MicroRNAs signatures, bioinformatics analysis of miRNAs, miRNA mimics and antagonists, and miRNA therapeutics in osteosarcoma

Epigenetic changes caused by early life stress in the pathogenesis of depression

Major depressive disorder (MDD) is a severe psychiatric disorder with a complex and poorly understood pathogenesis. Epigenetics, a rapidly advancing field of biology, has been implicated in various psychiatric conditions, including schizophrenia, anxiety, substance addiction, and autism. Furthermore, substantial research indicates that epigenetic modifications play a crucial role in the etiology of depression. Early life stress (ELS) refers to adverse experiences occurring during prenatal development (e.g., maternal physical and mental health complications during pregnancy) and/or postnatal life (e.g., abuse, neglect, poverty, parental loss, family conflict, violence, and malnutrition). These early-life adversities can lead to epigenetic modifications, which, in turn, influence key biological processes and contribute to the pathogenesis of MDD. This review provides an overview of the regulatory mechanisms and functions of various epigenetic modifications, including non-coding RNAs, DNA methylation, and histone modifications. We then examine ELS-induced epigenetic alterations and their biological consequences, such as dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, neurogenesis, and neuroplasticity. Finally, we explore their potential implications for both the pathogenesis and treatment of MDD. We hypothesize that ELS-induced epigenetic changes may serve as biomarkers for MDD diagnosis and offer novel therapeutic targets for its treatment.

MicroRNA signatures in osteosarcoma: diagnostic insights and therapeutic prospects

Osteosarcoma (OSa) is the most prevalent primary malignant bone tumor in children and adolescents, characterized by complex genetic and epigenetic alterations. Traditional treatments face significant challenges due to high rates of drug resistance and lack of targeted therapies. Recent advances in microRNA (miRNA) research have opened new avenues for understanding and treating osteosarcoma. This review explores the many critical functions of miRNAs in osteosarcoma, particularly their potential for clinical use. The review highlights two key areas where miRNAs could be beneficial. Firstly, miRNAs can act as biomarkers for diagnosing osteosarcoma and predicting patient prognosis. Secondly, specific miRNAs can regulate cellular processes like proliferation, cell death, migration, and even resistance to chemotherapy drugs in osteosarcoma. This ability to target multiple pathways within cancer cells makes miRNA-based therapies highly promising. Additionally, though the interaction between miRNAs and circular RNAs (circRNAs) falls outside the scope of the paper, it has also been discussed briefly. While miRNA-based therapies offer exciting possibilities for targeting multiple pathways in osteosarcoma, challenges remain. Efficient delivery, potential off-target effects, tumor complexity, and rigorous testing are hurdles to overcome before these therapies can reach patients. Despite these challenges, continued research and collaboration among scientists, clinicians, and regulatory bodies hold the promise of overcoming them. This collaborative effort can pave the way for the development of safe and effective miRNA-based treatments for osteosarcoma.

Unveiling novel regulatory mechanisms of miR-5195-3p in pelvic organ prolapse pathogenesis†

Pelvic organ prolapse is a condition that significantly affects women's quality of life. The pathological mechanism of pelvic organ prolapse is not yet fully understood, and its pathogenesis is often caused by multiple factors, including the metabolic imbalance of the extracellular matrix. This study aims to investigate the role of miR-5195-3p, a microRNA, in the pathology of pelvic organ prolapse and its regulatory mechanism. Using various molecular biology techniques such as real-time reverse transcription Polymerase Chain Reaction (PCR), fluorescence in situ hybridization, immunohistochemistry, and Western blot, miR-5195-3p expression was examined in vaginal wall tissues obtained from pelvic organ prolapse patients. Results revealed an up-regulation of miR-5195-3p expression in these tissues, showing a negative correlation with the expression of extracellular matrix-related proteins. Further analysis using bioinformatics tools identified Lipoxygenase (LOX) as a potential target in pelvic organ prolapse. Dual luciferase reporter gene experiments confirmed LOX as a direct target of miR-5195-3p. Interestingly, regulating the expression of LOX also influenced the transforming growth factor β1 signaling pathway and had an impact on extracellular matrix metabolism. This finding suggests that miR-5195-3p controls extracellular matrix metabolism by targeting LOX and modulating the TGF-β1 signaling pathway. In conclusion, this study unveils the involvement of miR-5195-3p in the pathological mechanism of pelvic organ prolapse by regulating extracellular matrix metabolism through the LOX/TGF-β1 axis. These findings reveal new mechanisms in the pathogenesis of pelvic organ prolapse, providing a theoretical foundation and therapeutic targets for further research on pelvic organ prolapse treatment.

Research Progress on Natural Products That Regulate miRNAs in the Treatment of Osteosarcoma

miRNAs are small non-coding RNA molecules that play critical roles in the regulation of gene expression and have been closely associated with various diseases, including cancer. These molecules significantly influence the cell cycle of tumor cells and control programmed cell death (apoptosis). Currently, research on miRNAs has become a major focus in developing cancer therapies. Osteosarcoma, a malignant neoplasm predominantly occurring during adolescence and later in life, is characterized by a high propensity for metastasis. This review explores the role of miRNAs in the initiation and progression of cancer, highlighting their potential as predictive biomarkers for disease. It discusses the mechanisms by which natural products modulate miRNA activity to influence apoptosis, ferroptosis, and autophagy in osteosarcoma cells, aiming to identify new strategies for osteosarcoma treatment. Recent studies on how natural products regulate miRNAs to reduce tumor cell resistance to chemotherapy are also reviewed. Furthermore, the review elaborates on how natural products regulate m6A modifications to influence miRNA expression, thereby exerting antitumor effects. In this process, interactions between m6A modifications and miRNAs have been identified, with both jointly influencing tumorigenesis and cancer progression, offering a new perspective in osteosarcoma treatment. These approaches could help uncover novel regulatory mechanisms in osteosarcoma pathways and provide a theoretical foundation for developing new drugs and identifying novel therapeutic targets.

The role of lncRNA and miRNA on the effects of occurrence and development of osteosarcoma

Osteosarcoma is a common primary malignant bone tumor with a high incidence in children and adolescents, with high invasiveness and lung metastases. Even after traditional surgical excision, chemoradiotherapy, and comprehensive treatment, the survival rate of patients is still low, and the prognosis is not ideal. As an important part of non-coding RNA family, lncRNA and miRNA have significant regulatory effects on the growth, proliferation, metastasis and apoptosis of osteosarcoma cells. Therefore, exploring the roles of lncRNAs and miRNAs in the occurrence and development of osteosarcoma is of great help for the subsequent diagnosis, treatment, and prognosis of osteosarcoma. This paper mainly reviews the current research progress on the effects and mechanisms of lncRNAs and miRNAs on osteosarcoma cells, in order to provide new ideas for future research on the development process, treatment methods, and prognosis of osteosarcoma.

Association of miRNA and Bone Tumors: Future Therapeutic Inroads

Small endogenous non-coding RNA molecules known as micro-ribonucleic acids (miRNAs) control post-transcriptional gene regulation. A change in miRNA expression is related to various diseases, including bone tumors. Benign bone tumors are categorized based on matrix production and predominant cell type. Osteochondromas and giant cell tumors are among the most common bone tumors. Interestingly, miRNAs can function as either tumor suppressor genes or oncogenes, thereby determining the fate of a tumor. In the present review, we discuss various bone tumors with regard to their prognosis, pathogenesis, and diagnosis. The association between miRNAs and bone tumors, such as osteosarcoma, Ewing's sarcoma, chondrosarcoma, and giant-cell tumors, is also discussed. Moreover, miRNA may play an important role in tumor proliferation, growth, and metastasis. Knowledge of the dysregulation, amplification, and deletion of miRNA can be beneficial for the treatment of various bone cancers. The miRNAs could be beneficial for prognosis, treatment, future drug design, and treatment of resistant cases of bone cancer.

m6A methylation regulators and ncRNAs in osteosarcoma: Potential therapeutic strategies

Osteosarcoma (OS) represents the primary form of bone cancer observed in paediatric and adolescent populations. Nearly 10%-15% of patients have metastases at diagnosis, and the 5-year survival rate was less than 20%. Although numerous investigators have offered significant efforts, the survival rates for patients with OS have remained almost unchanged over the past three decades. The most pervasive and abundant modification of internal transcripts in eukaryotic messenger RNAs (mRNAs) is N6-methyladenosine (m6A), and it is regulated by m6A methylation regulators. A number of recent studies have demonstrated that m6A modifications can regulate the biological activities of tumour cells and are intimately linked with cancer development, prognosis, drug resistance, and therapy. N6-methyladenosine modification of Non-coding RNA (ncRNA) has likewise shown a broad potential in gene regulation and tumor biology. Epigenetic changes induced by mRNAs and ncRNAs methylation are important for a better understanding of OS development and targeted drug development. Therefore, this paper summarises the biological functions of m6A-modified regulators in osteosarcoma and the role of mutual regulation between m6A and ncRNAs in osteosarcoma. Furthermore, the potential clinical applications of m6A modifications in OS are presented for consideration. It provides new directions for the future research and clinical treatment strategies of osteosarcoma.

Effects of Different Photoperiods on the Transcriptome of the Ovary and Small White Follicles in Zhedong White Geese

Photoperiod can regulate the broodiness of geese and thus increase their egg-laying rate. The laying performance of geese is mainly determined by ovary and follicle development. To understand the effect of photoperiod on the ovary and small white follicles, sixteen 220-day-old healthy female Zhedong white geese were randomly divided into two groups for long photoperiods (15L:9D) and short photoperiods (9L:15D). The geese were euthanized after two months of feeding, and their ovaries and follicles were collected for transcriptome sequencing. RNA-seq analysis identified 187 and 448 differentially expressed genes in ovaries and small white follicles of different photoperiod groups, respectively. A long photoperiod promotes high expression of SPP1, C6, MZB1, GP1BA, and FCGBP genes in the ovaries, and increases the expression of SPP1, ANGPTL5, ALPL, ZP1, and CHRNA4 genes in small white follicles. Functional enrichment analysis showed that photoperiod could affect respiratory system development, smooth muscle cell proliferation in ovaries, and extracellular matrix-related function in small white follicles. WGCNA revealed 31 gene modules, of which 2 were significantly associated with ovarian weight and 17 with the number of small white follicles. Our results provide a better understanding of the molecular regulation in the photoperiod affecting goose reproduction.

Liposome-Mediated MicroRNA Delivery: An Additional Layer of Gene Network Regulation and Nuclear Reprogramming

Background

Developing miRNA-mediated cell engineering introduces a novel technology for cell reprogramming and generating patient-specific tissues for therapeutic use, facilitating basic research on human adult stem cells. Furthermore, optimizing a reprogramming method without transduction minimizes the risk of tumorigenesis, especially for reprogrammed cells. This study aimed to explore the use of liposomes as vehicles for delivering miRNAs to cells, focusing on their role in regulating gene networks and facilitating nuclear reprogramming.

Methods

This study utilized cationic liposomal nanoparticles preserved under different conditions to introduce miRNAs into hMSCs. Using qPCR, the effective induction of pluripotency factors (OCT4, SOX2, and NANOG) was examined.

Results

Results indicated that miR-302a and miR-34a regulate pluripotency by interacting with key transcription factors, including OCT4, SOX2, and NANOG. Notably, the expression pattern of OCT4 showed that lipoplexes containing miR-302a increased the expression of this gene, while in the case of miR-34a, it decreased. Additionally, the study found that pluripotency precursors can be induced by delivering liposomal microRNA (LP-miRs).

Conclusion

LP-miRs, as small-molecule therapeutics, can influence reprogramming/engineering and the conversion of cells into other lineages. These findings have significant implications for our understanding of the mechanisms underlying the regulation of pluripotency and may have potential applications in regenerative medicine.

MicroRNA-mediated metabolic regulation of immune cells in cancer: an updated review

The study of immunometabolism, which examines how immune cells regulate their metabolism to maintain optimal performance, has become an important area of focus in cancer immunology. Recent advancements in this field have highlighted the intricate connection between metabolism and immune cell function, emphasizing the need for further research. MicroRNAs (miRNAs) have gained attention for their ability to post-transcriptionally regulate gene expression and impact various biological processes, including immune function and cancer progression. While the role of miRNAs in immunometabolism is still being explored, recent studies have demonstrated their significant influence on the metabolic activity of immune cells, such as macrophages, T cells, B cells, and dendritic cells, particularly in cancer contexts. Disrupted immune cell metabolism is a hallmark of cancer progression, and miRNAs have been linked to this process. Understanding the precise impact of miRNAs on immune cell metabolism in cancer is essential for the development of immunotherapeutic approaches. Targeting miRNAs may hold potential for creating groundbreaking cancer immunotherapies to reshape the tumor environment and improve treatment outcomes. In summary, the recognition of miRNAs as key regulators of immune cell metabolism across various cancers offers promising potential for refining cancer immunotherapies. Further investigation into how miRNAs affect immune cell metabolism could identify novel therapeutic targets and lead to the development of innovative cancer immunotherapies.

MiR-6839-5p inhibits cell proliferation, migration and invasion; a possible correlation with the suppressing VEGFA expression in human chondrosarcoma cells

MicroRNAs play an important role in the proliferation, invasion, and metastasis of malignancy. In previous studies (detailed in our previous paper), the expression of miR-6839-5p was significantly increased in SW1353 cells after 125I seed 6 Gy irradiation, which indicated miR-6839-5p may play a tumor suppression function in chondrosarcoma cells. This study aimed to identify the effects of miR-6839-5p on the human chondrosarcoma cells, and investigate the potential target genes of miR-6839-5p. Firstly, chondrosarcoma cells (SW1353 and CAL78) were transfected with hsa-miR-6839-5p specific mimic. Secondly, Cell viability assay (MTT assay), Colony formation assay, Wound healing assay, Transwell assay, TUNEL staining and Western blotting experiments were performed, and the results proved miR-6839-5p can inhibit chondrosarcoma cells proliferation, migration and invasion. Meanwhile, miR-6839-5p significantly down-regulated apoptosis facilitator Bcl-2 expression, and promoted apoptosis of chondrosarcoma cells. It is reasonable to speculate miR-6839-5p might downregulate Bcl-2 expression to induce apoptosis in SW1353 human chondrosarcoma cells. Lastly, RNA extraction and bioinformatic analysis was performed on SW1353 cells transfected with hsa-miR-6839-5p specific mimic to investigate the potential target genes of miR-6839-5p. A total of 253 differentially expressed mRNA genes (105 up-regulated genes and 148 down-regulated genes) were found, and 23 differentially expressed downregulated genes were identified. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to validate the results, which demonstrated the expression of BST2, VEGFA, FPR3 and PPARA was significantly downregulated by miR-6839-5p mimic. Furthermore, miR-6839-5p inhibitor can restore or partially restore the expression value of the above four genes. The analysis results of miRNA target gene prediction database indicated VEGFA was the most likely direct target gene of miR-6839-5p.

Understanding the multifaceted role of miRNAs in Alzheimer's disease pathology

Small non-coding RNAs (miRNAs) regulate gene expression by binding to mRNA and mediating its degradation or inhibiting translation. Since miRNAs can regulate the expression of several genes, they have multiple roles to play in biological processes and human diseases. The majority of miRNAs are known to be expressed in the brain and are involved in synaptic functions, thus marking their presence and role in major neurodegenerative disorders, including Alzheimer's disease (AD). In AD, amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are known to be the major hallmarks. The clearance of Aβ and tau is known to be associated with miRNA dysregulation. In addition, the β-site APP cleaving enzyme (BACE 1), which cleaves APP to form Aβ, is also found to be regulated by miRNAs, thus directly affecting Aβ accumulation. Growing evidences suggest that neuroinflammation can be an initial event in AD pathology, and miRNAs have been linked with the regulation of neuroinflammation. Inflammatory disorders have also been associated with AD pathology, and exosomes associated with miRNAs are known to regulate brain inflammation, suggesting for the role of systemic miRNAs in AD pathology. Several miRNAs have been related in AD, years before the clinical symptoms appear, most of which are associated with regulating the cell cycle, immune system, stress responses, cellular senescence, nerve growth factor (NGF) signaling, and synaptic regulation. Phytochemicals, especially polyphenols, alter the expression of various miRNAs by binding to miRNAs or binding to the transcriptional activators of miRNAs, thus control/alter various metabolic pathways. Awing to the sundry biological processes being regulated by miRNAs in the brain and regulation of expression of miRNAs via phytochemicals, miRNAs and the regulatory bioactive phytochemicals can serve as therapeutic agents in the treatment and management of AD.

miRNA-Based Technologies in Cancer Therapy

The discovery of therapeutic miRNAs is one of the most exciting challenges for pharmaceutical companies. Since the first miRNA was discovered in 1993, our knowledge of miRNA biology has grown considerably. Many studies have demonstrated that miRNA expression is dysregulated in many diseases, making them appealing tools for novel therapeutic approaches. This review aims to discuss miRNA biogenesis and function, as well as highlight strategies for delivering miRNA agents, presenting viral, non-viral, and exosomic delivery as therapeutic approaches for different cancer types. We also consider the therapeutic role of microRNA-mediated drug repurposing in cancer therapy.

A positive feedback loop between miR-574-3p and HIF-1α in promoting angiogenesis under hypoxia

In our previous report, we presented evidence supporting the role of miR-574-3p in downregulating the expression of cullin 2 (CUL2) in gastric cancer (GC) cells. Expanding on those findings, the present study aims to confirm the direct interaction between miR-574-3p and the 3' untranslated region (3'UTR) of CUL2, which leads to the suppression of CUL2 expression and destabilization of the VCBCR complex. Based on these discoveries, we propose a novel pathway involving miR-574-3p, HIF-1α, and VEGF that contributes to angiogenesis. Through a series of meticulous experiments, we successfully validate this hypothesis. Specifically, our observations indicate that overexpression of miR-574-3p in GC cells induces an upregulation of HIF-1α and VEGF, resulting in enhanced proliferation, migration, invasion, and tube formation of HUVEC cells. Furthermore, employing a mouse model, we demonstrate that miR-574-3p facilitates the recruitment of endothelial cells towards matrigel xenografts. Additionally, we note a parallel increase in miR-574-3p and HIF-1α levels across multiple cell lines (including AGS, SGC-7901, Hela, and 293T cells) subjected to hypoxic conditions (2 % O2 or CoCl2 treatment), as well as in the myocardial muscles of sodium nitrite-induced hypoxic mice. Further investigations reveal that HIF-1α upregulates miR-574-3p expression by directly binding to the miR-574 promoter. Collectively, these findings strongly support the existence of a positive feedback loop between miR-574-3p and HIF-1α, which facilitates angiogenesis under hypoxic conditions.

Plant miRNA bol-miR159 Regulates Gut Microbiota Composition in Mice: In Vivo Evidence of the Crosstalk between Plant miRNAs and Intestinal Microbes

New evidence reveals that bol-miR159, an miRNA rich in fruits and vegetables, cross-kingdomly functions in mammalian bodies. However, whether the miRNA could regulate gut microbiota remains unclear. Here, the effect of miR159 on mouse intestinal microbes was comprehensively examined. The results showed that supplementation of miR159 to the chow diet significantly enhanced the diversity of mouse gut microbiota without causing pathological lesions or inflammatory responses on the intestines. At the phylum level, miR159 increased the abundance of Proteobacteria and decreased the Firmicute-to-Bacteroidetes (F/B) ratio. miR159 had prebiotic-like effects on mouse gut microbiota, as it promoted the growth of the bacteria that is beneficial for maintaining gut health. The miRNA can target bacteria genes and get into the bacteria cells. The data provide direct in vivo evidence on the crosstalk between plant miRNAs and intestinal microbes, highlighting the potential for miRNA-based strategies that modulate gut microbes to improve host health.

Autophagy Modulation as a Potential Therapeutic Strategy in Osteosarcoma: Current Insights and Future Perspectives

Autophagy, the process that enables the recycling and degradation of cellular components, is essential for homeostasis, which occurs in response to various types of stress. Autophagy plays an important role in the genesis and evolution of osteosarcoma (OS). The conventional treatment of OS has limitations and is not always effective at controlling the disease. Therefore, numerous researchers have analyzed how controlling autophagy could be used as a treatment or strategy to reverse resistance to therapy in OS. They highlight how the inhibition of autophagy improves the efficacy of chemotherapeutic treatments and how the promotion of autophagy could prove positive in OS therapy. The modulation of autophagy can also be directed against OS stem cells, improving treatment efficacy and preventing cancer recurrence. Despite promising findings, future studies are needed to elucidate the molecular mechanisms of autophagy and its relationship to OS, as well as the mechanisms underlying the functioning of autophagic modulators. Careful evaluation is required as autophagy modulation may have adverse effects on normal cells, and the optimization of autophagic modulators for use as drugs in OS is imperative.

Apelin promotes osteosarcoma metastasis by upregulating PLOD2 expression via the Hippo signaling pathway and hsa_circ_0000004/miR-1303 axis

Osteosarcoma is a highly mortal bone tumor, with a high metastatic potential, promoted in part by the enzyme procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2). Increasing level of PLOD2 in osteosarcoma tissue correlates with lymphatic and distant metastasis. The adipokine apelin (APLN) is also found in different cancers and APLN upregulation promotes angiogenesis and metastasis, but its effects on osteosarcoma metastasis are uncertain. We explored APLN functioning in metastatic osteosarcoma. An analysis of records from the Gene Expression Omnibus (GEO) database showed higher levels of APLN expression in osteosarcoma tissue than in normal tissue. Similarly, levels of APLN and PLOD2 mRNA synthesis were upregulated in osteosarcoma tissue. Levels of APLN and PLOD2 protein correlated positively with osteosarcoma clinical stages. APLN increased PLOD2 expression in human osteosarcoma cell lines and cell migration via the mammalian Sterile 20-like kinase 1 (MST1), monopolar spindle-one-binder protein (MOB)1, and YAP cascades, and through hsa_circ_0000004 functioning as a sponge of miR-1303. We also found that knockdown of APLN antagonized lung metastasis in mice with osteosarcoma. APLN may be a therapeutic target in osteosarcoma metastasis.

RNA therapeutics: updates and future potential

Recent advancements in the production, modification, and cellular delivery of RNA molecules facilitated the expansion of RNA-based therapeutics. The increasing understanding of RNA biology initiated a corresponding growth in RNA therapeutics. In this review, the general concepts of five classes of RNA-based therapeutics, including RNA interference-based therapies, antisense oligonucleotides, small activating RNA therapies, circular RNA therapies, and messenger RNA-based therapeutics, will be discussed. Moreover, we also provide an overview of RNA-based therapeutics that have already received regulatory approval or are currently being evaluated in clinical trials, along with challenges faced by these technologies. RNA-based drugs demonstrated positive clinical trial results and have the ability to address previously "undruggable" targets, which delivers great promise as a disruptive therapeutic technology to fulfill its full clinical potentiality.

Perspectives of using microRNA-loaded nanocarriers for epigenetic reprogramming of drug resistant colorectal cancers

Epigenetic regulation by microRNAs (miRs) demonstrated a promising therapeutic potential of these molecules to regulate genetic activity in different cancers, including colorectal cancers (CRCs). The RNA-based therapy does not change genetic codes in tumor cells but can silence oncogenes and/or reactivate inhibited tumor suppressor genes. In many cancers, specific miRs were shown to promote or stop tumor progression. Among confirmed and powerful epigenetic regulators of colon carcinogenesis and development of resistance are onco-miRs, which include let-7, miR-21, miR-22, miR-23a, miR-27a, miR-34, miR-92, miR-96, miR-125b, miR-135b, miR-182, miR-200c, miR-203, miR-221, miR-421, miR-451, and others. Moreover, various tumor-suppressor miRs (miR-15b-5b, miR-18a, miR-20b, miR-22, miR-96, miR-139-5p, miR-145, miR-149, miR-197, miR-199b, miR-203, miR-214, miR-218, miR-320, miR-375-3p, miR-409-3p, miR-450b-5p, miR-494, miR-577, miR-874, and others) were found silenced in drug-resistant CRCs. Re-expression of tumor suppressor miR is complicated by the chemical nature of miRs that are not long-lasting compounds and require protection from the enzymatic degradation. Several recent studies explored application of miRs using nanocarrier complexes. This study critically describes the most successfully tested nanoparticle complexes used for intracellular delivery of nuclear acids and miRs, including micelles, liposomes, inorganic and polymeric NPs, dendrimers, and aptamers. Nanocarriers shield incorporated miRs and improve the agent stability in circulation. Attachment of antibodies and/or specific peptide or ligands facilitates cell-targeted miR delivery. Addressing in vivo challenges, a broad spectrum of non-toxic materials has been tested and indicated reliable advantages of lipid-based (lipoplexes) and polymer-based liposomes. Recent cutting-edge developments indicated that lipid-based complexes with multiple cargo, including several miRs, are the most effective approach to eradicate drug-resistant tumors. Focusing on CRC-specific miRs, this review provides a guidance and insights towards the most promising direction to achieve dramatic reduction in tumor growth and metastasis using miR-nanocarrier complexes.

MiR-659-3p inhibits osteosarcoma progression and metastasis by inhibiting cell proliferation and invasion via targeting SRPK1

OBJECTIVE

Osteosarcoma is the most common primary bone cancer that affects mostly children and young adults. Despite the advances in osteosarcoma treatment, the long-term survival rate of metastatic patients has not significantly improved in the past few decades, thus demonstrating the need for novel therapeutic targets or methods to improve metastatic osteosarcoma treatment. In this study we aimed to elucidate the role of miR-659-3p and SRPK1 in osteosarcoma.

METHODS

We evaluated miR-659-3p and SRPK1 function in osteosarcoma cell proliferation, migration, and cell cycle progression in vitro by using gain- and loss-of-function strategies. The effect of miR-659-3p in tumor progression and metastasis was determined by in vivo mouse model.

RESULTS

We revealed that expression of miR-659-3p was significantly downregulated in osteosarcoma compared with normal bone cells and was inversely correlated with serine-arginine protein kinase 1 (SRPK1) expression. We proved that miR-659-3p targets 3' UTR of SRPK1 and negatively regulates SRPK1 expression in osteosarcoma cells via luciferase assay. In vitro studies revealed that gain of miR-659-3p function inhibited osteosarcoma cells growth, migration, and invasion by down-regulating SRPK1 expression. Inversely, inhibiting miR-659-3p in osteosarcoma cells promoted cell growth, migration, and invasion. Cell cycle profile analysis revealed that miR-659-3p inhibited osteosarcoma cells' G1/G0 phase exit by down-regulating SRPK1 expression. By using an in vivo mouse model, we demonstrated that miR-659-3p inhibits osteosarcoma tumor progression and lung metastasis by inhibiting SRPK1 expression and potentially downstream cell proliferation, and epithelial-to-mesenchymal transition genes.

CONCLUSIONS

This study demonstrated that miR-659-3p is a potential therapeutic method and SRPK1 is a potential therapeutic target for osteosarcoma treatment.

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone tumors in children and adolescents. Large numbers of studies have focused on the long non-coding RNA (lncRNA) that plays essential roles in the progression of osteosarcoma. Nevertheless, the functions and underlying mechanisms of LncRNA NDRG1 in osteosarcoma remain unknown.

METHODS

Differentially expressed lncRNAs between osteosarcoma and adjacent normal tissues were identified through RNA sequencing. The role of LncRNA NDRG1 in osteosarcoma proliferation and metastasis were investigated through in vitro and in vivo functional experiments. The interaction between LncRNA NDRG1 and miR-96-5p was verified through bioinformatic analysis and luciferase reporter assay. Regulation relationship between LncRNA NDRG1 and miR-96-5p was further evaluated by the rescue experiments. Additionally, the changes in the expression of epithelial-mesenchymal transition (EMT) and the PI3K/AKT pathway were verified by Western blot.

RESULTS

LncRNA NDRG1 was up-regulated in osteosarcoma cell lines and tissues and the expression of LncRNA NDRG1 was correlated with the overall survival of osteosarcoma patients. Functional experiments exhibited that LncRNA NDRG1 aggravated osteosarcoma proliferation and migration in vitro; meanwhile, animals experiments showed that LncRNA NDRG1 promoted osteosarcoma growth and metastasis in vivo. Mechanistically, LncRNA NDRG1 was found to aggravate osteosarcoma progression and regulate the PI3K/AKT pathway by sponging miR-96-5p.

CONCLUSIONS

LncRNA NDRG1 aggravates osteosarcoma progression and regulates the PI3K/AKT pathway by sponging miR-96-5p. Therefore, LncRNA NDRG1 could act as a prognostic marker and a therapeutic target for osteosarcoma in the future.

A six-miRNA signature as a novel biomarker for improving prediction of prognosis and patterns of immune infiltration in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of tumor-related death. MicroRNAs (miRNAs) belong to a subfamily of functional non-coding RNAs (ncRNAs) and are essential regulators of tumorigenesis. They affect tumor-related therapeutic response, tumor metastasis, and clinical outcomes of several human malignant tumors. However, the prognostic value of miRNAs and their role in the tumor immune microenvironment (TIME) of HCC have not been clarified.

MATERIALS AND METHODS

Raw RNA-sequencing data (mRNA and miRNA) and clinicopathological characteristics of HCC samples were downloaded from the TCGA-GDC database. The Perl programming language, R software, Cytoscape software, and several online databases were used to clarify the clinical significance and biological functions of miRNAs and their target genes in HCC.

RESULTS

A total of 424 mRNA-sequencing samples and 425 miRNA-sequencing samples were obtained from the TCGA database. There were 344 HCC cases with complete information in the TCGA dataset and they were randomly categorized into two subgroups. Six miRNAs were identified as independent prognostic biomarkers for HCC patients by univariate and multivariate Cox regression analysis. The constructed prognostic signature, which contains these six miRNAs, was significantly correlated with overall survival (OS). In addition, this prognostic signature is superior to single miRNA in predicting short-term prognosis of HCC patients. We also found that the prognostic signature was significantly associated with tumor-related immune cell infiltration, TIME, and immunotherapeutic response. Furthermore, a total of 4568 potential target genes of six miRNAs were identified. The miRNA-mRNA co-expression network, protein-protein interaction (PPI) network, and functional and pathway enrichment analysis demonstrated that these miRNA-related target genes have important biological effects during the initiation and progression of HCC.

CONCLUSIONS

This study demonstrates that the miRNA signature can accurately predict the prognosis of HCC patients and provide a basis for novel immunotherapy treatments.

Circular RNA_0078767 upregulates Kruppel-like factor 9 expression by targeting microRNA-889, thereby inhibiting the progression of osteosarcoma

Among kids and juveniles, osteosarcoma (OS) is a common bone malignancy. Circular RNAs (circs, circRNAs) play important roles in multiple malignancies including OS, yet circ_0078767ʹs biological functions in OS are far from well elucidated. This study is targeted at understanding circ_0078767ʹs biological functions in OS and its molecular mechanisms. This study confirmed that circ_0078767 expression was reduced in OS cell lines and tissues. Circ_0078767 overexpression remarkably inhibited OS cell growth, migration, invasion, epithelial-mesenchymal transition (EMT), and promoted apoptosis, whereas circ_0078767 knockdown resulted in the opposite effects. MicroRNA-889 (miR-889) was targeted and regulated by circ_0078767, and miR-889 could negatively modulate Kruppel-like factor 9 (KLF9) expression. Besides, circ_0078767 positively regulated KLF9 expression in OS cells via repressing miR-889. In conclusion, circ_0078767 enhances KLF9 expression by targeting miR-889 to inhibit OS progression.

Integrated bioinformatics analysis of validated and circulating miRNAs in ovarian cancer

Recent studies have focused on the early detection of ovarian cancer (OC) using tumor materials by liquid biopsy. The mechanisms of microRNAs (miRNAs) to impact OC and signaling pathways are still unknown. This study aims to reliably perform functional analysis of previously validated circulating miRNAs' target genes by using pathfindR. Also, overall survival and pathological stage analyses were evaluated with miRNAs' target genes which are common in the The Cancer Genome Atlas and GTEx datasets. Our previous studies have validated three downregulated miRNAs (hsa-miR-885-5p, hsa-miR-1909-5p, and hsalet7d-3p) having a diagnostic value in OC patients' sera, with high-throughput techniques. The predicted target genes of these miRNAs were retrieved from the miRDB database (v6.0). Active-subnetwork-oriented Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted by pathfindR using the target genes. Enrichment of KEGG pathways assessed by the analysis of pathfindR indicated that 24 pathways were related to the target genes. Ubiquitin-mediated proteolysis, spliceosome and Notch signaling pathway were the top three pathways with the lowest p-values (p < 0.001). Ninety-three common genes were found to be differentially expressed (p < 0.05) in the datasets. No significant genes were found to be significant in the analysis of overall survival analyses, but 24 genes were found to be significant with pathological stages analysis (p < 0.05). The findings of our study provide in-silico evidence that validated circulating miRNAs' target genes and enriched pathways are related to OC and have potential roles in theranostics applications. Further experimental investigations are required to validate our results which will ultimately provide a new perspective for translational applications in OC management.

Long noncoding RNA ADIRF antisense RNA 1 upregulates insulin receptor substrate 1 to decrease the aggressiveness of osteosarcoma by sponging microRNA-761

An increasing number of studies have supported the critical regulatory actions of long noncoding RNAs (lncRNAs) in osteosarcoma (OS). However, the detailed roles of adipogenesis regulatory factor-antisense RNA 1 (ADIRF-AS1) in OS have not been comprehensively described. Hence, we first detected ADIRF-AS1 expression in OS and evaluated its clinical significance. Functional experiments were then performed to determine the modulatory role of ADIRF-AS1 in OS progression. ADIRF-AS1 was found to be overexpressed in OS, and the overall survival of patients with OS who had high ADIRF-AS1 levels was shorter than that of those with low levels. ADIRF-AS1 knockdown led to restricted proliferation, migration, and invasiveness of OS cells and increased apoptosis. Additionally, ADIRF-AS1 downregulation impeded tumor growth in vivo. Mechanistically, ADIRF-AS1 acted as a competitive endogenous RNA for microRNA-761 (miR-761) that siphoned miR-761 away from its target, namely insulin receptor substrate 1 (IRS1), leading to IRS1 overexpression. Rescue experiments showed that low levels of miR-761 or restoration of IRS1 could neutralize the effects of ADIRF-AS1 ablation in OS cells. In summary, ADIRF-AS1 exacerbates the oncogenicity of the OS cells by targeting the miR-761/IRS1 axis. Our findings may aid in the advancement of lncRNA-directed therapeutics for OS.

Identification and expression analysis of ten novel small non-coding RNAs (sncRNAs) in cancer cells using a high-throughput sequencing approach

Non-coding RNAs are characterized as RNA molecules, which lack the capacity to encode protein structures and appear to include a level of internal signals. Moreover, they control various stages of gene expression, thus controlling the cell physiology and development. In this study, we implemented a high-throughput sequencing approach based on the primary semi-conductor technology and computational tools, in order to identity novel small non-coding RNAs. Fourteen human cancer cell lines were cultured, and RNA samples were enriched for small RNAs following semi-conductor next generation sequencing (NGS). Bioinformatics analysis of NGS data revealed the existence of several classes of ncRNAs using the miRDeep* and CPSS 2.0 software. To investigate the existence of the predicted non-coding RNA sequences in cDNA pools of cell lines, a developed qPCR-based assay was implemented. The structure of each novel small ncRNA was visualized, using the RNAfold algorithm. Our results support the existence of twenty (20) putative new small ncRNAs, ten (10) of which have had their expression experimentally validated and presented differential profiles in cancerous and normal cells. A deeper comprehension of the ncRNAs interactive network and its role in cancer can therefore be translated into a wide range of clinical applications. Despite this progress, further scientific research from different perspectives and in different fields is needed, so that the riddle of the human transcriptome can be solved.

Periostin promotes the proliferation and metastasis of osteosarcoma by increasing cell survival and activates the PI3K/Akt pathway

BACKGROUND

Silencing of the periostin gene (POSTN) can inhibit the biological process of several different cancers, and this inhibition may be related to down-regulation of PI3K/AKT signaling. However, the effect of POSTN on the progression, proliferation, and invasion of osteosarcoma (OS) remain unclear.

METHODS

We used the Gene Expression Omnibus (GEO) database to screen datasets on in situ OS and lung metastases to identify core genes and potential pathways. We used additional bioinformatics tools to identify protein-protein interactions (PPIs) and gene networks, and selected the top seven genes whose expression had the strongest correlations with other genes.

RESULTS

The results indicated that POSTN was a major hub gene. Subsequent analysis of gene expression profiles showed that POSTN was highly expressed in 262 cases with sarcoma and expression was closely related to poor prognosis. We also performed enrichment analysis to identify differentially expressed genes and used real-time PCR, western blotting, and immunohistochemistry analyses to measure POSTN expression in cells and tissues. Transfection of a POSTN-shRNA plasmid into cultured OS cells (Saos-2) effectively inhibited the proliferation, invasion, and migration of these cells. Taken together, our results suggest that POSTN may play a role in promoting the proliferation and metastasis of OS by activation of the PI3K/Akt signaling pathway.

CONCLUSIONS

Our results provide a preliminary characterization of the mechanism by which POSTN may regulate the migration and invasion of OS cells and also provide a theoretical basis for identifying biomarkers that have potential use for the diagnosis and treatment of OS.

Potential Anti-Metastatic Role of the Novel miR-CT3 in Tumor Angiogenesis and Osteosarcoma Invasion

Osteosarcoma (OS) is the most common primary bone tumor mainly occurring in young adults and derived from primitive bone-forming mesenchyme. OS develops in an intricate tumor microenvironment (TME) where cellular function regulated by microRNAs (miRNAs) may affect communication between OS cells and the surrounding TME. Therefore, miRNAs are considered potential therapeutic targets in cancer and one of the goals of research is to accurately define a specific signature of a miRNAs, which could reflect the phenotype of a particular tumor, such as OS. Through NGS approach, we previously found a specific molecular profile of miRNAs in OS and discovered 8 novel miRNAs. Among these, we deepen our knowledge on the fifth candidate renamed now miR-CT3. MiR-CT3 expression was low in OS cells when compared with human primary osteoblasts and healthy bone. Through TargetScan, VEGF-A was predicted as a potential biological target of miR-CT3 and luciferase assay confirmed it. We showed that enforced expression of miR-CT3 in two OS cell lines, SAOS-2 and MG-63, reduced expression of VEGF-A mRNA and protein, inhibiting tumor angiogenesis. Enforced expression of miR-CT3 also reduced OS cell migration and invasion as confirmed by soft agar colony formation assay. Interestingly, we found that miR-CT3 behaves inducing the activation of p38 MAP kinase pathway and modulating the epithelial-mesenchymal transition (EMT) proteins, in particular reducing Vimentin expression. Overall, our study highlights the novel role of miR-CT3 in regulating tumor angiogenesis and progression in OS cells, linking also to the modulation of EMT proteins.

Advances in the Biological Functions and Mechanisms of miRNAs in the Development of Osteosarcoma

Osteosarcoma is one of the most common primary malignant bone tumors, mainly occurring in children and adolescents, and is characterized by high morbidity and poor prognosis. MicroRNAs, a class of noncoding RNAs consisting of 19 to 25 nucleotides, are involved in cell proliferation, invasion, metastasis, and apoptosis to regulate the development and progression of osteosarcoma. Studies have found that microRNAs are closely related to the diagnosis, treatment, and prognosis of osteosarcoma patients and have an important role in improving drug resistance in osteosarcoma. This paper reviews the role of microRNAs in the pathogenesis of osteosarcoma and their clinical value, aiming to provide a new research direction for diagnosing and treating osteosarcoma and achieving a better prognosis.

MiR-451a Promotes Cell Growth, Migration and EMT in Osteosarcoma by Regulating YTHDC1-mediated m6A Methylation to Activate the AKT/mTOR Signaling Pathway

•

It’s first proved that miR-451a can promote the malignant progression of osteosarcoma cells through AKT/mTOR pathway.

•

It’s first proved that YTHDC1 modifies the m6A methylation of PDPK1.

•

It’s first proved that YTHDC1 can promote the malignant progression of osteosarcoma cells.

Background

Osteosarcoma is the most prevalent primary malignant bone tumor containing mesenchymal cells with poor prognosis. Being a hot spot of anti-tumor therapy researches, AKT/mammalian target of rapamycin (mTOR) signaling pathway could affect various cellular processes including transcription, protein synthesis, apoptosis, autophagy and growth.

Materials and methods

The levels of RNA and protein were detected by quantitative real-time polymerase chain reaction (q-PCR) and western blot analyses respectively. Functional assays were carried out to analyze the malignant phenotypes of osteosarcoma cells. RNA-binding protein immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP), RNA pulldown, luciferase reporter and in vitro kinase assays were conducted to uncover the specific mechanism of microRNA-451a (miR-451a) in osteosarcoma cells.

Results

Functionally, miR-451a represses the malignant progression of osteosarcoma. Mechanically, miR-451a could curb the AKT/mTOR pathway via 3-phosphoinositide dependent protein kinase 1 (PDPK1)-mediated phosphorylation modification. After the certification that YTH domain containing 1 (YTHDC1) regulates the m6A phosphorylation modification of PDPK1 mRNA, we further proved that miR-451a-mediated YTHDC1 stabilizes PDPK1 mRNA via m6A-dependent regulation.

Conclusion

This study demonstrated that miR-451a regulates YTHDC1-mediated m6A methylation to activate the AKT/mTOR pathway, stimulating the malignancy of osteosarcoma.

Epigenetic Regulation of miR-92a and TET2 and Their Association in Non-Hodgkin Lymphoma

MicroRNAs (miRNAs) are well known for their ability to regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. In various cancers, miRNAs regulate gene expression by altering the epigenetic status of candidate genes that are implicated in various difficult to treat haematological malignancies such as non-Hodgkin lymphoma by acting as either oncogenes or tumour suppressor genes. Cellular and circulating miRNA biomarkers could also be directly utilised as disease markers for diagnosis and monitoring of non-Hodgkin lymphoma (NHL); however, the role of DNA methylation in miRNA expression regulation in NHL requires further scientific inquiry. In this study, we investigated the methylation levels of CpGs in CpG islands spanning the promoter regions of the miR-17–92 cluster host gene and the TET2 gene and correlated them with the expression levels of TET2 mRNA and miR-92a-3p and miR-92a-5p mature miRNAs in NHL cell lines, tumour samples, and the whole blood gDNA of an NHL case control cohort. Increased expression of both miR-92a-3p and miR-92a-5p and aberrant expression of TET2 was observed in NHL cell lines and tumour tissues, as well as disparate levels of dysfunctional promoter CGI methylation. Both miR-92a and TET2 may play a concerted role in NHL malignancy and disease pathogenesis.

The role of microRNAs in diseases and related signaling pathways

MicroRNAs (miRNAs) are epigenetic regulators of the gene expression and act through posttranslational modification. They bind to 3'-UTR of target mRNAs to inhibit translation or increase the degradation mRNA in many tissues. Any alteration in the level of miRNA expression in many human diseases indicates their involvement in the pathogenesis of many diseases. On the other hand, the regulation of the signaling pathways is necessary for the maintenance of natural and physiological characteristics of any cell. It is worth mentioning that dysfunction of the signaling pathways manifests itself as a disorder or disease. The significant evidence report that miRNAs regulate the several signaling pathways in many diseases. Base on previous studies, miRNAs can be used for therapeutic or diagnostic purposes. According to the important role of miRNAs on the cell signaling pathways, this article reviews miRNAs involvement in incidence of diseases by changing signaling pathways.

Overexpression of Long Non-Coding RNA MIR22HG Represses Proliferation and Enhances Apoptosis via miR-629-5p/TET3 Axis in Osteosarcoma Cells

In this study, we evaluated the mechanism of long non-coding RNA MIR22 host gene (LncRNA MIR22HG) in osteosarcoma cells. Forty-eight paired osteosarcoma and adjacent tissues samples were collected and the bioinformatic analyses were performed. Target genes and potential binding sites of MIR22HG, microRNA (miR)-629-5p and tet methylcytosine dioxygenase 3 (TET3) were predicted by Starbase and TargetScan V7.2 and confirmed by dual-luciferase reporter assay. Cell Counting Kit-8, colony formation and flow cytometry assays were utilized to determine the viability, proliferation and apoptosis of transfected osteosarcoma cells. Pearson's analysis was introduced for the correlation analysis between MIR22HG and miR-629-5p in osteosarcoma tissue. Relative expressions of MIR22HG, miR-629-5p and TET3 were measured by quantitative real-time polymerase chain reaction or Western blot. MiR-629-5p could competitively bind with and was negatively correlated with MIR22HG, the latter of which was evidenced by the high expression of miR-629-5p and low expression of MIR22HG in osteosarcoma tissues. Overexpressed MIR22HG repressed the viability and proliferation but enhanced apoptosis of osteosarcoma cells, which was reversed by miR-629-5p upregulation. TET3 was the target gene of miR-629-5p, and the promotive effects of upregulated miR-629-5p on the viability and proliferation as well as its repressive effect on apoptosis were abrogated via overexpressed TET3. To sum up, overexpressed MIR22HG inhibits the viability and proliferation of osteosarcoma cells, which was achieved via regulation of the miR-629-5p/TET3 axis.

An Overview on the Role of miR-451 in Lung Cancer: Diagnosis, Therapy, and Prognosis

MicroRNAs (miRNAs) are highly conserved non-coding RNAs involved in many physiological processes such as cell proliferation, inhibition, development of apoptosis, differentiation, suppresses tumorigenicity, and regulating cell growth. The description of the alterations of miRNA expression patterns in cancers will be helpful to recognize biomarkers for early detection and possible therapeutic intervention in the treatment of cancers. Recent studies have shown that miR-451 is broadly dysregulated in lung cancer and is a crucial agent in lung tumor progression. This review summarizes recent advances of the potential role of miR-451 in lung cancer diagnosis, prognosis, and treatment and provides an insight into the potential use of miR-451 for the development of advanced therapeutic methods in lung cancer.

Targeting Wnt/β-catenin signaling by microRNAs as a therapeutic approach in chemoresistant osteosarcoma

Osteosarcoma (OS) is an adolescent and young adult malignancy that mostly occurs in long bones. The treatment of OS is still a big challenge for clinicians due to increasing chemoresistance, and many efforts are being made today to find more beneficial treatments. In this regard, the use of microRNAs has shown a high capacity to develop promising therapies. By targeting cancer-involved signaling pathways, microRNAs reduce the cellular level of these protein pathways; thereby reducing the growth and invasion of tumors, and even leading cancer cells to apoptosis. One of these oncogenic pathways that play an important role in OS development and can be targeted by microRNAs is the Wnt/β-catenin signaling pathway. Hence, the first goal of this review article is to explain the cross-talk of microRNAs and the Wnt/β-catenin signaling in OS and then discussing recent findings of the use of microRNAs as a therapeutic approach in OS.

miR-486-3p regulates CyclinD1 and promotes fluoride-induced osteoblast proliferation and activation

Fluoride is a persistent environmental pollutant, and its excessive intake contributes to skeletal and dental fluorosis. The mechanisms underlying fluoride-induced abnormal osteoblast proliferation and activation, which are related to skeletal fluorosis, have not yet been fully clarified. As important epigenetic regulators, microRNAs (miRNAs) participate in bone metabolism. On the basis of our previous miRNA-seq results and bioinformatics analysis, this study investigated the role and specific molecular mechanism of miR-486-3p in fluoride-induced osteoblast proliferation and activation via CyclinD1. Herein, in the fluoride-challenged population, we observed that miR-486-3p expression decreased while CyclinD1 and transforming growth factor (TGF)-β1 increased, and miR-486-3p level correlated negatively with the expression of CyclinD1 and TGF-β1 genes. Further, we verified that sodium fluoride (NaF) decreases miR-486-3p expression in human osteoblasts and overexpression of miR-486-3p reduces fluoride-induced osteoblast proliferation and activation. Meanwhile, we demonstrated that miR-486-3p regulates NaF-induced upregulation of CyclinD1 by directly targeting its 3'-untranslated region (3'-UTR). In addition, we observed that NaF activates the TGF-β1/Smad2/3/CyclinD1 axis and miR-486-3p mediates transcriptional regulation of CyclinD1 by TGF-β1/Smad2/3 signaling pathway via targeting TGF-β1 3'-UTR in vitro. This study, thus, contributes significantly in revealing the mechanism of miR-486-3p-mediated CyclinD1 upregulation in skeletal fluorosis and sheds new light on endemic fluorosis treatment.

MicroRNA as an Important Target for Anticancer Drug Development

Cancer has become the second greatest cause of death worldwide. Although there are several different classes of anticancer drugs that are available in clinic, some tough issues like side-effects and low efficacy still need to dissolve. Therefore, there remains an urgent need to discover and develop more effective anticancer drugs. MicroRNAs (miRNAs) are a class of small endogenous non-coding RNAs that regulate gene expression by inhibiting mRNA translation or reducing the stability of mRNA. An abnormal miRNA expression profile was found to exist widely in cancer cell, which induces limitless replicative potential and evading apoptosis. MiRNAs function as oncogenes (oncomiRs) or tumor suppressors during tumor development and progression. It was shown that regulation of specific miRNA alterations using miRNA mimics or antagomirs can normalize the gene regulatory network and signaling pathways, and reverse the phenotypes in cancer cells. The miRNA hence provides an attractive target for anticancer drug development. In this review, we will summarize the latest publications on the role of miRNA in anticancer therapeutics and briefly describe the relationship between abnormal miRNAs and tumorigenesis. The potential of miRNA-based therapeutics for anticancer treatment has been critically discussed. And the current strategies in designing miRNA targeting therapeutics are described in detail. Finally, the current challenges and future perspectives of miRNA-based therapy are conferred.

Upregulation of miR181a/miR212 Improves Myogenic Commitment in Murine Fusion-Negative Rhabdomyosarcoma

Fusion-negative rhabdomyosarcoma (FN-RMS) is the most common soft tissue sarcoma of childhood arising from undifferentiated skeletal muscle cells from uncertain origin. Currently used therapies are poorly tumor-specific and fail to tackle the molecular machinery underlying the tumorigenicity and uncontrolled proliferation of FN-RMS. We and other groups recently found that microRNAs (miRNA) network contributes to myogenic epigenetic memory and can influence pluripotent stem cell commitments. Here, we used the previously identified promyogenic miRNAs and tailored it to the murine FN-RMS. Subsequently, we addressed the effects of miRNAs in vivo by performing syngeneic transplant of pre-treated FN-RMS cell line in C57Bl/6 mice. miRNA pre-treatment affects murine FN-RMS cell proliferation in vivo as showed by bioluminescence imaging analysis, resulting in better muscle performances as highlighted by treadmill exhaustion tests. In conclusion, in our study we identified a novel miRNA combination tackling the anti-myogenic features of FN-RMS by reducing proliferation and described novel antitumorigenic therapeutic targets that can be further explored for future pre-clinical applications.

ARHGEF3 Associated with Invasion, Metastasis, and Proliferation in Human Osteosarcoma

Background

Osteosarcoma is a malignant bone tumor composed of mesenchymal cells producing osteoid and immature bone. This study is aimed at developing novel potential prognostic biomarkers and constructing a miRNA-mRNA network for progression in osteosarcoma.

Method

GSE70367 and GSE70414 were obtained in the Gene Expression Omnibus (GEO) database. GEO software and the GEO2R calculation method were used to analyze two gene profiles. The coexpression of differentially expressed miRNAs (DEMs) and genes (DEGs) was identified and searched for in the FunRich database for pathway and ontology analysis. Cytoscape was utilized to construct the mRNA-miRNA network. Survival analysis of identified miRNAs and mRNAs was performed by utilizing the Kaplan-Meier Plotter. Besides, expression levels of DEMs and target mRNAs were verified by performing quantitative real-time PCR (qRT-PCR) and Western blot (WB).

Results

Six differentially expressed microRNAs (DEMs) were identified, and 8 target genes were selected after screening. By using the KM Plotter software, miRNA-124 and ARHGEF3 were obviously associated with the overall survival of patients with osteosarcoma. Furthermore, ARHGEF3 was found downregulated in osteosarcoma cells by performing qRT-PCR and WB experiments. Results also showed that downregulated ARHGEF3 may associate with invasion, metastasis, and proliferation.

Conclusions

By using microarray and bioinformatics analysis, DEMs were selected, and a complete miRNA-mRNA network was constructed. ARHGEF3 may act as a therapeutic and prognostic target of osteosarcoma.

Bergamottin Induces DNA Damage and Inhibits Malignant Progression in Melanoma by Modulating miR-145/Cyclin D1 Axis

Background

Melanoma is a prevalent skin cancer with the high rate of metastasis and mortality, affecting the increasing number of people worldwide. Bergamottin (BGM) is a natural furanocoumarin derived from grapefruits and presents the potential anti-cancer activity in several tumor models. However, the role of BGM in the development of melanoma remains unclear. Here, we aimed to explore the effect of BGM on the DNA damage and progression of melanoma.

Methods

The effect of BGM on the melanoma progression was analyzed by CCK-8 assays, colony formation assays, transwell assays, Annexin V-FITC Apoptosis Detection Kit, cell-cycle analysis, in vivo tumorigenicity analysis. The mechanism investigation was performed using luciferase reporter gene assays, qPCR assays, and Western blot analysis.

Results

We identified that BGM repressed cell proliferation, migration, and invasion of melanoma cells. BGM induced cell cycle arrest at the G0/G1 phase and enhanced apoptosis of melanoma cells. The DNA damage in the melanoma cells was stimulated by the BGM treatment. Meanwhile, BGM was able to up-regulate the expression of miR-145 and miR-145 targeted Cyclin D1 in the melanoma cells. Furthermore, BGM inhibited the progression of melanoma by targeting miR-145/Cyclin D1 axis in vitro. BGM attenuated the tumor growth of melanoma in vivo.

Conclusion

Thus, we conclude that BGM induces DNA damage and inhibits tumor progression in melanoma by modulating the miR-145/Cyclin D1 axis. Our finding provides new insights into the mechanism by which BGM modulates the development of melanoma. BGM may be applied as a potential anti-tumor candidate for the clinical treatment of melanoma.

Highly enriched exosomal lncRNA OIP5-AS1 regulates osteosarcoma tumor angiogenesis and autophagy through miR-153 and ATG5

OBJECTIVE

This study aims to investigate the regulatory role of exosome lncRNA OIP5-AS1 in tumor progression and autophagy.

METHODS

Seventy-three cases of osteosarcoma (OS) tissues and 56 cases of adjacent normal tissues were collected to culture human OS cell line HOS. The exosomes secreted by OS cell line were isolated and collected. Apoptosis and exosome markers were detected by flow cytometry. A nude mouse model of OS was established. The gene expression levels of lncRNA OIP5-AS1, miR-153 and autophagy-related protein 5 (ATG5) were quantified by real-time quantitative PCR (RT-PCR). The binding sites of lncRNA OIP5-AS1 and miR-153 were predicted by Starbase3.0, and the binding sites of miR-153 and ATG5 were predicted by Targetscan7.2. The gene binding sites were verified by luciferase reporter gene detection or RNA immunoprecipitation (RIP). The relative level of protein was tested by Western blot. Transwell was applied to test migration and invasion of OS cells. The angiogenesis of OS cells was tested by tubule formation test.

RESULTS

The results of RT-PCR showed that lncRNA OIP5-AS1 levels were elevated in OS cells and exosomes secreted by cells. Cell function experiments revealed that the proliferation, migration, and invasion of OS cells were promoted by exosomal lncRNA OIP5-AS1. In exosomes, lncRNA OIP5-AS1 inhibited the expression of LC3-II and Beclin 1 proteins, indicating that exosomal lncRNA OIP5-AS1 inhibited autophagy. According to the results of bioinformatics tools and dual-luciferase reporter (DLR) assay or RNA immunoprecipitation (RIP), miR-153 targeted the 3'-UTR of lncRNA OIP5-AS1 and autophagy-related protein 5 (ATG5). The results of western blot (WB) assay showed that exosomal lncRNA OIP5-AS1 and down-regulated miR-153 led to the enhancement of ATG5 protein expression, while up-regulated miR-153 resulted in the decrease of ATG5 protein expression. ATG5 was negatively correlated with miR-153 and positively correlated with lncRNA OIP5-AS1. The results of tubule formation assay disclosed an increase in the angiogenesis level caused by the exosomal lncRNA OIP5-AS1, which was then reversed by the increase of miR-153 and decrease of ATG5.

CONCLUSION

Highly enriched exosomal lncRNA OIP5-AS1 can regulate OS tumor angiogenesis and autophagy through miR-153 and ATG5.

Role of p53-miRNAs circuitry in immune surveillance and cancer development: A potential avenue for therapeutic intervention

The genome's guardian, p53, is a master regulatory transcription factor that occupies sequence-specific response elements in many genes and modulates their expression. The target genes transcribe both coding RNA and non-coding RNA involved in regulating several biological processes such as cell division, differentiation, and cell death. Besides, p53 also regulates tumor immunology via regulating the molecules related to the immune response either directly or via regulating other molecules, including microRNAs (miRNAs). At the post-transcriptional level, the regulations of genes by miRNAs have been an emerging mechanism. Interestingly, p53 and various miRNAs cross-talk at different regulation levels. The cross-talk between p53 and miRNAs creates loops, turns, and networks that can influence cell metabolism, cell fate, cellular homeostasis, and tumor formation. Further, p53-miRNAs circuit has also been insinuated in the regulation of immune surveillance machinery. There are several examples of p53-miRNAs circuitry where p53 regulates immunomodulatory miRNA expression, such as miR-34a and miR-17-92. Similarly, a reverse process occurs in which miRNAs such as miR-125b and miR-let-7 regulate the expression of p53. Thus, the p53-miRNAs circuitry connects the immunomodulatory pathways and may shift the pro-inflammatory balance towards the pro-tumorigenic condition. In this review, we discuss the influence of p53-miRNAs circuitry in modulating the immune response in cancer development. We assume that thorough studies on the p53-miRNAs circuitry in various cancers may prove useful in developing effective new cancer therapeutics for successfully combating this disease.

MiR-506 exerts antineoplastic effects on osteosarcoma cells via inhibition of the Skp2 oncoprotein

S-phase kinase-associated protein 2 (Skp2) performs oncogenic functions in cancers; however, how Skp2 is regulated post-transcriptionally is elusive in osteosarcoma. Therefore, we determined whether miR-506 could directly target Skp2 in osteosarcoma to perform its tumor suppressive functions. Here, we found that miR-506 mimics suppressed cell viability, induced apoptosis, and attenuated migration and invasion in osteosarcoma cells. Moreover, upregulation of Skp2 accelerated cell viability and motility and rescued the tumor suppressive effect of miR-506 in osteosarcoma cells. Moreover, downregulation of Skp2 inhibited cell viability and decreased cell motility, which enhanced the antitumor activity induced by miR-506 mimic transfection in osteosarcoma cells. Our western blotting results implied that miR-506 inhibited Skp2 expression and subsequently upregulated Foxo1 and p57 in OS cells. In summary, miR-506 performs an anticancer activity via directly targeting Skp2 in osteosarcoma cells, indicating that inactivation of Skp2 by miR-506 might be an alternative strategy for treating osteosarcoma.

Noncoding RNAs in osteosarcoma: Implications for drug resistance

Osteosarcoma is the most frequent bone malignancy in children and adolescents. Despite advances of surgery and chemotherapy in osteosarcoma over the past decades, overall survival rates of osteosarcoma have reached a plateau. The development of multi-drug resistance (MDR) has become the main obstacle in improving chemotherapeutic effects in osteosarcoma treatment. Therefore, understanding detailed mechanisms of chemoresistance and developing novel therapeutic targets to overcome chemoresistance are crucial to improve the prognosis of osteosarcoma patients. Accumulating evidence has proved that multiple noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) play pivotal roles in osteosarcoma progression. Notably, a great number of ncRNAs are abnormally expressed and can regulate chemosensitivity through various mechanisms in osteosarcoma. In this review, we systematically summarize the roles of ncRNAs as well as the molecular mechanisms in modulating drug resistance of osteosarcoma and discuss the potential roles of ncRNAs as biomarkers and novel therapeutic targets for osteosarcoma.

Expressions and related mechanisms of miR-212 and KLF4 in rats with acute kidney injury

Acute kidney injury (AKI) occurs in 30%-70% of critically ill patients. Multiple organ failure (MOF), which is most often secondary to hypotension and septicemia, is a global public health problem. The prognosis of patients is poor. Currently, there is no specific therapeutic method. Finding new therapeutic targets is significant to improve the prognosis of AKI patients. This study explores expressions and related mechanisms of miR-212 and Kruppel-like factor 4 (KLF4) in rats with AKI. Sixty Wistar rats were randomly divided into 6 groups: Control group, sham operation group, model group, miR-212-agomir group, miR-212-antagomir group, miR-212-agomir+APTO-253 (joint group), n = 10. The expressions of miR-212, KLF4, inflammatory factors [tumor necrosis factor α (TNF-α), interleukin 6 (IL-6)], oxidative stress factors [superoxide dismutase (SOD), malondialdehyde (MDA)], and apoptosis-related proteins (bax, bcl-2) in renal tissue of rats were detected, and the relationship between miR-212 and KLF4 and the severity of AKI in rats were analyzed. The expression level of miR-212 increased (P < 0.05) and the expression level of KLF4 decreased (P < 0.05) in renal tissue of rats with AKI. miR-212 was negatively correlated with KLF4 expression (P < 0.05). MiR-212 was positively correlated with expressions of TNF-α, IL-6, MDA, and bax (P < 0.05), negatively correlated with expressions of SOD and bcl-2 (P < 0.05), KLF4 was negatively correlated with expressions of TNF-α, IL-6, MDA and bax (P < 0.05), and positively correlated with expressions of SOD and bcl-2 (P < 0.05). MiR-212 mimics can inhibit the luciferase activity of Wt-KLF4 (P < 0.05), and miR-212 inhibitor can promote the luciferase activity of Wt-KLF4 (P < 0.05). Down-regulation of miR-212 plays a protective role by targeting up-regulation of KLF4 to inhibit renal tissue inflammation, oxidative stress, and apoptosis in rats with AKI, which may be a potential target for clinical treatment of AKI in the future.

Long Noncoding RNA CCDC144NL-AS1 Promotes the Oncogenicity of Osteosarcoma by Acting as a Molecular Sponge for microRNA-490-3p and Thereby Increasing HMGA2 Expression

Purpose

The long noncoding RNA CCDC144NL antisense RNA 1 (CCDC144NL-AS1) exhibits important functions in gastric cancer. In this study, we aimed to investigate the roles of CCDC144NL-AS1 in modulating the phenotype of osteosarcoma (OS) cells in vitro and in vivo and elucidate its underlying mechanisms.

Methods

Reverse transcription quantitative polymerase chain reaction (PCR) was performed to determine the expression level of CCDC144NL-AS1 in OS tissues and cell lines. The proliferation, apoptosis, migration, and invasion in vitro as well as tumor growth in vivo were determined in OS cells using the Cell Counting Kit 8 assay, flow cytometric analysis, transwell migration and invasion assays, and xenograft experiments, respectively. Bioinformatics analysis was performed to identify the potential microRNA targets of CCDC144NL-AS1, which were subsequently confirmed using the luciferase reporter assay, RNA immunoprecipitation assay, reverse transcription quantitative PCR, Western blotting, and rescue experiments.

Results

CCDC144NL-AS1 expression was upregulated in OS tissues and cell lines. Patients with OS who exhibited high CCDC144NL-AS1 expression had shorter overall survival than those who exhibited low CCDC144NL-AS1 expression. Functionally, interference in CCDC144NL-AS1 expression led to a notable decrease in the proliferation, migration, and invasion of OS cells and an increase in cell apoptosis in vitro. Furthermore, CCDC144NL-AS1 knockdown impaired OS tumor growth in vivo. Mechanistically, CCDC144NL-AS1 directly bound to miR-490-3p in OS cells, where it functioned as a molecular sponge and subsequently increased the expression of high-mobility group AT-hook 2 (HMGA2). Rescue experiments further demonstrated that miR-490-3p suppression or HMGA2 restoration abated CCDC144NL-AS1 deficiency-induced cancer-inhibitory actions in OS cells.

Conclusion

CCDC144NL-AS1 exhibits pro-oncogenic roles in OS by functioning as a sponge for miR-490-3p and increasing HMGA2 expression. Our findings suggest that greater understanding of the CCDC144NL-AS1/miR-490-3p/HMGA2 pathway can provide useful information for OS diagnosis, prognosis, and therapy.

MiRNA-1225 Inhibits Osteosarcoma Tumor Growth and Progression by Targeting YWHAZ

Introduction

Osteosarcoma is the most common bone tumor and is characterized by the presence of malignant mesenchymal cells produced in the bone stroma. MiRNAs are known to function as post-transcriptional negative regulators of gene expression. Emerging evidence showed that miR-1225-5P functions as a tumor suppressor in several types of cancers. The detailed mechanisms of which miR-1225-5P suppresses tumor growth are not fully understood. The objective of the present study was to test the hypothesis that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ expression.

Methods

Real-time PCR and Western blot were carried out to test the expression of miR-1225-5P and YWHAZ in osteosarcoma cell lines. Luciferase assay was used to demonstrate whether miR-1225-5P targets YWHAZ 3ʹ UTR. To assess the function of miR-1225-5P in human osteosarcoma cell lines, gain-of-function and loss-of-function of miR-1225-5P were performed by transfecting miR-1225-5P mimic or miR-1225-5P inhibitor into osteosarcoma cell lines. Furthermore, cell cycle analysis was performed to elucidate the possible mechanisms of the action of miR-1225-5P and YWHAZ in human osteosarcoma cells. The potential therapeutic effect of miR-1225-5p was tested in human osteosarcoma xenograft mouse model, by intravenous injection of miR-1225-5P into nude mice. Tumor sizes were measured and lung metastasis was counted after the mice were sacrificed.

Results

The expression of miR-1225-5P was inversely correlated with the expression of YWHAZ in human osteosarcoma cell lines. Database search revealed that miR-1225-5P targeted YWHAZ 3ʹ UTR. Transfection of miR-1225-5P mimic downregulated YWHAZ expression, which was demonstrated by real-time PCR, Western blot and luciferase assay. Over-expression of miR-1225-5P reduced human osteosarcoma cell growth, migration and invasion by downregulating YWHAZ expression. Cell growth, migration and invasion were increased by inhibiting miR-1225-5P in human osteosarcoma cells. The inhibition of cell growth, migration and invasion was rescued by over-expression of YWHAZ in osteosarcoma cells. Cell cycle analysis revealed that miR-1225-5P inhibited G1/G0 phase exit. In vivo xenograft model demonstrated that miR-1225-5P inhibited in vivo osteosarcoma tumor growth and lung metastasis.

Conclusion

Our findings suggested that miR-1225-5P inhibits osteosarcoma cell growth in vitro and tumor growth in vivo by targeting YWHAZ. This study suggested that miR-1225-5P can serve as a potential therapeutic method for treating osteosarcoma.

Recent Insights into Therapy Resistance in Osteosarcoma

Osteosarcoma, the most common bone malignancy of childhood, has been a challenge to treat and cure. Standard chemotherapy regimens work well for many patients, but there remain minimal options for patients with progressive or resistant disease, as clinical trials over recent decades have failed to significantly improve survival. A better understanding of therapy resistance is necessary to improve current treatments and design new strategies for future treatment options. In this review, we discuss known mechanisms and recent scientific advancements regarding osteosarcoma and its patterns of resistance against chemotherapy, radiation, and other newly-introduced therapeutics.

Regulatory Mechanisms of Epigenetic miRNA Relationships in Human Cancer and Potential as Therapeutic Targets

Simple Summary

By the virtue of targeting multiple genes, a microRNA (miRNA) can infer variable consequences on tumorigenesis by appearing as both a tumour suppressor and oncogene. miRNAs can regulate gene expression by modulating genome-wide epigenetic status of genes that are involved in various cancers. These miRNAs perform direct inhibition of key mediators of the epigenetic machinery, such as DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) genes. Along with miRNAs gene expression, similar to other protein-coding genes, miRNAs are also controlled by epigenetic mechanisms. Overall, this reciprocal interaction between the miRNAs and the epigenetic architecture is significantly implicated in the aberrant expression of miRNAs detected in various human cancers. Comprehensive knowledge of the miRNA-epigenetic dynamics in cancer is essential for the discovery of novel anticancer therapeutics.

Abstract

Initiation and progression of cancer are under both genetic and epigenetic regulation. Epigenetic modifications including alterations in DNA methylation, RNA and histone modifications can lead to microRNA (miRNA) gene dysregulation and malignant cellular transformation and are hereditary and reversible. miRNAs are small non-coding RNAs which regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. miRNAs can target epigenetic modifier enzymes involved in epigenetic modulation, establishing a trilateral regulatory “epi–miR–epi” feedback circuit. The intricate association between miRNAs and the epigenetic architecture is an important feature through which to monitor gene expression profiles in cancer. This review summarises the involvement of epigenetically regulated miRNAs and miRNA-mediated epigenetic modulations in various cancers. In addition, the application of bioinformatics tools to study these networks and the use of therapeutic miRNAs for the treatment of cancer are also reviewed. A comprehensive interpretation of these mechanisms and the interwoven bond between miRNAs and epigenetics is crucial for understanding how the human epigenome is maintained, how aberrant miRNA expression can contribute to tumorigenesis and how knowledge of these factors can be translated into diagnostic and therapeutic tool development.