAs: novel targeted therapy for cancerous and noncancerous disease

miRNAs, small noncoding RNAs with crucial diagnostic and prognostic capabilities, play essential therapeutic roles in different human diseases. These biomarkers are involved in several biological mechanisms and are responsible for the regulation of multiple genes expressions in cells. miRNA-based therapy has shown a very bright future in the case of clinical interventions. Melatonin, the main product of the pineal gland, is a multifunctional neurohormone with numerous therapeutic potentials in human diseases. Melatonin is able to regulate miRNAs in different pathologies such as malignant and nonmalignant diseases, which can be considered as a novel kind of targeted therapy. Herein, this review discusses possible therapeutic utility of melatonin for the regulation of miRNAs in various pathological conditions.

Is Melatonin the Cornucopia of the 21st Century?

Melatonin, an indoleamine hormone produced and secreted at night by pinealocytes and extra-pineal cells, plays an important role in timing circadian rhythms (24-h internal clock) and regulating the sleep/wake cycle in humans. However, in recent years melatonin has gained much attention mainly because of its demonstrated powerful lipophilic antioxidant and free radical scavenging action. Melatonin has been proven to be twice as active as vitamin E, believed to be the most effective lipophilic antioxidant. Melatonin-induced signal transduction through melatonin receptors promotes the expression of antioxidant enzymes as well as inflammation-related genes. Melatonin also exerts an immunomodulatory action through the stimulation of high-affinity receptors expressed in immunocompetent cells. Here, we reviewed the efficacy, safety and side effects of melatonin supplementation in treating oxidative stress- and/or inflammation-related disorders, such as obesity, cardiovascular diseases, immune disorders, infectious diseases, cancer, neurodegenerative diseases, as well as osteoporosis and infertility.

A meta-analysis of microRNA networks regulated by melatonin in cancer: Portrait of potential candidates for breast cancer treatment

Melatonin is a ubiquitous molecule with a broad spectrum of functions including widespread anti-cancer activities. Identifying how melatonin intervenes in complex molecular signaling at the gene level is essential to guide proper therapies. Using meta-analysis approach, herein we examined the role of melatonin in regulating the expression of 46 microRNAs (miRNAs) and their target genes in breast, oral, gastric, colorectal, and prostate cancers, and glioblastoma. The deregulated miRNA-associated target genes revealed their involvement in the regulation of cellular proliferation, differentiation, apoptosis, senescence, and autophagy. Melatonin changes the expression of miRNA-associated genes in breast, gastric, and oral cancers. These genes are associated with cellular senescence, the hedgehog signaling pathway, cell proliferation, p53 signaling, and the hippo signaling pathway. Conversely, colorectal and prostate cancers as well as glioblastoma and oral carcinoma present a clear pattern of less pronounced changes in the expression of miRNA-associated genes. Most notably, colorectal cancer displayed a unique molecular change in response to melatonin. Considering breast cancer network complexity, we compared the genes found during the meta-analysis with RNA-Seq data from breast cancer-bearing mice treated with melatonin. Mechanistically, melatonin upregulated genes associated with immune responses and apoptotic processes, whereas it downregulated genes involved in cellular aggressiveness/metastasis (eg, mitosis, telomerase activity, and angiogenesis). We further characterized the expression profile of our gene subsets with human breast cancer and found eight upregulated genes and 16 downregulated genes that were appositively correlated with melatonin. Our results pose a multi-dimension network of tumor-associated genes regulated by miRNAs potentially targeted by melatonin.

Identification of miR-4644 as a suitable endogenous normalizer for circulating miRNA quantification in hepatocellular carcinoma

Background: Circulating microRNAs (miRNAs) have proved to be promising biomarkers for early diagnosis and therapeutic monitoring in cancers. Particularly for hepatocellular carcinoma (HCC), detection of circulating miRNA biomarkers as a new diagnostic approach has been written into the latest Guidelines for Diagnosis and Treatment of Primary Liver Cancer in China (2019 edition). However, no general consensus on an ideal endogenous normalizer for circulating miRNAs quantification has been reached, so it will affect the accuracy of quantitative results. In this study, we aim to identify a stable endogenous normalizer for analyzing circulating miRNAs.

Methods: Candidate miRNAs were selected by screening dataset GSE104310, as well as data statistics and analysis. Five commonly reference genes were chosen for further comparison and verification. Then, the expression levels of these genes in serum were analyzed by quantitative reverse transcription PCR (RT-qPCR) among four groups, including patients diagnosed with HCC, chronic hepatitis B (CHB), liver cirrhosis, and healthy subjects. Furthermore, the stability of target genes was evaluated using geNorm, NormFinder, comparative ΔCq programs, and validated by database. We also explored the availability of the miRNA combination, and compared the performance difference between combination and individuals, as well as the selectivity of miRNA references in the combinations.

Results: 11 candidate miRNAs were obtained, and miR-4644 stood out among these miRNAs, and proved to be much more stable than other endogenous miRNAs. Further study showed that miR-4644 exhibited higher stability and expression abundance than other commonly miRNA reference controls. Finally, we discovered the combination of miR-4644 and miR-16 revealed high performance in stability when compared to miRNA individuals. Furthermore, the combination consisted of references with closer nature could give rise to amplification effects in stability.

Conclusions: Our findings demonstrated that miR-4644 is an ideal endogenous normalizer for circulating microRNA quantification in hepatocellular carcinoma. Besides, combining miR-4644 with miR-16 into a whole as a reference control would greatly improve the accuracy of quantification.

Melatonin and gastrointestinal cancers: Current evidence based on underlying signaling pathways

Gastrointestinal (GI) cancers, leading causes of cancer-related deaths, have been serious challenging human diseases up to now. Because of high rates of mortality, late-stage diagnosis, metastasis to distant locations, and low effectiveness and adverse events of routine standard therapies, the quality of life and survival time are low in patients with GI cancers. Hence, many efforts need to be done to explore and find novel efficient treatments. Beneficial effects of melatonin have been reported in a wide variety of human diseases. Melatonin has antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. Various studies have showed the regulatory effects of melatonin on apoptotsis, autophagy and angiogenesis; these properties result in the inhibition of invasion, migration, and proliferation of GI cancer cells in vivo and in vitro. Together, this review suggests that melatonin in combination with anticancer agents may improve the efficacy of routine medicine and survival rate of patients with cancer.

Melatonin Enhances the Therapeutic Effect of Plasma Exosomes Against Cerebral Ischemia-Induced Pyroptosis Through the TLR4/NF-κB Pathway

Introduction

Ischemic stroke-induced inflammation and inflammasome-dependent pyroptotic neural death cause serious neurological injury. Nano-sized plasma exosomes have exhibited therapeutic potential against ischemia and reperfusion injury by ameliorating inflammation. To enhance its therapeutic potential in patients with ischemic injury, we isolated exosomes from melatonin-treated rat plasma and assessed the neurological protective effect in a rat model of focal cerebral ischemia.

Methods

Basal plasma exosomes and melatonin-treated plasma exosomes were isolated and intravenously injected into a rat model of focal cerebral ischemia. Neurological recovery was evaluated by determining the modified neurological severity score (mNSS), infarct volume, and brain water content. Pyroptosis in the ischemic cortex was detected through dUTP nick-end labeling (TUNEL) assay, lactate dehydrogenase (LDH) release, and gasdermin D (GSDMD) cleavage. NLRP3 inflammasome assembly and global inflammatory cytokine secretion were detected by enzyme-linked immunosorbent assay (ELISA) and Western blot assay. In immunized Sprague-Dawley rats, microglia pyroptosis was determined through a positive percentage of IBA1⁺ and caspase-1 (p20)⁺ cells. Finally, the microRNA (miRNA) profiles in melatonin-treated plasma exosomes were analyzed by exosome miRNA microarray analysis.

Results

Melatonin treatment enhanced plasma exosome therapeutic effects against ischemia-induced inflammatory responses and inflammasome-mediated pyroptosis. In addition, we confirmed that ischemic stroke-induced pyroptotic cell death occurred in the microglia and neuron, while the administration of melatonin-treated exosomes further effectively decreased the infarct volume and improved recovery of function via regulation of the TLR4/NF-κB signaling pathway. Finally, the altered miRNA profiles in the melatonin-treated plasma exosomes demonstrated the regulatory mechanisms involved in neurological recovery after ischemic injury.

Conclusion

This study suggests that nano-sized plasma exosomes with melatonin pretreatment might be a more effective strategy for patients with ischemic brain injury. Further exploration of key molecules in the plasma exosome may provide increased therapeutic value for cerebral ischemic injury.

miR-365 (microRNA): Potential Biomarker in Oral Squamous Cell Carcinoma Exosomes and Extracellular Vesicles

Introduction: miR-365 is a non-coding microRNA that regulates transcription and has been demonstrated to promote oncogenesis and metastasis in some cancers, while suppressing these effects in others. Many microRNAs are produced and then exported extracellularly in exosomes, which are small extracellular vesicles ranging from 30 to 100 nm that are found in eukaryotic fluids and facilitate many cellular functions. Exosomes and extracellular vesicles are produced by many cell types, including oral cancer cells—although no study to date has evaluated miR-365 and oral cancer exosomes or extracellular vesicles. Based on this information, our research question was to evaluate whether oral cancers produce exosomes or extracellular vesicles containing miR-365. Materials and Methods: Two commercially available oral cancer cell lines (SCC25 and CAL27) and a normal oral keratinocyte (OKF4) were grown in serum-free media, supplemented with exosome-depleted fetal bovine serum. Extracellular vesicles and exosomes were then isolated using the Invitrogen total exosome RNA and protein isolation kit for processing using the hsa-miR-365a-5p microRNA qPCR assay kit. Results: RNA was successfully isolated from the exosome-depleted supernatant from each cell line—SCC9, SCC15, SCC25, and CAL27 (oral squamous cell carcinomas) and OKF4 (oral epithelial cell line). Relative concentrations of RNA were similar among each cell line, which were not significantly different, p = 0.233. RNA quality was established by A260:A280 absorbance using a NanoDrop, revealing purity ranging 1.73–1.86. Expression of miR-16 was used to confirm the presence of microRNA from the extracted exosomes and extracellular vesicles. The presence of miR-365 was then confirmed and normalized to miR-16 expression, which demonstrated an increased level of miR-365 in both CAL27 and SCC25. In addition, the normalized relative quantity (RQ) for miR-365 exhibited greater variation among SCC25 (1.382–4.363) than CAL27 cells (1.248–1.536). Conclusions: These results confirm that miR-365 is not only expressed in oral cancer cell lines, but also is subsequently exported into exosomes and extracellular vesicles derived from these cultures. These data may help to contextualize the potential for this microRNA to contribute to the phenotypes and behaviors of oral cancers that express this microRNA. Future research will begin to investigate these potential mechanisms and pathways and to determine if miR-365 may be useful as an oral cancer biomarker for salivary or liquid biopsies.

Integrating Pathophysiology in Migraine: Role of the Gut Microbiome and Melatonin

BACKGROUND

The pathoetiology and pathophysiology of migraine are widely accepted as unknown.

METHODS

The current article reviews the wide array of data associated with the biological underpinnings of migraine and provides a framework that integrates previously disparate bodies of data.

RESULTS

The importance of alterations in stress- and pro-inflammatory cytokine- induced gut dysbiosis, especially butyrate production, are highlighted. This is linked to a decrease in the availability of melatonin, and a relative increase in the N-acetylserotonin/melatonin ratio, which has consequences for the heightened glutamatergic excitatory transmission in migraine. It is proposed that suboptimal mitochondria functioning and metabolic regulation drive alterations in astrocytes and satellite glial cells that underpin the vasoregulatory and nociceptive changes in migraine.

CONCLUSION

This provides a framework not only for classical migraine associated factors, such as calcitonin-gene related peptide and serotonin, but also for wider factors in the developmental pathoetiology of migraine. A number of future research and treatment implications arise, including the clinical utilization of sodium butyrate and melatonin in the management of migraine.

Extracellular Vesicles in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders: A Systematic Review

Extracellular vesicles (EVs) are secreted from most cell types and utilized in a complex network of near and distant cell-to-cell communication. Insight into this complex nanoscopic interaction in the development, progression and treatment of oral squamous cell carcinoma (OSCC) and precancerous oral mucosal disorders, termed oral potentially malignant disorders (OPMDs), remains of interest. In this review, we comprehensively present the current state of knowledge of EVs in OSCC and OPMDs. A systematic literature search strategy was developed and updated to December 17, 2019. Fifty-five articles were identified addressing EVs in OSCC and OPMDs with all but two articles published from 2015, highlighting the novelty of this research area. Themes included the impact of OSCC-derived EVs on phenotypic changes, lymph-angiogenesis, stromal immune response, mechanisms of therapeutic resistance as well as utility of EVs for drug delivery in OSCC and OPMD. Interest and progress of knowledge of EVs in OSCC and OPMD has been expanding on several fronts. The oral cavity presents a unique and accessible microenvironment for nanoparticle study that could present important models for other solid tumours.

Potential of Melatonin as Adjuvant Therapy of Oral Cancer in the Era of Epigenomics

The wide variety of epigenetic controls available is rapidly expanding the knowledge of molecular biology even overflowing it. At the same time, it can illuminate unsuspected ways of understanding the etiology of cancer. New emerging therapeutic horizons, then, promise to overcome the current antitumor strategies need. The translational utility of this complexity is particularly welcome in oral cancer (OC), in which natural history is alarmingly disappointing due to the invasive and mutilating surgery, the high relapsing rate, the poor quality of life and the reduced survival after diagnosis. Melatonin activates protective receptor-dependent and receptor-independent processes that prevent tissue cancerisation and inhibit progressive tumor malignancy and metastasis. Related evidence has shown that melatonin pleiotropy encompasses gene expression regulation through all the three best-characterized epigenetic mechanisms: DNA methylation, chromatin modification, and non-coding RNA. OC has received less attention than other cancers despite prognosis is usually negative and there are no significant therapy improvements recorded in the past decade. However, a large research effort is being carried out to elucidate how melatonin´s machinery can prevent epigenetic insults that lead to cancer. In the light of recent findings, a comprehensive examination of biochemistry through which melatonin may reverse epigenetic aberrations in OC is an extraordinary opportunity to take a step forward in the clinical management of patients.

Early Diagnosis on Oral and Potentially Oral Malignant Lesions: A Systematic Review on the VELscope® Fluorescence Method

The fluorescence method is an innovative technique used by pathologists for examining body mucosa, and for the abnormalities tissue screening, potentially leading to the earlier discovery of pre-cancer, cancer or other disease processes. The early detection is one of the best mechanisms for enabling treatment success, increasing survival rates and maintaining a high quality of life. The purpose of this review is to evaluate the clinical efficiency of this diagnostic tool applied to the oral cavity (VELscope^®). A literature systematic review has been performed. The initial research provided 53 results after applying the inclusion and exclusion criteria, and after a manual screening of the abstracts by the authors, only 25 results were eligible for review. The results and data contained in all the researches, no older than 10 years, were manually evaluated, and provided useful information on this diagnostic method. The VELscope^® mean value about sensitivity and specificity resulted of 70.19% and 65.95%, respectively, by results analysis, but despite this some studies disagree about its clinical effectiveness, and this diagnostic method is still much debated in scientific and clinical medical literature. Surely being able to have efficient and effective tools from this point of view could help the clinician in the diagnosis, and also make timelier the pharmacological or surgical therapy, improving the quality of life of the patient, and in some cases guaranteeing a longer survival term.