scholarly journals Circ-SFMBT2 drives the malignant phenotypes of esophageal cancer by the miR-107-dependent regulation of SLC1A5

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhiwei Chang ◽  
Yang Fu ◽  
Yongxu Jia ◽  
Ming Gao ◽  
Lijie Song ◽  
...  

Abstract Background Increasing studies focused on the regulatory roles of circular RNAs (circRNAs) in diverse cancers. This study was to evaluate the function and mechanism of circRNA Scm-like with four malignant brain tumor domains 2 (circ-SFMBT2) in esophageal cancer (EC). Methods The circ-SFMBT2, microRNA-107 (miR-107) and solute-linked carrier family A1 member 5 (SLC1A5) levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay, colony formation assay and EdU assay. Cell apoptosis and invasion were detected by flow cytometry and transwell assay. Glutamine metabolism was assessed by the corresponding kits for glutamine consumption, α-ketoglutarate production and glutamate production. Western blot was used for protein quantification. The binding analysis was performed using dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assays. The functional research of circ-SFMBT2 in vivo was performed by xenograft tumor assay. Exosomes were identified by morphological observation and protein detection. Results Circ-SFMBT2 was overexpressed in EC samples and cells. Circ-SFMBT2 downregulation inhibited EC cell proliferation, invasion and glutamine metabolism. Circ-SFMBT2 targeted miR-107 and the regulation of circ-SFMBT2 was achieved by sponging miR-107. SLC1A5 was a target of miR-107, and it worked as an oncogene in EC cells. MiR-107 retarded the EC progression by downregulating SLC1A5. Circ-SFMBT2 could affect the SLC1A5 expression by targeting miR-107. Circ-SFMBT2 regulated EC progression in vivo by miR-107/SLC1A5 axis. Circ-SFMBT2 was transferred by exosomes in EC cells. Conclusion These results suggested that circ-SFMBT2 upregulated the SLC1A5 expression to promote the malignant development of EC by serving as a miR-107 sponge.

2021 ◽  
Vol 12 ◽  
Author(s):  
Peng Gao ◽  
Xincheng Zhao ◽  
Keying Yu ◽  
Ziqiang Zhu

Osteosarcoma (OS) is the most representative bone cancer, and circular RNAs serve as pivotal regulators in the progression of OS. This research was designed to explore the role and functional mechanism of circ_0084582 in OS. Circ_0084582, microRNA-485-3p (miR-485-3p), and Jagged1 (JAG1) levels were measured by quantitative real-time polymerase chain reaction. Cell proliferation was examined via 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Cell cycle progression was analyzed by flow cytometry. Wound healing and transwell assays were performed for evaluating cell migration and invasion. Angiopoiesis was assessed using the tube formation assay. Protein detection was conducted using Western blot. The target relation was identified by the dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, and RNA pull-down assay. A xenograft experiment was applied for analyzing the effect of circ_0084582 on OS in vivo. Circ_0084582 was highly expressed in OS tissues and cells. Circ_0084582 knockdown reduced cell proliferation, cell cycle progression, migration, invasion, and angiopoiesis of OS cells. JAG1 was upregulated in OS, and its overexpression reversed the effects of circ_0084582 knockdown on OS cells. Circ_0084582 targeted miR-485-3p, and miR-485-3p targeted JAG1, and circ_0084582 could affect the JAG1 level by sponging miR-485-3p. The function of circ_0084582 in OS progression was also achieved by sponging miR-485-3p. Circ_0084582 knockdown decreased OS growth in vivo partly by the miR-485-3p–mediated JAG1 downregulation. These results indicate that circ_0084582 functions as a tumorigenic factor in OS via the regulation of miR-485-3p/JAG1 axis.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Jingpeng Wang ◽  
Shuyuan Li ◽  
Gaofeng Zhang ◽  
Huihua Han

Abstract Background Sevoflurane (Sev), a commonly used volatile anesthetic, has been reported to inhibit the process of colorectal cancer (CRC). Circular RNAs (circRNAs) are revealed to participate in the pathogenesis of CRC. This study aims to reveal the mechanism of hsa_circ_0000231 in Sev-mediated CRC progression. Methods The expression of hsa_circ_0000231 and microRNA-622 (miR-622) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein level was determined by western blot analysis. Cell proliferation was investigated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cell colony formation and DNA content quantitation assays. Cell apoptosis was detected by Annexin V-fluorescein isothiocyanate and propidium iodide double staining and caspase 3 activity assays. Cell migration and invasion were investigated by wound-healing and transwell invasion assays, respectively. The putative relationship between hsa_circ_0000231 and miR-622 was predicted by circular RNA Interactome online database, and identified by dual-luciferase reporter and RNA immunoprecipitation assays. The impacts of hsa_circ_0000231 on Sev-mediated tumor formation in vivo were presented by in vivo assay. Results Hsa_circ_0000231 expression was upregulated, while miR-622 was downregulated in CRC tissues and cells compared with control groups. Sev treatment decreased hsa_circ_0000231 expression, but increased miR-622 expression in CRC cells. Sev treatment suppressed cell proliferation, migration and invasion, and induced cell apoptosis. Hsa_circ_0000231 overexpression restored Sev-mediated CRC progression in vitro. Additionally, hsa_circ_0000231 acted as a sponge of miR-622, and miR-622 inhibitors reversed the impacts of hsa_circ_0000231 silencing on CRC process. Furthermore, Sev treatment inhibited tumor growth by regulating hsa_circ_0000231 in vivo. Conclusion Hsa_circ_0000231 attenuated Sev-aroused repression impacts on CRC development by sponging miR-622. This findings may provide an appropriate anesthetic protocol for CRC sufferers undergoing surgery.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Koudong Zhang ◽  
Hang Hu ◽  
Juan Xu ◽  
Limin Qiu ◽  
Haitao Chen ◽  
...  

Abstract Background Lung cancer (LC) is a malignant tumor originating in the bronchial mucosa or gland of the lung. Circular RNAs (circRNAs) are proved to be key regulators of tumor progression. However, the regulatory effect of circ_0001421 on lung cancer tumorigenesis remains unclear. Methods The expression levels of circ_0001421, microRNA-4677-3p (miR-4677-3p) and cell division cycle associated 3 (CDCA3) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Methyl thiazolyl tetrazolium (MTT), Transwell and Tumor formation assays were performed to explore the role of circ_0001421 in LC. Glucose consumption and lactate production were examined by a Glucose assay kit and a Lactic Acid assay kit. Western blot was utilized to examine the protein levels of Hexokinase 2 (HK2) and CDCA3. The interaction between miR-4677-3p and circ_0001421 or CDCA3 was confirmed by dual-luciferase reporter assay. Results Circ_0001421 was increased in LC tissues and cells, and knockdown of circ_0001421 repressed cell proliferation, migration, invasion and glycolysis in vitro. Meanwhile, circ_0001421 knockdown inhibited LC tumor growth in vivo. Mechanistically, circ_0001421 could bind to miR-4677-3p, and CDCA3 was a target of miR-4677-3p. Rescue assays manifested that silencing miR-4677-3p or CDCA3 overexpression reversed circ_0001421 knockdown-mediated suppression on cell proliferation, migration, invasion and glycolysis in LC cells. Conclusion Circ_0001421 promoted cell proliferation, migration, invasion and glycolysis in LC by regulating the miR-4677-3p/CDCA3 axis, which providing a new mechanism for LC tumor progression.


2019 ◽  
Vol 21 (10) ◽  
pp. 1284-1296 ◽  
Author(s):  
Shuai Zhang ◽  
Keman Liao ◽  
Zengli Miao ◽  
Qing Wang ◽  
Yifeng Miao ◽  
...  

Abstract Background Circular RNAs (circRNAs), a newly discovered type of endogenous noncoding RNA, have been proposed to mediate the progression of diverse types of tumors. Systematic studies of circRNAs have just begun, and the physiological roles of circRNAs remain largely unknown. Here, we focused on elucidating the potential role and molecular mechanism of circular forkhead box O3 (circFOXO3) in glioblastoma (GBM) progression. Methods First, we analyzed circFOXO3 alterations in GBM and noncancerous tissues through real-time quantitative reverse transcription PCR (qRT-PCR). Next, we used loss- and gain-of-function approaches to evaluate the effect of circFOXO3 on GBM cell proliferation and invasion. Mechanistically, fluorescent in situ hybridization, RNA pull-down, dual luciferase reporter, and RNA immunoprecipitation assays were performed to confirm the interaction between circFOXO3 and miR-138-5p/miR-432-5p in GBM. An animal model was used to verify the in vitro experimental findings. Results CircFOXO3 expression was significantly higher in GBM tissues than in noncancerous tissues. GBM cell proliferation and invasion were reduced by circFOXO3 knockdown and enhanced by circFOXO3 overexpression. Further biochemical analysis showed that circFOXO3 exerted its pro-tumorigenic activity by acting as a competing endogenous RNA (ceRNA) to increase expression of nuclear factor of activated T cells 5 (NFAT5) via sponging both miR-138-5p and miR-432-5p. Notably, tumor inhibition by circFOXO3 downregulation could be reversed by miR-138-5p/miR-432-5p inhibitors in GBM cells. Moreover, GBM cells with lower circFOXO3 expression developed less aggressive tumors in vivo. Conclusions Our data demonstrate that circFOXO3 can exert regulatory functions in GBM and that ceRNA-mediated microRNA sequestration might be a potential strategy for GBM therapy.


2020 ◽  
Author(s):  
Gaowu Hu ◽  
Wei Peng ◽  
Yongqing Cao

Abstract Background: Currently, more and more circular RNAs (circRNAs) have been identified to exert their functions in tumor progression, including colorectal cancer (CRC). However, the role of circSEC24A (circ_0003528) in CRC remains unknown.Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the levels of circSEC24A, SEC24A and microRNA-488-3p (miR-488-3p). The characterization of circSEC24A was investigated by Actinomycin D and RNase R digestion assays. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay was used to assess cell proliferation. Flow cytometry analysis was adopted for cell apoptosis and cell cycle process. Transwell assay was employed to evaluate cell migration and invasion. Western blot assay was performed to determine protein levels. Dual-luciferase reporter assay was utilized to explore the relationship between miR-488-3p and circSEC24A or transmembrane protein 106B (TMEM106B). Murine xenograft model was constructed to explore the effect of circSEC24A in vivo .Results: CircSEC24A level was increased in CRC tissues and cells. CircSEC24A deficiency impeded cell proliferation, cell cycle process, migration and invasion and induced apoptosis in CRC cells in vitro and blocked tumorigenesis in vivo . MiR-488-3p was a target of circSEC24A and miR-488-3p was downregulated in CRC tissues and cells. The inhibitory effect of circSEC24A silencing on CRC cell progression was restored by miR-488-3p inhibition. Moreover, TMEM106B could be negatively regulated by miR-488-3p via acting as a downstream gene of miR-488-3p. MiR-488-3p overexpression decelerated CRC cell progression by targeting TMEM106B.Conclusion: CircSEC24A facilitated CRC progression by regulating miR-488-3p/TMEM106B axis, which might provide a promising treatment approach for CRC.


2020 ◽  
Author(s):  
Wei Zhang ◽  
Bo Wang ◽  
Yang Yang ◽  
Zhen Zhang ◽  
Quan Wang ◽  
...  

Abstract Background circular RNAs (circRNAs) recently have been emerged as vital regulators for involvement of initiation and progression of diverse kinds of human cancers. This study aimed to investigate the role of circRNAs in colorectal cancer (CRC). Methods The expression profile of circRNAs in 5 pairs of CRC tissues and adjacent normal tissues were analyzed by Microarray. Quantitative real-time PCR and in situ hybridization and Base Scope Assay were used to determine the level and prognostic values of hsa_circ_0000231. Then, functional experiments in vitro and in vivo were performed to investigate the effects of hsa_circ_0000231 on cell proliferation. Mechanistically, fluorescent in situ hybridization, dual luciferase reporter assay, RNA pull-down and RNA immunoprecipitation experiments were performed to confirm the interaction between hsa_circ_0000231 and IGF2BP3 or has_miR-375. Results hsa_circ_0000231 was evidently up-regulated in CRC primary tissues, which was indicated to poor prognosis of CRC patients. The results demonstrated that hsa_circ_0000231 could promote CRC cell proliferation as well as tumorigenesis in vitro and in vivo. Mechanistic analysis showed that hsa_circ_0000231 might on the one hand act as a ceRNA (competing endogenous RNA) of miR-375 to regulate cyclin D2 (CCND2), and on the other hand bind to IGF2BP3 protein to protect CCND2 from being degraded. Conclusion Our findings suggest that hsa_circ_0000231 facilitated CRC progression by sponging miR-375 or binding to IGF2BP3 to modulate CCND2. This discovery implied that has_circ_0000231 may be a potential new diagnostic and therapeutic biomarker for CRC.


Author(s):  
Taoyue Yang ◽  
Peng Shen ◽  
Qun Chen ◽  
Pengfei Wu ◽  
Hao Yuan ◽  
...  

Abstract Background Circular RNAs (circRNAs) are becoming a unique member of non-coding RNAs (ncRNAs) with emerging evidence of their regulatory roles in various cancers. However, with regards to pancreatic ductal adenocarcinoma (PDAC), circRNAs biological functions remain largely unknown and worth investigation for potential therapeutic innovation. Methods In our previous study, next-generation sequencing was used to identify differentially expressed circRNAs in 3 pairs of PDAC and adjacent normal tissues. Further validation of circRHOBTB3 expression in PDAC tissues and cell lines and gain-and-loss function experiments verified the oncogenic role of circRHOBTB3. The mechanism of circRHOBTB3 regulatory role was validated by pull-down assays, RIP, luciferase reporter assays. The autophagy response of PANC-1 and MiaPaca-2 cells were detected by mCherry-GFP-LC3B labeling and confocal microscopy, transmission electron microscopy and protein levels of LC3B or p62 via Western blot. Results circRHOBTB3 is highly expressed in PDAC cell lines and tissues, which also promotes PDAC autophagy and then progression in vitro and in vivo. Mechanistically, circRHOBTB3 directly binds to miR-600 and subsequently acts as a miRNA-sponge to maintain the expression level of miR-600-targeted gene NACC1, which facilitates the autophagy response of PDAC cells for adaptation of proliferation via Akt/mTOR pathway. Moreover, the RNA-binding protein FUS (FUS) directly binds to pre-RHOBTB3 mRNA to mediate the biogenesis of circRHOBTB3. Clinically, circRHOBTB3, miR-600 and NACC1 expression levels are correlated with the prognosis of PDAC patients and serve as independent risk factors for PDAC patients. Conclusions FUS-mediated circRHOBTB3 functions as a tumor activator to promote PDAC cell proliferation by modulating miR-600/NACC1/Akt/mTOR axis regulated autophagy.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lei Zhang ◽  
Ranran Yu ◽  
Chunhua Li ◽  
Yu Dang ◽  
Xiaoyu Yi ◽  
...  

Abstract Background Emerging evidence reveals that the initiation and development of human cancers, including colorectal cancer (CRC), are associated with the deregulation of circular RNAs (circRNAs). Our study intended to disclose the role of circ_0026416 in the malignant behaviors of CRC. Methods The detection for circ_0026416 expression, miR-545-3p expression, and myosin VI (MYO6) mRNA expression was performed using quantitative real-time PCR (qPCR). CCK-8 assay, colony formation assay, transwell assay, and flow cytometry assay were applied for functional analysis to monitor cell proliferation, migration, invasion, and apoptosis. The protein levels of MYO6 and epithelial mesenchymal-transition (EMT) markers were detected by western blot. Mouse models were used to determine the role of circ_0026416 in vivo. The potential relationship between miR-545-3p and circ_0026416 or MYO6 was verified by dual-luciferase reporter assay and RIP assay. Results The expression of circ_0026416 was increased in CRC tumor tissues and cell lines. Circ_0026416 downregulation inhibited CRC cell proliferation, colony formation, migration, invasion, and EMT but induced cell apoptosis in vitro, and circ_0026416 knockdown also blocked tumor growth in vivo. MiR-545-3p was a target of circ_0026416, and rescue experiments indicated that circ_0026416 knockdown blocked CRC development by enriching miR-545-3p. In addition, miR-545-3p targeted MYO6 and inhibited MYO6 expression. MiR-545-3p enrichment suppressed CRC cell malignant behaviors by sequestering MYO6. Importantly, circ_0026416 knockdown depleted MYO6 expression by enriching miR-545-3p. Conclusion Circ_0026416 downregulation blocked the development of CRC through depleting MYO6 expression by enriching miR-545-3p. Highlights Circ_0026416 downregulation inhibits CRC development in vitro and in vivo. Circ_0026416 regulates the expression of MYO6 by targeting miR-545-3p. Circ_0026416 governs the miR-545-3p/MYO6 axis to regulate CRC progression.


2020 ◽  
Author(s):  
Shuo Yu ◽  
Min Wang ◽  
Xu Li ◽  
Xingjun Guo ◽  
Renyi Qin

Abstract Background: Circular RNAs (circRNAs) are engaged in hepatocellular carcinoma (HCC) progression, but the mechanisms remain to be elucidated. This study aimed to unveil the expression pattern and potential biological mechanisms of a newly indentified circRNA, circ-PAN3, in HCC. Methods: Cell Counting Kit-8 (CCK‐8) assay and colony formation assay were used to assess cell proliferation. Transcription-quantitative PCR (RT-qPCR) analysis and western blot analysis were used to determine the relative expression level of mRNA and protein, respectively. Cell apoptosis assay was used to evaluate the apoptosis rate of transfected cells. CircInteractome and Targetscan were utilized to predict the possible targets of circRNAs and miRNAs, respectively. Luciferase reporter assay and RNA pull-down assay were used to assess the direct interaction of RNAs. HCC cancer xenograft model was used to evaluate the biological process of circ-PAN3 in vivo. Student’s t test, χ2 test or one-way ANOVA was adopted appropriately.Results: Circ-PAN3 was elevated in HCC tissues, and patients with high Circ-PAN3 expression had a poor survival outcome. Knockdown of circ-PAN3 expression suppressed cell viability, colony formation and cell proliferation in vitro and in vivo. Circ-PAN3 elevates cyclin D1 expression to promote HCC progression. Subsequently, using CircInteractome, miR-153 were confirmed to interact with circ-PAN3 and was downregulated by circ-PAN3. Further, using Targetscan, cyclin D1 was validated to interact with miR-153 and was downregulated by miR-153. Addition of miR-153 expression with corresponsive mimics significantly reduced the expression of cyclin D1. Notably, the inhibition of cell viability, colony formation and proliferation induced by knockdown of circ-PAN3 were recovered following the combination with miR-153 inhibitor, cyclin D1, respectively. Conclusion: Together, this study demonstrated that a novel circ-PAN3/miR-153/cyclin D1 axis regulatory axis that promoted HCC progression.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rongcai Liu ◽  
Weimin Dai ◽  
An Wu ◽  
Yunping Li

Abstract Background Glioblastoma (GBM) is characterized by progressive growth and metastasis. Numerous studies claim that the deregulation of circular RNAs (circRNAs) is associated with cancer progression. However, the role of circRNAs in GBM is largely limited. The purpose of this study was to investigate the functions of circCDC45 in GBM and provide a feasible functional mechanism to support its role. Methods The expression of circCDC45, miR-485-5p and colony-stimulating factor 1 (CSF-1) mRNA was examined using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed using cell counting kit − 8 (CCK-8) assay and colony formation assay. Cell migration and cell invasion were monitored using transwell assay. The protein levels of proliferation-related markers and CSF-1 were determined using western blot. The target relationship was predicted using bioinformatics tools and validated using dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Animal models were constructed to verify the role of circCDC45 in vivo. Results The expression of circCDC45 and CSF-1 was elevated in GBM tissues and cells, while the expression of miR-485-5p was declined. Downregulation of circCDC45 or CSF-1 blocked GBM cell proliferation, invasion and migration as well as tumor growth in vivo. In mechanism, circCDC45 positively regulated the expression of CSF-1 by targeting miR-485-5p. Inhibition of miR-485-5p reversed the biological effects caused by circCDC45 downregulation in GBM cells. Conclusion CircCDC45 promoted the progression of GBM by mediating the miR-485-5p/CSF-1 axis, and circCDC45 might be a promising plasmatic biomarker for GBM diagnosis and treatment.


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