Role of exosomal miR‑21 in the tumor microenvironment and osteosarcoma tumorigenesis and progression (Review)

Manipulating the cGAS-STING Axis: advancing innovative strategies for osteosarcoma therapeutics

This paper explored the novel approach of targeting the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase-stimulator of interferon genes (cGAS-STING) pathway for the treatment of osteosarcoma (OS). Osteosarcoma is a common malignancy in adolescents. Most patients die from lung metastasis. It reviewed the epidemiology and pathological characteristics of OS, highlighting its highly malignant nature and tendency for pulmonary metastasis, underscoring the importance of identifying new therapeutic targets. The cGAS-STING pathway was closely associated with the malignant biological behaviors of OS cells, suggesting that targeting this pathway could be a promising therapeutic strategy. Currently, research on the role of the cGAS-STING pathway in OS treatment has been limited, and the underlying mechanisms remain unclear. Therefore, further investigation into the mechanisms of the cGAS-STING pathway in OS and the exploration of therapeutic strategies based on this pathway are of great significance for developing more effective treatments for OS. This paper offered a fresh perspective on the treatment of OS, providing hope for new therapeutic options for OS patients by targeting the cGAS-STING pathway.

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.

Exploring the clinical implications and applications of exosomal miRNAs in gliomas: a comprehensive study

Gliomas are aggressive brain tumors associated with poor prognosis and limited treatment options due to their invasive nature and resistance to current therapeutic modalities. Research suggests that exosomal microRNAs have emerged as key players in intercellular communication within the tumor microenvironment, influencing tumor progression and therapeutic responses. Exosomal microRNAs (miRNAs), small non-coding RNAs, are crucial in glioma development, invasion, metastasis, angiogenesis, and immune evasion by binding to target genes. This comprehensive review examines the clinical relevance and implications of exosomal miRNAs in gliomas, highlighting their potential as diagnostic biomarkers, therapeutic targets and prognosis biomarker. Additionally, we also discuss the limitations of current exsomal miRNA treatments and address challenges and propose future directions for leveraging exosomal miRNAs in precision oncology for glioma management.

Intelligent structure prediction and visualization analysis of non-coding RNA in osteosarcoma research

Background

Osteosarcoma (OS) is the most common bone malignant tumor in children and adolescents. Recent research indicates that non-coding RNAs (ncRNAs) have been associated with OS occurrence and development, with significant progress made in this field. However, there is no intelligent structure prediction and literature visualization analysis in this research field. From the perspective of intelligent knowledge structure construction and bibliometrics, this study will comprehensively review the role of countries, institutions, journals, authors, literature citation relationships and subject keywords in the field of ncRNAs in OS. Based on this analysis, we will systematically analyze the characteristics of the knowledge structure of ncRNAs in OS disease research and identify the current research hotspots and trends.

Methods

The Web of Science Core Collection (WoSCC) database was searched for articles on ncRNAs in OS between 2001 and 2023. This bibliometric analysis was performed using VOSviewers, CiteSpace, and Pajek.

Results

This study involved 15,631 authors from 2,631 institutions across 57 countries/regions, with a total of 3,642 papers published in 553 academic journals. China has the highest number of published papers in this research field. The main research institutions include Nanjing Medical University (n = 129, 3.54%), Shanghai Jiao Tong University (n = 128, 3.51%), Zhengzhou University (n = 110, 3.02%), and China Medical University (n = 109, 2.99%). Oncology Letters (n =139, 3.82%), European Review for Medical Pharmacological Sciences (120, 3.31%), and Molecular Medicine Reports (n = 95, 2.61%) are the most popular journals in this field, with Oncotarget being the most co-cited journal (Co-Citation = 4,268). Wei Wang, Wei Liu, and Zhenfeng Duan published the most papers, with Wang Y being the most co-cited author. "miRNA", "lncRNA" and "circRNA" are the main focuses of ncRNAs in OS studies. Key themes include "migration and invasion", "apoptosis and proliferation", "prognosis", "biomarkers" and "chemoresistance". Since 2020, hotspots and trends in ncRNA research in OS include "tumor microenvironment", "immune" and "exosome".

Conclusion

This study represents the first comprehensive bibliometric analysis of the knowledge structure and development of ncRNAs in OS. These findings highlight current research hotspots and frontier directions, offering valuable insights for future studies on the role of ncRNAs in OS.

N6-methyladenosine (m6A) modification in osteosarcoma: expression, function and interaction with noncoding RNAs - an updated review

Osteosarcoma, originating from primitive bone-forming mesenchymal cells, is the most common malignant bone tumour among children and adolescents. N6-methyladenosine (m6A), the most ubiquitous type of posttranscriptional modification, is a methylation that occurs in the N6-position of adenosine. m6A dramatically affects the splicing, export, translation, and stability of various RNAs, including mRNA and noncoding RNAs (ncRNAs). Increasing evidence suggests that ncRNAs, especially microRNAs (miRNA), long noncoding RNAs (lncRNA), and circular RNAs (circRNAs), regulate the m6A modification process by affecting the expression of m6A-associated enzymes. m6A modification interactions with ncRNAs provide new perspectives for exploring the underlying mechanisms of tumorigenesis and progression. In the current review, we summarized the expression and biological functions of m6A regulators in osteosarcoma. At the same time, the present review systematically elucidated the functional and mechanical interactions between m6A modification and ncRNAs in osteosarcoma. In addition, we discussed the effect of m6A and ncRNAs in the tumour microenvironment and potential clinical applications of osteosarcoma.

Exosomes: potential diagnostic markers and drug carriers for adenomyosis

Adenomyosis is a common benign gynecological disorder and an important factor leading to infertility in fertile women. Adenomyosis can cause deep lesions and is persistent and refractory in nature due to its tumor-like biological characteristics, such as the ability to implant, adhere, and invade. The pathogenesis of adenomyosis is currently unclear. Therefore, new therapeutic approaches are urgently required. Exosomes are nanoscale vesicles secreted by cells that carry proteins, genetic materials and other biologically active components. Exosomes play an important role in maintaining tissue homeostasis and regulating immune responses and metabolism. A growing body of work has shown that exosomes and their contents are key to the development and progression of adenomyosis. This review discusses the current research progress, future prospects and challenges in this emerging therapeutic tool by providing an overview of the changes in the adenomyosis uterine microenvironment and the biogenesis and functions of exosomes, with particular emphasis on the role of exosomes and their contents in the regulation of cell migration, proliferation, fibrosis formation, neovascularization, and inflammatory responses in adenomyosis.

Macrophages and small extracellular vesicle mediated-intracellular communication in the peritoneal microenvironment: Impact on endometriosis development

Endometriosis is an inflammatory disease that is defined as the growth of endometrium-like tissue outside the uterus, commonly on the lining of the pelvic cavity, visceral organs and in the ovaries. It affects around 190 million women of reproductive age worldwide and is associated with chronic pelvic pain and infertility, which greatly impairs health-related life quality. The symptoms of the disease are variable, this combined with a lack of diagnostic biomarkers and necessity of surgical visualisation to confirm disease, the prognosis can take an average timespan of 6-8 years. Accurate non-invasive diagnostic tests and the identification of effective therapeutic targets are essential for disease management. To achieve this, one of the priorities is to define the underlying pathophysiological mechanisms that contribute to endometriosis. Recently, immune dysregulation in the peritoneal cavity has been linked to endometriosis progression. Macrophages account for over 50% of immune cells in the peritoneal fluid and are critical for lesion growth, angiogenesis, innervation and immune regulation. Apart from the secretion of soluble factors like cytokines and chemokines, macrophages can communicate with other cells and prime disease microenvironments, such as the tumour microenvironment, via the secretion of small extracellular vesicles (sEVs). The sEV-mediated intracellular communication pathways between macrophages and other cells within the peritoneal microenvironment in endometriosis remain unclear. Here, we give an overview of peritoneal macrophage (pMΦ) phenotypes in endometriosis and discuss the role of sEVs in the intracellular communication within disease microenvironments and the impact they may have on endometriosis progression.

Effect of Long Noncoding RNA HULC on Proliferation, Migration, and Invasion of Osteosarcoma Cells

Background

Previous studies had shown that lncRNA HULC exhibited different effects in human cancers. However, the role of HULC was not reported in osteosarcoma. Hence, we designed this research to explore the function of HULC in osteosarcoma.

Methods

Firstly, HULC expression was measured in osteosarcoma tissues and cells via the RT-qPCR assay. The protein expression was detected through western blot. Then, CCK-8 and Transwell assays were conducted to measure cell proliferation, migration, and invasion.

Results

The expression of HULC was obviously higher in osteosarcoma tissues and cells compared with normal control. Moreover, cell proliferation, migration, and invasion were inhibited by HULC knockdown in osteosarcoma cells. HULC overexpression markedly increased osteosarcoma cell proliferation and tumor size in vivo. Furthermore, HULC increased the activity of AKT-PI3K-mTOR pathway by blocking PTEN in osteosarcoma cells. LY294002 inhibited the phosphorylation of AKT, mTOR, and PI3K. Overexpressing HULC enhanced cell migration and invasion of SAOS-2 cells and MG63 cells, while LY294002 reversed the effects.

Conclusion

HULC enhanced the progression of osteosarcoma through targeting PTEN.

Ho2O3-TiO2 Nanobelts Electrode for Highly Selective and Sensitive Detection of Cancer miRNAs

The design and engineering of effective electrode materials is critical in the development of electrochemical sensors. In the present study, Ho2O3-TiO2 nanobelts were synthesized by an alkaline hydrothermal process. The structure and morphology were investigated by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) measurements. The Ho2O3-TiO2 nanobelts showed a distinctly enhanced (004) reflection peak and rough surfaces and were used for the electrochemical selective sensing of various cancer miRNAs, such as prostate cancer miR-141, osteosarcoma miR-21, and pancreatic cancer miR-1290. Voltammetric measurements showed an oxidation peak at +0.4, +0.2, and +1.53 V for the three different cancer biomarkers, respectively, with the detection limit as low as 4.26 aM. The results suggest that the Ho2O3-TiO2 nanobelts can be used as active materials to detect early cancers, for in vitro screening of anticancer drugs, and molecular biology research.

Extracellular vesicles from bone mesenchymal stem cells transport microRNA-206 into osteosarcoma cells and target NRSN2 to block the ERK1/2-Bcl-xL signaling pathway

Osteosarcoma (OS) is a kind of malignant tumor originating from mesenchymal tissues. Bone mesenchymal stem cells-derived extracellular vesicles (BMSCs-EVs) can play important roles in OS. This study investigated the mechanism of BMSCs-EVs on OS. BMSC surface antigens and adipogenic and osteogenic differentiation were detected by flow cytometry, and oil red O and alizarin red staining. EVs were isolated from BMSCs by differential centrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot (WB). miR-206 and neurensin-2 (NRSN2) levels in human osteoblast hFOB 1.19 or OS cells (143B, MG-63, Saos2, HOS) were detected by RT-qPCR. Human OS cells with lower miR-206 levels were selected and treated with BMSCs-EVs or pSUPER-NRSN2. The uptake of EVs by 143B cells, cell proliferation, apoptosis, invasion, and migration were detected by immunofluorescence, 5-ethynyl-2’-deoxyuridine (EdU) and colony formation assays, flow cytometry, scratch test, and transwell assays. The binding sites between miR-206 and NRSN2 were predicted by Starbase database and verified by dual-luciferase assay. The OS xenograft model was established and treated with BMSCs-EVs. Tumor growth rate and volume, cell proliferation, and p-ERK1/2, ERK1/2, and Bcl-xL levels were detected by vernier caliper, immunohistochemistry, and WB. BMSCs-EVs were successfully extracted. miR-206 was diminished and NRSN2 was promoted in OS cells. BMSCs-EVs inhibited proliferation, migration, and invasion, and promoted apoptosis of OS cells. BMSCs-EVs carried miR-206 into OS cells. Inhibition of miR-206 in EVs partially reversed the inhibitory effect of EVs on malignant behaviors of OS cells. miR-206 targeted NRSN2. Overexpression of NRSN2 reversed the inhibitory effect of EVs on OS cells. NRSN2 activated the ERK1/2-Bcl-xL pathway. BMSC-EVs inhibited OS growth in vivo. In summary, BMSC-EVs targeted NRSN2 and inhibited the ERK1/2-Bcl-xL pathway by carrying miR-206 into OS cells, thus inhibiting OS progression.

Crosstalk of Exosomal Non-Coding RNAs in The Tumor Microenvironment: Novel Frontiers

The tumor microenvironment (TME) is defined as a complex and dynamic tissue entity composed of endothelial, stromal, immune cells, and the blood system. The homeostasis and evolution of the TME are governed by intimate interactions among cellular compartments. The malignant behavior of cancer cells, such as infiltrating growth, proliferation, invasion, and metastasis, is predominantly dependent on the bidirectional communication between tumor cells and the TME. And such dialogue mainly involves the transfer of multifunctional regulatory molecules from tumor cells and/or stromal cells within the TME. Interestingly, increasing evidence has confirmed that exosomes carrying regulatory molecules, proteins, and nucleic acids act as an active link in cellular crosstalk in the TME. Notably, extensive studies have identified non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), that could be encapsulated by exosomes, which regulate the coordinated function within the TME and thus participate in cancer development and progression. In this review, we summarize recent literature around the topic of the functions and mechanisms of exosomal ncRNAs in the TME and highlight their clinical significance.

Small but Powerful: The Human Vault RNAs as Multifaceted Modulators of Pro-Survival Characteristics and Tumorigenesis

Simple Summary

Small non-protein-coding RNAs have been recognized as valuable regulators of gene expression in all three domains of life. Particularly in multicellular organisms, ncRNAs-mediated gene expression control has evolved as a central principle of cellular homeostasis. Thus, it is not surprising that non-coding RNA misregulation has been linked to various diseases. Here, we review the contributions of the four human vault RNAs to cellular proliferation, apoptosis and cancer biology.

Abstract

The importance of non-coding RNAs for regulating gene expression has been uncovered in model systems spanning all three domains of life. More recently, their involvement in modulating signal transduction, cell proliferation, tumorigenesis and cancer progression has also made them promising tools and targets for oncotherapy. Recent studies revealed a class of highly conserved small ncRNAs, namely vault RNAs, as regulators of several cellular homeostasis mechanisms. The human genome encodes four vault RNA paralogs that share significant sequence and structural similarities, yet they seem to possess distinct roles in mammalian cells. The alteration of vault RNA expression levels has frequently been observed in cancer tissues, thus hinting at a putative role in orchestrating pro-survival characteristics. Over the last decade, significant advances have been achieved in clarifying the relationship between vault RNA and cellular mechanisms involved in cancer development. It became increasingly clear that vault RNAs are involved in controlling apoptosis, lysosome biogenesis and function, as well as autophagy in several malignant cell lines, most likely by modulating signaling pathways (e.g., the pro-survival MAPK cascade). In this review, we discuss the identified and known functions of the human vault RNAs in the context of cell proliferation, tumorigenesis and chemotherapy resistance.

Exosome-Mediated miR-21 Was Involved in the Promotion of Structural and Functional Recovery Effect Produced by Electroacupuncture in Sciatic Nerve Injury

PURPOSE

Our study is aimed at investigating the mechanism by which electroacupuncture (EA) promoted nerve regeneration by regulating the release of exosomes and exosome-mediated miRNA-21 (miR-21) transmission. Furthermore, the effects of Schwann cells- (SC-) derived exosomes on the overexpression of miR-21 for the treatment of PNI were investigated.

METHODS

A sciatic nerve injury model of rat was constructed, and the expression of miR-21 in serum exosomes and damaged local nerves was detected using RT-qPCR after EA treatment. The exosomes were identified under a transmission electron microscope and using western blotting analysis. Then, the exosome release inhibitor, GW4869, and the miR-21-5p-sponge used for the knockdown of miR-21 were used to clarify the effects of exosomal miR-21 on nerve regeneration promoted by EA. The nerve conduction velocity recovery rate, sciatic nerve function index, and wet weight ratio of gastrocnemius muscle were determined to evaluate sciatic nerve function recovery. SC proliferation and the level of neurotrophic factors were assessed using immunofluorescence staining, and the expression levels of SPRY2 and miR-21 were detected using RT-qPCR analysis. Subsequently, the transmission of exosomal miR-21 from SC to the axon was verified in vitro. Finally, the exosomes derived from the SC infected with the miR-21 overexpression lentivirus were collected and used to treat the rat SNI model to explore the therapeutic role of SC-derived exosomes overexpressing miR-21.

RESULTS

We found that EA inhibited the release of serum exosomal miR-21 in a PNI model of rats during the early stage of PNI, while it promoted its release during later stages. EA enhanced the accumulation of miR-21 in the injured nerve and effectively promoted the recovery of nerve function after PNI. The treatment effect of EA was attenuated when the release of circulating exosomes was inhibited or when miR-21 was downregulated in local injury tissue via the miR-21-5p-sponge. Normal exosomes secreted by SC exhibited the ability to promote the recovery of nerve function, while the overexpression of miR-21 enhanced the effects of the exosomes. In addition, exosomal miR-21 secreted by SC could promote neurite outgrowth in vitro.

CONCLUSION

Our results demonstrated the mechanism of EA on PNI from the perspective of exosome-mediated miR-21 transport and provided a theoretical basis for the use of exosomal miR-21 as a novel strategy for the treatment of PNI.

Research Progress of Exosome-Loaded miRNA in Osteosarcoma

Currently, although the improvement of surgical techniques and the development of chemotherapy drugs have brought a certain degree of development to the treatment of osteosarcoma, the treatment of osteosarcoma has many shortcomings, and its treatment is limited. MiRNAs and exosomes can be used as diagnostic tools, and they play an important role in the occurrence and chemotherapy resistance of osteosarcoma. Therefore, providing a new method for the treatment of osteosarcoma is the key to solving this problem. To systematically summarize the research status of exoskeleton drug-loaded miRNA in osteosarcoma, we identified and evaluated 208 studies and found that exosome-carrying miRNA can be used as an index for the diagnosis and prognosis of osteosarcoma and share a certain relationship with chemosensitivity. In addition, exosomes can also be used as a carrier of genetic drugs able to regulate the progression of osteosarcoma. Based on the above findings, we propose suggestions for the future development of this field, aiming to bring new ideas for the early diagnosis and treatment of osteosarcoma.

The basic characteristics of extracellular vesicles and their potential application in bone sarcomas

Bone sarcomas are rare cancers accompanied by metastatic disease, mainly including osteosarcoma, Ewing sarcoma and chondrosarcoma. Extracellular vesicles (EVs) are membrane vesicles released by cells in the extracellular matrix, which carry important signal molecules, can stably and widely present in various body fluids, such as plasma, saliva and scalp fluid, spinal cord, breast milk, and urine liquid. EVs can transport almost all types of biologically active molecules (DNA, mRNA, microRNA (miRNA), proteins, metabolites, and even pharmacological compounds). In this review, we summarized the basic biological characteristics of EVs and focused on their application in bone sarcomas. EVs can be use as biomarker vehicles for diagnosis and prognosis in bone sarcomas. The role of EVs in bone sarcoma has been analyzed point-by-point. In the microenvironment of bone sarcoma, bone sarcoma cells, mesenchymal stem cells, immune cells, fibroblasts, osteoclasts, osteoblasts, and endothelial cells coexist and interact with each other. EVs play an important role in the communication between cells. Based on multiple functions in bone sarcoma, this review provides new ideas for the discovery of new therapeutic targets and new diagnostic analysis.

Screening a novel signature and predicting the immune landscape of metastatic osteosarcoma in children via immune-related lncRNAs

BACKGROUND

The immune microenvironment plays an essential role in osteosarcoma (OSs); however, differences in immune-related long non-coding ribonucleic acids (irlncRNAs) in children with localized OSs and metastatic OSs have not yet been investigated.

METHODS

The clinical data and the transcriptome of OSs were obtained from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, and the immune-related genes were derived from the imported dataset. The correlations between immune-related genes and lncRNAs were examined. Next, the differential expressions of the irlncRNA pairs (IRLPs) in localized OSs and distant metastatic OSs were analyzed, and a prognostic model was constructed based on the significant differentially expressed IRLPs. We also analyzed the association between the IRLPs' signature risk score and the infiltration of the immune cells. Finally, we investigated the correlation between risk score and drug resistance.

RESULTS

Thirty upregulated and 22 downregulated lncRNAs were identified in the localized and metastatic OSs samples. Univariate and multivariate cox regression analyses were undertaken to select 6 lncRNA pairs to establish the prognostic signature, the model was valuable in predicting OSs prognosis. Further, the expression of the finally selected irlncRNAs indicated that VPS9D1-AS1 (P=0.031), AP003086.2 (P=0.041), AL031847.1 (P=0.008), AL020997.3 (P=0.020), AC011444.1 (P=0.025), and AC006449.2 (P=0.003) were significantly upregulated in metastasis patients, but USP27X-AS1 (P=0.046), AL008721.2 (P=0.005), AC002091.1 (P=0.033), and AL118558.4 (P=0.049) were significantly overexpressed in localized patients. The overexpression of AC002091.1 (P=0.038) and AL118558.4 (P=0.004) resulted in better overall survival, but the upregulation of AC011444.1 (P=0.045), AL031847.1 (P=0.020), VPS9D1-AS1 (P=0.039), and AC006449.2 (0.006) led to a poor outcome. Differences in immune cell infiltration indicated that metastatic patients and localized have significant difference of 4 (CD4) T cells (P=0.006), monocytes (P=0.029), activated mast cells (P=0.018), and neutrophils (P=0.026), and a high abundance of activated dendritic cells (P=0.010) and activated mast cells (P=0.049) resulted in poor prognosis. Patients in the high-risk-score group were resistant to axitinib, but sensitive to dasatinib, bortezomib, and cisplatin.

CONCLUSIONS

In the present study, IRLPs were used to construct a novel and practical model for predicting the prognosis of localized and metastatic OSs in children.

Information Transfer and Biological Significance of Neoplastic Exosomes in the Tumor Microenvironment of Osteosarcoma

Osteosarcoma is a highly invasive kind of malignant bone tumor. Exosomes are a type of extracellular vesicles that play an important role in intercellular communication in the microenvironment. Tumor cell progression is promoted through the interaction between exosomes and cells in the microenvironment (including immune cells, mesenchymal cells, and endothelial cells) during tumor development. Neoplastic exosomes can carry a variety of biological information molecules, such as proteins, lipids, and nucleic acids. These molecules play an important clinical role, not only being able domesticate the recipient cells but also being recognized as tumor specific markers. At the same time, exosomes secreted by osteosarcoma can also cooperate with antigen-presenting cells to activate the body's immune response and then to exert anti-tumor effects. Studies on exosomes may be a breakthrough in the search for a new osteosarcoma treatment. In this study, we review the role of neoplastic exosomes in the osteosarcoma microenvironment, summarize their potential as tumor markers, and investigate their clinical application prospects.