Regulatory effects of microRNA‑184 on osteosarcoma via the Wnt/β‑catenin signaling pathway

microRNA-184 in the landscape of human malignancies: a review to roles and clinical significance

MicroRNAs (miRNAs) are a class of non-coding RNAs (ncRNAs) with a short length of 19-22 nucleotides. miRNAs are posttranscriptional regulators of gene expression involved in various biological processes like cell growth, apoptosis, and angiogenesis. miR-184 is a well-studied miRNA, for which most studies report its downregulation in cancer cells and tissues and experiments support its role as a tumor suppressor inhibiting malignant biological behaviors of cancer cells in vitro and in vivo. To exert its functions, miR-184 affects some signaling pathways involved in tumorigenesis like Wnt and β-catenin, and AKT/mTORC1 pathway, oncogenic factors (e.g., c-Myc) or apoptotic proteins, such as Bcl-2. Interestingly, clinical investigations have shown miR-184 with good performance as a prognostic/diagnostic biomarker for various cancers. Additionally, exogenous miR-184 in cell and xenograft animal studies suggest it as a therapeutic anticancer target. In this review, we outline the studies that evaluated the roles of miR-184 in tumorigenesis as well as its clinical significance.

Lnc-SELPLG-2:1 enhanced osteosarcoma oncogenesis via hsa-miR-10a-5p and the BTRC cascade

BACKGROUND

To investigate the potential role of Long Non-coding RNAs (lncRNAs) in the progression of osteosarcoma.

METHODS

The candidate lncRNAs were screened with RNA-seq and confirmed with quantitative real-time PCR. Using MTS, transwell assay, and flow cytometric analysis, the effects of overexpressed lnc-SELPLG-2:1 on cell functions were determined. Immunohistochemical staining, fluorescence in situ hybridization, and luciferase reporter assay were used to evaluate the potential mechanism of lnc-SELPLG-2:1 in vivo and in vitro using a tumor model. Moreover, the effects of overexpression of hsa-miR-10a-5p on the functions of SaOS2 cells were determined using functional cell analysis. A response test was used to confirm the mechanism by which lnc-SELPLG-2:1 sponge hsa-miR-10a-5p promotes the expression of BTRC to regulate osteosarcoma.

RESULTS

Lnc-SELPLG-2:1 was highly expressed in osteosarcoma compared to normal cells and bone and marrow samples. Inhibition of lnc-SELPLG-2:1 accelerated cell apoptosis and suppressed cell proliferation, migration, and invasion, whereas lnc-SELPLG-2:1 overexpression had the opposite effect. Moreover, inhibiting lnc-SELPLG-2:1 in an in vivo model decreased tumor size and suppressed the expression of cell migration-related proteins. The prediction, dual luciferase assay, and response test results indicated that hsa-miR-10-5p and BTRC were involved in the lnc-SELPLG-2:1 cascade. Unlike lnc-SELPLG-2:1, hsa-hsa-miR-10a-5p had opposite expression and function. Competitive binding of lnc-SELPLG-2:1 to hsa-hsa-miR-10a-5p prevented BTRC from miRNA-mediated degradation, thereby activating the expression of VIM, MMP9, and MMP2, promoting osteosarcoma cell proliferation, migration, and invasion, and inhibiting apoptosis.

CONCLUSION

Lnc-SELPLG-2:1 is an oncogenesis activator in osteosarcoma, and its functions are performed via hsa-miR-10a-5p /BTRC cascade.

Effect of miR-184 and miR-205 on the tumorigenesis of conjunctival mucosa associated lymphoid tissue lymphoma through regulating RasL10B and TNFAIP8

AIM

To explore the effect of miR-184 and miR-205 on the proliferation and metastasis of conjunctival mucosa associated lymphoid tissue (MALT) lymphoma.

METHODS

Tissue of tumor and adjacent normal control from 5 patients with conjunctival MALT was included. RPMI8226 cell line was selected to verify the effect of miRNAs in B cells. The function of microRNA on the RPMI8226 cell apoptosis, migration and invasion was evaluated by apoptosis assay and Transwell assay. The mRNA and protein expression were examined by quantitative RT-PCR and Western blotting. The effect of microRNA on regulation of downstream gene expression was evaluated by luciferase report assay.

RESULTS

A decreased level of miR-184 and miR-205 was observed in MALT lymphoma tissue. Exogenous miR-184 and miR-205 analogues promoted apoptosis, and inhibited the survival, migration, and invasion of RPMI8226 cells. miR-184 and miR-205 inhibitor reversed the process. The RNA and protein level of RasL10B and TNFAIP8 were downregulated in MALT lymphoma tissue. The exogenous of miR-184 and miR-205 promoted the expression of RasL10B and TNFAIP8. Meanwhile, inhibition of miR-184 and miR-205 repressed the expression of target gene, RasL10B and TNFAIP8.

CONCLUSION

miR-184 and miR-205 suppresses the tumorigenesis of conjunctival MALT lymphoma through regulating RasL10B and TNFAIP8.

Hsa_circ_0004674 promotes osteosarcoma doxorubicin resistance by regulating the miR-342-3p/FBN1 axis

Background

The occurrence of chemoresistance is a common problem in tumor treatment. Circular RNA (circRNA) has been confirmed to be related to tumor chemoresistance. However, the role and the underlying molecular mechanism of hsa_circ_0004674 in the chemoresistance of osteosarcoma (OS) are still unclear.

Methods

The expression of hsa_circ_0004674, miR-342-3p, and fibrillin-1 (FBN1) was determined by qRT-PCR. Cell counting kit 8 assay was used to evaluate the doxorubicin (DXR) resistance of cells. The proliferation and apoptosis of cells were measured using colony formation assay and flow cytometry. Western blot analysis was utilized to examine the protein levels of resistance markers, Wnt/β-catenin pathway markers and FBN1. The interaction between miR-342-3p and hsa_circ_0004674 or FBN1 was confirmed by dual-luciferase reporter assay and RNA pull-down assay. Moreover, animal experiments were performed to assess the effect of hsa_circ_0004674 silencing on the DXR sensitive of OS in vivo.

Results

The upregulated hsa_circ_0004674 was found in DXR-resistant OS tissues and cells. Knockdown of hsa_circ_0004674 could inhibit the DXR resistance of OS cells in vitro and promote the DXR sensitive of OS tumors in vivo. In addition, we discovered that hsa_circ_0004674 could sponge miR-342-3p, and miR-342-3p could target FBN1. MiR-342-3p inhibitor could reverse the inhibition effect of hsa_circ_0004674 knockdown on the DXR resistance of OS cells. Similarly, the suppressive effect of miR-342-3p on the DXR resistance of OS cells also could be reversed by FBN1 overexpression. Furthermore, we revealed that hsa_circ_0004674 silencing inhibited the activity of Wnt/β-catenin pathway by the miR-342-3p/FBN1 axis.

Conclusion

Hsa_circ_0004674 facilitated the DXR resistance of OS through Wnt/β-catenin pathway via regulating the miR-342-3p/FBN1 axis, suggesting that hsa_circ_0004674 was a promising target for the chemoresistance of OS.

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.

Analysis of a Preliminary microRNA Expression Signature in a Human Telangiectatic Osteogenic Sarcoma Cancer Cell Line

Telangiectatic osteosarcoma (TOS) is an aggressive variant of osteosarcoma (OS) with distinctive radiographic, gross, microscopic features, and prognostic implications. Despite several studies on OS, we are still far from understanding the molecular mechanisms of TOS. In recent years, many studies have demonstrated not only that microRNAs (miRNAs) are involved in OS tumorigenesis, development, and metastasis, but also that the presence in high-grade types of OS of cancer stem cells (CSCs) plays an important role in tumor progression. Despite these findings, nothing has been described previously about the expression of miRNAs and the presence of CSCs in human TOS. Therefore, we have isolated/characterized a putative CSC cell line from human TOS (TOS-CSCs) and evaluated the expression levels of several miRNAs in TOS-CSCs using real-time quantitative assays. We show, for the first time, the existence of CSCs in human TOS, highlighting the in vitro establishment of this unique stabilized cell line and an identification of a preliminary expression of the miRNA profile, characteristic of TOS-CSCs. These findings represent an important step in the study of the biology of one of the most aggressive variants of OS and the role of miRNAs in TOS-CSC behavior.

Micro-RNA Expression Patterns Predict Metastatic Spread in Solid Pseudopapillary Neoplasms of the Pancreas

Solid pseudopapillary neoplasm (SPN) of pancreas is a rare pancreatic neoplasm with a low metastatic potential. Up to 10% of patients with localized disease at presentation will develop systemic metastases, usually in the peritoneum or the liver. Due to the rarity of SPNs and the overall excellent prognosis, reliable prognostic factors to predict malignant biological behavior remain undetermined. Therefore, we aimed to define clinical, histological, and microRNA patterns that are associated with metastatic disease. We conducted a retrospective single center study on all patients operated for SPN of pancreas between 1995 and 2018. Clinical and pathological data were collected, and expression patterns of 2,578 human microRNAs were analyzed using microRNA array (Affimetrix 4.1) in normal pancreases (NPs), localized tumors (LTs), and metastatic tumors (MTs). The diagnosis of SPN was confirmed in 35 patients who included 28 females and 3 males, with a mean age of 33.8 ± 13.9 years. The only clinical factor associated with metastases was tumor size (mean tumor size 5.20 ± 3.78 in LT vs. 8.13± 1.03 in MT, p < 0.012). Microscopic features of malignancy were not associated with metastases, nor were immunohistochemical stains, including the proliferative index KI67. Higher expressions of miR-184, miR-10a, and miR-887, and lower expressions of miR-375, miR-217, and miR-200c were observed in metastatic tissues on microarray, and validated by real-time polymerase chain reaction. Hierarchal clustering demonstrated that the microRNA expression pattern of MTs was significantly different from that of LTs. The only clinical factor associated with metastases of SPN of pancreas was tumor size. Histological features and immunohistological staining were not predictive of metastases. A panel of six microRNAs was differentially expressed in MTs, and these findings could potentially be used to predict tumor behavior. Validation of these results is needed in larger series.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.