Research Progress of Exosome-Loaded miRNA in Osteosarcoma

Cutaneous squamous cell carcinoma-derived exosomal MicroRNA-31 acts as an oncogene by targeting the tumor suppressor RhoBTB1

Tumor-derived exosomes that transport MicroRNAs significantly influence cutaneous squamous cell carcinoma(CSCC) progression. However, the molecular mechanisms of exosomal MicroRNA-31 regulation of CSCC are mostly undefined. To determine whether a targeting relationship exists between MicroRNA-31 (miR-31) in CSCC-derived exosomes and the tumor suppressor RhoBTB1, and the regulatory effect of the relationship on tumor cells. Immunoblotting and quantitative PCR were used to measure miR-31 and RhoBTB1 levels in various cells and exosomes. Differential ultracentrifugation was used to isolate exosomes. MTT and Transwell assays were used to assess cell proliferation, migration, and invasion. Dual luciferase reporter assays were used to assess the direct interaction between miR-31 and the tumor suppressor RhoBTB1 in cutaneous squamous cell carcinoma (CSCC)-derived exosomes. Compared with a human skin keratinocyte cell line, in CSCC cell lines RhoBTB1 was downregulated and miR-31 levels were elevated. Exosomal miR-31 from CSCC cell lines directly targeted RhoBTB1 by binding to the 3' UTR of RhoBTB1. This interaction suppressed expression of RhoBTB1 and enhanced CSCC cell proliferation, migration, and invasion. MicroRNA-31 in CSCC-derived exosomes can enhance CSCC cell proliferation, migration, and invasion by suppressing expression of RhoBTB1. This finding explains, in part, the molecular mechanism of CSCC. Investigative approaches focused on suppressing miR-31 or enhancing RhoBTB1 signaling pathways are promising avenues for developing targeted therapies for CSCC.

Osteosarcoma in a ceRNET perspective

Osteosarcoma (OS) is the most prevalent and fatal type of bone tumor. It is characterized by great heterogeneity of genomic aberrations, mutated genes, and cell types contribution, making therapy and patients management particularly challenging. A unifying picture of molecular mechanisms underlying the disease could help to transform those challenges into opportunities.This review deeply explores the occurrence in OS of large-scale RNA regulatory networks, denominated "competing endogenous RNA network" (ceRNET), wherein different RNA biotypes, such as long non-coding RNAs, circular RNAs and mRNAs can functionally interact each other by competitively binding to shared microRNAs. Here, we discuss how the unbalancing of any network component can derail the entire circuit, driving OS onset and progression by impacting on cell proliferation, migration, invasion, tumor growth and metastasis, and even chemotherapeutic resistance, as distilled from many studies. Intriguingly, the aberrant expression of the networks components in OS cells can be triggered also by the surroundings, through cytokines and vesicles, with their bioactive cargo of proteins and non-coding RNAs, highlighting the relevance of tumor microenvironment. A comprehensive picture of RNA regulatory networks underlying OS could pave the way for the development of innovative RNA-targeted and RNA-based therapies and new diagnostic tools, also in the perspective of precision oncology.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

CircECE1 promotes osteosarcoma progression through regulating RAB3D by sponging miR-588

BACKGROUND

Circular RNAs (circRNAs) have been confirmed to be involved in cancer pathogenesis. However, the underlying mechanism of circRNA endothelin converting enzyme 1 (circECE1) in osteosarcoma (OS) development is still not understood.

METHODS

The expression levels of circECE1, microRNA-588 (miR-588) and RAB3D, member RAS oncogene family (RAB3D) were gauged by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. OS cell proliferation was assessed by cell counting kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. OS cell apoptosis rate and metastasis were identified by flow cytometry and transwell assay. Dual-luciferase reporter analysis and RNA immunoprecipitation (RIP) assay were performed to confirm the interactions among circECE1, miR-588 and RAB3D. Xenograft tumor models were established to explore circECE1 function in vivo. Immunohistochemistry (IHC) assay was applied to analyze RAB3D level after circECE1 knockdown.

RESULTS

In OS, circECE1 expression was higher than that in normal chondroma tissues. High levels of circECE1 were positively linked to OS cell viability, proliferation, migration and invasion, and negatively linked to OS cell apoptosis rate. It was found that circECE1 was a miR-588 sponge, and miR-588 inhibitor abrogated the influence of si-circECE1 on OS cells. MiR-588 targeted RAB3D to further regulate the pathological process of OS. Moreover, silencing circECE1 blocked OS tumor growth in vivo.

CONCLUSION

We elucidated the function of a novel circECE1/miR-588/RAB3D axis in OS progression.

Osteoclast-Derived Exosomal miR-5134-5p Interferes with Alveolar Bone Homeostasis by Targeting the JAK2/STAT3 Axis

Background

In chronic periodontitis, exosomes transport various informative substances between osteoclasts and osteoblasts in alveolar bone. Herein, we aimed to investigate the effect of exosomal micro-ribonucleic acid (miRNA/miR)-5134-5p derived from osteoclasts on osteoblastic proliferation and differentiation and the development of periodontitis in vivo and in vitro.

Methods

The effects of OC-Exos on the proliferation and differentiation of osteoblasts were identified by Real-time quantitative reverse polymerase chain reaction (qRT-PCR), Western blot(WB), alkaline phosphatase(ALP) staining, etc. Exosomal miRNA expression was analyzed by sequencing. The sites of miRNA action were predicted through TargetScan and tested by double luciferase assay. After transfecting miR-5134-5p mimic/inhibitor into osteoblasts, we measured the proliferation and differentiation of osteoblasts by ALP staining and WB, etc. Furthermore, OC-Exos were injected into the gingival sulcus at the ligation site. Inflammation was observed by Hematoxylin-eosin (H&E) staining, the expression of inflammatory factors were detected by qRT-PCR, the resorption of alveolar bone was observed by Micro CT.

Results

Osteoblastic proliferation and differentiation were negatively regulated by OC-Exos in vitro. miRNA sequencing analysis revealed that miR-5134-5p expression was significantly elevated in OC-Exos, which also increased in osteoblasts following OC-Exo intervention. The dual-luciferase assay revealed that miR-5134-5p and Janus kinase 2 (JAK2) had binding sites. miR-5134-5p-mimics could upregulate miR-5134-5p expression in osteoblasts while downregulating Runt-related transcription factor 2(Runx2), phosphorylated-JAK2 (p-JAK2), and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3) expression and inhibited osteogenic differentiation. However, miR-5134-5p-inhibitor had the opposite effect. In vivo, the OC-Exo group demonstrated morphological disruption of periodontal tissue, massive inflammatory cell infiltration, upregulation of inflammatory factors mRNA expression, a significant decrease in BV/TV, and an increase in the cementoenamel junction and alveolar bone crest distance.

Conclusion

Osteoclast-derived exosomal miR-5134-5p inhibits osteoblastic proliferation and differentiation via the JAK2/STAT3 pathway. OC-Exos exacerbate periodontal tissue inflammation and accelerate alveolar bone resorption in mice with experimental periodontitis.

Long non-coding RNA and circular RNA and coding RNA profiling of plasma exosomes of osteosarcoma by RNA seq

Osteosarcoma (OS) is a primary bone tumor with high malignancy and the mechanism of hematogenous metastasis in OS is still not clear. The plasma exosomes derived from osteosarcoma play a key role in the process of tumor metastasis. Here, we established RNA-seq dataset for lncRNAs, circRNAs and mRNAs in plasma exosomes from 10 OS patients and 5 healthy donors. A total of 329.52 Gb of clean data was obtained. Besides, 1754 lincRNAs, 7096 known and 1935 new circRNA was identified. Finally, gene expression profiles and differentially expressed genes (DEGs) were analyzed among these 15 samples. There were 331 DEGs of mRNA, 132 of lincRNA and 489 of circRNA was obtained, respectively. This data set provides a significant resource for relevant researchers to excavate potential dysregulated lncRNAs, circRNAs and mRNAs of plasma exosomes in OS versus normal conditions.

Colorimetric miRNA detection based on self-primer-initiated CRISPR-Cas12a-assisted amplification

miRNAs alter significantly throughout pregnancy to support the development of the fetus. However, sensitive detection of miRNA remains a challenge. Herein, a reliable miRNA detection approach integrating self-assembly-triggered signal amplification and CRISPR-Cas12a-system cleavage-based color generation is described. The colorimetric approach contains three signal amplification processes. The first signal amplification is formed by the released miRNA in a chain extension process. The produced sequence that is similar to the target miRNA initiates the second signal recycle. Finally, CRISPR-Cas12a-based transcleavage on linker sequences induces the third signal amplification. The method exhibits high sensitivity and a low limit of detection of 254 aM, showing promising prospects in disease diagnosis.

The promising roles of exosomal microRNAs in osteosarcoma: A new insight into the clinical therapy

Osteosarcoma is the most common malignant bone sarcoma in children. Chemotherapy drugs resistance significantly hinders the overall survival of patients. Due to high biocompatibility and immunocompatibility, exosomes have been explored extensively. Multiple parent cells can actively secrete numerous exosomes, and the membrane structure of exosomes can protect miRNAs from degradation. Based on these characteristics, exosomal miRNAs play an important role in the occurrence, development, drug resistance. Therefore, in-depth exploration of exosome biogenesis and role of exosomal miRNAs will provide new strategies and targets for understanding the pathogenesis of osteosarcoma and overcoming chemotherapy drug resistance. Moreover, advancing evidences have showed that engineering modification could attribute stronger targeting to exosomes to deliver cargos to recipient cells more effectively. In this review, we focus on the mechanisms of exosomal miRNAs on the occurrence and development of osteosarcoma and the potential to function as tumor biomarkers for diagnosis and prognosis prediction. In addition, we also summarize recent advances in the clinical application values of engineering exosomes to provide novel ideas and directions for overcoming the chemotherapy resistance in osteosarcoma.

Potential nanocarrier-mediated miRNA-based therapy approaches for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune neuroinflammatory disorder attributed to neurodegeneration and demyelination, resulting in neurological impairment. miRNA has a significant role in biological processes in MS. In this review, we focus on the feasibility of delivering miRNAs through nanoformulations for managing MS. We provide a brief discussion of miRNA synthesis and evidence for miRNA dysregulation in MS. We also highlight formulation strategies and resulting technologies for the effective delivery of miRNAs through nanocarrier systems for achieving high therapeutic benefits.