scholarly journals CircFOXM1 promotes the proliferation, migration, invasion, and glutaminolysis of glioblastoma by regulating the miR-577/E2F5 axis

Author(s):  
Xuhui Fan ◽  
Meng Liu ◽  
Li Fei ◽  
Zhihui Huang ◽  
Yufeng Yan

Circular RNA (circRNA) is a key regulator of tumor progression. However, the role of circFOXM1 in glioblastoma (GBM) progression is unclear. The aim of this study was to investigate the role of circFOXM1 in GBM progression. The expression levels of circFOXM1, miR-577 and E2F transcription factor 5 (E2F5) were examined by real-time quantitative PCR. Cell counting kit 8 assay, EdU staining and transwell assay were used to detect cell proliferation, migration, and invasion. The levels of glutamine, glutamate and α-ketoglutarate were determined to evaluate the glutaminolysis ability of cells. Protein expression was tested by western blot analysis. Dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation assay were employed to verify the interaction between miR-577 and circFOXM1 or E2F5. Mice xenograft model for GBM was constructed to perform in vivo experiments. Our results showed that circFOXM1 was highly expressed in GBM tumor tissues and cells. Silencing of circFOXM1 inhibited GBM cell proliferation, migration, invasion, glutaminolysis, as well as tumor growth. MiR-577 could be sponged by circFOXM1, and its inhibitor could reverse the suppressive effect of circFOXM1 downregulation on GBM progression. E2F5 was a target of miR-577, and the effect of its knockdown on GBM progression was consistent with that of circFOXM1 silencing. CircFOXM1 positively regulated E2F5 expression, while miR-577 negatively regulated E2F5 expression. In conclusion, our data confirmed that circFOXM1 could serve as a sponge of miR-577 to enhance the progression of GBM by targeting E2F5, which revealed that circFOXM1 might be a biomarker for GBM treatment.

Author(s):  
Chenyu Ding ◽  
Zanyi Wu ◽  
Honghai You ◽  
Hongliang Ge ◽  
Shufa Zheng ◽  
...  

Abstract Background Circular RNA nuclear factor I X (circNFIX) has been reported to play an important role in glioma progression. However, the mechanism by which circNFIX participates in glioma progression remains poorly understood. Methods GERIA online were used to analyze the abnormally expressed genes in glioma tissues. The expression levels of circNFIX, microRNA (miR)-378e and Ribophorin-II (RPN2) were measured by quantitative real-time polymerase chain reaction or western blot. Cell cycle distribution, apoptosis, glycolysis, migration and invasion were determined by flow cytometry, special kit and trans-well assays, respectively. The target association between miR-378e and circNFIX or RPN2 was confirmed by luciferase reporter assay, RNA immunoprecipitation and pull-down. Xenograft model was established to investigate the role of circNFIX in vivo. Results The expression of circNFIX was enhanced in glioma tissues and cells compared with matched controls and high expression of circNFIX indicated poor outcomes of patients. Knockdown of circNFIX led to arrest of cell cycle, inhibition of glycolysis, migration and invasion and promotion of apoptosis in glioma cells. circNFIX was a sponge of miR-378e. miR-378e overexpression suppressed cell cycle process, glycolysis, migration and invasion but promoted apoptosis. miR-378e silence abated the suppressive role of circNFIX knockdown in glioma progression. RPN2 as a target of miR-378e was positively regulated via circNFIX by competitively sponging miR-378e. Silencing circNFIX decreased glioma xenograft tumor growth by regulating miR-378e/RPN2 axis. Conclusion Knockdown of circNFIX inhibits progression of glioma in vitro and in vivo by increasing miR-378e and decreasing RPN2, providing a novel mechanism for understanding the pathogenesis of glioma.


2018 ◽  
Vol 51 (3) ◽  
pp. 1364-1375 ◽  
Author(s):  
Dan Fei ◽  
Xiaona Zhang ◽  
Jinxiang Liu ◽  
Long Tan ◽  
Jie Xing ◽  
...  

Background/Aims: Novel long non-coding RNA Fer-1-like protein 4 (FER1L4) has been reported to play crucial regulatory roles in tumor progression. However, its clinical significance and biological role in osteosarcoma (OS) is completely unknown. The aim of the present study was to investigate the role of FER1L4 in OS progression and the underlying mechanism. Methods: We analyzed the expression levels of FER1L4 in tissues of OS patients and cell lines via quantitative RT-PCR (qRT-PCR). The effect of FER1L4 on cell proliferation, colony formation, migration and invasion was analyzed by cell counting kit-8 (CCK-8), colony formation, wound healing and transwell invasion assay, respectively. Novel targets of FER1L4 were selected through a bioinformatics soft and confirmed using a dual-luciferase reporter system and qRT-PCR. To detect the role of FER1L4 in vivo tumorigenesis, tumor xenografts were created. Results: We found that the expression of FER1L4 was significantly downregulated in OS tissues and cell lines; moreover, low expression of FER1L4 was associated with advanced tumor-nude-metastasis (TNM) stage, lymph node metastases, and poor overall survival. Functional assays showed that upregulation of FER1L4 significantly inhibited OS cell proliferation, colony formation, migration, and invasion in vitro, as well as suppressed tumor growth in vivo. Assays performed to determine the underlying mechanism, indicated that FER1L4 interacted directly with miR-18a-5p. Subsequently, we found that FER1L4 significantly increased PTEN expression, a known target of miR-18a-5p, in OS cells. Furthermore, PTEN was found to be down-regulated, and positively correlated with FER1L4 in OS tissues. Conclusion: These findings suggest that FER1L4, acting as a competing endogenous RNA (ceRNA) of miR-18a-5p, exerts its anti-cancer role by modulating the expression of PTEN. Thus, FER1L4 may be a novel target for the prevention and treatment of OS.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ruijie Liu ◽  
Ping Deng ◽  
Yonglian Zhang ◽  
Yonglan Wang ◽  
Cuiping Peng

Abstract Background Circular RNAs (circRNAs) are a class of endogenous single-strand RNA transcripts with crucial regulation in human cancers. The objective of this study is to investigate the role of circ_0082182 in CRC and its specific functional mechanism. Methods The quantitative real-time polymerase chain reaction (qRT-PCR) was performed to measure the levels of circ_0082182, microRNA-411 (miR-411) and microRNA-1205 (miR-1205). Cell proliferation was detected by Cell counting Kit-8 (CCK-8) and colony formation assays. Flow cytometry was used for determining cell cycle and cell apoptosis. Cell apoptosis was also assessed by caspase3 and caspase9 activities. Cell migration and invasion were examined using scratch assay and transwell assay. The interaction between circ_0082182 and miRNA was validated by the dual-luciferase reporter and biotinylated RNA pull-down assays. Wnt/β-catenin pathway and epithelial-mesenchymal transition (EMT)-associated proteins were quantified by Western blot. Xenograft model was established for the research of circ_0082182 in vivo. Results Circ_0082182 was upregulated in CRC and could predict the poor prognosis of CRC patients. Functionally, circ_0082182 promoted CRC cell proliferation, cell cycle progression, and metastasis while inhibited apoptosis. Subsequently, circ_0082182 was shown to act as the sponges of miR-411 and miR-1205. MiR-411 and miR-1205 were identified as tumor inhibitors in CRC. Furthermore, circ_0082182 promoted the CRC progression via sponging miR-411 and miR-1205. Moreover, circ_0082182 facilitated the Wnt/β-catenin pathway and EMT process by targeting miR-411 and miR-1205. In vivo, circ_0082182 accelerated the CRC tumorigenesis and EMT process by activating the Wnt/β-catenin pathway by downregulating the expression of miR-411 or miR-1205. Conclusion This study showed that circ_0082182 functioned as an oncogene in the developing process of CRC by sponging miR-411 or miR-1205 to activate the Wnt/β-catenin pathway. Circ_0082182 might be a molecular target in the diagnosis and treatment of CRC.


2020 ◽  
Vol 15 (1) ◽  
pp. 108-121
Author(s):  
Zhangxing Yin ◽  
Liqing Liao ◽  
Sheng Mao ◽  
Ying Liu ◽  
Tao Xie ◽  
...  

AbstractThe dysregulated lncRNA play essential roles in glioma development. This study aimed to investigate the role and mechanism of lncRNA potassium voltage-gated channel subfamily Q member 1 opposite strand/ antisense transcript 1 (KCNQ1OT1) in glioma progression. Tumor tissues and adjacent normal samples were collected from 30 glioma patients. The expression levels of lncRNA KCNQ1OT1, microRNA (miR)-338-3p and ribonucleotide reductase M2 (RRM2) were detected by quantitative real-time polymerase chain reaction or western blot analyses. Levels of cell viability, apoptosis, cell migration and invasion in glioma cell lines were determined using cell counting kit-8, flow cytometry with annexin V-FITC and trans-well assays, respectively. The role of KCNQ1OT1 in glioma development in vivo was investigated using a xenograft model. The target association between miR-338-3p and KCNQ1OT1 or RRM2 was validated by luciferase reporter assay. The results found that expression of KCNQ1OT1 was enhanced in glioma tissues and cells, and KCNQ1OT1 knockdown inhibited cell viability, migration and invasion, and xenograft tumor growth, but promoted apoptosis. miR-338-3p was targeted via KCNQ1OT1 and could reverse the effect of KCNQ1OT1 on glioma progression. RRM2 was targeted via miR-338-3p and attenuated the suppressive effect of miR-338-3p on glioma cell viability, migration and invasion. Besides, KCNQ1OT1 overexpression increased RRM2 expression, and this event was weakened via miR-338-3p up-regulation. In conclusion, the present finding suggest that silencing of KCNQ1OT1 can suppress the development and progression of glioma by up-regulating miR-338-3p and down-regulating RRM2.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Wei Wei ◽  
Liefeng Ji ◽  
Wanli Duan ◽  
Jiang Zhu

Abstract Background Circular RNAs (circRNAs) have been shown to participate in the chemoresistance and tumorigenesis of multiple cancers. The purpose of this research was to investigate the function of circ_0081001 in methotrexate (MTX) resistance of osteosarcoma (OS) and its potential molecular mechanism. Methods The expression of circ_0081001, cytochrome P450 family 51 subfamily A member 1 (CYP51A1), and miR-494-3p was detected by qRT-PCR. Cell viability, apoptosis, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and transwell assay, respectively. Western blot (WB) assay was used to measure the protein levels of cleaved-caspase3 (cleaved-casp3), E-cadherin, N-cadherin, and transglutaminase-2 (TGM2). The interaction between miR-494-3p and circ_0081001 or TGM2 was predicted by bioinformatics analysis and verified using the dual-luciferase reporter assay. The mice xenograft model was established to investigate the roles of circ_0081001 in MTX resistance of OS in vivo. Results Circ_0081001 and TGM2 were upregulated, and miR-494-3p was downregulated in MTX-resistant OS tissues and cells. Moreover, circ_0081001 interference enhanced cell sensitivity to MTX through promoting apoptosis and inhibiting cell viability and metastasis in vitro. Furthermore, circ_0081001 was identified as a molecular sponge of miR-494-3p to upregulate TGM2 level. In addition, circ_0081001 knockdown inhibited MTX resistance via upregulating miR-494-3p and downregulating TGM2. Besides, circ_0081001 downregulation improved MTX sensitivity of OS in vivo. Conclusion Knockdown of circ_0081001 enhanced MTX sensitivity of OS cells through downregulating TGM2 by sponging miR-494-3p, elucidating a novel regulatory mechanism for chemoresistance of OS and providing a potential circRNA-targeted therapy for OS.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yanfei Liang ◽  
Kaiyi Meng ◽  
Rui Qiu

Background: Circular RNAs (circRNAs) have emerged as important regulators in diverse human malignancies, including ovarian cancer (OC). This study was performed to explore the function and regulatory mechanism underlying circ_0013958 in OC progression.Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot assay was applied to examine the expression of circ_0013958, microRNA-637 (miR-637), and Plexin B2 (PLXNB2). The target relationship between miR-637 and circ_0013958 or PLXNB2 was verified by dual-luciferase reporter assay or RNA immunoprecipitation (RIP) assay. Cell Counting Kit-8 (CCK-8) and colony formation assays were employed to detect cell viability and clonogenicity ability, respectively. Cell migration and invasion were analyzed by Transwell assay. Cell apoptosis was monitored by flow cytometry. The role of circ_0013958 in vivo was determined by xenograft tumor assay.Results: Circ_0013958 and PLXNB2 were upregulated, while miR-637 was downregulated in OC tissues and cells. Circ_0013958 acted as a sponge for miR-637 to regulate the expression of PLXNB2 in OC cells. The repression effects of circ_0013958 knockdown on cell proliferation, migration, invasion, and apoptosis in OC cells were partly attenuated by the miR-637 inhibitor. And miR-637 targeted PLXNB2 to suppress OC cell proliferation, migration, and invasion. Moreover, circ_0013958 silencing blocked OC tumor growth in vivo.Conclusion: Circ_0013958 knockdown impeded OC development through modulating the miR-637/PLXNB2 axis, highlighting a therapeutic target for OC.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hongli Li ◽  
Yiwei Zhang ◽  
Huiqin Song ◽  
Li Li

Abstract Background Circular RNAs (circRNAs) are implicated in the carcinogenesis of human cancers. However, the functional roles of circRFX3 in glioma are not elucidated. Methods Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed for the levels of circRFX3, RFX3, miR-1179, miR-1229 and vasodilator stimulated phosphoprotein (VASP). Actinomycin D assay and RNase R assay were employed to analyze the characteristics of circRFX3. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were conducted for cell proliferation. Transwell assay was used for cell migration and invasion. Flow cytometry analysis was adopted for cell apoptosis. RNA pull-down assay, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were employed to analyze the interaction between miR-1179/miR-1229 and circRFX3 or VASP. Western blot assay was conducted for VASP protein level. Murine xenograft model assay was used to investigate the role of circRFX3 in vivo. Results CircRFX3 level was increased in glioma tissues and cells. Knockdown of circRFX3 suppressed glioma cell proliferation, migration and invasion and promoted apoptosis in vitro and repressed tumorigenesis of glioma in vivo. MiR-1179 and miR-1229 were identified to be the targets of circRFX3. MiR-1179 or miR-1229 inhibition reversed the impacts of circRFX3 knockdown on glioma cell malignant behaviors. Additionally, VASP was demonstrated to be the target gene of miR-1179 and miR-1229, and VASP overexpression abolished the effect of circRFX3 knockdown on glioma cell progression. Conclusion CircRFX3 served as a tumor promoter in glioma via modulating miR-1179/miR-1229-VASP axis, which might provide a novel target for glioma therapy.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Xiaoguang Gu ◽  
Jianan Zhang ◽  
Yajuan Ran ◽  
Hena Pan ◽  
JinHong Jia ◽  
...  

AbstractCircular RNAs have been reported to play significant roles in regulating pathophysiological processes while also guiding clinical diagnosis and treatment of hepatocellular carcinoma (HCC). However, only a few circRNAs have been identified thus far. Herein, we investigated the role of a specific closed-loop structure of hsa_circ_101555 that was generated by back-splicing of the host gene casein kinase 1 gamma 1 (CSNK1G1) in the development and proliferation of HCC. We investigated the expression of Hsa_circ_101555 in HCC and normal tissues using bioinformatics. The expression level of hsa_circ_101555 was further detected by fluorescence in situ hybridization and qRT-PCR in ten HCC patients. Transwell, migration, WST-1 assays, and colony formation assays were used to evaluate the role of hsa_circ_101555 in HCC development and proliferation. The regulatory mechanisms of hsa_circ_101555 in miR-145-5p and CDCA3 were determined by dual luciferase reporter assay. A mouse xenograft model was also used to determine the effect of hsa_circ_101555 on HCC growth in vivo. hsa_circ_101555 showed greater stability than the linear RNA; while in vitro and in vivo results demonstrated that hsa_circ_101555 silencing significantly suppressed cell proliferation, migration, and invasion of HCC cells. Rescue experiments further demonstrated that suppression of miR-145-5p significantly attenuated the biological effects of hsa_circ_101555 knockdown in HCC cells. We also identified a putative oncogene CDCA3 as a potential miR-145-5p target. Thus, our results demonstrated that hsa_circ_101555 might function as a competing endogenous RNA of miR-145-5p to upregulate CDCA3 expression in HCC. These findings suggest that hsa_circ_101555 may be a potential therapeutic target for patients with HCC.


2021 ◽  
Author(s):  
Yunxin Zhang ◽  
Kexin Shen ◽  
Hanyi Zha ◽  
Wentao Zhang ◽  
Haishan Zhang

Abstract BackgroundCircular RNA-BTG3 associated nuclear protein (circ-BANP) was identifified to involve in cell proliferation of colorectal cancer (CRC). The aerobic glycolysis is a key metabolism mediating cancer progression. However, the role of circ-BANP on aerobic glycolysis in CRC remains unknown. MethodsThe expression of circ-BANP, microRNA (miR)-874-3p, and mitogen-activated protein kinase 1 (MAPK1) mNRA was detected using quantitative real-time polymerase chain reaction. Cell viability and invasion were measured by cell counting kit-8 assay or transwell assay. Glucose consumption and lactate production were assessed by a glucose and lactate assay kit. XF Extracellular Flux Analyzer was used to determine extracellular acidifification rate (ECAR). Western blot was used to analyze the levels of hexokinase-2 (HK2), pyruvate kinase M2 (PKM2), MAPK1, proliferating cell nuclear antigen (PCNA), Cyclin D1, N-cadherin, E-cadherin, hypoxia inducible factor-1α (HIF-1α), glucose transport protein 1(GLUT1), and c-Myc. The interaction between miR-874-3p and circ-BANP or MAPK1 was confifirmed by dual luciferase reporter assay. In vivo experiments were conducted through the murine xenograft model. ResultsCirc-BANP was up-regulated in CRC tissues and cell lines. Circ-BANP knockdown suppressed CRC cell proliferation, invasion and aerobic glycolysis in vitro as well as inhibited tumor growth in vivo. Circ-BANP was a sponge of miR-874-3p and performed anti-tumor effffects by binding to miR-874-3p in CRC cells. Subsequently, we confifirmed MAPK1 was a target of miR-874-3p and circ-BANP indirectly regulated MAPK1 expression by sponging miR-874-3p. After that, we found MAPK1 overexpression partially reversed circ-BANP deletion-mediated inhibition on cell carcinogenesis and aerobic glycolysis in CRC. ConclusionCirc-BANP accelerated cell carcinogenesis and aerobic glycolysis by regulating MAPK1 through miR- 874-3p in CRC, suggesting a promising therapeutic strategy for CRC treatment.


Author(s):  
Xinping Chen ◽  
Weihua Xu ◽  
Zhichao Ma ◽  
Juan Zhu ◽  
Junjie Hu ◽  
...  

Background: Increasing circular RNAs (circRNAs) are reported to participate in cancer progression. Nonetheless, the role of circRNAs in nasopharyngeal carcinoma (NPC) has not been fully clarified. This work is aimed to probe the role of circ_0000215 in NPC.Methods: Circ_0000215 expression in NPC tissues and cell lines was examined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay, 5-bromo-2′-deoxyuridine (BrdU) assay, scratch healing assay and Transwell experiment were executed to investigate the regulatory function of circ_0000215 on the proliferation, migration and invasion of NPC cells. RNA immunoprecipitation (RIP), pull-down and dual-luciferase reporter experiments were utilized to determine the binding relationship between circ_0000215 and miR-512-5p, and between miR-512-5p and phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) 3′UTR. The effects of circ_0000215 on NPC growth and metastasis in vivo were examined with nude mice model. Western blot was applied to detect the regulatory effects of circ_0000215 and miR-512-5p on PIK3R1 expression.Results: Circ_0000215 was overexpressed in NPC tissues and cell lines. The functional experiments confirmed that knockdown of circ_0000215 impeded the growth and metastasis of NPC cells in vitro and in vivo. Additionally, circ_0000215 could also work as a molecular sponge to repress miR-512-5p expression. PIK3R1 was validated as a target gene of miR-512-5p, and circ_0000215 could increase the expression level of PIK3R1 in NPC cells via suppressing miR-512-5p.Conclusion: Circ_0000215 is overexpressed in NPC and exerts oncogenic effects in NPC through regulating miR-512-5p/PIK3R1 axis.


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