Melatonin Inhibits the Proliferation of Gastric Cancer Cells Through Regulating the miR-16-5p-Smad3 Pathway

Melatonin for gastric cancer treatment: where do we stand?

Gastric cancer (GC) is the third leading reason of death in men and the fourth in women. Studies have documented an inhibitory function of melatonin on the proliferation, progression and invasion of GC cells. MicroRNAs (miRNAs) are small, non-coding RNAs that play an important function in regulation of biological processes and gene expression of the cells. Some studies reported that melatonin can suppress the progression of GC by regulating the exosomal miRNAs. Thus, melatonin represents a promising potential therapeutic agent for subjects with GC. Herein, we evaluate the existing data of both in vivo and in vitro studies to clarify the molecular processes involved in the therapeutic effects of melatonin in GC. The data emphasize the critical function of melatonin in several signaling ways by which it may inhibit cancer cell proliferation, decrease chemo-resistance, induce apoptosis as well as limit invasion, angiogenesis, and metastasis. This review provides a resource that identifies some of the mechanisms by which melatonin controls GC enlargement. In light of the findings, melatonin should be considered a novel and testable therapeutic mediator for GC treatment.

Therapeutic applications of melatonin in disorders related to the gastrointestinal tract and control of appetite

Most animals have large amounts of the special substance melatonin, which is controlled by the light/dark cycle in the suprachiasmatic nucleus. According to what is now understood, the gastrointestinal tract (GIT) and other areas of the body are sites of melatonin production. According to recent studies, the GIT and adjacent organs depend critically on a massive amount of melatonin. Not unexpectedly, melatonin's many biological properties, such as its antioxidant, anti-inflammatory, pro-apoptotic, anti-proliferative, anti-metastasis, and antiangiogenic properties, have drawn the attention of researchers more and more. Because melatonin is an antioxidant, it produces a lot of secretions in the GIT's mucus and saliva, which shields cells from damage and promotes the development of certain GIT-related disorders. Melatonin's ability to alter cellular behavior in the GIT and other associated organs, such as the liver and pancreas, is another way that it functions. This behavior alters the secretory and metabolic activities of these cells. In this review, we attempted to shed fresh light on the many roles that melatonin plays in the various regions of the gastrointestinal tract by focusing on its activities for the first time.

Natural Compounds for Preventing Age-Related Diseases and Cancers

Aging is a multifaceted process influenced by hereditary factors, lifestyle, and environmental elements. As time progresses, the human body experiences degenerative changes in major functions. The external and internal signs of aging manifest in various ways, including skin dryness, wrinkles, musculoskeletal disorders, cardiovascular diseases, diabetes, neurodegenerative disorders, and cancer. Additionally, cancer, like aging, is a complex disease that arises from the accumulation of various genetic and epigenetic alterations. Circadian clock dysregulation has recently been identified as an important risk factor for aging and cancer development. Natural compounds and herbal medicines have gained significant attention for their potential in preventing age-related diseases and inhibiting cancer progression. These compounds demonstrate antioxidant, anti-inflammatory, anti-proliferative, pro-apoptotic, anti-metastatic, and anti-angiogenic effects as well as circadian clock regulation. This review explores age-related diseases, cancers, and the potential of specific natural compounds in targeting the key features of these conditions.

Melatonin and Its Role in the Epithelial-to-Mesenchymal Transition (EMT) in Cancer

The epithelial-to-mesenchymal transition (EMT) is a cell-biological program that occurs during the progression of several physiological processes and that can also take place during pathological situations such as carcinogenesis. The EMT program consists of the sequential activation of a number of intracellular signaling pathways aimed at driving epithelial cells toward the acquisition of a series of intermediate phenotypic states arrayed along the epithelial-mesenchymal axis. These phenotypic features include changes in the motility, conformation, polarity and functionality of cancer cells, ultimately leading cells to stemness, increased invasiveness, chemo- and radioresistance and the formation of cancer metastasis. Amongst the different existing types of the EMT, type 3 is directly involved in carcinogenesis. A type 3 EMT occurs in neoplastic cells that have previously acquired genetic and epigenetic alterations, specifically affecting genes involved in promoting clonal outgrowth and invasion. Markers such as E-cadherin; N-cadherin; vimentin; and transcription factors (TFs) like Twist, Snail and ZEB are considered key molecules in the transition. The EMT process is also regulated by microRNA expression. Many miRNAs have been reported to repress EMT-TFs. Thus, Snail 1 is repressed by miR-29, miR-30a and miR-34a; miR-200b downregulates Slug; and ZEB1 and ZEB2 are repressed by miR-200 and miR-205, respectively. Occasionally, some microRNA target genes act downstream of the EMT master TFs; thus, Twist1 upregulates the levels of miR-10b. Melatonin is an endogenously produced hormone released mainly by the pineal gland. It is widely accepted that melatonin exerts oncostatic actions in a large variety of tumors, inhibiting the initiation, progression and invasion phases of tumorigenesis. The molecular mechanisms underlying these inhibitory actions are complex and involve a great number of processes. In this review, we will focus our attention on the ability of melatonin to regulate some key EMT-related markers, transcription factors and micro-RNAs, summarizing the multiple ways by which this hormone can regulate the EMT. Since melatonin has no known toxic side effects and is also known to help overcome drug resistance, it is a good candidate to be considered as an adjuvant drug to conventional cancer therapies.

The miR-224-5p/SIRT3/AMPK/mTOR axis is involved in the melatonin-mediated inhibition of glucocorticoid-induced osteoporosis by activating autophagy

Melatonin has been shown to exert an inhibitory effect on osteoporosis. This study investigates the function of the miR-224-5p/SIRT3/AMPK/mTOR axis in melatonin-mediated effects against osteoporosis. Human bone marrow mesenchymal stem cells (hBMSCs) were treated with glucocorticoid dexamethasone to induce an in vitro osteoporosis model. After melatonin treatment, miR-224-5p and SIRT3 levels were measured by RT‒PCR. Transmission electron microscopy and immunofluorescence were conducted for evaluating autophagy. Western blotting was carried out to determine the expression of osteogenesis-related proteins (Runx2, OSX, OPN, and OCN), SIRT3-AMPK-mTOR axis, and autophagy-related markers (LC3 and p62). Alizarin red staining was used to measure matrix mineralization. The data showed that melatonin inhibited dexamethasone-induced osteoporosis in vitro, and enhanced autophagic levels (as indicated by increased LC3 puncta, LC3II/I ratio, and autophagic vacuoles). In terms of the mechanisms, melatonin decreased miR-224-5p expression and increased SIRT3. SRIT3 was shown to be a direct target of miR-224-5p. miR-224-5p upregulation or SIRT3 downregulation reversed the effects of melatonin on osteoporosis and suppressed autophagy. Additionally, miR-224-5p inhibited SIRT3 expression and AMPK pathway activation. In summary, we discovered that melatonin suppressed glucocorticoid-induced osteoporosis and autophagy inhibition via the miR-224-5p/SIRT3/AMPK/mTOR axis.

MicroRNAs miR-16 and miR-519 control meningioma cell proliferation via overlapping transcriptomic programs shared with the RNA-binding protein HuR

Introduction

Meningiomas are the most common type of primary central nervous system tumors. In about 80% cases, these tumors are benign and grow very slowly, but the remainder 20% can unlock higher proliferation rates and become malignant. In this study we examined two miRs, miR-16 and miR-519, and evaluated their role in tumorigenesis and cell growth in human meningioma.

Methods

A cohort of 60 intracranial grade 1 and grade 2 human meningioma plus 20 healthy meningeal tissues was used to quantify miR-16 and miR-519 expressions. Cell growth and dose-response assays were performed in two human meningioma cell lines, Ben-Men-1 (benign) and IOMM-Lee (aggressive). Transcriptomes of IOMM-lee cells were measured after both miR-mimics transfection, followed by integrative bioinformatics to expand on available data.

Results

In tumoral tissues, we detected decreased levels of miR-16 and miR-519 when compared with arachnoid cells of healthy patients (miR-16: P=8.7e-04; miR-519: P=3.5e-07). When individually overexpressing these miRs in Ben-Men-1 and IOMM-Lee, we observed that each showed reduced growth (P<0.001). In IOMM-Lee cell transcriptomes, downregulated genes, among which ELAVL1/HuR (miR-16: P=6.1e-06; miR-519:P=9.38e-03), were linked to biological processes such as mitotic cell cycle regulation, pre-replicative complex, and brain development (FDR<1e-05). Additionally, we uncovered a specific transcriptomic signature of miR-16/miR-519-dysregulated genes which was highly enriched in HuR targets (>6-fold; 79.6% of target genes).

Discussion

These results were confirmed on several public transcriptomic and microRNA datasets of human meningiomas, hinting that the putative tumor suppressor effect of these miRs is mediated, at least in part, via HuR direct or indirect inhibition.

Melatonin inhibited the progression of gastric cancer induced by Bisphenol S via regulating the estrogen receptor 1

In recent years, Bisphenol S (BPS) has increasingly been used as an alternative to Bisphenol A (BPA) in food, paper, and personal care products. It is imperative to clarify the relationship between BPS and tumors in order to treat and prevent diseases. This study discovered a new method for predicting tumor correlations between BPS interactive genes. According to analyses conducted by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, interactive genes were primarily found in gastric cancer. Based on gene-targeted prediction and molecular docking, BPS appears to exert potential gastric cancer-causing effects through estrogen receptor 1 (ESR1). In addition, gastric cancer patients' prognosis could be accurately predicted by a bisphenol-based prognostic prediction model. Subsequently, the proliferation and migration abilities of gastric cancer cells were further demonstrated to be significantly enhanced by BPS. Similarly, molecular docking analysis revealed that melatonin is also highly correlated with gastric cancer and BPS. In cell proliferation and migration assays, melatonin and BPS exposure inhibited the invasion abilities of gastric cancer cells compared to BPS-exposure. Our research provided a new direction for the exploration the correlation between cancer and environmental toxicity.

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.

LOC554202 contributes to chordoma progression by sponging miR-377-3p and up-regulating SMAD3

Chordoma is a rare malignant bone tumor originating from the remnants of the notochord. Here, the role of long noncoding LOC554202 in chordoma progression and its associated mechanism were explored. Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide and colony formation assays. Flow cytometry was conducted to analyze cell apoptosis rate. The migration and invasion of chordoma cells were analyzed by transwell migration and invasion assays and wound healing assays. A xenograft tumor model was established in nude mice to explore the role of LOC554202 in regulating tumor growth in vivo . The interaction between microRNA-377-3p (miR-377-3p) and LOC554202 or sekelsky mothers against d PP (SMAD) family member 3 (SMAD3) was verified by dual-luciferase reporter and RNA immunoprecipitation assays. The glycolytic rate of chordoma cells was analyzed using glucose assay kit, lactic acid kit and ApoSENSOR ADP/ATP ratio assay kit. LOC554202 expression was upregulated in chordoma tissues and cell lines. LOC554202 silencing suppressed the proliferation, migration and invasion and induced the apoptosis of chordoma cells. LOC554202 knockdown restrained xenograft tumor growth in vivo . miR-377-3p was confirmed as a target of LOC554202, and miR-377-3p silencing largely overturned LOC554202 knockdown-mediated anti-tumor effects in chordoma cells. miR-377-3p interacted with the 3' untranslated region (3'UTR) of SMAD3 and miR-377-3p overexpression-mediated antitumor effects in chordoma cells were largely attenuated by SMAD3 overexpression. LOC554202 could positively regulate SMAD3 expression by sponging miR-377-3p in chordoma cells. LOC554202 contributed to the glycolysis of chordoma cells by targeting binding to miR-377-3p/SMAD3 axis. LOC554202 facilitated the proliferation, migration, invasion and glycolysis and inhibited the apoptosis of chordoma cells by mediating miR-377-3p/SMAD3 axis.

Interactions of melatonin with various signaling pathways: implications for cancer therapy

Melatonin is a neuro-hormone with conserved roles in evolution. Initially synthetized as an antioxidant molecule, it has gained prominence as a key molecule in the regulation of the circadian rhythm. Melatonin exerts its effect by binding to cytoplasmic and intra-nuclear receptors, and is able to regulate the expression of key mediators of different signaling pathways. This ability has led scholars to investigate the role of melatonin in reversing the process of carcinogenesis, a process in which many signaling pathways are involved, and regulating these pathways may be of clinical significance. In this review, the role of melatonin in regulating multiple signaling pathways with important roles in cancer progression is discussed, and evidence regarding the beneficence of targeting malignancies with this approach is presented.

The mechanisms and roles of melatonin in gastrointestinal cancer

Gastrointestinal (GI) cancer is a global health problem with wide lesions and numerous cases. The increased morbidity and mortality of GI cancer is a socio-economic challenge for decades to come. Melatonin, a nature indolamine, exerts a crucial role in molecular interactions involved in multiple functional and physiological processes. Increasing evidence indicates that melatonin can modulate GI tract, decrease the occurrence of GI cancer, and enhance the sensitivity to chemoradiotherapy. However, little is known about the exact role of melatonin in anti-carcinogenesis. In this review, we discuss the action of the beneficial effects of melatonin in GI carcinogenesis. Furthermore, we compile the understanding of the role of melatonin in GI cancer, including esophageal cancer (EC), gastric cancer (GC), hepatocellular carcinoma (HCC), colorectal cancer (CRC), and pancreatic cancer (PC). In addition, the potential therapeutic application and clinical evaluation of melatonin in GI cancer are also discussed.

A review on the role of mir-16-5p in the carcinogenesis

miR-16-5p is microRNA with important roles in the development of diverse malignancies including neuroblastoma, osteosarcoma, hepatocellular carcinoma, cervical cancer, breast cancer, brain tumors, gastrointestinal cancers, lung cancer and bladder cancer. This miRNA has 22 nucleotides. hsa-miR-16-5p is produced by MIR16-1 gene. First evidence for its participation in the carcinogenesis has been obtained by studies reporting deletion and/or down-regulation of these miRNAs in chronic lymphocytic leukemia. Subsequent studies have shown down-regulation of miR-16-5p in a variety of cancer cell lines and clinical samples. Besides, tumor suppressor role of miR-16-5p has been verified in animal models of different types of cancers. Studies in these models have shown that over-expression of this miRNA or modulation of expression of lncRNAs that sponge this miRNA can block carcinogenic processes. In the current review, we summarize function of miR-16-5p in the development and progression of different cancers.

Circular RNA circPGD contributes to gastric cancer progression via the sponging miR-16-5p/ABL2 axis and encodes a novel PGD-219aa protein

CircRNAs have critical effects on tumor development and progression. However, circPGD effect on gastric cancer (GC) is still elusive. Nuclear and cytoplasmic RNA fractionation, and RNA-FISH assay examined the localization of circPGD in MGC-803 cells. qRT-PCR was conducted to detect the expression and prognostic significance of circPGD, miR-16-5p, and ABL2 within GC tissues. Meanwhile, qRT-PCR, luciferase reporter assays, rescue, and western blotting assays confirmed the interactions between circPGD, miR-16-5p, and ABL2. Transwell, wound healing, and colony-formation assays, as well as CCK-8 and cell apoptosis assays, analyzed the functions of circPGD, miR-16-5p, ABL2, as well as PGD-219aa within GC cells. Western blotting and cell immunofluorescence experiments detected the differences in the expression of the related proteins. Finally, xenograft and metastatic mouse models were used to investigate circPGD function in vivo. Mass spectrometry was used to detect the existence of PGD-219aa in MGC-803 cells. CircPGD was localized in the cytoplasm and nucleus of MGC-803 cells. Compared with the control, circPGD and ABL2 expression increased within GC tissues and cells, and the miR-16-5p level was decreased. Functionally, circPGD promoted cell proliferation, migration and suppressed apoptosis in vitro. Mechanistically, circPGD sponged miR-16-5p for relieving miR-16-5p suppression on the corresponding target ABL2 via the SMAD2/3 and YAP signaling pathways. In addition, circPGD encodes a novel PGD-219aa protein that can enhance the growth and migration of GC cells, while inhibiting GC cells apoptosis via the SMAD2/3 and YAP signaling pathways. Furthermore, circPGD overexpression enhanced tumor aggressiveness, while circPGD knockdown inhibited tumor growth. Overall, circPGD has a novel oncogenic effect on GC cells, indicating the potential of circPGD as the tumorigenic factor and a promising diagnostic marker for GC.

Melatonin may suppress lung adenocarcinoma progression via regulation of the circular noncoding RNA hsa_circ_0017109/miR-135b-3p/TOX3 axis

Melatonin is a hormone synthesized in the pineal gland and has widespread physiological and pharmacological functions. Moreover, it can activate protective receptor-dependent processes. These processes can prevent tissue carcinogenesis and inhibit malignant tumor progression and metastasis. Therefore, we investigated the regulatory effects of melatonin on dysregulated circular RNAs in human lung adenocarcinoma (LUAD) cells. In this study, we treated LUAD cells with melatonin and measured the expression of hsa_circ_0017109, miR-135b-3p, and TOX3 by quantitative reverse transcription polymerase chain reaction. Colony formation and cell counting kit-8 assays were used to determine cell proliferation. The wound-healing assay and Transwell experiment were carried out to evaluate the migration potential and invasive capacity of LUAD cells. Also, cell apoptosis was detected using a cell apoptosis kit, and protein production was identified by Western blot. It was suggested that melatonin could inhibit LUAD progression in vivo and in vitro, and the role of TOX3 in this process was explored. Additionally, hsa_circ_0017109 was found to sponge miR-135b-3p, a downstream factor of circ_0017109, which was demonstrated to target TOX3 in LUAD cells and could promote the Hippo pathway and epithelial-mesenchymal transition pathway. To summarize, we demonstrated that melatonin decreases the expression of circ_0017109 and suppresses the non-small-cell lung cancer cell migration, invasion, and proliferation through decreasing TOX3 expression via direct activation of miR-135b-3p.

The Prospective Application of Melatonin in Treating Epigenetic Dysfunctional Diseases

In the past, different human disorders were described by scientists from the perspective of either environmental factors or just by genetically related mechanisms. The rise in epigenetic studies and its modifications, i.e., heritable alterations in gene expression without changes in DNA sequences, have now been confirmed in diseases. Modifications namely, DNA methylation, posttranslational histone modifications, and non-coding RNAs have led to a better understanding of the coaction between epigenetic alterations and human pathologies. Melatonin is a widely-produced indoleamine regulator molecule that influences numerous biological functions within many cell types. Concerning its broad spectrum of actions, melatonin should be investigated much more for its contribution to the upstream and downstream mechanistic regulation of epigenetic modifications in diseases. It is, therefore, necessary to fill the existing gaps concerning corresponding processes associated with melatonin with the physiological abnormalities brought by epigenetic modifications. This review outlines the findings on melatonin’s action on epigenetic regulation in human diseases including neurodegenerative diseases, diabetes, cancer, and cardiovascular diseases. It summarizes the ability of melatonin to act on molecules such as proteins and RNAs which affect the development and progression of diseases.

Melatonin inhibits the malignant progression of glioblastoma via regulating miR-16-5p/PIM1

OBJECTIVES

Melatonin (MT) is a pineal hormone with antineoplastic potential. This study aims to explore the therapeutic potential and mechanism of MT on glioblastoma (GBM).

METHODS

A human GBM cell line, LN229 was used for evaluating the function of MT. Cell viability, apoptosis, and migration were detected by CCK-8, flow cytometry, and transwell assays, respectively. The mRNA and protein expression of specific genes were measured by qRT-PCR and western blot, respectively. The regulatory relationship between miR-16-5p and PIM1 was validated by dual luciferase reporter gene assay. A mouse xenograft model was established to prove the anti-tumor effect and related mechanisms of MT in vivo.

RESULTS

MT inhibited the viability and migration, and promoted the apoptosis of LN229 cells in a dose-dependent manner. MiR-16-5p was dose-dependently up-regulated by MT in LN229 cells, which negatively regulated its target PIM1. MiR-16-5p inhibitor eliminated the anti-tumor effect of MT in LN229 cells, while si-PIM1 reversed the effect of miR-16-5p inhibitor in MT-treated cells. MT inhibited the tumor growth in vivo and MT-induced PIM1 down-regulation was reversed by miR-16-5p inhibition in tumor tissues.

CONCLUSIONS

MT inhibits the malignant progression of GBM via regulating miR-16-5p-midiated PIM1.

Antitumor and Protective Effects of Melatonin: The Potential Roles of MicroRNAs

MicroRNAs (miRNAs) are endogenous short noncoding RNAs with approximately 22 nucleotides. The primary function of miRNAs is the negative regulation of target gene expression via mRNA degradation or translation inhibition. During recent years, much attention has been made toward miRNAs' role in different disorders; particularly cancer and compounds with modulatory effects on miRNAs are of interest. Melatonin is one of these compounds which is secreted by the pineal gland. Also, melatonin is present in the leaves, fruits, and seeds of plants. Melatonin has several valuable biological activities such as antioxidant, anti-inflammation, antitumor, and antiaging activities. This important agent is extensively used to treat different disorders such as cancer and neurodegenerative and cardiovascular diseases. This review aims to describe the modulatory effect of melatonin on miRNAs as novel targets.

Plasma MicroRNA Signature Panel Predicts the Immune Response After Antiretroviral Therapy in HIV-Infected Patients

Background

Approximately 10–40% of people with human immunodeficiency virus (HIV) infection are unable to obtain successful improvements in immune function after antiretroviral therapy (ART). These patients are at greater risk of developing non-acquired immunodeficiency syndrome (AIDS)-related conditions, with the accompanying increased morbidity and mortality. Discovering predictive biomarkers can help to identify patients with a poor immune response earlier and provide new insights into the mechanisms of this condition.

Methods

A total of 307 people with HIV were enrolled, including 110 immune non-responders (INRs) and 197 immune responders (IRs). Plasma samples were taken before ART, and quantities of plasma microRNAs (miRNAs) were determined using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). Candidate biomarkers were established through four phases: discovery, training, validation, and blinded test. Binary logistic regression was used to analyze the combined predictive capacity of the identified miRNAs. The effect of one miRNA, miR-16-5p, on T cell function was assessed in vitro.

Results

Expression of five miRNAs (miR-580, miR-627, miR-138-5p, miR-16-5p, and miR-323-3p) was upregulated in the plasma of INRs compared with that in IRs. Expression of these miRNAs was negatively correlated with both CD4⁺ T cell counts and the increase in the proportion of CD4⁺ T cells after one year of ART. These five miRNAs were combined in a predictive model, which could effectively identify INRs or IRs. Furthermore, we found that miR-16-5p inhibits CD4⁺ T cell proliferation by regulating calcium flux.

Conclusion

We established a five-miRNA panel in plasma that accurately predicts poor immune response after ART, which could inform strategies to reduce the incidence of this phenomenon and improve the clinical management of these patients.

Long non-coding RNA LINC00649 regulates YES-associated protein 1 (YAP1)/Hippo pathway to accelerate gastric cancer (GC) progression via sequestering miR-16-5p

Although long non-coding RNA (LncRNA) LINC00649 is reported to be closely associated with acute myeloid leukemia (AML), prostate cancer and colorectal cancer, its role in regulating other types of cancer, such as gastric cancer (GC), has not been studied. This study analyzed the expression status of LINC00649 in GC tissues and cells by performing Real-Time qPCR analysis, and we found that LINC00649 tended to be enriched in cancerous tissues and cells but not in their normal counterparts, which were supported by the data from TCGA dataset. Next, by performing the gain- and loss-of-function experiments, we expectedly found that LINC00649 acted as an oncogene to accelerate GC cell proliferation, migration and epithelial-mesenchymal transition (EMT) in vitro and promote its tumorigenesis in vivo. Moreover, the online miRDB software predicted that miR-16-5p bound to both LINC00649 and 3' untranslated region (3'UTR) of YAP1 mRNA, which were validated by the following dual-luciferase reporter gene system assay and RNA pull-down assay. Finally, we proved that LINC00649 exerted its tumor-promoting effects in GC by regulating the miR-16-5p/YES-associated protein 1 (YAP1)/Hippo pathway. Mechanistically, knock-down of LINC00649 suppressed YAP1 expressions by releasing miR-16-5p, resulting in the recovery of the Hippo pathway, which suppressed the expression levels of the downstream oncogenes, including EGFR, SOX2 and OCT4, leading to the inhibition of the malignant phenotypes in GC cells. In conclusion, this study, for the first time, evidenced that LINC00649 promoted GC progression by targeting the miR-16-5p/YAP1/Hippo signaling pathway, which provided potential diagnostic and therapeutic indicators for GC treatment for clinical utilization.

The lncRNA H19/miR-541-3p/Wnt/β-catenin axis plays a vital role in melatonin-mediated osteogenic differentiation of bone marrow mesenchymal stem cells

Implant dentures become the first choice for denture restoration in patients with tooth loss. However, oral implants often fail in osteoporosis (OP) patients. Melatonin (MT) induces osteogenic differentiation of bone mesenchymal stem cells (BMSCs), suggesting its therapeutic potential in OP treatment. Long non-coding RNA H19 induces osteogenic differentiation of BMSCs, while its regulatory mechanism in MT-involved osteogenic and adipogenic differentiation of BMSCs remains elusive. Ovariectomized (OVX) rat was used to construct an OP model, and bone quality was assessed. Meanwhile, the expression of H19, miR-541-3p, MT and adiponectin (APN) was examined by quantitative reverse transcription-PCR (qRT-PCR) or ELISA. The adipogenic and osteogenic differentiation of BMSCs were determined by oil red O staining and alizarin red S staining, respectively. The targeting relationships between H19, miR-541-3p and APN mRNA were predicted by bioinformatics and confirmed by RNA immunoprecipitation and dual-luciferase reporter assay. The results showed that MT, H19 and APN were down-regulated, while miR-541-3p was up-regulated in the OVX rat model. At the cellular level, MT reduced adipogenic differentiation, heightened osteogenic differentiation of BMSCs, and activated Wnt/β-catenin pathway, which were reversed by the MT2 selective inhibitor 4-P-PDOT. Overexpressing H19 facilitated the osteogenic differentiation and inhibited the adipogenic differentiation of BMSCs mediated by MT, while H19 knockdown or overexpressing miR-541-3p had the opposite effect. Moreover, H19 functioned as a competitive endogenous RNA and sponged miR-541-3p, and miR-541-3p targeted APN. Overall, MT modulates the osteogenic and adipogenic differentiation of BMSCs by mediating H19/miR-541-3p/APN axis, providing a new reference for the targeted therapy of OP.

Multiple interactions between melatonin and non-coding RNAs in cancer biology

The melatonin hormone secreted by the pineal gland is involved in physiological functions such as growth and maturation, circadian cycles, and biological activities including antioxidants, anti-tumor, and anti-ischemia. Melatonin not only interacts with proteins but also has functional effects on regulatory RNAs such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs). In this study, we overview various physiological and pathological conditions affecting melatonin through lncRNA and miRNA. The information compiled herein will serve as a solid foundation to formulate ideas for future mechanistic studies on melatonin. It will also provide a chance to more clarify the emerging functions of the non-coding transcriptome.

MicroRNAs are involved in the development and progression of gastric cancer

MicroRNAs (miRNAs) are recognized as an essential component of the RNA family, exerting multiple and intricate biological functions, particularly in the process of tumorigenesis, proliferation, and metastatic progression. MiRNAs are altered in gastric cancer (GC), showing activity as both tumor suppressors and oncogenes, although their true roles have not been fully understood. This review will focus upon the recent advances of miRNA studies related to the regulatory mechanisms of gastric tumor cell proliferation, apoptosis, and cell cycle. We hope to provide an in-depth insight into the mechanistic role of miRNAs in GC development and progression. In particular, we summarize the latest studies relevant to miRNAs' impact upon the epithelial-mesenchymal transition, tumor microenvironment, and chemoresistance in GC cells. We expect to elucidate the molecular mechanisms involving miRNAs for better understanding the etiology of GC, and facilitating the development of new treatment regimens for the treatment of GC.

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.

Prognostic value of small mother against decapentaplegic expression in human gastric cancer

Gastric cancer is the fifth most common malignancy in the world with alow 5-year survival rate. To date, no study has investigated the prognostic role of the small mother against decapentaplegic (SMAD) in gastric cancer. The association of SMADs with overall survival (OS) of gastric cancer was analyzed on the online Kaplan-Meier (KM) plotter database. Clinical data such as stage, differentiation, gender, treatment, and Her2 mutation status of gastric cancer patients were analyzed. The (E)-SIS3 was used to inhibit SMAD3 expression in gastric cancer cells, and the effects of SMAD3 on gastric cancer cells were analyzed via real-time cellular analysis (RTCA), flow cytometry, colony formation, and immunofluorescence assay. The results showed that the high expression of three members of SMADs (SMAD1, SMAD2, SMAD4) was correlated with afavorable OS of gastric cancer patients. Meanwhile, SMAD3 expression level indicated highly differentiated cancer. We also observed that surgical treatment was associated with high expression level of SMAD1 and SMAD2. Besides, the effect of Her2 on gastric cancer was not noticeable. Moreover, (E)-SIS3 pharmacological assay revealed that inhibition of expression of SMAD3 suppressed the proliferation and migration ability of gastric cancer cells via inducing apoptosis. Collectively, these results demonstrate that the high expression level of three members of SMADs (SMAD1, SMAD2, and SMAD4) is significantly correlated with favorable OS of gastric cancer patients, which is opposite to SMAD3. Thus, SMADs regulate the differentiation of cancer and can be used to guide treatment decisions.

Specific epigenetic age acceleration patterns among four molecular subtypes of gastric cancer and their prognostic value

Aims: To determine the association of the methylation age (Horvath epigenetic clock) of gastric cancer (GC) tissues with molecular subtypes and patient survival. Materials & methods: Multivariate regression models were used to determine the association of methylation age acceleration (AA) with the clinical and molecular characteristics of 333 GC patients. Results: Relative to the chromosomal instability subtype, the epigenetic AA was 49.8 (95% CI: 42.7-56.9) years for Epstein-Barr virus, 16.1 (10.6-21.6) years for microsatellite instability, and 6.05 (0.1-11.1) years for genomic stability subtype. GC patients with accelerated aging of tumor tissues had better outcomes (adjusted hazard ratio: 3.13; p = 0.03). Differentially methylated probes in patients with accelerated and decelerated methylation aging enriched in pathways including BMP signaling, HMGB1 signaling, STAT3 signaling and human embryonic stem cell pluripotency. Conclusions: Our results highlight the prognostic value of epigenetic AA in GC and suggest that epigenetic AA is also an indicator of molecular subtype in GC.

An updated review of mechanistic potentials of melatonin against cancer: pivotal roles in angiogenesis, apoptosis, autophagy, endoplasmic reticulum stress and oxidative stress

Cancers are serious life-threatening diseases which annually are responsible for millions of deaths across the world. Despite many developments in therapeutic approaches for affected individuals, the rate of morbidity and mortality is high. The survival rate and life quality of cancer patients is still low. In addition, the poor prognosis of patients and side effects of the present treatments underscores that finding novel and effective complementary and alternative therapies is a critical issue. Melatonin is a powerful anticancer agent and its efficiency has been widely documented up to now. Melatonin applies its anticancer abilities through affecting various mechanisms including angiogenesis, apoptosis, autophagy, endoplasmic reticulum stress and oxidative stress. Regarding the implication of mentioned cellular processes in cancer pathogenesis, we aimed to further evaluate the anticancer effects of melatonin via these mechanisms.

LncRNA PROX1-AS1 Facilitates Gastric Cancer Progression via miR-877-5p/PD-L1 Axis

Introduction

Growing evidences imply that multiple long non-coding RNAs (lncRNAs) play a significant role in the treatment of cancer. Therefore, it is of great significance to discover new biomarkers or therapeutic targets of gastric cancer (GC). However, the potential molecular mechanism of lncPROX1-AS1 in GC remains unknown. The objective of current study is to investigate the effect of PROX1-AS1 in GC.

Methods

Thus, we detect that PROX1-AS1 is over-expressed in tissues and cell lines of GC using qRT-PCR analysis. CCK-8, colony formation, flow cytometry, wounding healing and transwell analyses were performed to explore the effect of PROX1-AS1 on GC malignant behaviors.

Results

It is further disclosed that silencing of PROX1-AS1 represses cell proliferation, migration, and invasion, whereas promotes cell apoptosis in GC. Bioinformatics analysis suggests that miR-877-5p is negatively regulated by PROX1-AS1 and ectopic of miR-877-5p alleviates the malignant behaviors of GC. Subsequently, miR-877-5p suppresses the activity of PD-L1-3ʹ UTR. At last, rescue assays demonstrated that the GC progression is suppressed by sh-PROX1-AS1 and facilitated on account of miR-877-5p inhibitors and then is retrieved by sh-PD-L1.

Discussion

Our findings reveal that PROX1-AS1 exerts its role via miR-877-5p/PD-L1 axis in the GC progression, suggesting that PROX1-AS1 may represent a new therapeutic target for the diagnosis and treatment of GC patients.

Exosomal microRNA panels as biomarkers for hematological malignancies

Hematological malignancies are classified as a heterogeneous category of cancers with various degrees of incidence and prognosis and different etiologies. Due to their aggressive essence they should be diagnosed as early as possible to improve prognosis, treatment outcome and survival. Bases on the limitations of previously identified biomarkers in terms of sensitivity, specificity and predictability, it is necessary to develop new diagnostic tools and biomarkers for the early diagnosis of hematological malignancies. Exosomes are nanovesicles secreted by almost all cell types in both physiological and pathological conditions. They play major roles in intercellular communication and are recently being considered as disease biomarkers. These nanovesicles carry proteins, lipids and nucleic acids like microRNAs (miRNAs). miRNAs are small noncoding RNAs, which act as translational suppressors via regulating protein-coding genes. The aberrant expression of miRNAs has been shown in various conditions including hematological malignancies. Moreover, it is now known that tumor cells secrete higher amounts of exosomes compared to normal cells. The idea of using exosomal miRNAs in serum as biomarkers is based on their surprisingly high stability and specificity. In the present paper, we reviewed and recommended exosomal miRNA panels including (miR-150, miR-155 and miR-1246), (miR-17-5p, miR-20a-5p, miR-16-5p and miR-5a-5p), (miR-18a, Let-7b) and (miR192-5p, miR21-5p, miR320b and Let-7d), for their potential to be used as non-invasive biomarkers in different hematological malignancies such as multiple myeloma, leukemia, and lymphoma.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

Melatonin inhibits proliferation and viability and promotes apoptosis in colorectal cancer cells via upregulation of the microRNA-34a/449a cluster

Colorectal cancer (CRC) has a significant burden on healthcare systems worldwide, and is associated with high morbidity and mortality rates in patients. In 2020, the estimated new cases of colon cancer in the United States are 78,300 in men and 69,650 in women. Thus, developing effective and novel alternative agents and adjuvants with reduced side effects is important to reduce the lethality of the disease and improve the quality of life of patients. Melatonin, a pineal hormone that possesses numerous physiological functions, including anti-inflammatory and antitumor activities, can be found in various tissues, including the gastrointestinal tract. Melatonin exerts anticarcinogenic effects via various mechanisms; however, the identified underlying molecular mechanisms do not explain the full breadth of anti-CRC effects mediated by melatonin. MicroRNAs (miRs) serve critical roles in tumorigenesis, however, whether melatonin can inhibit CRC by regulating miRs is not completely understood. In the present study, the roles and mechanism underlying melatonin in CRC were investigated. The proliferation of human CRC cells was tested by CCK8, EDU and colony formation assay. The apoptosis of cancer cells was detected by flow cytometry and western blotting. A xenograft mouse model was constructed and the proliferation and apoptosis of tumor tissue was detected by Ki-67 and TUNEL staining assay respectively. Reverse transcription-quantitative PCR and western blotting were performed to measure the regulation of miRs on mRNA, and the dual-luciferase report analysis experiment was used to verify the direct target genes of miRs. Compared with the control group, melatonin inhibited viability and proliferation, and induced apoptosis in CRC cells. Additionally, the effect of melatonin in a xenograft mouse model was assessed. Compared with the control group, melatonin significantly enhanced the expression levels of the miR-34a/449a cluster, reduced CRC cell proliferation and viability, and increased CRC cell apoptosis. Finally, the dual-luciferase reporter assay indicated that Bcl-2 and Notch1 were the target mRNAs of the miR-34a/449a cluster. To the best of our knowledge, the present study was the first to suggest that melatonin inhibited proliferation and viability, and promoted apoptosis in CRC cells via upregulating the expression of the miR-34a/449a cluster in vitro and in vivo. Therefore, melatonin may serve as a potential therapeutic for CRC.

A Translational Model for Venous Thromboembolism: MicroRNA Expression in Hibernating Black Bears

BACKGROUND

Hibernating American black bears have significantly different clotting parameters than their summer active counterparts, affording them protection against venous thromboembolism during prolonged periods of immobility. We sought to evaluate if significant differences exist between the expression of microRNAs in the plasma of hibernating black bears compared with their summer active counterparts, potentially contributing to differences in hemostasis during hibernation.

MATERIALS AND METHODS

MicroRNA sequencing was assessed in plasma from 21 American black bears in summer active (n = 11) and hibernating states (n = 10), and microRNA signatures during hibernating and active state were established using both bear and human genome. MicroRNA targets were predicted using messenger RNA (mRNA) transcripts from black bear kidney cells. In vitro studies were performed to confirm the relationship between identified microRNAs and mRNA expression, using artificial microRNA and human liver cells.

RESULTS

Using the bear genome, we identified 15 microRNAs differentially expressed in the plasma of hibernating black bears. Of these microRNAs, three were significantly downregulated (miR-141-3p, miR-200a-3p, and miR-200c-3p), were predicted to target SERPINC1, the gene for antithrombin, and demonstrated regulatory control of the gene mRNA expression in cell studies.

CONCLUSIONS

Our findings suggest that the hibernating black bears' ability to maintain hemostasis and achieve protection from venous thromboembolism during prolonged periods of immobility may be due to changes in microRNA signatures and possible upregulation of antithrombin expression.

The Effect of Melatonin Modulation of Non-coding RNAs on Central Nervous System Disorders: An Updated Review

Melatonin is a hormone produced in and secreted by the pineal gland. Besides its role in regulating circadian rhythms, melatonin has a wide range of protective functions in the central nervous system (CNS) disorders. The mechanisms underlying this protective function are associated with the regulatory effects of melatonin on related genes and proteins. In addition to messenger ribonucleic acid (RNA) that can be translated into protein, an increasing number of non-coding RNAs in the human body are proven to participate in many diseases. This review discusses the current progress of research on the effects of melatonin modulation of non-coding RNAs (ncRNAs), including microRNA, long ncRNA, and circular RNA. The role of melatonin in regulating common pathological mechanisms through these ncRNAs is also summarized. Furthermore, the ncRNAs, currently shown to be involved in melatonin signaling in CNS diseases, are discussed. The information compiled in this review will open new avenues for future research into melatonin mechanisms and provide a further understanding of ncRNAs in the CNS.

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.

Melatonin Inhibits the Progression of Oral Squamous Cell Carcinoma via Inducing miR-25-5p Expression by Directly Targeting NEDD9

Melatonin exerts anti-cancer roles in various types of cancers. However, to the best of our knowledge, its role in oral squamous cell carcinoma (OSCC) is unknown. The present study aimed to investigate the role of melatonin and its underlying mechanism in OSCC. MTT, colony formation, wound healing, and transwell invasion assays proved that melatonin played anti-tumor effects in OSCC cells by inhibiting cell viability, proliferation, migration, and invasion in a concentration-dependent manner. The RT-qPCR analysis showed that miR-25-5p was significantly upregulated after melatonin treatment. Further, miR-25-5p might be involved in melatonin-induced inhibitory effects on the biological behavior of OSCC. The expression of miR-25-5p was decreased in tumor tissues and OSCC cells detected by RT-qPCR. MTT assay, colony formation assay, and TUNEL staining indicated miR-25-5p overexpression inhibited OSCC cell viability, proliferation, and induced OSCC cell apoptosis. Furthermore, wound healing, transwell invasion assay, and animal experiments suggested that miR-25-5p might exert suppressive effects on the migration, invasion, and tumor formation of OSCC cells, while miR-25-5p knockdown exhibited the opposite effects in OSCC cells. Bioinformatics analysis, western blot analysis, and luciferase reporter assay suggested that neural precursor cell expressed developmentally downregulated protein 9 (NEDD9) was proved to be a putative target for miR-25-5p. The role of NEDD9 in inhibiting OSCC cell proliferation, invasion, and migration was verified with NEDD9 siRNA transfection. Thus, melatonin exerted anti-proliferative, anti-invasive, and anti-migrative effects on OSCC via miR-25-5p/NEDD9 pathway. Melatonin could be applied as a potential novel drug on treating OSCC.

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.

Melatonin restores the pluripotency of long-term-cultured embryonic stem cells through melatonin receptor-dependent m6A RNA regulation

N6-methyladenosine (m6A) methylation is the most common and abundant modification on mammalian messenger RNA (mRNA) and regulates the pluripotency of embryonic stem cells (ESCs). Research has shown that melatonin plays a fundamental role in DNA and histone modifications. However, the effect of melatonin on RNA modification is unknown. Here, for the first time, we investigated the effect of melatonin on m6A modifications in long-term-cultured ESCs. Pluripotency studies indicated that 10 μmol/L melatonin sufficiently maintained ESCs with stemness features over 45 passages (more than 90 days). Notably, treatment of ESCs with melatonin led to a significant decrease in the nuclear presence of m6A methyltransferase complex and decreased global m6A modification. Depletion of melatonin receptor 1 (MT1) by CRISPR/Cas9 significantly reduced the effects of melatonin on ESC pluripotency and m6A modification. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) revealed that melatonin promotes stabilization of core pluripotency factors, such as Nanog, Sox2, Klf4, and c-Myc, by preventing m6A-dependent mRNA decay. Using cell signaling pathway profiling systems, melatonin was shown to regulate m6A modification predominantly through the MT1-JAK2/STAT3-Zfp217 signal axis. This study reveals a new dimension regarding melatonin regulation of gene expression at the RNA level.

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.

miR-16-5p Suppresses Progression and Invasion of Osteosarcoma via Targeting at Smad3

Background

MicroRNAs are known to regulate carcinogenesis of osteosarcoma. Although, miR-16-5p is known to exert inhibitory effects on several forms of cancers, its effects on the growth and invasion of osteosarcoma have not been studied.

Methods

We collected human osteosarcoma specimens and adjacent tissues to detect the expression of miR-16-5p by real-time polymerase chain reaction, immunoblotting, and immunohistochemistry. The proliferation, migration, and invasion of MG63 and HOS cells following miR-16-5p overexpression and inhibition were detected with cell counting kit-8, wound healing assay, and Transwell assay, respectively. An expression vector carrying a mutated 3'-untranslated region of mothers against decapentaplegic homolog 3 (Smad3) was constructed.

Results

The results showed that miR-16-5p expression was downregulated in osteosarcoma tissues and cells as compared with adjacent counterparts, while Smad3 was overexpressed in osteosarcoma cells. The overexpression of miR-16-5p resulted in the inhibition of the proliferation, migration, and invasion of osteosarcoma cells and enhanced the therapeutic effect of cisplatin. These effects were attenuated with miR-16-5p expression inhibition. In cells transfected with miR-16-5p mimic, Smad3 expression decreased, while this effect was absent in the cells carrying mutated Smad3.

Conclusions

Therefore, miR-16-5p inhibits the growth and invasion of osteosarcoma by targeting Smad3.

Therapeutic Potential of Melatonin in the Regulation of MiR-148a-3p and Angiogenic Factors in Breast Cancer

BACKGROUND

The high mortality rate of breast cancer is related to the occurrence of metastasis, a process that is promoted by tumor angiogenesis. MicroRNAs are small molecules of noncoding mRNA that play a key role in gene regulation and are directly involved in the progression and angiogenesis of various tumor types, including breast cancer. Several miRNAs have been described as promoters or suppressors angiogenesis and may be associated with tumor growth and metastasis. Melatonin is an oncostatic agent with a capacity of modifying the expression of innumerable genes and miRNAs related to cancer.

OBJECTIVE

The aim of this study was to evaluate the role of melatonin and the tumor suppressor miR- 148a-3p on angiogenesis of breast cancer.

METHOD

MDA-MB-231 cells were treated with melatonin and modified with the overexpression of miR-148a-3p. The relative quantification in real-time of miR-148a-3p, IGF-IR and VEGF was performed by real-time PCR. The protein expression of these targets was performed by immunocytochemistry and immunohistochemistry. Survival, migration and invasion rates of tumor cells were evaluated. Finally, the xenograft model of breast cancer was performed to confirm the role of melatonin in the tumor.

RESULTS

The melatonin was able to increase the gene level of miR-148a-3p and decreased the gene and protein expression of IGF-1R and VEGF, both in vitro and in vivo. In addition, it also had an inhibitory effect on the survival, migration and invasion of breast tumor cells.

CONCLUSION

Our results confirm the role of melatonin in the regulation of miR-148a-3p and decrease of angiogenic factors.

Differential expression of circulating serum miR-1249-3p, miR-3195, and miR-3692-3p in non-small cell lung cancer

Global deregulation in miRNA expression is a hallmark of cancer cell. An estimated 2300 mature miRNAs are encoded by human genome; role of many of which in carcinogenesis and as cancer biomarkers remains unexplored. In this study, we investigated the utility of miR-3692-3p, miR-3195, and miR-1249-3p as biomarkers in non-small cell lung cancer (NSCLC). For this prospective study, 115 subjects, including 75 NSCLC patients and 40 controls, were recruited. The expression of miR-3692-3p, miR-3195, and miR-1249-3p was checked using qRT-PCR. The miRNA expression was correlated with survival outcome and therapeutic response. There were no significant differences in the mean age of NSCLC patients and controls (56.2 and 55.3 years, respectively; p = 0.3242). Majority of NSCLC patients (67%) were smokers. We observed a significant upregulation of miR-3692-3p expression (p < 0.0001), while the expression of miR-3195 (p = 0.0017) and miR-1249-3p was significantly downregulated (p < 0.0001) in the serum of NSCLC patients as compared to controls. The expression of miR-1249-3p was significantly upregulated in lung adenocarcinoma versus lung squamous cell carcinoma (p = 0.0178). Interestingly, patients who responded to chemotherapy had higher expression of miR-1249-3p than non-responders (p = 0.0107). Moreover, patients with higher expression of miR-3195 had significantly longer overall survival (p = 0.0298). In multivariate analysis, miR-3195 emerged as independent prognostic factor for overall survival. We conclude that the miR-3195 may have prognostic significance, while miR-1249-3p may predict therapeutic response in NSCLC. Further studies are warranted to elucidate the role of these miRNAs in lung carcinogenesis and their utility as candidate cancer biomarkers.

circRNA-14723 promotes hepatocytes proliferation in rat liver regeneration by sponging rno-miR-16-5p

Circular RNA (circRNA) is a subclass of noncoding RNA (ncRNA) detected within mammalian tissues and cells. However, its regulatory role during the proliferation phase of rat liver regeneration (LR) remains unreported. This study was designed to explore their regulatory mechanisms in cell proliferation of LR. The circRNA expression profile was detected by high-throughput sequencing. It was indicated that 260 circRNAs were differentially expressed during the proliferation phase of rat LR. Among them, circ-14723 displayed a significantly differential expression. We further explored its regulatory mechanism in rat hepatocytes (BRL-3A cells). First, EdU, flow cytometry and western blot (WB) indicated that knocking down circ-14723 inhibited BRL-3A cells proliferation. Second, RNA-Pulldown and dual-luciferase report assay showed that circ-14723 could sponge rno-miR-16-5p. At last, WB showed that the reported target genes of rno-miR-16-5p, CCND1, and CCNE1 were downregulated after knocking down circ-14723. In conclusion, we found that circ-14723 exerted a critical role in G1/S arrest to promote cell proliferation via rno-miR-16-5p/CCND1 and CCNE1 axis in rat LR. This finding further revealed the regulatory mechanisms of circRNA on cell proliferation of LR, and might provide a potential target for clinical problems.

Research Progress in microRNA-Based Therapy for Gastric Cancer

Gastric cancer (GC) is one of the leading causes of tumor-related mortality. In addition to surgery and endoscopic resection, systemic therapy remains the main treatment option for GC, especially for advanced-stage disease and for cases not suitable for surgical therapy. Hence, improving the efficacy of systemic therapy is still an urgent problem to overcome. In the past decade, the essential roles of microRNAs (miRNAs) in tumor treatment have been increasingly recognized. In particular, miRNAs were recently shown to reverse the resistance to chemotherapy drugs such as 5-fluorouracil, cisplatin, and doxorubicin. Synthesized nanoparticles loaded with mimics or inhibitors of miRNAs can directly target tumor cells to suppress their growth. Moreover, exosomes may serve as promising safe carriers for mimics or inhibitors of miRNAs to treat GC. Some miRNAs have also been shown to play roles in the mechanism of action of other anti-tumor drugs. Therefore, in this review, we highlight the research progress on microRNA-based therapy in GC and discuss the challenges and prospects associated with this strategy. We believe that microRNA-based therapy has the potential to offer a clinical benefit to GC patients, and this review would contribute to and motivate further research to promote this field toward this ultimate goal.

Dendrobium officinale Polysaccharides Inhibit 1-Methyl-2-Nitro-1-Nitrosoguanidine Induced Precancerous Lesions of Gastric Cancer in Rats through Regulating Wnt/β-Catenin Pathway and Altering Serum Endogenous Metabolites

Dendrobium officinale is a herb in traditional Chinese medicine where D. officinale polysaccharides (DOP) are the main active ingredient. This study aimed at evaluating DOP efficiency at inhibiting 1-Methyl-2-nitro-1-nitrosoguanidine (MNNG) induced precancerous lesions of gastric cancer (PLGC) in rats through the Wnt/b-catenin pathway and analyzing the variations of serum endogenous metabolites. PLGC was established in male Sprague-Dawley (SD) rats by administering 150 μg/mL MNNG in drinking water for 7 months and giving 0.1 mL of 10% NaCl once weekly during the initial 20 weeks. Treatment with DOP inhibited the progress of PLGC through decreasing the expression of β-catenin by immunohistochemical analysis. The futher study indicated DOP downregulated gene expression of Wnt2β, Gsk3β, PCNA, CyclinD1, and β-catenin, as well as protein expression of Wnt2β, PCNA, and β-catenin. On the other hand, there were nine endogenous metabolites identified after the DOP treatment. Among these, the most significant one is betaine because of its strong antioxidant activity, leading to an anti-tumor effect. DOP can inhibit MNNG-induced PLGC models via regulating Wnt/β-catenin pathway and by changing endogenous metabolites.

MicroRNA-92b-5p modulates melatonin-mediated osteogenic differentiation of bone marrow mesenchymal stem cells by targeting ICAM-1

Osteoporosis is closely associated with the dysfunction of bone metabolism, which is caused by the imbalance between new bone formation and bone resorption. Osteogenic differentiation plays a vital role in maintaining the balance of bone microenvironment. The present study investigated whether melatonin participated in the osteogenic commitment of bone marrow mesenchymal stem cells (BMSCs) and further explored its underlying mechanisms. Our data showed that melatonin exhibited the capacity of regulating osteogenic differentiation of BMSCs, which was blocked by its membrane receptor inhibitor luzindole. Further study demonstrated that the expression of miR‐92b‐5p was up‐regulated in BMSCs after administration of melatonin, and transfection of miR‐92b‐5p accelerated osteogenesis of BMSCs. In contrast, silence of miR‐92b‐5p inhibited the osteogenesis of BMSCs. The increase in osteoblast differentiation of BMSCs caused by melatonin was attenuated by miR‐92b‐5p AMO as well. Luciferase reporter assay, real‐time qPCR analysis and western blot analysis confirmed that miR‐92b‐5p was involved in osteogenesis by directly targeting intracellular adhesion molecule‐1 (ICAM‐1). Melatonin improved the expression of miR‐92b‐5p, which could regulate the differentiation of BMSCs into osteoblasts by targeting ICAM‐1. This study provided novel methods for treating osteoporosis.

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

Objective: Extracellular vesicles derived from oral cancer cells, which include Exosomes and Oncosomes, are membranous vesicles secreted into the surrounding extracellular environment. These extracellular vesicles can regulate and modulate oral squamous cell carcinoma (OSCC) progression through the horizontal transfer of bioactive molecules including proteins, lipids and microRNA (miRNA). The primary objective of this study was to examine the potential to isolate and evaluate extracellular vesicles (including exosomes) from various oral cancer cell lines and to explore potential differences in miRNA content. Methods: The OSCC cell lines SCC9, SCC25 and CAL27 were cultured in DMEM containing 10% exosome-free fetal bovine serum. Cell-culture conditioned media was collected for exosome and extracellular vesicle isolation after 72 h. Isolation was completed using the Total Exosome Isolation reagent (Invitrogen) and extracellular vesicle RNA was purified using the Total Exosome RNA isolation kit (Invitrogen). Extracellular vesicle miRNA content was evaluated using primers specific for miR-16, -21, -133a and -155. Results: Extracellular vesicles were successfully isolated from all three OSCC cell lines and total extracellular vesicle RNA was isolated. Molecular screening using primers specific for several miRNA revealed differential baseline expression among the different cell lines. The addition of melatonin significantly reduced the expression of miR-155 in all of the OSCC extracellular vesicles. However, miR-21 was significantly increased in each of the three OSCC isolates. No significant changes in miR-133a expression were observed under melatonin administration. Conclusions: Although many studies have documented changes in gene expression among various cancers under melatonin administration, few studies have evaluated these effects on microRNAs. These results may be among the first to evaluate the effects of melatonin on microRNA expression in oral cancers, which suggests the differential modulation of specific microRNAs, such as miR-21, miR-133a and miR-155, may be of significant importance when evaluating the mechanisms and pathways involved in melatonin-associated anti-tumor effects.

RNA-Seq transcriptome analysis shows anti-tumor actions of melatonin in a breast cancer xenograft model

Melatonin is a pleiotropic anti-cancer molecule that controls cancer growth by multiple mechanisms. RNA-Seq can potentially evaluate therapeutic response and its use in xenograft tumor models can differentiate the changes that occur specifically in tumor cells or in the tumor microenvironment (TME). Melatonin actions were evaluated in a xenograft model of triple-negative breast cancer. Balb/c nude mice bearing MDA-MB-231 tumors were treated with melatonin or vehicle. RNA-Seq was performed on the Illumina HiSeq. 2500 and data were mapped against human and mouse genomes separately to differentiate species-specific expression. Differentially expressed (DE) genes were identified and Weighted Gene Co-expression Network Analysis (WGCNA) was used to detect clusters of highly co-expressed genes. Melatonin treatment reduced tumor growth (p < 0.01). 57 DE genes were identified in murine cells, which represented the TME, and were mainly involved in immune response. The WGCNA detected co-expressed genes in tumor cells and TME, which were related to the immune system among other biological processes. The upregulation of two genes (Tnfaip8l2 and Il1f6) by melatonin was validated in the TME, these genes play important roles in the immune system. Taken together, the transcriptomic data suggests that melatonin anti-tumor actions occur through modulation of TME in this xenograft tumor model.

Melatonin May Increase Anticancer Potential of Pleiotropic Drugs

Melatonin (N-acetyl-5-methoxytryptamine) is not only a pineal hormone, but also an ubiquitary molecule present in plants and part of our diet. Numerous preclinical and some clinical reports pointed to its multiple beneficial effects including oncostatic properties, and as such, it has become one of the most aspiring goals in cancer prevention/therapy. A link between cancer and inflammation and/or metabolic disorders has been well established and the therapy of these conditions with so-called pleiotropic drugs, which include non-steroidal anti-inflammatory drugs, statins and peroral antidiabetics, modulates a cancer risk too. Adjuvant therapy with melatonin may improve the oncostatic potential of these drugs. Results from preclinical studies are limited though support this hypothesis, which, however, remains to be verified by further research.

Melatonin and cardioprotection against ischaemia/reperfusion injury: What's new? A review

Melatonin is a pleiotropic hormone with several functions. It binds to specific receptors and to a number of cytosolic proteins, activating a vast array of signalling pathways. Its potential to protect the heart against ischaemia/reperfusion damage has attracted much attention, particularly in view of its possible clinical applications. This review will focus mainly on the possible signalling pathways involved in melatonin-induced cardioprotection. In particular, the role of the melatonin receptors and events downstream of receptor activation, for example, the reperfusion injury salvage kinase (RISK), survivor activating factor enhancement (SAFE) and Notch pathways, the sirtuins, nuclear factor E2-related factor 2 (Nrf2) and translocases in the outer membrane (TOM70) will be discussed. Particular attention is given to the role of the mitochondrion in melatonin-induced cardioprotection. In addition, a brief overview will be given regarding the status quo of the clinical application of melatonin in humans.

Mechanisms Underlying Tumor Suppressive Properties of Melatonin

There is considerable evidence that melatonin may be of use in the prevention and treatment of cancer. This manuscript will review some of the human, animal and cellular studies that provide evidence that melatonin has oncostatic properties. Confirmation that melatonin mitigates pathogenesis of cancer will be described from both direct study of its effects on carcinogenesis, and from indirect findings implicating disruption of the circadian cycle. A distinction is made between the role of melatonin in preventing the initiation of the tumorigenic pathway and the ability of melatonin to retard the progression of cancer. Melatonin appears to slow down the rate of advancement of established tumors and there is evidence that it constitutes a valuable complement to standard pharmacological and radiation treatment modalities. There are instances of the beneficial outcomes in cancer treatment which utilize a range of hormones and vitamins, melatonin being among the constituents of the mix. While these complex blends are empirically promising, they are only briefly mentioned here in view of the confounding influence of a multiplicity of agents studied simultaneously. The last section of this review examines the molecular mechanisms that potentially underlie the oncostatic effects of melatonin. Alterations in gene expression following activation of various transcription factors, are likely to be an important mediating event. These changes in gene activity not only relate to cancer but also to the aging process which underlies the onset of most tumors. In addition, epigenetic events such as modulation of histone acetylation and DNA methylation patterns throughout the lifespan of organisms need to be considered. The antioxidant and immunoregulatory roles of melatonin may also contribute to its cancer modulatory properties. Naturally, these mechanisms overlap and interact extensively. Nevertheless, in the interest of clarity and ease of reading, each is discussed as a separate topic section. The report ends with some general conclusions concerning the clinical value of melatonin which has been rather overlooked and understudied.