scholarly journals METTL3 Facilitates Colorectal Carcinoma Progression via Regulating m6A-CRB3-Hippo Axis

Author(s):  
Feng Liu ◽  
Xiaoli Xiao ◽  
Jiashu Pan ◽  
Ruohui Xu ◽  
Liang Dai ◽  
...  

Abstract Background Colorectal carcinoma (CRC) is the third most common cancer and the second most common cause of cancer-related death worldwide. RNA N6-methyladnosine (m6A) and methyltransferase-like 3 (METTL3) play an important role in cancer. However, the roles of m6A and METTL3 in CRC progression are still elusive. Methods Adenoma and CRC samples were applied to detect m6A and METTL3 levels, and tissue microarrays were performed to evaluate their associations with survival of CRC patients. The biological functions of METTL3 were investigated by CCK8, wound healing and transwell assays. M6A epitranscriptomic microarray, RNA stability and luciferase reporter assays were performed to explore the mechanism of METTL3 in CRC. Results m6A and METTL3 levels were significantly upregulated in both adenoma and CRC tissues, and the CRC patients with high m6A or METTL3 level had both shorter overall survival. METTL3 knockdown markedly inhibited the proliferation, migration and invasion of CRC cells. M6A epitranscriptomic microarray revealed that the cell polarity regulator Crumbs3 (CRB3) was the downstream target of METTL3. METTL3 knockdown markedly inhibited the degradation of CRB3 mRNA to increase the CRB3 expression. In addition, CRB3 level was also markedly reduced in both adenoma and CRC tissues, and the CRC patients with high CRB3 level had higher overall survival and disease free survival. CRB3 knockdown significantly promoted the proliferation, migration and invasion of CRC cells. Finally, CRB3 knockdown inhibited Hippo pathway, and increased nuclear localization of YAP. Conclusions The m6A and METTL3 levels were significantly increased in both adenoma and CRC tissues. The CRC patients with high m6A or METTL3 levels had shorter overall survival. Mechanistically, METTL3 regulated the initiation and progression of CRC via regulating m6A-CRB3-Hippo pathway.

Author(s):  
Jiashu Pan ◽  
Feng Liu ◽  
Xiaoli Xiao ◽  
Ruohui Xu ◽  
Liang Dai ◽  
...  

Abstract Background Colorectal carcinoma (CRC) is the third most common cancer and second most common cause of cancer-related deaths worldwide. Ribonucleic acid (RNA) N6-methyladnosine (m6A) and methyltransferase-like 3 (METTL3) play key roles in cancer progression. However, the roles of m6A and METTL3 in CRC progression require further clarification. Methods Adenoma and CRC samples were examined to detect m6A and METTL3 levels, and tissue microarrays were performed to evaluate the association of m6A and METTL3 levels with the survival of patients with CRC. The biological functions of METTL3 were investigated through cell counting kit-8, wound healing, and transwell assays. M6A epitranscriptomic microarray, methylated RNA immunoprecipitation-qPCR, RNA stability, luciferase reporter, and RNA immunoprecipitation assays were performed to explore the mechanism of METTL3 in CRC progression. Results M6A and METTL3 levels were substantially elevated in CRC tissues, and patients with CRC with a high m6A or METTL3 levels exhibited shorter overall survival. METTL3 knockdown substantially inhibited the proliferation, migration, and invasion of CRC cells. An m6A epitranscriptomic microarray revealed that the cell polarity regulator Crumbs3 (CRB3) was the downstream target of METTL3. METTL3 knockdown substantially reduced the m6A level of CRB3, and inhibited the degradation of CRB3 mRNA to increase CRB3 expression. Luciferase reporter assays also showed that the transcriptional level of wild-type CRB3 significantly increased after METTL3 knockdown but not its level of variation. Knockdown of YT521-B homology domain–containing family protein 2 (YTHDF2) substantially increased CRB3 expression. RNA immunoprecipitation assays also verified the direct interaction between the YTHDF2 and CRB3 mRNA, and this direct interaction was impaired after METTL3 inhibition. In addition, CRB3 knockdown significantly promoted the proliferation, migration, and invasion of CRC cells. Mechanistically, METTL3 knockdown activated the Hippo pathway and reduced nuclear localization of Yes1-associated transcriptional regulator, and the effects were reversed by CRB3 knockdown. Conclusions M6A and METTL3 levels were substantially elevated in CRC tissues relative to normal tissues. Patients with CRC with high m6A or METTL3 levels exhibited shorter overall survival, and METTL3 promoted CRC progression. Mechanistically, METTL3 regulated the progression of CRC by regulating the m6A–CRB3–Hippo pathway.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yanjiao Ou ◽  
Yong Deng ◽  
Hong Wang ◽  
Qingyi Zhang ◽  
Huan Luo ◽  
...  

Objective: Increasing evidence highlights antisense long non-coding RNAs (lncRNAs) as promising therapeutic targets for cancers. Herein, this study focused on the clinical implications and functions of a novel antisense lncRNA PRKAG2-AS1 in hepatocellular carcinoma (HCC).Methods: PRKAG2-AS1 expression was examined in a cohort of 138 HCC patients by RT-qPCR. Overall survival (OS) and disease-free survival (DFS) analyses were presented based on PRKAG2-AS1 expression, followed by ROCs. After silencing PRKAG2-AS1, cell proliferation was assessed via CCK-8, colony formation and EdU staining assays. Migrated and invasive capacities were assessed by wound healing and transwell assays. The relationships between PRKAG2-AS1, miR-502-3p and BICD2 were validated by luciferase reporter, RIP and RNA pull-down assays. The expression and prognostic value of BICD2 were analyzed in TCGA database.Results: PRKAG2-AS1 was up-regulated in HCC than normal tissue specimens. High PRKAG2-AS1 expression was indicative of poorer OS and DFS time. Area under the curves (AUCs) for OS and DFS were 0.8653 and 0.7891, suggesting the well predictive efficacy of PRKAG2-AS1 expression. Targeting PRKAG2-AS1 distinctly inhibited proliferation, migration, and invasion in HCC cells. PRKAG2-AS1 was mainly expressed in cytoplasm of HCC cells. PRKAG2-AS1 may directly bind to the sites of miR-502-3p. Up-regulation of BICD2 was found in HCC tissues and associated with unfavorable prognosis. BICD2 was confirmed to be a downstream target of miR-502-3p. PRKAG2-AS1 could regulate miR-502-3p/BICD2 axis.Conclusion: Our findings identified a novel lncRNA PRKAG2-AS1 that was associated with clinical implications and malignant behaviors. Thus, PRKAG2-AS1 could become a promising therapeutic target.


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.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Li Zhang ◽  
Xin Zhang ◽  
Xin Wang ◽  
Miao He ◽  
Shixing Qiao

Triple-negative breast cancer (TNBC) harbors genetic heterogeneity and generally has more aggressive clinical outcomes. As such, there is urgency in identifying new prognostic targets and developing novel therapeutic strategies. In this study, miR-224 was overexpressed in breast cancer cell lines and TNBC primary cancer samples. Knockdown of miR-224 in MDA-MB-231 cancer cells reduced cell proliferation, migration, and invasion. Through integrating in silico prediction algorithms with KEGG pathway and Gene Ontology analyses, CASP9 was identified to be a potential target of miR-224. miR-224 knockdown significantly increased CASP9 transcript and protein levels. Furthermore, luciferase reporter assays confirmed a direct interaction of miR-224 with CASP9. Our findings have demonstrated that the miR-224/CASP9 axis plays an important role in TNBC progression, providing evidence in support of a promising therapeutic strategy for this disease.


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


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Zhaosheng Chen ◽  
Honglei Wu ◽  
Zhen Zhang ◽  
Guangchun Li ◽  
Bin Liu

Abstract Background Gastric cancer (GC) is a common-sighted cancer which is hard to cure over the world. Substantial researches revealed that long non-coding RNAs (lncRNAs) were fundamental regulators in the process of cancers. Nevertheless, the biological function of LINC00511 and how LINC00511 was involved in the regulatory system in GC remained unclear. Methods RIP assays and luciferase reporter assays were performed to illustrate combination between LINC00511 and miR-625-5p. Loss-of-function assays were applied for identifying LINC00511 function in GC. Results In our study, LINC00511 was discovered significantly high in expression in GC tissues and cell lines. Moreover, LINC00511 showed a strong expression in I/II and III/IV stage. Knockdown of LINC00511 could inhibit the cell proliferation while enhanced cell apoptosis rate in GC. We used nuclear–cytoplasmic fractionation to judge the subcellular localization of LINC00511. Furthermore, miR-625-5p was found to have binding sites for LINC00511 and negatively regulated by LINC00511. Overexpression of miR-625-5p repressed the course of GC. And knockdown of miR-625-5p could recover the effects of LINC00511 silence. Besides, NFIX was discovered as a downstream target of miR-625-5p and overexpression of NFIX could offset the influence of LINC00511 silence. The results of vivo studies manifested that down-regulation of LINC00511 could reduce the Ki67 expression and NFIX while lifted the expression of miR-625-5p. Conclusion Overall, the results from our study demonstrated that LINC00511 could function as a tumor promoter by targeting miR-625-5p NFIX axis, suggesting LINC00511 could be considered as a target for GC treatment.


2018 ◽  
Vol 314 (6) ◽  
pp. C690-C701 ◽  
Author(s):  
Yun-xiao Zhou ◽  
Chuan Wang ◽  
Li-wei Mao ◽  
Yan-li Wang ◽  
Li-qun Xia ◽  
...  

LncRNA homeobox (HOX) transcript antisense intergenic RNA (HOTAIR) has been confirmed to be involved in the tumorigenic progression of endometrial carcinoma (EC). However, the molecular mechanisms of HOTAIR in EC are not fully elucidated. The expression of HOTAIR and miR-646 in human EC tissues was determined by qRT-PCR. The effect of miR-646 on EC cells was assessed by the cell viability, migration, and invasion using CCK-8 assays and transwell assays. RNA-binding protein immunoprecipitation assays and RNA pull-down assays were performed to explore the interaction between HOTAIR and miR-646. The regulation of miR-646 on nucleophosmin 1 (NPM1) was tested using luciferase reporter assays. MiR-646 expression was significantly decreased both in human EC tissues ( n = 23) and cell lines (Ishikawa and HEC-1-A) compared with the control. Moreover, miR-646 expression was negatively related to HOTAIR in human EC tissues ( n = 23). Our results also showed that miR-646 overexpression considerably attenuated the E2-promoted viability, migration, and invasion of Ishikawa and HEC-1-A cells in vitro. In addition, HOTAIR was confirmed to regulate the viability, migration, and invasion of EC cells through negative regulating miR-646. More importantly, we also demonstrated that NPM1 was the target of miR-646, and HOTAIR promoted NPM1 expression through interacting with miR-646 in EC cells. Taken together, our findings presented that HOTAIR could regulate NPM1 via interacting with miR-646, thereby governing the viability, migration, and invasion of EC cells.


2020 ◽  
Author(s):  
Shi-lei Liu ◽  
Xiang-song Wu ◽  
Feng-nan Li ◽  
Wen-yan Yao ◽  
Zi-you Wu ◽  
...  

Abstract Background: Estrogen-related receptor alpha (ERRα), an orphan nuclear receptor, was reported to be highly associated with the progression and tumorigenesis of several human malignancies. However, the biological role and underlying molecular mechanisms of ERRα in pancreatic cancer (PC) remain unknown.Methods: The expression of ERRα in PC tissues was determined by qRT-PCR and immunohistochemistry. A series of in vitro and in vivo assays were performed to investigate the function of ERRα and Plasminogen activator inhibitor 1 (PAI1) in tumorigenesis in PC cells. The relationship between ERRα and PAI1 was identified by RNA sequencing, Chromatin immunoprecipitation and dual-luciferase reporter assays. The effects of ERRα on the MEK/ERK signaling pathway were determined by western blotting and rescue assays using ERK inhibitor GDC-0994.Results: ERRα was significantly overexpressed in PC tissues and cell lines. Its high expression was correlated with tumor size, distant metastasis, TNM stage, tumor differentiation and poor prognosis of PC. Subsequent functional assays showed that ERRα promoted PC cell proliferation, tumor growth, as well as migration and invasion via activating the epithelial-mesenchymal transition. In addition, knockdown of ERRα induced apoptosis and G0/G1 cell cycle arrest in PC cells. PAI1 was identified by RNA sequencing, knockdown of which could suppress the cell proliferation, migration and invasion that promoted by ERRα overexpression. Further mechanistic investigation using chromatin immunoprecipitation and dual-luciferase reporter assays revealed that ERRα could bind to the PAI1 promoter region and transcriptionally enhance PAI1 expression. Moreover, our data indicated that ERRα played its oncogenic role in PC via activating the MEK/ERK pathway.Conclusions: Our study demonstrates that ERRα promotes PC progression by enhancing the transcription of PAI1 and activation of the MEK/ERK pathway, pointing to ERRα as a novel diagnostic and therapeutic target for PC.


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.


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