Circ0085539 Promotes Osteosarcoma Progression by Suppressing miR-526b-5p and PHLDA1 Axis

Alteration in the Expression of Circular Rnas and its association with the Development and Progression of Osteosarcoma, an Integrative Review with High Sensitivity Research

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumor, mainly affecting children, young adults, and the elderly. It is an aggressive cancer with a poor prognosis, exhibiting low survival rates even with standard treatment. Recently, circular RNA molecules capable of influencing gene expression through various functions, with their main role being acting as microRNA sponges and reducing their intracellular expression, have been identified. Recent studies have linked circular RNAs to osteosarcoma development and progression. Therefore, the present study aimed to investigate the alteration in circular RNA expression during osteosarcoma development and progression.

METHODS

An integrative literature review was conducted from September 10th to November 12th, 2021, using the following databases: PubMed/MEDLINE, SCOPUS, Web of Science, OVID, and EMBASE. 129 full articles were included in the review. The obtained data were organized using a standardized data collection instrument, which included the following information: altered expression profile of circular RNAs, associated cancer hallmarks, clinical-pathological relationships of circular RNAs, and perspectives on the studied circular RNAs.

RESULTS

A total of 94 distinct circular RNAs were identified, predominantly showing an increased expression pattern. Approximately 91% of the studies that aimed to identify the mechanisms of action of circular RNAs highlighted the function of circular RNAs as microRNA sponges. The most associated cancer hallmarks with the identified circular RNAs were proliferative signaling induction, invasion and metastasis, and resistance to cell death. The altered expression of these circular RNAs generally correlated with a worse prognosis for patients, as evidenced by clinical features such as shorter survival, advanced Enneking and/or TNM stage, higher incidence of metastasis, larger tumor size, and increased chemoresistance.

CONSLUSION

These findings indicate the significance of circular RNA molecules in osteosarcoma carcinogenesis, suggesting their potential as new prognostic and/or diagnostic biomarkers, as well as alternative therapeutic targets in the fight against osteosarcoma.

LINC01343 targets miR-526b-5p to facilitate the development of hepatocellular carcinoma by upregulating ROBO1

Long noncoding RNAs (lncRNAs) contribute to hepatocellular carcinoma (HCC) progression and development. However, the function and molecular mechanisms of action of LINC01343 in HCC remain unclear. qRT-PCR and western blotting were performed to assess miR-526b-5p, LINC01343, and ROBO1 levels in HCC cell lines and tissue samples. Flow cytometry, transwell, and cell counting kit-8 assays were conducted in vitro to assess how LINC01343 influences the apoptosis, migration, and proliferation of HCC cells. In addition, the role of LINC01343 in the growth of tumors was verified using an in vivo xenograft tumor assay. Specific binding of miR-526b-5p to LINC01343/ROBO1 was validated using RNA immunoprecipitation and dual-luciferase reporter experiments. LINC01343 was upregulated in HCC cells and tissues. In vitro, LINC01343-knockdown Hep3B and Huh-7 cells exhibited enhanced apoptosis and suppressed proliferation and migration. An in vivo study further validated that LINC01343-knockdown repressed tumor growth. In terms of mechanisms, LINC01343 directly sponged miR-526b-5p, negatively modulating its expression. Moreover, further experiments revealed that inhibiting miR-526b-5p could counteract the tumor-suppressive effects of LINC01343-knockdown in Hep3B and Huh-7 cells. ROBO1 was identified as a direct target of miR-526b-5p. ROBO1 knockdown weakens the migratory and proliferative abilities of Hep3B and Huh-7 cells. Nonetheless, the inhibition of miR-526b-5p mitigated this effect. These findings revealed that LINC01343 serves as a vital oncogene in HCC. Moreover, the LINC01343/miR-526b-5p/ROBO1 axis may be a prospective target for HCC treatment.

miR-526b-5p/c-Myc/Foxp1 participates in recurrent spontaneous abortion by regulating the proliferation, migration, and invasion of trophoblasts

PURPOSE

As a member of the C19MC family, miR-526b-5p is mainly expressed in the placental tissue and is a well-known tumor suppressor microRNA. However, its effect on the function of trophoblasts and its role in the development of recurrent spontaneous abortion (RSA) remains unclear.

METHODS

Transcriptome sequencing, quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, 5-ethynyl-2'-deoxyuridine (Edu) proliferation analysis, cell counting kit-8 (CCK8) assay, Transwell assays, and wound healing were used to detect the proliferation, migration, and invasion capacity of trophoblasts. Target genes of miR-526b-5p were obtained by the dual luciferase reporter system. The promoter-reporter system and ChIP-qPCR were used to prove that c-Myc positively regulated the expression of Foxp1 RESULTS: The miR-526b-5p levels were significantly higher in patients with RSA than in controls. High expression of miR-526b-5p inhibited the proliferation, migration, and invasion of trophoblast cell line. By contrast, low expression of miR-526b-5p promoted the proliferation and migration of trophoblast cell line. Target genes of miR-526b-5p were c-Myc and Foxp1. c-Myc positively regulated the expression of Foxp1 by binding to the Foxp1 promoter location -146/-135. Finally, miR-526b-5p impeded the proliferation, migration, and invasion of trophoblasts by negatively regulating c-Myc by rescue experiments.

CONCLUSION

Thus, miR-526b-5p affected the proliferation, migration, and invasion of trophoblasts by targeting c-Myc and Foxp1. Low expression of c-Myc further deactivated the positive transcriptional regulation of c-Myc on Foxp1, which may be the mechanism of RSA. This study provides potential therapeutic targets and clues for the diagnosis and treatment of RSA.

Circ_0062166 aggravates cerebral ischemia-reperfusion injury through targeting miR-526b-5p/BCL2L13 axis

BACKGROUND

Cerebral ischemia-reperfusion (CIR) injury is a severe disease, which may cause serious dysfunction of the brain. Most circular RNAs (circRNAs) have been demonstrated to play a significant role in CIR injury. However, a novel circRNA, circ_0062166 (circ_BCL2L13) has not been investigated for CIR injury. Hence, we aim to disclose the role of circ_0062166 in CIR injury in this study.

METHODS

Firstly, RT-qPCR was applied to examine the expression of circ_0062166 in oxygen-glucose deprivation and reoxygenation (OGD/R) cell model. Functional assays were conducted to detect the role of circ_0062166 in CIR injury. RNA pull down, RIP and luciferase reporter assays were implemented to probe into the regulatory mechanism of circ_0062166.

RESULTS

Circ_0062166 was significantly up-regulated in neuro-2A (N2A) neuroblastoma cells following OGD/R. Functionally, the silencing of circ_0062166 inhibited cell proliferation and promoted cell apoptosis under OGD/R condition. From the perspective of mechanism, circ_0062166 functioned as a competing endogenous RNA (ceRNA) for microRNA-526b-5p (miR-526b-5p) and regulated BCL2 like 13 (BCL2L13). Eventually, the promoting role of the circ_0062166/miR-526b-5p/BCL2L13 axis in the CIR injury was verified.

CONCLUSION

To sum up, the present study has demonstrated that circ_0062166/miR-526b-5p/BCL2L13 axis accelerated the progression of CIR injury, which might provide effective strategies for CIR injury therapy.

NCK1-AS1 promotes the progression of melanoma by accelerating cell proliferation and migration via targeting miR-526b-5p/ADAM15 axis

Background

Long non-coding RNAs (lncRNAs) are vital regulators of gene expression and cellular processes in multiple cancers, including melanoma. Nevertheless, the function of lncRNA NCK1-antisense 1 (NCK1-AS1) in melanoma remains unknown.

Methods

RT-qPCR was used to analyze the expression of NCK1-AS1, microRNA-526b-5p (miR-526b-5p) and ADAM metallopeptidase domain 15 (ADAM15). Cell proliferation was determined by CCK-8, colony formation and EdU assays. Cell migration was assessed by transwell migration and wound healing assays. Mechanism experiments including luciferase reporter, RIP and RNA pull down assays were conducted to demonstrate the interactions between RNAs. Xenograft model was established to verify the function of NCK1-AS1 and miR-526b-5p in melanoma in vivo.

Results

NCK1-AS1 was overexpressed in melanoma cell lines and NCK1-AS1 knockdown hampers the proliferation and migration of melanoma cells. Besides, miR-526b-5p binds to NCK1-AS1 in melanoma and ADAM15 was validated as its downstream target. Further, the inhibitory effects of NCK1-AS1 knockdown on cell proliferation and migration in melanoma were reversed by the depletion of miR-526b-5p and further counteracted by ADAM15 knockdown. The growth of melanoma tumors was hindered by the down-regulation of NCK1-AS1 or up-regulation of miR-526b-5p.

Conclusion

NCK1-AS1 facilitates cell proliferation and migration in melanoma via targeting miR-526b-5p/ADAM15 axis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02055-y.