MiRNA-206 suppresses the metastasis of osteosarcoma via targeting Notch3

hsa_circ_0020378 regulating miR-339-3p/COL1A1 promotes osteosarcoma progression

Osteosarcoma is a malignant orthopedic tumor that is frequently diagnosed in the pediatric population. Several studies have summarized the functions of circular RNAs (circRNAs) in the progression of osteosarcoma. This study aimed to investigate a novel circRNA, hsa_circ_0020378 (circ_0020378), and elucidate its functions and underlying mechanisms during osteosarcoma progression. The expression levels of circ_0020378, miR-339-3p, and COL1A1 in osteosarcoma cells and tissues were determined using RT-qPCR or Western blotting. CCK8, transwell migration, colony formation, and xenograft experiments were performed to assess the malignancy of osteosarcoma cells. Luciferase and RNA immunoprecipitation (RIP) experiments were employed to validate the interactions of miR-339-3p with circ_0020378 and COL1A1 3'UTR. Osteosarcoma cells and tissues showed significant upregulation of circ_0020378 and COL1A1 and downregulation of miR-339-3p. Silencing circ_0020378 in osteosarcoma cells inhibited their proliferation, colony formation, and migration. The inhibitive influence of circ_0020378 silencing during osteosarcoma tumorigenesis in vitro was verified in vivo. Circ_0020378 sponged miR-339-3p which targeted COL1A1 3'UTR. Circ _0020378 silencing disrupted the tumor-promoting effect of the miR-339-3p inhibitor in osteosarcoma cells. Furthermore, miR-339-3p inhibitor attenuated the suppressive effect of COL1A1 downregulation on malignant osteosarcoma cell phenotypes. Circ_0020378 stimulates osteosarcoma progression by downregulating miR-339-3p/COL1A1 expression. These findings provide a theoretical basis for the discovery of novel osteosarcoma targets.

miRNA-23b-5p affects the proliferation, migration and invasion of osteosarcoma by targeting TMEM127

BACKGROUND

Osteosarcoma (OS) has become one of the highest mortality cancers in the world due to its late diagnosis, rapid metastasis and rapid recurrence. MicroRNAs can regulate a variety of signaling pathwas involved in cancer development, such as cell proliferation, apoptosis and migration.

OBJECTIVE

In this study, we studied the biological effects and molecular regulation of mir-23b-5p on human osteosarcoma cells.

METHODS

The proliferation of mir-23b-5p in osteosarcoma was measured by CCK8 method and EDU method. In addition, the target population was screened through the database, and the luciferase reporter gene was used to determine the association between miRNA and target gene TMEM127. We verified this result by Western blot.

RESULTS

We found that mir-23b-5p promotes the progression of osteosarcoma by regulating TMEM127.

CONCLUSIONS

The results of this study show that mir-23b-5p affects the proliferation, metastasis and invasion of OS by targeting TMEM127.

Hsa_circ_0008259 modulates miR-21-5p and PDCD4 expression to restrain osteosarcoma progression

BACKGROUND

Osteosarcoma (OS) is one of the most common primary bone tumors in children and adolescents. However, the molecular mechanism of OS tumorigenesis is still little known. Circular RNA (circRNA) is a key player in the progression of many cancers. This study is performed to decipher the role and mechanism of circ_0008259 in the progression of OS.

METHODS

A differentially expressed circRNA, circ_0008259, was screened out by analyzing the expression profile of circRNA in OS tissue. Circ_0008259, miR-21-5p and programmable cell death 4 (PDCD4) mRNA expression levels in OS tissues and cells were detected by qRT-PCR. Cell viability, metastatic potential and apoptosis were evaluated by cell counting kit-8 assay, Transwell and flow cytometry. The targeting relationship between circ_0008259 and miR-21-5p, and miR-21-5p and PDCD4 mRNA was analyzed and probed by bioinformatics analysis and dual-luciferase reporter assay, RNA-binding protein immunoprecipitation assay and RNA-pull down assay. The regulatory effects of circ_0008259 and miR-21-5p on PDCD4 protein expression in OS cells were detected by Western blot assay.

RESULTS

Circ_0008259 expression and PDCD4 expression were down-regulated and miR-21-5p expression was elevated in the OS tissues and cells. Functional experiments showed that circ_0008259 overexpression significantly inhibited the proliferation and metastatic potential of OS cells and promoted the apoptosis. Besides, PDCD4 was validated as the target gene of miR-21-5p, and circ_0008259 could competitively bind to miR-21-5p, thus up-regulating PDCD4 expression in OS cells.

CONCLUSIONS

Circ_0008259 suppresses OS progression via regulating miR-21-5p/PDCD4 axis.

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.

Cantharidin inhibits osteosarcoma proliferation and metastasis by directly targeting miR-214-3p/DKK3 axis to inactivate β-catenin nuclear translocation and LEF1 translation

Background: As the leading primary bone cancer in adolescents and children, osteosarcoma patients with metastasis show a five-year-survival-rate of 20-30%, without improvement over the past 30 years. Wnt/β-catenin is important in promoting osteosarcoma development. DKK3 is a Wnt/β-catenin antagonist and predicted to have the specific binding site in 3′-UTR with miR-214-3p.

Methods: miR-214-3p and DKK3 levels were investigated in human osteosarcoma tissues and cells by RT-qPCR; the prognostic importance of DKK3 level in osteosarcoma patients was determined with Log-rank test; direct binding between DKK3 with miR-214-3p was identified with targetscan; anti-osteosarcoma mechanism of cantharidin was investigated by miR-214-3p silence/over-expression with or without cantharidin treatment, and nuclear/cytoplasmic protein assay in osteosarcoma cells.

Results: Down-regulated DKK3 indicated poor prognosis of osteosarcoma patients. Up-regulated miR-214-3p promoted proliferation and migration, while suppressed apoptosis of osteosarcoma cells by increasing β-catenin nuclear translocation and LEF1 translation via degradation of DKK3. Cantharidin suppressed viabilities, migration and invasion, while promoted cell cycle arrest and apoptosis in 143B and U-2 OS cells via down-regulating miR-214-3p to up-regulate DKK3, thus inhibited p-GSK-3β expression, β-catenin nuclear translocation and LEF1 translation. Meanwhile, cantharidin inhibited tumor growth in xenograft-bearing mice with 143B cell injection in tibia.

Conclusion: miR-214-3p mediated Wnt/β-catenin/LEF1 signaling activation by targeting DKK3 to promote oncogenesis of osteosarcoma; cantharidin inhibited proliferation and metastasis of osteosarcoma cells via down-regulating miR-214-3p to up-regulate DKK3 and decrease β-catenin nuclear translocation, indicating that cantharidin may be a prospective candidate for osteosarcoma treatment by targeting miR-214-3p/DKK3/β-catenin signaling.

The Role of Notch3 Signaling in Cancer Stemness and Chemoresistance: Molecular Mechanisms and Targeting Strategies

Aberrant Notch signaling profoundly affects cancer progression. Especially the Notch3 receptor was found to be dysregulated in cancer, where its expression is correlated with worse clinicopathological features and poor prognosis. The activation of Notch3 signaling is closely related to the activation of cancer stem cells (CSCs), a small subpopulation in cancer that is responsible for cancer progression. In addition, Notch3 signaling also contributes to tumor chemoresistance against several drugs, including doxorubicin, platinum, taxane, epidermal growth factor receptor (EGFR)–tyrosine kinase inhibitors (TKIs) and gemcitabine, through complex mechanisms. In this review, we mainly focus on discussing the molecular mechanisms by which Notch3 modulates cancer stemness and chemoresistance, as well as other cancer behaviors including metastasis and angiogenesis. What’s more, we propose potential treatment strategies to block Notch3 signaling, such as non-coding RNAs, antibodies and antibody-drug conjugates, providing a comprehensive reference for research on precise targeted cancer therapy.