scholarly journals circLMTK2 acts as a sponge of miR-150-5p and promotes proliferation and metastasis in gastric cancer

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Sen Wang ◽  
Dong Tang ◽  
Wei Wang ◽  
Yining Yang ◽  
Xiaoqing Wu ◽  
...  

Abstract Background As a novel class of non-coding RNAs, circular RNAs (circRNAs) are key regulators of the development and progression of different cancers. However, little is known about the function and biological mechanism of circLMTK2, also named hsa_circ_0001725, in gastric cancer (GC) tumourigenesis. Methods circLMTK2 was identified in ten paired cancer specimens and adjacent normal tissues by RNA sequencing and genome-wide bioinformatic analysis and verified by quantitative real-time PCR (qRT-PCR). Knockdown or exogenous expression of circLMTK2 combined with in vitro and in vivo assays were performed to prove the functional significance of circLMTK2. The molecular mechanism of circLMTK2 was demonstrated by searching the CircNet database and confirmed by RNA in vivo precipitation assays, western blotting, luciferase assays and rescue experiments. Results circLMTK2 was frequently upregulated in GC tissues, and high circLMTK2 expression was associated with poor prognosis, lymph node metastasis and poor TNM stage in GC patients. Functionally, circLMTK2 overexpression promoted GC cell proliferation and tumourigenicity in vitro and in vivo. Furthermore, ectopic circLMTK2 expression enhanced GC cell migration and invasion in vitro and tumour metastasis in vivo. In addition, we demonstrated that circLMTK2 could sponge miR-150-5p, thus indirectly regulating the c-Myc expression and contributing to GC tumourigenesis. Conclusion Our findings demonstrate that circLMTK2 functions as a tumour promoter in GC through the miR-150-5p/c-Myc axis and could thus be a prognostic predictor and therapeutic target for GC.

2021 ◽  
Author(s):  
Xuan Li ◽  
Haisheng Qian ◽  
Hao Dong ◽  
Yini Dang ◽  
Lei Peng ◽  
...  

Abstract Background: Circular RNA (circRNA) is rising as an indispensable regulatory molecule in the progression of various kinds of malignant growth. However, little is known about the capacity and instruments of circRNA_0008727 in gastric cancer (GC). Our point was to recognize a novel circRNA-microRNA-mRNA useful system in gastric cancer. Method: CircRNA_0008278 was identified in three paired cancer specimens and adjacent normal tissues by RNA sequencing and genome-wide bioinformatic analysis and verified by quantitative real-time PCR (qRT-PCR). Knockdown or exogenous expression of circRNA_0008278 combined with in vitro and in vivo assays were performed to prove the functional significance of circRNA_0008278. The molecular mechanism of circRNA_0008278 was demonstrated by searching the CircNet database and confirmed by RNA in vivo precipitation assays, western blotting, luciferase assays and rescue experiments.Results: CircRNA_0008278 was frequently upregulated in GC tissues, and high circRNA_0008278 expression was associated with poor prognosis, lymph node metastasis and poor TNM stage in GC patients. Functionally, circRNA_0008278 overexpression promoted GC cell proliferation and tumourigenicity in vitro and in vivo. Furthermore, circRNA_0008278 over-expression enhanced GC cell migration and invasion in vitro and tumour metastasis in vivo. In addition, we demonstrated that circRNA_0008278 could sponge miR-378, thus indirectly regulating theYY1 expression and contributing to GC tumourigenesis.Conclusion: Our findings demonstrate that circRNA_0008278 functions as a tumour promoter in GC, and a new pathway circRNA_0008278/miR-378/YY1 which may be potential method for gastric cancer treatment.


2021 ◽  
Vol 30 ◽  
pp. 096368972097539
Author(s):  
Jian Li ◽  
Yongjing Yang ◽  
Dequan Xu ◽  
Ling Cao

Gastric cancer (GC) is a big threat to human life and health. Circular RNAs (circRNAs), a subclass of noncoding RNAs, were reported to play a critical role in GC progression. Here, we investigated the role of a novel circRNA named hsa_circ_0023409 in GC and its mechanism. Hsa_circ_0023409 expression in GC and adjacent tissues was examined by quantitative real-time polymerase chain reaction and in situ hybridization. The functions of hsa_circ_0023409 in GC cells were assessed both in vitro and in vivo. Immunofluorescence staining was performed for the localization of hsa_circ_0023409 and miR-542-3p in cells. The interaction between hsa_circ_0023409 and miR-542-3p, and miR-542-3p and insulin receptor substrate 4 (IRS4) was detected by dual-luciferase reporter assay. The effect of hsa_circ_0023409, miR-542-3p, and IRS4 on IRS4/phosphatidylinositol 3-kinase (PI3K)/AKT pathway was detected by western blot. The results showed that hsa_circ_0023409 was mainly located in cytoplasm and highly expressed in GC tissues and cells. Moreover, hsa_circ_0023409 showed positive correlation with tumor size, histological grade, and tumor–node–metastasis staging of GC patients. Functional studies showed that hsa_circ_0023409 promoted cell viability, proliferation, migration, and invasion and suppressed apoptosis in GC. Mechanism studies demonstrated that hsa_circ_0023409 upregulated IRS4 via sponging miR-542-3p in GC cells. Furthermore, IRS4 overexpression activated the PI3K/AKT pathway and reversed the inhibitory effect of hsa_circ_0023409 knockdown on the PI3K/AKT pathway. Taken together, we prove that hsa_circ_0023409 activates IRS4/PI3K/AKT pathway by acting as a sponge for miR-542-3p, thus promoting GC progression, indicating that hsa_circ_0023409 may serve as a potential target for treatment of GC and prognosis of GC patients.


2021 ◽  
Author(s):  
Jixu Wang ◽  
Futao Hou ◽  
Lusheng Tang ◽  
Ke Xiao ◽  
Tengfei Yang ◽  
...  

Abstract Background: An increasing number of studies have demonstrated that long non-coding RNAs (lncRNAs) serve as key regulators in tumor development and progression. However, only a few lncRNAs have been functionally characterized in gastric cancer (GC). Methods: Bioinformatics analysis was conducted to find lncRNAs that are associated with GC metastasis. RNA FISH, RIP, and RNA pull down assays were used to study the complementary binding of LINC01564 complementary to the 3’UTR of transcription factor POU2F1. The transcription activation of LINC01564 by POU2F1 as a transcription factor was examined by ChIP assay. In vitro assays such as MTT, cell invasion assay, and clonogenic assay were conducted to examined the impacts of LINC01564 and POU2F1 on GC cell proliferation and invasion. Experiments in vivo were performed to access the impacts of LINC01564 and POU2F1 on GC metastasis. Results: The results showed that LINC01564 complementary bound to the 3’UTR of POU2F1 to form an RNA duplex, whereby stabilizing POU2F1 mRNA and increasing the enrichment in cells. The level of LINC01564 was also increased by POU2F1 through transcription activation. In vitro assays showed that LINC01564 promoted the proliferation, invasion and migration of GC cells through increasing POU2F1. In vivo experiments indicate the promotion of GC proliferation and metastasis by the interaction between LINC01564 and POU2F1. Conclusion: Taken together, our results indicate that the interaction between LINC01564 and POU2F1 promotes the proliferation, migration and invasion of GC cells.


2021 ◽  
Vol 8 ◽  
Author(s):  
Zengliang Li ◽  
Hao Fan ◽  
Wangwang Chen ◽  
Jian Xiao ◽  
Xiang Ma ◽  
...  

MicroRNAs (miRNAs) are emerging as significant regulators of the tumorigenesis of gastric cancer (GC), and may be effective biomarkers for diagnosis, prognosis, and therapeutic targeting for GC. In this study, miR-653-5p was found to be significantly upregulated in GC tissues, serum, and cell lines and was strongly associated with poor prognosis in patients with GC. Furthermore, miR-653-5p promoted GC cell proliferation and metastasis in vivo and in vitro. Suppressor of cytokine signaling 6 (SOCS6) was directly targeted by miR-653-5p, and SOCS6 attenuated miR-653-5p-mediated GC cell growth, migration, and invasion. In addition, SOCS6-mediated inactivation of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway was also reversed by the administration of miR-653-5p. The findings from this study support a novel regulatory axis between miR-653-5p, SOCS6, and JAK2/STAT3 that may be a target for diagnosis and therapeutic intervention for GC.


2021 ◽  
Vol 11 ◽  
Author(s):  
Lei Yang ◽  
Yong-ning Zhou ◽  
Miao-miao Zeng ◽  
Nan Zhou ◽  
Bin-sheng Wang ◽  
...  

BackgroundCircular RNAs (circRNAs) are closely associated with the occurrences and progress of gastric cancer (GC). We aimed to delve into the function and pathological mechanism of Circular RNA-0002570 (circ-0002570) in GC progression.MethodsCircRNAs differentially expressed in GC were screened using bioinformatics technology. The expression of circ-0002570 was detected in GC specimens and cells via qRT-PCR, and the prognostic values of circ-0002570 were determined. The functional roles of circ-0002570 on proliferation, migration, and invasion in GC cells were explored in vitro and in vivo. Interaction of circ-0002570, miR-587, and VCAN was confirmed by dual-luciferase reporter assays, Western blotting, and rescue experiments.ResultsCirc-0002570 expression was distinctly increased in GC tissues compared to adjacent normal specimens, and GC patients with higher circ-0002570 expressions displayed a short survival. Functionally, knockdown of circ-0002570 resulted in the inhibition of cell proliferation, migration, and invasion, and suppressed tumor growth in vivo. Mechanistically, miR-587 was sponged by circ-0002570. VCAN expression in NSCLC was directly inhibited by miR-587. Overexpression of circ-0002570 prevented VCAN from miR-587-mediated degradation and thus facilitated GC progression.ConclusionThe circ-0002570-miR-587-VCAN regulatory pathway promoted the progression of GC. Our findings provided potential new targets for the diagnosis and therapy of GC.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Qi Shi ◽  
Chuanwen Zhou ◽  
Rui Xie ◽  
Miaomiao Li ◽  
Peng Shen ◽  
...  

Abstract Background Circular RNAs (circRNAs) have been reported to play an important role in tumor progression in various cancer types, including gastric cancer. The aim of this study was to investigate the role of circCNIH4 (hsa_circ_0000190) in gastric cancer and the underlying mechanism. Methods The expression levels of circCNIH4 and Wnt antagonist genes were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The protein levels of β-catenin, Ki67, Dickkopf 2 (DKK2) and Frizzled related protein (FRZB) were measured by western blot. Ectopic overexpression or knockdown of circCNIH4, proliferation, apoptosis, migration and invasion by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry and transwell assay in vitro, and in vivo experiment, were employed to assess the role of circCNIH4 in gastric cancer. Results CircCNIH4 was downregulated in gastric cancer tissues and cells. Overexpression of circCNIH4 inhibited gastric cancer cell proliferation, migration and invasion and promoted apoptosis by inactivating Wnt/β-catenin pathway in vitro. CircCNIH4 induced the expression of DKK2 and FRZB in gastric cancer cells. Moreover, silencing of DKK2 or FRZB reversed circCNIH4 overexpression-mediated effects on gastric cancer cells. Additionally, circCNIH4 suppressed tumor growth via regulating DKK2 and FRZB expression in gastric cancer in vivo. Conclusion Our study demonstrated that circCNIH4 played a tumor-inhibiting role through upregulating DKK2 and FRZB expression and suppressing Wnt/β-catenin pathway in gastric cancer, which might provide a potential biomarker for the diagnosis and treatment of gastric cancer.


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.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Dawei Rong ◽  
Chen Lu ◽  
Betty Zhang ◽  
Kai Fu ◽  
Shuli Zhao ◽  
...  

Abstract Background Circular RNAs (circRNAs) are a class of non-coding RNAs with a loop structure, but its functions remain largely unknown. Growing evidence has revealed that circRNAs play a striking role as functional RNAs in the progression of malignant disease. However, the precise role of circRNAs in gastric cancer (GC) remains unclear. Methods CircRNAs were determined by human circRNA array analysis and quantitative reverse transcription polymerase reaction. Luciferase reporter, RNA pull down, and fluorescence in situ hybridization assays were employed to test the interaction between circPSMC3 and miR-296-5p. Ectopic over-expression and siRNA-mediated knockdown of circPSMC3, proliferation, migration and invasion in vitro, and in vivo experiment of metastasis were used to evaluate the function of circPSMC3. Results CircPSMC3 rather than liner PSMC3 mRNA was down-regulated in GC tissues, corresponding plasmas from GC patients as well as GC cell lines compared to normal controls. Lower circPSMC3 expression in GC patients was correlated with higher TNM stage and shorter overall survival. Over-expression of circPSMC3 and miR-296-5p inhibitor could inhibit the tumorigenesis of gastric cancer cells in vivo and vitro whereas co-transfection of circPSMC3 and miRNA-296-5p could counteract this effect. Importantly, we demonstrated that circPSMC3 could act as a sponge of miR-296-5p to regulate the expression of Phosphatase and Tensin Homolog (PTEN), and further suppress the tumorigenesis of gastric cancer cells. Conclusion Our study reveals that circPSMC3 can serve as a novel potential circulating biomarker for detection of GC. CircPSMC3 participates in progression of gastric cancer by sponging miRNA-296-5p with PTEN, providing a new insight into the treatment of gastric cancer.


2021 ◽  
Vol 118 (33) ◽  
pp. e2012881118
Author(s):  
Xiaolin Wang ◽  
Jingxin Li ◽  
Xing Bian ◽  
Cheng Wu ◽  
Jinghan Hua ◽  
...  

Circular RNAs (circRNAs) have emerged as key regulators of human cancers, yet their modes of action in gastric cancer (GC) remain largely unknown. Here, we identified circURI1 back-spliced from exons 3 and 4 of unconventional prefoldin RPB5 interactor 1 (URI1) from circRNA profiling of five-paired human gastric and the corresponding nontumor adjacent specimens (paraGC). CircURI1 exhibits the significantly higher expression in GC compared with paraGC and inhibitory effects on cell migration and invasion in vitro and GC metastasis in vivo. Mechanistically, circURI1 directly interacts with heterogeneous nuclear ribonucleoprotein M (hnRNPM) to modulate alternative splicing of genes, involved in the process of cell migration, thus suppressing GC metastasis. Collectively, our study expands the current knowledge regarding the molecular mechanism of circRNA-mediated cancer metastasis via modulating alternative splicing.


Author(s):  
Xianxiong Ma ◽  
Hengyu Chen ◽  
Lei Li ◽  
Feng Yang ◽  
Chuanqing Wu ◽  
...  

Abstract Background Circular RNAs (circRNAs) are a class of non-coding RNA that play critical roles in the development and pathogenesis of various cancers. The circRNA circGSK3B (hsa_circ_0003763) has been shown to enhance cell proliferation, migration, and invasion in hepatocellular carcinoma. However, the specific functions and underlying mechanistic involvement of circGSK3B in gastric cancer (GC) have not yet been explored. Our study aimed to investigate the effect of circGSK3B on the progression of GC and to identify any potential mechanisms underlying this process. Methods CircRNA datasets associated with GC were obtained from the PubMed, GEO, and ArrayExpress databases, and circRNAs were validated via RT-qPCR and Sanger sequencing. Biotin-labeled RNA pull-down, mass spectrometry, RNA immunoprecipitation, and in vitro binding assays were employed to determine proteins demonstrating interactions with circGSK3B. Gene expression regulation was assessed through RT-qPCR, chromatin immunoprecipitation, and western blot assays. Gain- and loss-of-function assays were used to analyze any effects of circGSK3B and its partner regulatory molecule (EZH2) on the proliferation, invasion, and migration abilities of GC cells both in vitro and in vivo. Results CircGSK3B was mainly identified in the nucleus. This circRNA was present at a reduced concentration in GC tissues and cell lines. Overexpression of circGSK3B was shown to inhibit the growth, invasion, and metastasis of GC cells both in vitro and in vivo. Mechanistically, circGSK3B directly interacted with EZH2, acting to suppress the binding of EZH2 and H3K27me3 to the RORA promoter, and leading to an elevation in RORA expression and ultimately the suppression of GC progression. Conclusions CircGSK3B acts as a tumor suppressor, reducing EZH2 trans-inhibition and GC progression. This demonstrates the potential use of this RNA as a therapeutic target for GC.


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