scholarly journals Deficiency of Mettl3 in Bladder Cancer Stem Cells Inhibits Bladder Cancer Progression and Angiogenesis

Author(s):  
Ganping Wang ◽  
Yarong Dai ◽  
Kang Li ◽  
Maosheng Cheng ◽  
Gan Xiong ◽  
...  

RNA N6-methyladenosine is a key step of posttranscriptional modulation that is involved in governing gene expression. The m6A modification catalyzed by Mettl3 has been widely recognized as a critical epigenetic regulation process for tumorigenic properties in various cancer cell lines, including bladder cancer. However, the in vivo function of Mettl3 in bladder cancer remains largely unknown. In our study, we found that ablation of Mettl3 in bladder urothelial attenuates the oncogenesis and tumor angiogenesis of bladder cancer using transgenic mouse model. In addition, conditional knockout of Mettl3 in K14+ bladder cancer stem cell population leads to inhibition of bladder cancer progression. Coupled with the global transcriptome sequencing and methylated RNA immunoprecipitation sequencing results, we showed that deletion of Mettl3 leads to the suppression of tyrosine kinase endothelial (TEK) and vascular endothelial growth factor A (VEGF-A) through reduced abundance of m6A peaks on a specific region. In addition, the depletion of Mettl3 results in the decrease in both messenger RNA (mRNA) and protein levels of TEK and VEGF-A in vitro. Taken together, Mettl3-mediated m6A modification is required for the activation of TEK–VEGF-A-mediated tumor progression and angiogenesis. Our findings may provide theoretical basis for bladder cancer treatment targeting Mettl3.

2020 ◽  
Author(s):  
Ganping Wang ◽  
Yarong Dai ◽  
Kang Li ◽  
Maosheng Cheng ◽  
Gan Xiong ◽  
...  

Abstract Background: RNA N6-methyladenosine is a key step of post-transcriptional modulation which involves in governing gene expression. The m6A modification catalyzed by Mettl3 has been widely recognized as a critical epigenetic regulation process for tumorigenic properties in various cancer cell lines, including bladder cancer. However, the in vivo function of Mettl3 in bladder cancer remains largely unknown. Methods: Establishment of transgenic mouse model for exploring the role and mechanisms of Mettl3 in bladder cancer. Coupled global transcriptome sequencing and methylated RNA immunoprecipitation sequencing is performed to identify targets modulated by Mettl3.Results: We found that ablation of Mettl3 in bladder urothelial attenuates the oncogenesis and tumor angiogenesis of bladder cancer. In addition, conditional knockout of Mettl3 in K14+ bladder cancer stem cell population leads to inhibition of bladder cancer progression. And deletion of Mettl3 leads to the suppression of TEK and VEGF-A through reduced abundance of m6A peaks on specific region. Conclusions: Taken together, Mettl3-mediated m6A modification is required for the activation of TEK-VEGF-A-mediated tumor progression and angiogenesis. Our findings may provide theoretical basis for bladder cancer treatment targeting Mettl3.


Author(s):  
Zhibin Liao ◽  
Hongwei Zhang ◽  
Chen Su ◽  
Furong Liu ◽  
Yachong Liu ◽  
...  

Abstract Background Aberrant expressions of long noncoding RNAs (lncRNAs) have been demonstrated to be related to the progress of HCC. The mechanisms that SNHG14 has participated in the development of HCC are obscure. Methods Quantitative real-time PCR (qRT-PCR) was used to measure the lncRNA, microRNA and mRNA expression level. Cell migration, invasion and proliferation ability were evaluated by transwell and CCK8 assays. The ceRNA regulatory mechanism of SNHG14 was evaluated by RNA immunoprecipitation (RIP) and dual luciferase reporter assay. Tumorigenesis mouse model was used to explore the roles of miR-876-5p in vivo. The protein levels of SSR2 were measured by western blot assay. Results In this study, we demonstrated that SNHG14 was highly expressed in HCC tissues, meanwhile, the elevated expression of SNHG14 predicted poor prognosis in patients with HCC. SNHG14 promoted proliferation and metastasis of HCC cells. We further revealed that SNHG14 functioned as a competing endogenous RNA (ceRNA) for miR-876-5p and that SSR2 was a downstream target of miR-876-5p in HCC. Transwell, CCK8 and animal experiments exhibited miR-876-5p inhibited HCC progression in vitro and in vivo. By conducting rescue experiments, we found the overexpression of SSR2 or knocking down the level of miR-876-5p could reverse the suppressive roles of SNHG14 depletion in HCC. Conclusion SNHG14 promotes HCC progress by acting as a sponge of miR-876-5p to regulate the expression of SSR2 in HCC.


2020 ◽  
Vol 9 (2) ◽  
pp. 91-100 ◽  
Author(s):  
Xuan Qiu ◽  
Yufa Miao ◽  
Xingchao Geng ◽  
Xiaobing Zhou ◽  
Bo Li

Abstract There have been intensive efforts to identify in vivo biomarkers that can be used to monitor drug-induced kidney damage before significant impairment occurs. Kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, clusterin, β2-microglobulin and cystatin C (CysC) have been validated as clinical or preclinical biomarkers in urinary and plasma predictive of acute and chronic kidney injuries and diseases. A high-throughput in vitro assay predictive of nephrotoxicity could potentially be implemented in early drug discovery stage to reduce attrition at later stages of drug development. To assess the potential of these known in vivo biomarkers for in vitro evaluation of drug-induced nephrotoxicity, we selected four nephrotoxic agents (cisplatin, cyclosporin, aristolochic acid I and gentamicin) and detected their effects on the protein levels of nephrotoxic biomarkers in RPTEC/TERT1 cells. The protein levels of clusterin, CysC, GSTπ and TIMP-1 significantly increased in the conditioned media of RPTEC/TERT1 cells treated with cisplatin, cyclosporin, aristolochic acid I and gentamicin. The messenger RNA levels of clusterin, CysC, GSTπ and TIMP-1 also increased in RPTEC/TERT1 cells treated with cisplatin, cyclosporin, aristolochic acid I and gentamicin, indicating that drug-induced upregulation involves transcriptional activation. Taken together, the results clearly demonstrate that among the known in vivo nephrotoxic biomarkers, clusterin, CysC, GSTπ and TIMP-1 can be effectively used as in vitro biomarkers for drug-induced nephrotoxicity in RPTEC/TERT1 cells.


2020 ◽  
Vol 34 ◽  
pp. 205873842095459
Author(s):  
Jijun Wang ◽  
Fan Wu ◽  
Yaoyao Li ◽  
Lei Pang ◽  
Xiaohong Wang ◽  
...  

Introduction: This work was to explore the connection of KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) and microRNA-4319 (miR-4319), and to investigate the associated underlying mechanisms in gastric cancer (GC) progression. Methods: Quantitative real-time PCR was performed to measure KCNQ1OT1, miR-4319 and DNA-damage regulated autophagy modulator 2 (DRAM2) expression levels in GC cells. Moreover, expression level of KCNQ1OT1 and DRAM2 in GC tissues was analyzed at ENCORI website ( http://starbase.sysu.edu.cn/index.php ). Cell proliferation, colony formation assay and flow cytometry assays were performed to analyze effects of KCNQ1OT1, miR-4319 and DRAM2 on cell growth and death. Dual-luciferase activity reporter assay and RNA immunoprecipitation assay was conducted to verify the interactions of KCNQ1OT1 or DRAM2 and miR-4319. Results and Conclusion: We found KCNQ1OT1 level was increased in tumor tissues and cells. Force the expression of KCNQ1OT1 promotes, while knockdown KCNQ1OT1 inhibits GC cell growth. Further studies indicated miR-4319 functioned as a bridge between KCNQ1OT1 and DRAM2. Finally, we showed KCNQ1OT1/miR-4319/DRAM2 axis regulates GC cell growth in vitro and in vivo. lncRNA KCNQ1OT1 promotes GC progression by sponging miR-4319 to upregulate DRAM2, indicating KCNQ1OT1 might be a promising target for GC treatment.


Blood ◽  
2003 ◽  
Vol 102 (2) ◽  
pp. 638-645 ◽  
Author(s):  
Nicola Giuliani ◽  
Simona Colla ◽  
Mirca Lazzaretti ◽  
Roberto Sala ◽  
Giovanni Roti ◽  
...  

AbstractPatients with multiple myeloma (MM) have increased bone marrow (BM) angiogenesis; however, the proangiogenic properties of myeloma cells and the mechanisms of MM-induced angiogenesis are not completely clarified. The angiopoietin system has been identified as critical in the regulation of vessel formation. In this study we have demonstrated that myeloma cells express several proangiogenic factors, and, in particular, we found that angiopoietin-1 (Ang-1), but not its antagonist Ang-2, was expressed by several human myeloma cell lines (HMCLs) at the mRNA and the protein levels. In a transwell coculture system, we observed that myeloma cells up-regulated the Ang-1 receptor Tie2 in human BM endothelial cells. Moreover, in an experimental model of angiogenesis, the conditioned medium of HMCLs significantly stimulated vessel formation compared with control or vascular endothelial growth factor (VEGF) treatment. The presence of anti-Tie2 blocking antibody completely blunted the proangiogenic effect of XG-6. Finally, our in vitro results were supported by the in vivo finding of Ang-1, but not Ang-2, mRNA and protein expression in purified MM cells obtained from approximately 47% of patients and by high BM angiogenesis in patients with MM positive for Ang-1, suggesting that the angiopoietin system could be involved, at least in part, in MM-induced angiogenesis.


2021 ◽  
Author(s):  
Dexiang Feng ◽  
Jiancheng Lv ◽  
Kai Li ◽  
Qiang Cao ◽  
Jie Han ◽  
...  

Abstract Circular RNAs (circRNAs) have been extensively studied in tumor development and treatment. CircZNF609 has been shown to act as an oncogene in a variety of solid tumors and may serve as a novel biomarker for tumor diagnosis and treatment. However, the underlying role and mechanism of circZNF609 in bladder cancer (BCa) development and cisplatin chemosensitivity were unknown. Quantitative real-time PCR (qRT-PCR) was applied to determine the expression of circZNF609, microRNA 1200 (miR-1200) and CDC25B in BCa cells and tissues. Western blot was used to detect the protein level of CDC25B. Functional assays in vitro and in vivo were conducted to investigate the effects of circZNF609 on tumor development and cisplatin chemosensitivity in BCa. RNA sequencing and online databases were used to predict the interactions among circZNF609, miR-1200 and CDC25B. Dual luciferase reporter assay, RNA pull-down assay and RNA fluorescence in situ hybridization (FISH) were applied to confirm the mechanism. CircZNF609 expression was significantly up-regulated in BCa cell lines and tissues. Increased expression of circZNF609 was related to a worse survival in BCa patients. In vitro and in vivo, enforced-expression of circZNF609 enhanced BCa cells proliferation, migration and cisplatin chemoresistance. Mechanistically, circZNF609 alleviated the inhibition effect on target CDC25B expression by sponging miR-1200. CircZNF609 promoted tumor growth through novel circZNF609/miR-1200/CDC25B axis, implying that circZNF609 has significant potential to serve as a new diagnostic biomarker and therapeutic target for BCa patients.


2020 ◽  
Author(s):  
Lining Huang ◽  
Xingming Jiang ◽  
Zhenglong Li ◽  
Jinglin Li ◽  
Xuan Lin ◽  
...  

Abstract Background: Cholangiocarcinoma (CCA) is a mortal cancer with high mortality, whereas the function and mechanism of occurrence and progression of CCA are still mysterious. Long non-coding RNAs (lncRNAs) could function as important regulators in carcinogenesis and cancer progression. Growing evidences have indicated that the novel lncRNA linc00473 plays an important role in cancer progression and metastasis. However, its function and molecular mechanism in CCA remain unknown. Methods: The linc00473 expression in CCA tissues and cell lines was analyzed using qRT-PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of linc00473 both in vitro and in vivo. Insights into the underlying mechanisms of competitive endogenous RNAs (ceRNAs) were determined by bioinformatics analysis, dual-luciferase reporter assays, qRT-PCR arrays, RNA immunoprecipitation (RIP) and rescue experiments. Results: Linc00473 was highly expressed in CCA tissues and cell lines. Linc00473 knockdown inhibited CCA growth and metastasis. Furthermore, linc00473 acted as miR-506 sponge and regulated its target gene DDX5 expression. Rescue assays verified that linc00473 modulated the tumorigenesis of CCA by regulating miR-506. Conclusions: The data indicated that linc00473 played an oncogenic role in CCA growth and metastasis, and could serve as a novel molecular target for treating CCA.


2020 ◽  
Author(s):  
Yeyu Zhang ◽  
Yuxing Zhu ◽  
Mengqing Xiao ◽  
Yaxin Cheng ◽  
Dong He ◽  
...  

Abstract BackgroundBladder cancer (BC) is the most common malignant tumor of the urinary system. Increasing evidence indicates long non-coding RNAs (lncRNAs) play crucial roles in cancer tumorigenesis, development, and progression. However, the role of TMPO antisense RNA 1 (TMPO-AS1) is still need to be explored in BC.MethodsThe lncRNA TMPO-AS1 expression was evaluated by bioinformatics analysis and further validated by qRT-PCR. Loss- and gain-of- function assays were performed to determine the biological functions of TMPO-AS1 in BC proliferation, migration, and invasion. Chromatin immunoprecipitation, luciferase reporter assays, western blotting, RNA pull-down, RNA immunoprecipitation assays, and fluorescence in situ hybridization were conducted to explore the molecular mechanisms of TMPO-AS1/E2F transcription factor 1 (E2F1) loop. ResultsTMPO-AS1 is upregulated in bladder cancer and is associated with BC patients’ poor prognoses. Functional experiments demonstrated that TMPO-AS1 promotes bladder cancer cell proliferation, migration, invasion, and inhibits cell apoptosis in vivo and in vitro. Mechanically, E2F1 is responsible for the TMPO-AS1 upregulation. Additionally, TMPO-AS1 facilitates the interaction of E2F1 with OTU domain-containing ubiquitin aldehyde binding 1 (OTUB1), leading to E2F1 deubiquitination and stabilization, thereby promotes BC malignant phenotypes. Furthermore, rescue experiments showed that TMPO-AS1 promotes BC growth in an E2F1-dependent manner.ConclusionsOur study is the first to uncover a novel positive regulatory loop of TMPO-AS1/E2F1 important for the promotion of BC malignant behaviors. The TMPO-AS1/E2F1 loop should be considered in the quest for new BC therapeutic options.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Wen Ni ◽  
Su Yao ◽  
Yunxia Zhou ◽  
Yuanyuan Liu ◽  
Piao Huang ◽  
...  

Abstract Background YAP activation is crucial for cancer development including colorectal cancer (CRC). Nevertheless, it remains unclear whether N6-Methyladenosine (m6A) modified transcripts of long noncoding RNAs (lncRNAs) can regulate YAP activation in cancer progression. We investigated the functional link between lncRNAs and the m6A modification in YAP signaling and CRC progression. Methods YAP interacting lncRNAs were screened by RIP-sequencing, RNA FISH and immunofluorescence co-staining assays. Interaction between YAP and lncRNA GAS5 was studied by biochemical methods. MeRIP-sequencing combined with lncRNA-sequencing were used to identify the m6A modified targets of YTHDF3 in CRC. Gain-of-function and Loss-of-function analysis were performed to measure the function of GAS5-YAP-YTHDF3 axis in CRC progression in vitro and in vivo. Results GAS5 directly interacts with WW domain of YAP to facilitate translocation of endogenous YAP from the nucleus to the cytoplasm and promotes phosphorylation and subsequently ubiquitin-mediated degradation of YAP to inhibit CRC progression in vitro and in vivo. Notably, we demonstrate the m6A reader YTHDF3 not only a novel target of YAP but also a key player in YAP signaling by facilitating m6A-modified lncRNA GAS5 degradation, which profile a new insight into CRC progression. Clinically, lncRNA GAS5 expressions is negatively correlated with YAP and YTHDF3 protein levels in tumors from CRC patients. Conclusions Our study uncovers a negative functional loop of lncRNA GAS5-YAP-YTHDF3 axis, and identifies a new mechanism for m6A-induced decay of GAS5 on YAP signaling in progression of CRC which may offer a promising approach for CRC treatment.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jinan Guo ◽  
Zhixin Chen ◽  
Hongtao Jiang ◽  
Zhou Yu ◽  
Junming Peng ◽  
...  

Abstract Background Bladder cancer is the most common human urological malignancies with poor prognosis, and the pathophysiology of bladder cancer involves multi-linkages of regulatory networks in the bladder cancer cells. Recently, the long noncoding RNAs (lncRNAs) have been extensively studied for their role on bladder cancer progression. In this study, we evaluated the expression of DLX6 Antisense RNA 1 (DLX6-AS1) in the cancerous bladder tissues and studied the possible mechanisms of DLX6-AS1 in regulating bladder cancer progression. Methods Gene expression was determined by qRT-PCR; protein expression levels were evaluated by western blot assay; in vitro functional assays were used to determine cell proliferation, invasion and migration; nude mice were used to establish the tumor xenograft model. Results Our results showed the up-regulation of DLX6-AS1 in cancerous bladder cancer tissues and bladder cell lines, and high expression of DLX6-AS1 was correlated with advance TNM stage, lymphatic node metastasis and distant metastasis. The in vitro experimental data showed that DLX6-AS1 overexpression promoted bladder cancer cell growth, proliferation, invasion, migration and epithelial-to-mesenchymal transition (EMT); while DLX6-AS1 inhibition exerted tumor suppressive actions on bladder cancer cells. Further results showed that DLX6-AS1 overexpression increased the activity of Wnt/β-catenin signaling, and the oncogenic role of DLX6-AS1 in bladder cancer cells was abolished by the presence of XAV939. On the other hand, DLX6-AS1 knockdown suppressed the activity of Wnt/β-catenin signaling, and the tumor-suppressive effects of DLX6-AS1 knockdown partially attenuated by lithium chloride and SB-216763 pretreatment. The in vivo tumor growth study showed that DLX6-AS1 knockdown suppressed tumor growth of T24 cells and suppressed EMT and Wnt/β-catenin signaling in the tumor tissues. Conclusion Collectively, the present study for the first time identified the up-regulation of DLX6-AS1 in clinical bladder cancer tissues and in bladder cancer cell lines. The results from in vitro and in vivo assays implied that DLX6-AS1 exerted enhanced effects on bladder cancer cell proliferation, invasion and migration partly via modulating EMT and the activity of Wnt/β-catenin signaling pathway.


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