scholarly journals Circular RNA circLMO7 acts as a microRNA-30a-3p sponge to promote gastric cancer progression via the WNT2/β-Catenin pathway

2020 ◽  
Author(s):  
Jiacheng Cao ◽  
Xing Zhang ◽  
Penghui Xu ◽  
Haixiao Wang ◽  
Sen Wang ◽  
...  

Abstract Background : Gastric cancer (GC) is one of the most common malignant tumors worldwide. Currently, the overall survival rate of GC is still unsatisfactory despite progress in diagnosis and treatment. Therefore, studying the molecular mechanisms involved in GC is vital for diagnosis and treatment. CircRNAs, a type of noncoding RNA, have been proven to act as miRNA sponges that can widely regulate various cancers. By this mechanism, circRNA can regulate tumors at the genetic level by releasing miRNA from inhibiting its target genes. The WNT2/β-Catenin regulatory pathway is one of the canonical signaling pathways in tumors. It can not only promote the development of tumors but also provide energy for tumor growth through cell metabolism (such as glutamine metabolism). Methods: Through RNA sequencing, we found that hsa_circ_0008259 (circLMO7) was highly expressed in GC tissues. After verifying the circular characteristics of circLMO7, we determined the downstream miRNA (miR-30a-3p) of circLMO7 by RNA pull-down and luciferase reporter assays. We verified the effect of circLMO7 and miR-30a-3p on GC cells through a series of functional experiments, including colony formation, 5-ethynyl-2’-deoxyuridine and Transwell assays. Through Western blot and immunofluorescence analyses, we found that WNT2 was the downstream target gene of miR-30a-3p and further confirmed that the circLMO7-miR-30a-3p-WNT2 axis could promote the development of GC. In addition, measurement of related metabolites confirmed that this axis could also provide energy for the growth of GC cells through glutamine metabolism. We found that circLMO7 could promote the growth and metastasis of GC in vivo by the establishment of nude mouse models. Finally, we also demonstrated that HNRNPL could bind to the flanking introns of the circLMO7 exons to promote circLMO7 cyclization. Results: CircLMO7 acted as a miR-30a-3p sponge affecting the WNT2/β-Catenin pathway to promote the proliferation, migration and invasion of GC cells. Moreover, animal results also showed that circLMO7 could promote GC growth and metastasis in vivo . CircLMO7 could also affect the glutamine metabolism of GC cells through the WNT2/β-Catenin pathway to promote its malignant biological function. In addition, we proved that HNRNPL could promote the self-cyclization of circLMO7. Conclusions: CircLMO7 promotes the development of GC by releasing the inhibitory effect of miR-30a-3p on its target gene WNT2.

Author(s):  
Jiacheng Cao ◽  
Xing Zhang ◽  
Penghui Xu ◽  
Haixiao Wang ◽  
Sen Wang ◽  
...  

Abstract Background Gastric cancer (GC) is one of the most common malignant tumors worldwide. Currently, the overall survival rate of GC is still unsatisfactory despite progress in diagnosis and treatment. Therefore, studying the molecular mechanisms involved in GC is vital for diagnosis and treatment. CircRNAs, a type of noncoding RNA, have been proven to act as miRNA sponges that can widely regulate various cancers. By this mechanism, circRNA can regulate tumors at the genetic level by releasing miRNA from inhibiting its target genes. The WNT2/β-Catenin regulatory pathway is one of the canonical signaling pathways in tumors. It can not only promote the development of tumors but also provide energy for tumor growth through cell metabolism (such as glutamine metabolism). Methods Through RNA sequencing, we found that hsa_circ_0008259 (circLMO7) was highly expressed in GC tissues. After verifying the circular characteristics of circLMO7, we determined the downstream miRNA (miR-30a-3p) of circLMO7 by RNA pull-down and luciferase reporter assays. We verified the effect of circLMO7 and miR-30a-3p on GC cells through a series of functional experiments, including colony formation, 5-ethynyl-2′-deoxyuridine and Transwell assays. Through Western blot and immunofluorescence analyses, we found that WNT2 was the downstream target gene of miR-30a-3p and further confirmed that the circLMO7-miR-30a-3p-WNT2 axis could promote the development of GC. In addition, measurement of related metabolites confirmed that this axis could also provide energy for the growth of GC cells through glutamine metabolism. We found that circLMO7 could promote the growth and metastasis of GC in vivo by the establishment of nude mouse models. Finally, we also demonstrated that HNRNPL could bind to the flanking introns of the circLMO7 exons to promote circLMO7 cyclization. Results CircLMO7 acted as a miR-30a-3p sponge affecting the WNT2/β-Catenin pathway to promote the proliferation, migration and invasion of GC cells. Moreover, animal results also showed that circLMO7 could promote GC growth and metastasis in vivo. CircLMO7 could also affect the glutamine metabolism of GC cells through the WNT2/β-Catenin pathway to promote its malignant biological function. In addition, we proved that HNRNPL could promote the self-cyclization of circLMO7. Conclusions CircLMO7 promotes the development of GC by releasing the inhibitory effect of miR-30a-3p on its target gene WNT2.


2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Run Liu ◽  
Xianwu Yang

Abstract Background This study aimed to explore the role and underlying molecular mechanisms of long non-coding RNA (lncRNA) LINC00342 in gastric cancer (GC). Methods The expression of LINC00342 in GC tissues was evaluated by Quantitative reverse transcription polymerase chain reaction (qRT-PCR). Silencing of LINC00342 was conducted to investigate the effect of LINC00342 in vitro and in vivo. The underlying molecular mechanisms of LINC00342 were determined by dual luciferase reporter assay, Western blotting analysis and rescue experiments. Biological functions of LINC00342 were evaluated by cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and Transwell assays. In addition, a tumor model was used to verify the effect of LINC00342 in tumorigenesis in vivo. Results LINC00342 was significantly upregulated in GC tissues and cell lines. Silencing of LINC00342 efficiently inhibited proliferation, migration and invasion of AGS cells in vitro, and also suppressed the tumorigenesis of GC in vivo. Functional experiments showed that LINC00342 regulated the expression of canopy fibroblast growth factor signaling regulator 2 (CNPY2) by competitively sponging miR-545-5p. Rescue experiments showed that inhibition of miR-545-5p and overexpression of CNPY2 significantly reversed cell phenotypes caused by silencing of LINC00342. Conclusion LINC00342 plays a potential oncogenic role in GC by targeting the miR545-5p/CNPY2 axis, and might act as a novel therapeutic target for GC.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Qun Dai ◽  
Jingyi Deng ◽  
Jinrong Zhou ◽  
Zhuhong Wang ◽  
Xiao-feng Yuan ◽  
...  

Abstract Background Accumulating evidence indicates that the long noncoding RNA taurine upregulated gene 1(TUG1) plays a critical role in cancer progression and metastasis. However, the overall biological role and clinical significance of TUG1 in hepatocellular carcinoma (HCC) remain largely unknown. Methods The expressions of TUG1, microRNA-216b-5p and distal-less homeobox 2 (DLX2) were detected by Quantitative real-time polymerase chain reaction (qRT-PCR). The target relationships were predicted by StarBase v.2.0 or TargetScan and confirmed by dual-luciferase reporter assay. The cell growth, apoptosis, migration and invasion were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Flow cytometry and Transwell assays, respectively. All protein expression levels were detected by western blot. Tumor xenografts were implemented to explore the role of TUG1 in vivo. Results We found that there was a marked rise in TUG1 expression in HCC tissues and cells, and knockdown of TUG1 repressed the growth and metastasis and promoted apoptosis of HCC cells. In particular, TUG1 could act as a ceRNA, effectively becoming a sink for miR-216b-5p to fortify the expression of DLX2. Additionally, repression of TUG1 impared the progression of HCC cells by inhibiting DLX2 expression via sponging miR-216b-5p in vitro. More importantly, TUG1 knockdown inhibited HCC tumor growth in vivo through upregulating miR-216b-5p via inactivation of the DLX2. Conclusion TUG1 interacting with miR-216b-5p contributed to proliferation, metastasis, tumorigenesis and retarded apoptosis by activation of DLX2 in HCC.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yixun Lu ◽  
Benlong Zhang ◽  
Baohua Wang ◽  
Di Wu ◽  
Chuang Wang ◽  
...  

Abstract Background Gastric cancer (GC) is the fifth most commonly diagnosed cancer worldwide. Due to the dismal prognosis, identifying novel therapeutic targets in GC is urgently needed. Evidences have shown that miRNAs played critical roles in the regulation of tumor initiation and progression. GLI family zinc finger 2 (GLI2) has been reported to be up-regulated and facilitate cancer progression in multiple malignancies. In this study, we focused on identifying GLI2-targeted miRNAs and clarifying the underlying mechanism in GC. Methods Paired fresh gastric cancer tissues were collected from gastrectomy patients. GLI2 and miRNAs expression were detected in gastric cancer tissues and cell lines. Bioinformatics analysis was used to predict GLI2-targeted miRNAs and dual-luciferase reporter assay was applied for target verification. CCK-8, clone formation, transwell and flow cytometry were carried out to determine the proliferation, migration, invasion and cell cycle of gastric cancer cells. Tumorsphere formation assay and flow cytometry were performed to detail the stemness of gastric cancer stem cells (GCSCs). Xenograft models in nude mice were established to investigate the role of the miR-144-3p in vivo. Results GLI2 was frequently upregulated in GC and indicated a poor survival. Meanwhile, miR-144-3p was downregulated and negatively correlated with GLI2 in GC. GLI2 was a direct target gene of miR-144-3p. MiR-144-3p overexpression inhibited proliferation, migration and invasion of gastric cancer cells. Enhanced miR-144-3p expression inhibited tumorsphere formation and CD44 expression of GCSCs. Restoration of GLI2 expression partly reversed the suppressive effect of miR-144-3p. Xenograft assay showed that miR-144-3p could inhibit the tumorigenesis of GC in vivo. Conclusions MiR-144-3p was downregulated and served as an essential tumor suppressor in GC. Mechanistically, miR-144-3p inhibited gastric cancer progression and stemness by, at least in part, regulating GLI2 expression.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Feng Qu ◽  
Bin Zhu ◽  
Yi-Lin Hu ◽  
Qin-Sheng Mao ◽  
Ying Feng

Abstract Background Gastric cancer (GC) is among the most common and deadliest cancers globally. Many long non-coding RNAs (lncRNAs) are key regulators of GC pathogenesis. This study aimed to define the role of HOXA-AS3 in this oncogenic context. Methods Levels of HOXA-AS3 expression in GC were quantified via qPCR. The effects of HOXA-AS3 knockdown on GC cells function were evaluated in vitro using colony formation assays, wound healing assays and transwell assays. Subcutaneous xenograft and tail vein injection tumor model systems were generated in nude mice to assess the effects of this lncRNA in vivo. The localization of HOXA-AS3 within cells was confirmed by subcellular fractionation, and predicted microRNA (miRNA) targets of this lncRNA and its ability to modulate downstream NF-κB signaling in GC cells were evaluated via luciferase-reporter assays, immunofluorescent staining, and western blotting. Results GC cells and tissues exhibited significant HOXA-AS3 upregulation (P < 0.05), and the levels of this lncRNA were found to be correlated with tumor size, lymph node status, invasion depth, and Helicobacter pylori infection status. Knocking down HOXA-AS3 disrupted GC cell proliferation, migration, and invasion in vitro and tumor metastasis in vivo. At a mechanistic level, we found that HOXA-AS3 was able to sequester miR-29a-3p, thereby regulating the expression of LTβR and modulating NF-κB signaling in GC. Conclusion HOXA-AS3/miR-29a-3p/LTβR/NF-κB regulatory axis contributes to the progression of GC, thereby offering novel target for the prognosis and treatment of GC.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shujun Cao ◽  
Na Li ◽  
Xihong Liao

Abstract Background Ovarian cancer is the leading lethal gynecological cancer and is generally diagnosed during late-stage presentation. In addition, patients with ovarian cancer still face a low 5-year survival rate. Thus, innovative molecular targeting agents are required to overcome this disease. The present study aimed to explore the function of miR-362-3p and the underlying molecular mechanisms influencing ovarian cancer progression. Methods The expression levels of miR-362-3p were determined using qRT-PCR. Gain-of-function and loss-of-function methods were used to detect the effects of miR-362-3p on cell proliferation, cell migration, and tumor metastasis in ovarian cancer. A luciferase reporter assay was performed to confirm the potential target of miR-362-3p, and a rescue experiment was employed to verify the effect of miR-362-3p on ovarian cancer by regulating its target gene. Results miR-362-3p was significantly downregulated in ovarian cancer tissues and cell lines. In vitro, our data showed that miR-362-3p suppressed cell proliferation and migration. In vivo, miR-362-3p inhibited ovarian cancer growth and metastasis. Mechanistically, SERBP1 was identified as a direct target and functional effector of miR-362-3p in ovarian cancer. Moreover, SERBP1 overexpression rescued the biological function of miR-362-3p. Conclusions Our data reveal that miR-362-3p has an inhibitory effect on ovarian cancer. miR-362-3p inhibits the development and progression of ovarian cancer by directly binding its target gene SERBP1.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yi Gao ◽  
Yanfeng Wang ◽  
Xiaofei Wang ◽  
Changan Zhao ◽  
Fenghui Wang ◽  
...  

Abstract Background Recent studies have established the roles of microRNAs (miRNAs) in cancer progression. The aberrant expression of miR-335-5p has been reported in many cancers, including gastric cancer (GC). In this study, the precise roles of miR-335-5p in GC as well as the molecular mechanisms underlying its effects, including the role of its target MAPK10, were evaluated. Methods Quantitative real-time PCR was used to evaluate miR-335-5p levels in GC cell lines and tissues. MTT and colony formation assays were used to detect cell proliferation, and Transwell and wound-healing assays were used to evaluate the invasion and migration of GC cells. The correlation between levels of miR-335-5p and the cell cycle-related target gene mitogen-activated protein kinase 10 (MAPK10) in GC was analyzed. In addition, the candidate target was evaluated by a luciferase reporter assay, qRT-PCR, and western blotting. Results The levels of miR-335-5p were downregulated in GC tissues and cell lines. Furthermore, miR-335-5p inhibited the proliferation and migration of GC cells and induced apoptosis. Additionally, miR-335-5p arrested the cell cycle at the G1/S phase in GC cells in vitro. Levels of miR-335-5p and the cell cycle-related target gene MAPK10 in GC were correlated, and MAPK10 was directly targeted by miR-335-5p. Conclusions These data suggest that miR-335-5p is a tumor suppressor and acts via MAPK10 to inhibit GC progression.


2019 ◽  
Author(s):  
Shuaijun Dong ◽  
Xiefu Zhang ◽  
Dechun Liu

AbstractLong non-coding RNAs (lncRNAs) have emerged as important regulators of human cancers. LncRNA GAS5 (GAS5) is identified tumor suppressor involved in several cancers. However, the roles of GAS5 and the mechanisms responsible for its functions in gastric cancer (GC) have not been well undocumented. Herein, the decreased GAS5 and increased miRNA-106a-5p levels were observed in GC and cell lines. GAS5 expression level was significantly inversely correlated with miRNA-106a-5p level in GC tissues. Moreover, luciferase reporter and qRT-PCR assays showed that GAS5 bound to miRNA-106a-5p and negatively regulated its expression in GC cells. Functional experiments showed that GAS5 overexpression suppressed GC cell proliferation, migration, and invasion capabilities and promoted apoptosis, while miRNA-106a-5p overexpression inversed the functional effects induced by GAS5 overexpression. In vivo, GAS5 overexpression inhibited tumor growth by negatively regulating miRNA-106a-5p expression. Mechanistic investigations revealed that GAS5 overexpression inactivating the Akt/mToR pathway by suppressing miRNA-106a-5p expression in vitro and in vivo. Taken together, our findings conclude the GAS5 overexpression suppresses tumorigenesis and development of gastric cancer by sponging miR-106a-5p through the Akt/mToR pathway.


2020 ◽  
Vol 40 (8) ◽  
Author(s):  
Lili Mi ◽  
Lianhui Lei ◽  
Xiaolei Yin ◽  
Ning Li ◽  
Jianfei Shi ◽  
...  

Abstract Background: Gastric cancer (GC) remains one of the most common malignancies worldwide. Increasing evidence has demonstrated that circRNAs serve as critical roles in human cancer, including GC. In the present study, we focused on the detailed function and mechanism of circ_0000144 on GC progression. Methods: The levels of circ_0000144, miR-623 and G-protein-coupled receptor, family C, group 5, member A (GPRC5A) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Targeted relationships among circ_0000144, miR-623 and GPRC5A were confirmed using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell proliferation, colony formation, apoptosis, migration and invasion were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry and transwell assays. Measurement of glutamine and α-ketoglutarate (α-KG) levels was performed using a corresponding assay kit. GPRC5A protein expression was detected using Western blot. In vivo assays were used to explore the impact of circ_0000144 on tumor growth. Results: Our data indicated that circ_0000144 was up-regulated and miR-623 was down-regulated in GC tissues and cells. Circ_0000144 interacted with miR-623 through directly binding to miR-623. Moreover, the knockdown of circ_0000144 weakened GC cell proliferation, colony formation, migration, invasion and glutaminolysis and accelerated cell apoptosis by up-regulating miR-623. GPRC5A was a direct target of miR-623 and circ_0000144 protected against GPRC5A repression through sponging miR-623. Furthermore, miR-623-mediated regulation on GC cell progression was reversed by the stored expression of GPRC5A. Additionally, circ_0000144 depletion inhibited tumor growth in vivo. Conclusion: Our study indicated that circ-0000144 knockdown repressed GC progression at least partly by regulating GPRC5A expression via sponging miR-623, illumining a novel therapeutic target for GC treatment.


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