scholarly journals Bile acids increase intestinal markers via FXR/SNAI2/miR-1 axis in the stomach

2020 ◽  
Author(s):  
Na Wang ◽  
Min Chen ◽  
Jiaoxia Zeng ◽  
Guofang Lu ◽  
Jiaojiao Wang ◽  
...  
Keyword(s):  
Bile Acids ◽  
Transcriptional Activation ◽  
Chromatin Immunoprecipitation ◽  
Bioinformatics Analysis ◽  
Precancerous Lesion ◽  
Tissue Microarrays ◽  
Luciferase Reporter ◽  
Binding Region ◽  
Aberrant Expression ◽  
Gastric Cells

Abstract Background Intestinal metaplasia (IM) is a precancerous lesion that increases risk of subsequent gastric cancer (GC). However, factors governing the transformation from normal gastric epithelial cells to IM remain unclear. Previously, miR-1 turned out to play an essential role in the initiation of bile acids (BA)-induced IM. Here, we investigate the mechanism underlying miR-1 inhibition by BA in gastric cells. Methods We conducted IPA analysis to determine the potential molecular interacting BA with miR-1. The changes of FXR and SNAI2 after BA treatment were detected by western blot and qRT-PCR. IHC was performed to assess the expression level of FXR and SNAI2 in normal and IM tissue microarrays. The transcriptional regulation of SNAI2 or miR-1 was verified by bioinfamatics, luciferase reporter assay and chromatin immunoprecipitation PCR. Results BA treatment caused aberrant expression of FXR and IM markers in gastric cells. Augmented FXR led to the transcriptional activation of SNAI2 which further stimulates the expression of downstream IM markers. Bioinformatics analysis indicated that SNAI2 had miR-1 promoter binding region and we identified that SNAI2 negatively regulated miR-1 transcription. Both FXR and SNAI2 were increased in patients with IM. Conclusions This study demonstrated that FXR might be responsible for a series molecular changes in gastric cells after BA, and FXR/SNAI2/miR-1 axis exert a crucial role in BA-induced IM progression. Blocking the activation of the FXR-oriented axis may provide a promising approach for IM or even GC treatment.

scholarly journals Bile acids increase intestinal marker expression via the FXR/SNAI2/miR-1 axis in the stomach

2021 ◽  
Vol 44 (5) ◽  
pp. 1119-1131
Author(s):  
Na Wang ◽  
Siran Wu ◽  
Jing Zhao ◽  
Min Chen ◽  
Jiaoxia Zeng ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Chromatin Immunoprecipitation ◽  
Deoxycholic Acid ◽  
Precancerous Lesion ◽  
Inverse Correlation ◽  
Tissue Microarrays ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Normal Tissues ◽  
Gastric Cells

Abstract Purpose Intestinal metaplasia (IM) is a precancerous lesion that increases the risk of subsequent gastric cancer (GC) development. Previously, miR-1 has been shown to play an essential role in the initiation of bile acid (BA)-induced IM. The objective of the present study was to investigate the mechanism underlying miR-1 inhibition by BA in gastric cells. Methods Ingenuity pathway analysis (IPA) was used to identify molecules acting upstream of miR-1. The effects of deoxycholic acid (DCA), FXR and SNAI2 on the expression of intestinal markers were assessed using quantitative real-time PCR (qRT-PCR) and Western blotting. The expression level of major molecules was detected by immunohistochemistry (IHC) in tissue microarrays. The transcriptional regulation of miR-1 was verified using luciferase reporter and chromatin immunoprecipitation (ChIP) assays. Results We found that BA treatment caused aberrant expression of FXR and intestinal markers in gastric cells. Augmented FXR led to transcriptional activation of SNAI2, which in turn suppressed the miR-1 promoter. Moreover, we found that compared with normal tissues, the expression levels of both FXR and SNAI2 were increased and positively correlated with each other in IM tissues. Additionally, their expression showed an inverse correlation with that of miR-1 in IM tissues. Conclusions Our findings indicate that FXR may be responsible for a series of molecular changes in gastric cells after BA treatment, and that the FXR/SNAI2/miR-1 axis exhibits a crucial role in BA-induced progression of IM. Blocking the FXR-oriented axis may provide a promising approach for IM or even GC treatment.

scholarly journals HDAC6/FOXP3/HNF4α Axis Promotes Bile Acids Induced Gastric Intestinal Metaplasia

2021 ◽  
Author(s):  
Na Wang ◽  
Siran Wu ◽  
Luyao Zhang ◽  
Min Chen ◽  
Jiaoxia Zeng ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Intestinal Metaplasia ◽  
Bile Acids ◽  
Epigenetic Modification ◽  
Bile Reflux ◽  
Precancerous Lesion ◽  
Ectopic Expression ◽  
Histone Deacetylation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene

Abstract Background: Gastric intestinal metaplasia (IM) is an important precancerous lesion. Our previous study has shown that ectopic expression of HDAC6 promotes the activation of intestinal markers in bile acids (BA) induced gastric IM cells; however, the mechanism underlying how HDAC6-mediated epigenetic modifications regulate intestinal markers is not clear.Methods: RNA-sequencing (RNA-seq) was used to detect the molecular changes in GES-1 cells after HDAC6 overexpression. The potential binding sites of FOXP3 with the promoter region of HNF4α were verified by ChIP and luciferase reporter gene assays. The ChIP assay was also used to detect the histone deacetylation. The levels of mucin in gastric or intestinal mucosa were detected by AB-PAS staining. Transgenic mice were used to explore the pro-metaplastic function of DCA and HNF4α in vivo.Results: Deoxycholic acid (DCA) upregulated HDAC6 in gastric cells, which further inhibited the transcription of FOXP3. Then, FOXP3 transcriptionally inhibited HNF4α, which further inhibits the expression of downstream intestinal markers. These molecules have been shown to be clinically relevant, as FOXP3 levels were negatively correlated with HDAC6 and HNF4α in IM tissues. Transgenic mice experiments confirmed that HNF4α overexpression combined with DCA induced gastric mucosa to secrete intestinal mucus and caused an abnormal mucosal structure. Conclusions: Our findings suggest that HDAC6 reduces FOXP3 through epigenetic modification, thus forming HDAC6/FOXP3/HNF4α axis to promote gastric IM. Inhibition of HDAC6 may be a potential approach to prevent gastric IM in patients with bile reflux.

Mechanism for the transcriptional repression by c-Myc on PDGF (β)-receptor

2001 ◽  
Vol 114 (8) ◽  
pp. 1533-1544 ◽  
Author(s):  
H. Izumi ◽  
C. Molander ◽  
L.Z. Penn ◽  
A. Ishisaki ◽  
K. Kohno ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Transcriptional Repression ◽  
Platelet Derived Growth Factor ◽  
Luciferase Reporter ◽  
Binding Region ◽  
Glutathione S Transferase ◽  
Reporter Activity ◽  
Β Receptor ◽  
Cycle Dependent

c-Myc plays a key role in the cell cycle dependent control of the PDGF (β)-receptor mRNA. The mouse platelet-derived growth factor (PDGF) (β)-receptor promoter contains a CCAAT motif, and NF-Y plays an essential role in its transcription. Coexpression of c-Myc represses PDGF (β)-receptor luciferase reporter activity, and the CCAAT motif in the promoter is indispensable for this repression. Here we show that c-Myc binds NF-Y subunits, YB and YC, by immunoprecipitation from cotransfected COS-1 cells. The in vitro-translated c-Myc also binds the glutathione S-transferase (GST)-NF-YB fusion protein and GST-NF-YC, but not GST-NF-YA. The most C-terminal region of HAP domains of NF-YB and NF-YC, and the Myc homology boxes, but not the C-terminal bHLHZip domain, are indispensable for the coimmunoprecipitation, and also for the repression of PDGF (β)-receptor. c-Myc binds NF-Y complex without affecting the efficiency of NF-Y binding to DNA. However, the expression of Myc represses the transcriptional activation of NF-YC when fused to the GAL4 DNA binding domain. Furthermore, this repression was seen only when Myc homology boxes are present, and NF-YC contains the c-Myc binding region.

scholarly journals HDAC6/HNF4α loop mediated by miR-1 promotes bile acids-induced gastric intestinal metaplasia

2020 ◽  
Vol 24 (1) ◽  
pp. 103-116
Author(s):  
Na Wang ◽  
Min Chen ◽  
Zhen Ni ◽  
Ting Li ◽  
Jiaoxia Zeng ◽  
...  
Keyword(s):  
Mouse Model ◽  
Intestinal Metaplasia ◽  
Bile Acids ◽  
Transgenic Mouse ◽  
Cell Model ◽  
Critical Role ◽  
Precancerous Lesion ◽  
Transgenic Mouse Model ◽  
Luciferase Reporter ◽  
Gastric Intestinal Metaplasia

Abstract Background Gastric intestinal metaplasia (IM) is considered a precancerous lesion, and bile acids (BA) play a critical role in the induction of IM. Ectopic expression of HNF4α was observed in a BA-induced IM cell model. However, the mechanisms underlying the upregulation of the protein in IM cells remains to be elucidated. Methods The effects of HNF4α on gastric mucosal cells in vivo were identified by a transgenic mouse model and RNA-seq was used to screen downstream targets of deoxycholic acid (DCA). The expression of pivotal molecules and miR-1 was detected by immunohistochemistry and in situ hybridization in normal, gastritis and IM tissue slides or microarrays. The transcriptional regulation of HDAC6 was investigated by chromatin immunoprecipitation (ChIP) and luciferase reporter assays. Results The transgenic mouse model validated that HNF4α stimulated the HDAC6 expression and mucin secretion in gastric mucosa. Increased HDAC6 and HNF4α expression was also detected in the gastric IM cell model and patient specimens. HNF4α could bind to and activate HDAC6 promoter. In turn, HDAC6 enhanced the HNF4α protein level in GES-1 cells. Furthermore, miR-1 suppressed the expression of downstream intestinal markers by targeting HDAC6 and HNF4α. Conclusions Our findings show that the HDAC6/HNF4α loop regulated by miR-1 plays a critical role in gastric IM. Blocking the activation of this loop could be a potential approach to preventing BA-induced gastric IM or even gastric cancer (GC).

scholarly journals ZNF395 Is an Activator of a Subset of IFN-Stimulated Genes

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Linda Schroeder ◽  
Christine Herwartz ◽  
Darko Jordanovski ◽  
Gertrud Steger
Keyword(s):  
Immune Response ◽  
Transcriptional Activation ◽  
Transcriptional Control ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Antiviral Immune Response ◽  
Cellular Transcription Factor ◽  
Activation Of Transcription ◽  
Reporter Assays ◽  
The Stability

Activation of the interferon (IFN) pathway in response to infection with pathogens results in the induction of IFN-stimulated genes (ISGs) including proinflammatory cytokines, which mount the proper antiviral immune response. However, aberrant expression of these genes is pathogenic to the host. In addition to IFN-induced transcription factors non-IFN-regulated factors contribute to the transcriptional control of ISGs. Here, we show by genome wide expression analysis, siRNA-mediated suppression and Doxycycline-induced overexpression that the cellular transcription factor ZNF395 activates a subset of ISGs including the chemokines CXCL10 and CXCL11 in keratinocytes. We found that ZNF395 acts independently of IFN but enhances the IFN-induced expression of CXCL10 and CXCL11. Luciferase reporter assays revealed a requirement of intact NFκB-binding sites for ZNF395 to stimulate the CXCL10 promoter. The transcriptional activation of CXCL10 and CXCL11 by ZNF395 was abolished after inhibition of IKK by BMS-345541, which increased the stability of ZNF395. ZNF395 encodes at least two motifs that mediate the enhanced degradation of ZNF395 in response to IKK activation. Thus, IKK is required for ZNF395-mediated activation of transcription and enhances its turn-over to keep the activity of ZNF395 low. Our results support a previously unrecognized role of ZNF395 in the innate immune response and inflammation.

scholarly journals HDAC6/FOXP3/HNF4α axis promotes bile acids induced gastric intestinal metaplasia

2021 ◽  
Author(s):  
Na Wang ◽  
Siran Wu ◽  
Luyao Zhang ◽  
Min Chen ◽  
Jiaoxia Zeng ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Intestinal Metaplasia ◽  
Bile Acids ◽  
Epigenetic Modification ◽  
Bile Reflux ◽  
Precancerous Lesion ◽  
Ectopic Expression ◽  
Histone Deacetylation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene

Abstract Background: Gastric intestinal metaplasia (IM) is an important precancerous lesion. Our previous study has shown that ectopic expression of HDAC6 promotes the activation of intestinal markers in bile acids (BA) induced gastric IM cells; however, the mechanism underlying how HDAC6-mediated epigenetic modifications regulate intestinal markers is not clear.Methods: RNA-sequencing (RNA-seq) was used to detect the molecular changes in GES-1 cells after HDAC6 overexpression. The potential binding sites of FOXP3 with the promoter region of HNF4α were verified by ChIP and luciferase reporter gene assays. The ChIP assay was also used to detect the histone deacetylation. The levels of mucin in gastric or intestinal mucosa were detected by AB-PAS staining. Transgenic mice were used to explore the pro-metaplastic function of DCA and HNF4α in vivo.Results: Deoxycholic acid (DCA) upregulated HDAC6 in gastric cells, which further inhibited the transcription of FOXP3. Then, FOXP3 transcriptionally inhibited HNF4α, which further inhibits the expression of downstream intestinal markers. These molecules have been shown to be clinically relevant, as FOXP3 levels were negatively correlated with HDAC6 and HNF4α in IM tissues. Transgenic mice experiments confirmed that HNF4α overexpression combined with DCA induced gastric mucosa to secrete intestinal mucus and caused an abnormal mucosal structure. Conclusions: Our findings suggest that HDAC6 reduces FOXP3 through epigenetic modification, thus forming HDAC6/FOXP3/HNF4α axis to promote gastric IM. Inhibition of HDAC6 may be a potential approach to prevent gastric IM in patients with bile reflux.

scholarly journals MicroRNA-92a-1–5p increases CDX2 by targeting FOXD1 in bile acids-induced gastric intestinal metaplasia

Gut ◽  
2019 ◽  
Vol 68 (10) ◽  
pp. 1751-1763 ◽  
Author(s):  
Ting Li ◽  
Hanqing Guo ◽  
Hong Li ◽  
Yanzhi Jiang ◽  
Kun Zhuang ◽  
...  
Keyword(s):  
Intestinal Metaplasia ◽  
Bile Acids ◽  
Messenger Rna ◽  
Tissue Microarrays ◽  
Chronic Atrophic Gastritis ◽  
Gastric Epithelium ◽  
Gastric Intestinal Metaplasia ◽  
Gastric Cells ◽  
Regulatory Circuits ◽  
Gastric Cancer Cell Lines

Background and aimsGastric intestinal metaplasia (IM) is common in the gastric epithelium of patients with chronic atrophic gastritis. CDX2 activation in IM is driven by reflux of bile acids and following chronic inflammation. But the mechanism underlying how bile acids activate CDX2 in gastric epithelium has not been fully explored.MethodsWe performed microRNA (miRNA) and messenger RNA (mRNA) profiling using microarray in cells treated with bile acids. Data integration of the miRNA/mRNA profiles with gene ontology (GO) analysis and bioinformatics was performed to detect potential miRNA-mRNA regulatory circuits. Transfection of gastric cancer cell lines with miRNA mimics and inhibitors was used to evaluate their effects on the expression of candidate targets and functions. Immunohistochemistry and in situhybridisation were used to detect the expression of selected miRNAs and their targets in IM tissue microarrays.ResultsWe demonstrate a bile acids-triggered pathway involving upregulation of miR-92a-1–5p and suppression of its target FOXD1 in gastric cells. We first found that miR-92a-1–5p was increased in IM tissues and induced by bile acids. Moreover, miR-92a-1–5p was found to activate CDX2 and downstream intestinal markers by targeting FOXD1/FOXJ1 axis and modulating activation of nuclear factor kappa B (NF-κB) pathway. Furthermore, these effects were found to be clinical relevant, as high miR-92a-1–5p levels were correlated with low FOXD1 levels and high CDX2 levels in IM tissues.ConclusionThese findings suggest a miR-92a-1–5p/FOXD1/NF-κB/CDX2 regulatory axis plays key roles in the generation of IM phenotype from gastric cells. Suppression of miR-92a-1–5p and restoration of FOXD1 may be a preventive approach for gastric IM in patients with bile regurgitation.

scholarly journals miR-29a sensitizes the response of glioma cells to temozolomide by modulating the P53/MDM2 feedback loop

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Qiudan Chen ◽  
Weifeng Wang ◽  
Shuying Chen ◽  
Xiaotong Chen ◽  
Yong Lin
Keyword(s):  
Molecular Mechanism ◽  
Feedback Loop ◽  
Glioma Cells ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Transcriptional Level ◽  
Aberrant Expression ◽  
Altered Expression ◽  
P53 Signaling

AbstractRecently, pivotal functions of miRNAs in regulating common tumorigenic processes and manipulating signaling pathways in brain tumors have been recognized; notably, miR‐29a is closely associated with p53 signaling, contributing to the development of glioma. However, the molecular mechanism of the interaction between miR-29a and p53 signaling is still to be revealed. Herein, a total of 30 glioma tissues and 10 non-cancerous tissues were used to investigate the expression of miR‐29a. CCK-8 assay and Transwell assay were applied to identify the effects of miR-29a altered expression on the malignant biological behaviors of glioma cells in vitro, including proliferation, apoptosis, migration and invasion. A dual-luciferase reporter assay was used to further validate the regulatory effect of p53 or miR-29a on miR-29a or MDM2, respectively, at the transcriptional level. The results showed that miR-29a expression negatively correlated with tumor grade of human gliomas; at the same time it inhibited cell proliferation, migration, and invasion and promoted apoptosis of glioma cells in vitro. Mechanistically, miR-29a expression was induced by p53, leading to aberrant expression of MDM2 targeted by miR-29a, and finally imbalanced the activity of the p53-miR-29a-MDM2 feedback loop. Moreover, miR-29a regulating p53/MDM2 signaling sensitized the response of glioma cells to temozolomide treatment. Altogether, the study demonstrated a potential molecular mechanism in the tumorigenesis of glioma, while offering a possible target for treating human glioma in the future.

scholarly journals KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated β-catenin pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yarong Guo ◽  
Bao Chai ◽  
Junmei Jia ◽  
Mudan Yang ◽  
Yanjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Luciferase Reporter ◽  
Aberrant Expression ◽  
Proliferation And Invasion ◽  
Hcc Cells

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

scholarly journals Circular RNA hsa_circ_0000277 sequesters miR-4766-5p to upregulate LAMA1 and promote esophageal carcinoma progression

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Peng Li Zhou ◽  
Zhengyang Wu ◽  
Wenguang Zhang ◽  
Miao Xu ◽  
Jianzhuang Ren ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Bioinformatics Analysis ◽  
Epithelial Mesenchymal Transition ◽  
Expression Profiles ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Circular Rnas ◽  
Mesenchymal Transition ◽  
Dismal Prognosis ◽  
Advanced Tumor

AbstractGrowing evidence has indicated that circular RNAs (circRNAs) play a pivotal role as functional RNAs in diverse cancers. However, most circRNAs involved in esophageal squamous cell carcinoma (ESCC) remain undefined, and the underlying molecular mechanisms mediated by circRNAs are largely unclear. Here, we screened human circRNA expression profiles in ESCC tissues and found significantly increased expression of hsa_circ_0000277 (termed circPDE3B) in ESCC tissues and cell lines compared to the normal controls. Moreover, higher circPDE3B expression in patients with ESCC was correlated with advanced tumor-node-metastasis (TNM) stage and dismal prognosis. Functional experiments demonstrated that circPDE3B promoted the tumorigenesis and metastasis of ESCC cells in vitro and in vivo. Mechanistically, bioinformatics analysis, a dual-luciferase reporter assay, and anti-AGO2 RNA immunoprecipitation showed that circPDE3B could act as a competing endogenous RNA (ceRNA) by harboring miR-4766-5p to eliminate the inhibitory effect on the target gene laminin α1 (LAMA1). In addition, LAMA1 was significantly upregulated in ESCC tissues and was positively associated with the aggressive oncogenic phenotype. More importantly, rescue experiments revealed that the oncogenic role of circPDE3B in ESCC is partly dependent on the miR-4766-5p/LAMA1 axis. Furthermore, bioinformatics analysis combined with validation experiments showed that epithelial-mesenchymal transition (EMT) activation was involved in the oncogenic functions of the circPDE3B–miR-4766-5p/LAMA1 axis in ESCC. Taken together, we demonstrate for the first time that the circPDE3B/miR-4766-5p/LAMA1 axis functions as an oncogenic factor in promoting ESCC cell proliferation, migration, and invasion by inducing EMT, implying its potential prognostic and therapeutic significance in ESCC.

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