Hsa_circ_0013731 Mediated by E2F1 Inhibits Ferroptosis in Hepatocellular Carcinoma Cells by Sponging miR-877-3p and Targeting SLC7A11

2020 ◽  
Author(s):  
Zhongwei Zhao ◽  
Jingjing Song ◽  
Dengke Zhang ◽  
Fazong Wu ◽  
Jianfei Tu ◽  
...  

Abstract Background: The regulatory loop between circular RNAs and microRNAs has a vital role in cell death. Ferroptosis is the form of iron-dependent cell death, which is distinct from necroptosis and apoptosis. Increasing evidences showed that ferroptosis is an important form of cell death in hepatocellular carcinoma.Methods: Real-time PCR were used to examine the expression level of circ_0013731 in hepatocellular carcinoma tissues. Edu and colony formation were performed to detect the cell proliferation. A luciferase reporter assay was used to determine the relationship between circ_0013731, miR-877-3p and SLC7A11. ChIP-qPCR assays were performed to examine the potential binding of E2F1 to the circ_0013731 promoter. Iron Assay Kit (Sigma Aldrich) was used to detect total iron or Fe2+. C11 BODIPY 581/591 staining and flow cytometer were used to examine the Lipid ROS. The role of circ_0013731 was examined in xenograft tumors model. Results: We revealed that the expression level of circ_0013731 was elevated in hepatocellular carcinoma. Moreover, E2F1 promote the transcription of circ_0013731. Overexpression of circ_0013731 promoted cell growth and inhibited ferroptosis in SMMC-7721 and QGY-7703 in vitro. miR-877-3p was proved as the direct target of circ_0013731. Then, inhibition of miR-877-3p enhanced cell growth and inhibited ferroptosis. Further mechanism research demonstrated that circ_0013731 upregulated the expression level of SLC7A11 by sponging miR-877-3p. Finally, circ_0013731 promoted HCC growth via miR-877-3p/ SLC7A11 axis in vivo.Conclusions: Our data reveal that circ_0013731 mediated by E2F1 facilitates cell growth and suppressed the ferroptosis via miR-877-3p/ SLC7A11 axis in hepatocellular carcinoma. Therefore, circ_0013731 could be acted as potential therapeutical target for hepatocellular carcinoma.

2021 ◽  
Author(s):  
Shiji Fang ◽  
Weiqian Chen ◽  
Jiayi Ding ◽  
Dengke Zhang ◽  
Liyun Zheng ◽  
...  

Abstract Background: The regulatory loop between circular RNAs and microRNAs has a vital role in cell death. Ferroptosis is the form of iron-dependent cell death, which is distinct from necroptosis and apoptosis. Increasing evidences showed that ferroptosis is an important form of cell death in hepatocellular carcinoma.Methods: Real-time PCR were used to examine the expression level of circ_0013731 in hepatocellular carcinoma tissues. Edu and colony formation were performed to detect the cell proliferation. A luciferase reporter assay was used to determine the relationship between circ_0013731, miR-877-3p and SLC7A11. ChIP-qPCR assays were performed to examine the potential binding of E2F1 to the circ_0013731 promoter. Iron Assay Kit (Sigma Aldrich) was used to detect total iron or Fe2+. C11 BODIPY 581/591 staining and flow cytometer were used to examine the Lipid ROS. The role of circ_0013731 was examined in xenograft tumors model. Results: We revealed that the expression level of circ_0013731 was elevated in hepatocellular carcinoma. Moreover, E2F1 promote the transcription of circ_0013731. Overexpression of circ_0013731 promoted cell growth and inhibited ferroptosis in SMMC-7721 and QGY-7703 in vitro. miR-877-3p was proved as the direct target of circ_0013731. Then, inhibition of miR-877-3p enhanced cell growth and inhibited ferroptosis. Further mechanism research demonstrated that circ_0013731 upregulated the expression level of SLC7A11 by sponging miR-877-3p. Finally, circ_0013731 promoted HCC growth via miR-877-3p/ SLC7A11 axis in vivo.Conclusions: Our data reveal that circ_0013731 mediated by E2F1 facilitates cell growth and suppressed the ferroptosis via miR-877-3p/ SLC7A11 axis in hepatocellular carcinoma. Therefore, circ_0013731 could be acted as potential therapeutical target for hepatocellular carcinoma.


Author(s):  
Yang Ji ◽  
Shikun Yang ◽  
Xueqi Yan ◽  
Li Zhu ◽  
Wenjie Yang ◽  
...  

Mounting evidence has demonstrated that circular RNAs have an important function in tumorigenesis and cancer evolvement. CircCRIM1 has been shown to be a poor prognostic element in multiple human malignancies. However, the clinical significance and mechanism of circCRIM1 in hepatocellular carcinoma (HCC) is still unclear. The present study confirmed the expression level of circCRIM1 using quantitative real-time PCR. In addition, circCRIM1 siRNA and overexpression vectors were used for transfection into LM3 or Huh7 cells to down- or up-regulate the expression of circCRIM1. In vitro and in vivo experiments were performed to explore the function of circCRIM1 in HCC. RNA pull-down, RNA immunoprecipitation, fluorescent in situ hybridization, and luciferase reporter assays were conducted to confirm the relationship between miR-378a-3p and circCRIM1 or S-phase kinase-associated protein 2 (SKP2) in HCC. Then, circCRIM1 was up-regulated in HCC and its expression level was significantly associated with poor prognosis and clinicopathologic characteristics. CircCRIM1 enhanced the proliferation and angiogenesis of HCC cells in vitro and promoted xenograft growth in vivo. Moreover, circCRIM1 upregulated the expression of SKP2 by functioning as a sponge for miR-378a-3p. These findings suggest that circCRIM1 boosts the HCC progression via the miR-378-3p/SKP2 axis and may act as a crucial epigenetic therapeutic molecule target in HCC.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Liang Liu ◽  
Peng Zhang ◽  
Xuchen Dong ◽  
Haoran Li ◽  
Suwen Li ◽  
...  

AbstractMany studies have reported that circular RNAs play a vital role in the malignant progression of human cancers. However, the role and underlying mechanism of circRNAs in the development of gliomas have not been fully clarified. In this study, we found that circ_0001367 was downregulated in glioma tissues and showed a close correlation with glioma patient survival. Functional assays demonstrated that upregulation of circ_0001367 could suppress the proliferation, migration and invasion of glioma cells in vitro and inhibit glioma growth in vivo. Furthermore, bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay indicated that circ_0001367 can serve as a sponge for miR-431 and that miR-431 acts as an oncogene by regulating neurexin 3 (NRXN3). In addition, rescue experiments verified that circ_0001367 could regulate both the expression and function of NRXN3 in a miR-431-dependent manner. In conclusion, circ_0001367 functions as an suppressor in glioma by targeting the miR-431/NRXN3 axis and may be a promising therapeutic target against gliomas.


2020 ◽  
Author(s):  
Weisheng Guo ◽  
Lin Zhao ◽  
Yaguang Wei ◽  
Peng Liu ◽  
Yu Zhang ◽  
...  

Abstract Background: Hepatocellular carcinoma (HCC) is the leading threat of cancer-related death in humans with poor therapeutic effects. Circular RNAs (circRNAs) are important indicators in cancer diagnosis and prognosis. This study intended to explore the function and mechanism of circ_0015756 in HCC, providing the additional opinion for HCC treatment.Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression of circ_0015756 and miR-610. Cell viability was assessed by cell counting kit-8 (CCK-8) assay, and colony formation capacity was ascertained by colony formation assay. Cell proliferation and invasion were monitored by transwell assay. Cell cycle progression and apoptosis were analyzed by flow cytometry assay. Circ_0015756 oncogenicity was determined by Xenograft models. The prediction of targets was performed using the bioinformatics tools, and the verification of targeted relationship was conducted using RNA pull-down, RNA immunoprecipitation (RIP) and dual-luciferase reporter assays. The expression level of fibroblast growth factor receptor 1 (FGFR1) was measured by western blot.Result: The expression of circ_0015756 was increased in HCC tissues, serums and cells. Circ_0015756 downregulation impaired HCC cell viability, colony formation capacity, invasion and migration, induced cell cycle arrest and apoptosis, and inhibited tumor growth in vivo. MiR-610 was ensured as a target of circ_0015756, and miR-610 absence reversed the effects of circ_0015756 downregulation. Further, FGFR1 was interacted by miR-610, and FGFR1 overexpression overturned the effects of miR-610 restoration in vitro. Circ_0015756 could regulate FGFR1 expression by targeting miR-610.Conclusion: Circ_0015756 played its tumorigenic properties in HCC by activating FGFR1 and sponging miR-610, and circ_0015756 was expected to be a vital indicator in HCC diagnosis and treatment.


2021 ◽  
Vol 11 ◽  
Author(s):  
Yong Liu ◽  
Hao Wu ◽  
Jiangpeng Jing ◽  
Huanfa Li ◽  
Shan Dong ◽  
...  

BackgroundIt has been shown that circular RNAs (circRNAs) play a vital role in the progression of glioma. Recently, hsa_circ_0001836 was found to be upregulated in glioma tissues, but the role of hsa_circ_0001836 in glioma remains unclear.MethodsEdU staining and flow cytometry assays were used to measure the viability and death of glioma cells. In addition, scanning electron microscopy (SEM) was used to observe the morphology of cells undergoing cell death.ResultsHsa_circ_0001836 expression was upregulated in U251MG and SHG-44 cells. In addition, hsa_circ_0001836 knockdown significantly reduced the viability and proliferation of U251MG and SHG-44 cells. Moreover, hsa_circ_0001836 knockdown markedly induced the pyroptosis of U251MG and SHG-44 cells, evidenced by the increased expressions of NLRP1, cleaved caspase 1 and GSDMD-N. Meanwhile, methylation specific PCR (MSP) results indicated that hsa_circ_0001836 knockdown epigenetically increased NLRP1 expression via mediating DNA demethylation of NLRP1 promoter region. Furthermore, downregulation of hsa_circ_0001836 notably induced pyroptosis and inhibited tumor growth in a mouse xenograft model of glioma.ConclusionCollectively, hsa_circ_0001836 knockdown could induce pyroptosis cell death in glioma cells in vitro and in vivo via epigenetically upregulating NLRP1 expression. These findings suggested that hsa_circ_0001836 may serve as a potential therapeutic target for the treatment of glioma.


Author(s):  
Rui Zhou ◽  
Wei Jia ◽  
Xiaofeng Gao ◽  
Fuming Deng ◽  
Kai Fu ◽  
...  

Circular RNAs (circRNA) have been reported to exert evident functions in many human carcinomas. However, the possible mechanisms concerning the circRNA in various tumors are still elusive. In this research, we analyzed the expression profile and biological functions of circular RNA CDYL (circCDYL, circBase ID: hsa_circ_0008285) in Wilms’ tumor. Here, miRNA and gene expression were examined by real-time PCR in Wilms’ tumor tissues and cell lines. The functions of circCDYL and its potential targets to influence cell proliferation, migration, and invasion in Wilms’ tumor cells were determined by biological functional experiments in vitro and in vivo. We predicted and analyzed potential miRNA targets through online bioinformatic tools. To validate the interactions between circCDYL and its targets, we performed RNA fluorescence in situ hybridization, biotin-coupled miRNA capture assay, and biotin-coupled probe pull-down assay. Tight junction protein l (TJP1) was proved to be the target gene of the predicted miRNA by dual-luciferase reporter assay. The expression level of TJP1 in Wilms’ tumor cells was identified via Western blot. We showed that circCDYL was downregulated in WT tissue compared with adjacent non-tumor tissue. Upregulation of circCDYL could reduce cell proliferation, migration, and invasion. Mechanically, circCDYL, functioning as a miRNA sponge, decreased the expression level of miR-145-5p and TJP1 3′UTR was validated as the target of miR-145-5p, facilitating the circCDYL/miR-145-5p/TJP1 axis. In conclusion, our study suggested circCDYL as a novel biomarker and therapeutic target for WT treatment.


2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Hanqing Hong ◽  
Hai Zhu ◽  
Shujun Zhao ◽  
Kaili Wang ◽  
Nan Zhang ◽  
...  

AbstractAs a new class of non-coding RNA, circular RNAs (circRNAs) play crucial roles in the development and progression of various cancers. However, the detailed functions of circRNAs in cervical cancer have seldom been reported. In this study, circRNA sequence was applied to detect the differentially expressed circRNAs between cervical cancer tissues and adjacent normal tissues. The relationships between circCLK3 level with clinicopathological characteristics and prognosis were analyzed. In vitro CCK-8, cell count, cell colony, cell wound healing, transwell migration and invasion, and in vivo tumorigenesis and lung metastasis models were performed to evaluate the functions of circCLK3. The pull-down, RNA immunoprecipitation (RIP), luciferase reporter and rescue assays were employed to clarify the interaction between circCLK3 and miR-320a and the regulation of miR-320a on FoxM1. We found that the level of circCLK3 was remarkably higher in cervical cancer tissues than in adjacent normal tissues, and closely associated with tumor differentiation, FIGO stage and depth of stromal invasion. Down-regulated circCLK3 evidently inhibited cell growth and metastasis of cervical cancer in vitro and in vivo, while up-regulated circCLK3 significantly promoted cell growth and metastasis in vitro and in vivo. The pull-down, luciferase reporter and RIP assays demonstrated that circCLK3 directly bound to and sponge miR-320a. MiR-320a suppressed the expression of FoxM1 through directly binding to 3′UTR of FoxM1 mRNA. In addition, FoxM1 promoted cell proliferation, migration, and invasion of cervical cancer, while miR-320a suppressed cell proliferation, migration, and invasion through suppressing FoxM1, and circCLK3 enhanced cell proliferation, migration and invasion through sponging miR-320a and promoting FoxM1 expression. In summary, circCLK3 may serve as a novel diagnostic biomarker for disease progression and a promising molecular target for early diagnoses and treatments of cervical cancer.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Huang ◽  
Wenhao Ge ◽  
Yuan Ding ◽  
Lufei Zhang ◽  
Jiarong Zhou ◽  
...  

Abstract Background Circular RNAs (circRNAs), which are endogenous non-coding RNAs, are associated with various biological processes including development, homeostatic maintenance, and pathological responses. Accumulating evidence has implicated non-coding RNAs in cancer progression, and the role of circRNAs in particular has drawn wide attention. However, circRNA expression patterns and functions in hepatocellular carcinoma (HCC) remain poorly understood. Methods CircRNA sequencing was performed to screen differentially expressed circRNAs in HCC. Northern blotting, quantitative real-time polymerase chain reaction, nucleocytoplasmic fractionation, and fluorescence in situ hybridization analyses were conducted to evaluate the expression and localization of circSLC7A11 in HCC tissues and cells. CircSLC7A11 expression levels were modified in cultured HCC cell lines to explore the association between the expression of circSLC7A11 and the malignant behavior of these cells using several cell-based assays. The modified cells were implanted into immunocompetent nude mice to assess tumor growth and metastasis in vivo. We applied bioinformatics methods, RNA pulldown, RNA immunoprecipitation, and luciferase reporter assays to explore the mechanisms of circSLC7A11 in HCC. Results CircSLC7A11 (hsa_circ_0070975) was conserved and dramatically overexpressed in HCC tissues and cells. HCC patients showing high circSLC7A11 expression had worse prognoses. Our in vitro and in vivo experiments showed that circSLC7A11 markedly accelerated HCC progression and metastasis through the circSLC7A11/miR-330-3p/CDK1 axis. Conclusions The acceleration of HCC progression and metastasis by circSLC7A11 through the circSLC7A11/miR-330-3p/CDK1 axis suggests that circSLC7A11 is a potential novel diagnostic and therapeutic target for HCC treatment.


Author(s):  
Yangyang Dong ◽  
Xinyu Li ◽  
Zhibin Lin ◽  
Wenbing Zou ◽  
Yan Liu ◽  
...  

Abstract Background Gastric cancer (GC) is one of the most prevalent and deadly malignancies worldwide. Accumulating reports have indicated the participation of long non-coding RNAs (lncRNAs) in the onset and progression of GC. Methods GSE109476 data was utilized to screen out lncRNAs dysregulated in GC. Gene expressions were determined by qRT-PCR and western blot. Both in vitro and in vivo experiments were carried out to assess the function of HOXC-AS1 in GC. The association between genes was verified via RIP, ChIP, CoIP, RNA pull down and luciferase reporter assays, as appropriate. Results HOXC-AS1 was discovered to be upregulated in GC and located both in cytoplasm and in nucleus in GC cells. Functionally, inhibition of HOXC-AS1 restrained GC cell growth and metastasis both in vitro and in vivo. Moreover, HOXC-AS1 was proved to be trans-activated by c-MYC in GC. In return, HOXC-AS1 positively regulated MYC expression in GC through targeting miR-590-3p/MYC axis in cytoplasm and modulating BRG1/β-catenin complex-activated MYC transcription in nucleus. Furthermore, the rescue assays verified that MYC mediated HOXC-AS1-affected GC progression. Conclusion Our research illustrated a feedback loop of HOXC-AS1-MYC in aggravating GC cell growth and metastasis, highlighting HOXC-AS1 as a promising target for GC diagnosis and treatment.


2021 ◽  
Vol 16 (1) ◽  
pp. 229-241
Author(s):  
Sihai Liu ◽  
Jing Zhang ◽  
Ting Zheng ◽  
Xiongneng Mou ◽  
Wenwei Xin

Abstract Background Emerging evidence has shown that circular RNAs (circRNAs) are vital regulators in osteosarcoma (OS) progression. However, the effects of circ_WWC3 in OS have not been explored. In this research, the functions and mechanisms of circ_WWC3 in OS were investigated. Methods Quantitative reverse trancription polymerase chain reaction (qRT-PCR) was adopted to determine the levels of circ_WWC3, WW and WWC3 mRNA, miR-421, and phosphodiesterase 7B (PDE7B) mRNA. RNase R assay was used to determine the characteristic of circ_WWC3. Colony formation assay and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay were applied for cell growth. Transwell assay was performed for cell migration and invasion. Flow cytometry analysis was utilized for cell apoptosis. Western blot assay was conducted for the levels of apoptosis-related proteins and PDE7B protein. Dual-luciferase reporter assay was carried out to analyze the targeting relationship between miR-421 and circ_WWC3 or PDE7B. The murine xenograft model was established to explore the effect of circ_WWC3 in vivo. Results Compared to normal tissues and cells, circ_WWC3 and PDE7B were downregulated in OS tissues and cells. Overexpression of circ_WWC3 or PDE7B suppressed OS cell growth, migration, and invasion and promoted apoptosis in vitro. Regarding the mechanism analysis, circ_WWC3 positively modulated PDE7B expression by targeting miR-421. MiR-421 overexpression restored the impacts of circ_WWC3 on OS cell growth, metastasis, and apoptosis. Inhibition of miR-421 repressed the malignant behaviors of OS cells by targeting PDE7B. In addition, circ_WWC3 inhibited the tumorigenicity of OS in vivo. Conclusion Circ_WWC3 overexpression slowed the development of OS by elevating PDE7B via sponging miR-421.


Sign in / Sign up

Export Citation Format

Share Document