scholarly journals Novel circular RNA circNF1 acts as a molecular sponge, promoting gastric cancer by absorbing miR-16

2019 ◽  
Vol 26 (3) ◽  
pp. 265-277 ◽  
Author(s):  
Zhe Wang ◽  
Ke Ma ◽  
Steffie Pitts ◽  
Yulan Cheng ◽  
Xi Liu ◽  
...  

Circular RNAs (circRNAs) are a new class of RNA involved in multiple human malignancies. However, limited information exists regarding the involvement of circRNAs in gastric carcinoma (GC). Therefore, we sought to identify novel circRNAs, their functions and mechanisms in gastric carcinogenesis. We analyzed next-generation RNA sequencing data from GC tissues and cell lines, identifying 75,201 candidate circRNAs. Among these, we focused on one novel circRNA, circNF1 , which was upregulated in GC tissues and cell lines. Loss- and gain-of-function studies demonstrated that circNF1 significantly promotes cell proliferation. Furthermore, luciferase reporter assays showed that circNF1 binds to miR-16, thereby derepressing its downstream target mRNAs, MAP7 and AKT3. Targeted silencing or overexpression of circNF1 had no effect on levels of its linear RNA counterpart, NF1. Taken together, these results suggest that circNF1 acts as a novel oncogenic circRNA in GC by functioning as a miR-16 sponge.

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Xuexiu Zhang ◽  
Jianning Yao ◽  
Haoling Shi ◽  
Bing Gao ◽  
Haining Zhou ◽  
...  

AbstractCircular RNAs (circRNAs) have been reported to play crucial roles in the progression of various cancers, including colorectal cancer (CRC). SP1 (Sp1 transcription factor) is a well-recognized oncogene in CRC and is deemed to trigger the Wnt/β-catenin pathway. The present study was designed to investigate the role of circRNAs which shared the same pre-mRNA with SP1 in CRC cells. We identified that hsa_circ_0026628 (circ_0026628), a circular RNA that originated from SP1 pre-mRNA, was upregulated in CRC cells. Sanger sequencing and agarose gel electrophoresis verified the circular characteristic of circ_0026628. Functional assays including CCK-8, colony formation, transwell, immunofluorescence staining, and sphere formation assay revealed the function of circ_0026628. RNA pull-down and mass spectrometry disclosed the proteins interacting with circ_0026628. Mechanistic assays including RIP, RNA pull-down, CoIP, ChIP, and luciferase reporter assays demonstrated the interplays between molecules. The results depicted that circ_0026628 functioned as a contributor to CRC cell proliferation, migration, EMT, and stemness. Mechanistically, circ_0026628 served as the endogenous sponge of miR-346 and FUS to elevate SP1 expression at the post-transcriptional level, thus strengthening the interaction between SP1 and β-catenin to activate the Wnt/β-catenin pathway. In turn, the downstream gene of Wnt/β-catenin signaling, SOX2 (SRY-box transcription factor 2), transcriptionally activated SP1 and therefore boosted circ_0026628 level. On the whole, SOX2-induced circ_0026628 sponged miR-346 and recruited FUS protein to augment SP1, triggering the downstream Wnt/β-catenin pathway to facilitate CRC progression.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Fei Pan ◽  
Dongqing Zhang ◽  
Na Li ◽  
Mei Liu

circRNAs (circular RNAs) are a family of noncoding RNAs and have diverse physiological and pathological functions. However, the functions and mechanisms of circRNAs in the development and progression of colorectal cancer (CRC) remain largely unknown. Here, we aimed to explore the functions and roles of circFAT1(e2) in CRC. qRT-PCR revealed that circFAT1(e2) in CRC tumor tissues was upregulated compared with that in adjacent normal tissues and was also upregulated in CRC cell lines. Small interfering RNAs (siRNAs) against circFAT1(e2) were used to decrease the expression of circFAT1(e2) in HCT116 and RKO cells in vitro. The roles of circFAT1(e2) in CRC cell metastasis and proliferation were then determined by transwell and CCK-8 assays. The results showed that circFAT1(e2) silencing markedly suppressed CRC growth. Moreover, we identified circFAT1(e2) as a promoter of CRC metastasis. Knockdown of circFAT1(e2) evidently reduced HCT116 and RKO cell migration and invasion. Furthermore, the regulatory relationship between circFAT1(e2) and its target miRNAs was verified by a luciferase reporter assay. We demonstrated that circFAT1(e2) could sponge miR-30e-5p, which regulated the expression level of integrin α6 (ITGA6), the downstream target gene of miR-30e-5p. Rescue assays demonstrated that knockdown of miR-30e-5p enhanced CRC proliferation and migration via ITGA6. Taken together, our results reveal the novel oncogenic roles of circFAT1(e2) in CRC through the miR-30e-5p/ITGA6 axis.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Deng Xiang ◽  
Yugang Li ◽  
Yanshui Lin

In recent years, the mechanism of cancer research has become hotspots of life science and medicine, especially due to the rapid development of molecular medicine and bioinformatics research. Similarly, the molecular mechanism also has received increasing attention in osteosarcoma (OS) research. Also, a considerable amount of research confirmed that circular RNAs (circRNAs) could regulate cancer cell growth and metastasis. This study aimed to explore the effect of a circRNA, circCCDC66, on OS and reveal its potential molecular mechanism. High circCCDC66 expression level was found in OS patient-derived tissue samples and OS cell lines by qRT-PCR. The abilities cell proliferation and metastatic of U2OS and SW1353 cells were then assessed by Cell Counting Kit-8 and transwell assay, respectively. The interaction between circCCDC66 and its target miRNAs were verified by the dual-luciferase reporter assay. Through functional experiments, we found that circCCDC66 knockdown promoted the inhibition of cell proliferation and metastatic of OS cell lines. From mechanistic perspective, circCCDC66 upregulated PTP1B by sponging miR-338-3p. Collectively, our findings demonstrated that circCCDC66 contributed to malignant behaviors of OS cells by miR-338-3p/PTP1B pathway, which suggested circCCDC66/miR-338-3p/PTP1B axis might be a potential therapeutic target.


2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Renjie Wang ◽  
Sai Zhang ◽  
Xuyi Chen ◽  
Nan Li ◽  
Jianwei Li ◽  
...  

Abstract Background Circular RNAs (circRNAs) have been found to play critical roles in the development and progression of various cancers. However, little is known about the effects of the circular RNA network on glioblastoma multiforme (GBM). Methods A microarray was used to screen circRNA expression in GBM. Quantitative real-time PCR was used to detect the expression of circMMP9. GBM cells were transfected with a circMMP9 overexpression vector or siRNA, and cell proliferation, migration and invasion, as well as tumorigenesis in nude mice, were assessed to examine the effect of circMMP9 in GBM. Biotin-coupled miRNA capture, fluorescence in situ hybridization and luciferase reporter assays were conducted to confirm the relationship between circMMP9 and miR-124. Results In this study, we screened differentially expressed circRNAs and identified circMMP9 in GBM. We found that circMMP9 acted as an oncogene, was upregulated in GBM and promoted the proliferation, migration and invasion abilities of GBM cells. Next, we verified that circMMP9 served as a sponge that directly targeted miR-124; circMMP9 accelerated GBM cell proliferation, migration and invasion by targeting miR-124. Furthermore, we found that cyclin-dependent kinase 4 (CDK4) and aurora kinase A (AURKA) were involved in circMMP9/miR-124 axis-induced GBM tumorigenesis. Finally, we found that eukaryotic initiation factor 4A3 (eIF4A3), which binds to the MMP9 mRNA transcript, induced circMMP9 cyclization and increased circMMP9 expression in GBM. Conclusions Our findings indicate that eIF4A3-induced circMMP9 is an important underlying mechanism in GBM cell proliferation, invasion and metastasis through modulation of the miR-124 signaling pathway, which could provide pivotal potential therapeutic targets for the treatment of GBM. Graphical abstract


Author(s):  
Tong Li ◽  
Jianguo Xu ◽  
Yi Liu

An increasing number of studies have indicated that circular RNAs (circRNAs) participate in the progression of numerous tumors. However, the functions of circRNAs in glioblastoma (GBM) remain largely unknown. In this study, we focused on a novel circRNA (hsa_circRFX3_003) that was spliced from RFX3, which we named circRFX3. We confirmed that the expression of circRFX3 was substantially increased in GBM cell lines and clinical GBM tissues. The results of a series of overexpression and knockdown assays indicated that circRFX3 could boost the proliferation, invasion, and migration of GBM cells. By performing dual-luciferase reporter gene and RNA pull-down assays, we verified that circRFX3 could sponge microRNA-587 (miR-587) to exercise its function as a competing endogenous RNA (ceRNA) in the development of GBM. In addition, PDIA3 was proven to be a downstream target of miR-587 and to regulate the Wnt/β-catenin pathway. In conclusion, circRFX3 could act as a cancer-promoting circRNA to boost the development of GBM and regulate the miR-587/PDIA3/β-catenin axis. This study might provide a novel target for the treatment of GBM with molecular therapy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Yin ◽  
Fuyi Tong ◽  
Yulan Ye ◽  
Tong Hu ◽  
Lijuan Xu ◽  
...  

Circular RNAs (circRNAs) play important roles in the pathogenesis of Crohn’s disease (CD). We discovered that hsa_circRNA_103124 was upregulated in CD patients in our previous study. Nonetheless, the function of hsa_circRNA_103124 is unclear. In this study, hsa_circRNA_103124 was predicted to interact with hsa-miR-650. Gene Ontology (GO) and pathway analyses identified AKT serine/threonine kinase 2 (AKT2) as the downstream target protein of hsa-miR-650. Activated AKT2 inhibits autophagy, but promotes cell proliferation. Recent studies suggest that the inhibition of autophagy is one of the mechanisms of CD pathogenesis. Therefore, we inferred that hsa_circRNA_103124 might regulate autophagy and proliferation by targeting AKT2 as a sponge for hsa-miR-650. Here, quantitative reverse transcription PCR (RT-QPCR) results revealed that upregulated hsa_circRNA_103124 expression in patients with CD was negatively correlated with hsa-miR-650 expression but positively correlated with the white blood cell count and calprotectin levels. TSC complex subunit 1 (TSC1), one of the proteins upstream of autophagy was downregulated in patients with CD. Consisting with the bioinformatics prediction, it was verified that hsa_circRNA_103124 targeted to hsa-miR650 by fluorescence in situ hybridization (FISH) and luciferase reporter assays. A hsa-miR-650 inhibitor reversed the promotion of rapamycin-induced autophagy and the inhibition of cell proliferation by the hsa_circRNA_103124 siRNA. However, hsa-miR-650 mimics reversed the inhibition of rapamycin-induced autophagy and the promotion of cell proliferation through hsa_circRNA_103124 overexpression. These results indicate that hsa_circRNA_103124 upregulation in patients with CD promotes cell proliferation and inhibits autophagy by regulating the hsa-miR-650/AKT2 signaling pathway.


2020 ◽  
Author(s):  
Ning Lyu ◽  
Yan Zeng ◽  
Yanan Kong ◽  
Qifeng Chen ◽  
Haijing Deng ◽  
...  

Abstract Background: Circular RNAs (circRNAs) is a class of non-coding RNAs and have been demonstrated to play important roles in tumorigenesis. Nevertheless, how circRNAs regulate the progression of hepatocellular cancer (HCC) remains unclear.Methods: CircRNA microarrays was performed in HCC tissues to screen circRNAs that are extinct expressed. Quantitative real-time PCR (qRT-PCR) was conducted in HCC cell lines, and tissues and circ0097009 were found to be significantly up-regulated. Then, we explored the functions of circ0097009 in HCC by a series of experiments including cell proliferation, invasion and mouse xenograft assay. Additionally, luciferase assay and RNA immunoprecipitation (RIP) assay was used to explore the interactions of circ0097009, miRNA-1261 and SLC7A11 (a key regulator in cancer cell ferroptosis) in HCC.Results: Microarray analysis and qRT-PCR verified a circRNA circ0097009, which was significantly up-regulated in HCC tissues and cell lines. Knockdown of circ0097009 inhibited proliferation and invasion in HCC. Luciferase reporter assays showed that circ0097009 and SLC7A11 directly bind to miR-1261. Subsequent experiments showed that circ0097009 and SLC7A11 regulated the expression of each other by sponging miR-1261.Conclusions: Circ0097009 act as a competing endogenous RNA (ceRNA) to regulate SLC7A11 expression, a key regulator in cancer cell ferroptosis through sponging miR-1261 in HCC. Circ0097009 may be used as a diagnostic biomarker and potential target for HCC therapy.


2020 ◽  
Author(s):  
Jiabin Du ◽  
Jianhua Xu ◽  
Junxing Chen ◽  
Weinan Liu ◽  
Pengcheng Wang ◽  
...  

Abstract Background: Growing evidences have revealed that long non-coding RNAs (lncRNAs) including circular RNAs (circRNAs) involve in numerous carcinogenesis. However, the roles of circRNAs in the cancer biology of colorectal cancer (CRC) remain vague. Methods: qRT-PCR and western-blot were used to detecte the circRAE1 levels in CRC tissues and CRC cell lines. Cell proliferation, migration and invasion were detected using wound healing assays, and transwell assays. The interaction between circRAE1 and miR-338-3p and TRYO3 was confirmed by dual-luciferase reporter assays. Results: We uncovered that a novel circRNA Hsa_circ_0060967 (also known as circRAE1) was remarkably increased in CRC tissues, and high circRAE1 level was positively associated with advanced tumor stage, lymph node metastasis, and tumor size. Loss-of-function assay indicated that circRAE1 accelerated cell proliferation, migration and invasion. Besides, miR-338-3p , lowly expressed in CRC tissues and CRC cell lines. dual-luciferase reporter assays showed that circRAE1 could sponge miR-338-3p, which targeted TRYO3 in CRC cells. Furthermore, overexpression of circRAE1 could recue the impaired migration and invasion triggered by miR-338-3p mimics or si-TYRO3 in CRC cells and vice versa. Conclusion : We figured out the network of circRAE1, miR-338-3p, and TYRO3 in CRC cells and revealed that increased circRAE1 served as an oncogene through sponging miR-338-3p, resulting in upregulated TYRO3 expression, which suggested that circRAE1 would be a potential therapeutic target and diagnostic marker for CRC treatment.


2021 ◽  
Author(s):  
Tian Rong Zhang ◽  
WeiQiang Huang

Abstract Background Angiogenesis is an important factor in promoting vascular repair and a valuable process in the treatment of cardiovascular diseases. Circular RNAs (circRNAs) are widely expressed in eukaryotic cells and play an important role in the regulation of endothelial cells (ECs). In our study, bioinformatics analysis and real-time fluorescent PCR detection revealed that circRNA 0010928 (circ-0010928) is differentially expressed in human cardiac microvascular endothelial cells (HCMECs). Material & Methods We evaluated the role of circ-0010928 in HCMECs. Then, we can verify the function of circ-0010928 in HCMECs by cell counting kit-8 (CCK8), scratch test, transwell experiment, tube forming experiment, flow cytometry. Use dual luciferase experiment to detect the binding relationship between circ-0010928, miR-921 and LSM14A. Results Overexpression of circ-0010928 inhibited the proliferation, migration and tube formation of HCMECs under hypoxic conditions and promoted their apoptosis. In addition, dual luciferase reporter assays confirmed that circ-0010928 acted as a sponge of miR-921 and LSM14A as a downstream target gene of miR-921. Silencing miR-921 could also inhibit the proliferation, migration and tube formation of HCMECs and negatively regulate angiogenesis. Conclusion CircRNA-0010928 may inhibit the function of miRNA-921by combining with miRNA-921, and then miRNA-921 plays a role in regulating LSM14A, thereby regulating the state of angiogenesis.


2020 ◽  
Author(s):  
Jiabin Du ◽  
Jianhua Xu ◽  
Junxing Chen ◽  
Weinan Liu ◽  
Pengcheng Wang ◽  
...  

Abstract Background: Growing evidences have revealed that long non-coding RNAs (lncRNAs) including circular RNAs (circRNAs) involve in numerous carcinogenesis. However, the roles of circRNAs in the cancer biology of colorectal cancer (CRC) remain vague. Methods: qRT-PCR and western-blot were used to detecte the circRAE1 levels in CRC tissues and CRC cell lines.,Cell proliferation, migration and invasion were detected using wound healing assays, and transwell assays. The interaction between circRAE1 and miR-338-3p and TRYO3 was confirmed by dual-luciferase reporter assays. Results: We uncovered that a novel circRNA Hsa_circ_0060967 (also known as circRAE1) was remarkably increased in CRC tissues, and high circRAE1 level was positively associated with advanced tumor stage, lymph node metastasis, and tumor size. Loss-of-function assay indicated that circRAE1 accelerated cell proliferation, migration and invasion. Besides, miR-338-3p , lowly expressed in CRC tissues and CRC cell lines. dual-luciferase reporter assays showed that circRAE1 could sponge miR-338-3p, which targeted TRYO3 in CRC cells. Furthermore, overexpression of circRAE1 could recue the impaired migration and invasion triggered by miR-338-3p mimics or si-TYRO3 in CRC cells and vice versa. Conclusion : we figured out the network of circRAE1, miR-338-3p, and TYRO3 in CRC cells and revealed that increased circRAE1 served as an oncogene through sponging miR-338-3p, resulting in upregulated TYRO3 expression, which suggested that circRAE1 would be a potential therapeutic target and diagnostic marker for CRC treatment.


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