HNF4α and TCF4 (TCF7L2) ChIPseq in Tet-On HCT116 inducible cell lines that express either the human HNF4α2 or HNF4α8 under the control of doxycycline (DOX) [ChIP-Seq]
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ABSTRACT: Purpose: Aim of the study is to determine how many of the dysregulated genes in the RNAseq are direct targets of (P1) HNF4α2 and (P2) HNF4α8 and examine HNF4α and TCF4 binding in vivo. We performed ChIPseq on TCF4 in the absense or presence of DOX in the Tet-On inducible HCT116 HNF4α2 and HNF4α8 lines, and ChIPseq for HNF4α (a445 Ab) in the presence of DOX. Methods: HNF4α2 and HNF4α8 lines were induced with 0.3 μg/mL DOX for 24 hours. Samples were generated by deep sequencing, using the NEXTflex ChIPseq. Result: There were more HNF4α2 peaks than HNF4α8 peaks, with some common peaks bound by HNF4α2 and HNF4α8. Binding patterns were observed between HNF4α and TCF4. Conclusion: HNF4α2 can displace TCF4 better than HNF4α8 on AP-1 bound sites.
Project description:Purpose: Aim of the study is to determine how many of the dysregulated genes in the RNAseq are direct targets of (P1) HNF4α2 and (P2) HNF4α8 and examine HNF4α and TCF4 binding in vivo. We performed ChIPseq on TCF4 in the absense or presence of DOX in the Tet-On inducible HCT116 HNF4α2 and HNF4α8 lines, and ChIPseq for HNF4α (a445 Ab) in the presence of DOX. Methods: HNF4α2 and HNF4α8 lines were induced with 0.3 μg/mL DOX for 24 hours. Samples were generated by deep sequencing, using the NEXTflex ChIPseq. Result: There were more HNF4α2 peaks than HNF4α8 peaks, with some common peaks bound by HNF4α2 and HNF4α8. Binding patterns were observed between HNF4α and TCF4. Conclusion: HNF4α2 can displace TCF4 better than HNF4α8 on AP-1 bound sites. Tet-On inducible HCT116 cell (HNF4α2 and HNF4α8) lines, treated with (0.3 μg/mL) or without DOX for 24 hours, were 50bp single-end sequenced using Illumina-compatible-NEXTflex ChIP kit (Bioo Scientific).
Project description:β-catenin signaling can be both a physiological and an oncogenic pathway in the liver. It controls compartmentalized gene expression, allowing the liver to ensure its essential metabolic function. It is activated by mutations in 20 to 40% of hepatocellular carcinomas with specific metabolic features. We decipher the molecular determinants of β-catenin-dependent zonal transcription using mice with β-catenin-activated or -inactivated hepatocytes, characterizing in vivo their chromatin occupancy by Tcf4 and β-catenin, their transcriptome and their metabolome. We find that Tcf4 DNA-bindings depend on β-catenin. Tcf4/β-catenin binds Wnt-responsive elements preferentially around β-catenin-induced genes. In contrast, genes repressed by β-catenin bind Tcf4 on Hnf4-responsive elements. β-catenin, Tcf4 and Hnf4α interact, dictating β-catenin transcription which is antagonistic to that elicited by Hnf4α. Finally, we find the drug/bile metabolism pathway to be the one most heavily targeted by β-catenin, partly through xenobiotic nuclear receptors. We conclude that β-catenin patterns the zonal liver together with Tcf4, Hnf4α and xenobiotic nuclear receptors. This network represses lipid metabolism, and exacerbates glutamine, drug and bile metabolism, mirroring hepatocellular carcinomas with β-catenin mutational activation. In vivo liver samples in 4 conditions: Betacat activated (WCE, Tcf4 chipseq, Betacat chipseq, mRNAseq with 2 replicates), Betacat null (WCE, Tcf4 chipseq, mRNAseq with 2 replicates), Betacat control (mRNAseq with 2 replicates), Wild type (mRNAseq with 2 replicates)
Project description:Hepatocyte Nuclear Factor 4α (HNF4α), master regulator of hepatocyte differentiation, is regulated by two promoters (P1 and P2). P1-HNF4α but not P2-HNF4α is expressed in normal adult liver while both P1- and P2-HNF4α are expressed in fetal liver and liver cancer. To determine the physiological function of the HNF4α isoforms, we compared P2-HNF4α-expressing exon swap mice to wildtype (WT) using RNA-seq, ChIP-seq, proteomics, protein binding microarrays (PBMs) and metabolomics. P2-HNF4α orchestrates a distinct transcriptomic and metabolomic profile.
Project description:Hepatocyte Nuclear Factor 4α (HNF4α), master regulator of hepatocyte differentiation, is regulated by two promoters (P1 and P2). P1-HNF4α but not P2-HNF4α is expressed in normal adult liver in fed conditions. Both P1- and P2-HNF4α are expressed in fetal liver. P2-HNF4α expression is increased in fasted conditions, high fat diet, alcoholic liver and liver cancer. To determine the target genes of the P1- and P2-HNF4α isoforms, we compared P2-HNF4α-expressing exon swap mice (a7HMZ) to wildtype (WT) male mice. Liver ChIP-seq samples were taken at 10:30 AM (ZT 3.5)
Project description:HNF4α is a nuclear receptor regulating the transcription of genes involved mainly in development, cell differentiation and metabolism. Opposite functions for the two classes of P1 and P2 isoforms of HNF4α have recently been highlighted. These classes include 12 variants of HNF4α that can be expressed by the use of two promoters and by alternative splicing. Until now, the characterization of this transcription factor has ignored this diversity and has remained confined to the study of a fraction of the isoforms. We therefore wanted to clarify the situation by specifically characterizing the transcriptional functions of the 12 isoforms of HNF4α. We have generated for this purpose stable lines expressing each isoform of HNF4α in HCT 116 cells. We analyzed the whole transcriptome associated with each isoform by sequencing RNA, as well as their proteome by a BioID approach coupled to quantitative mass spectrometry. We noted major differences in the transcriptional function of the 12 isoforms. The α4, α5 and α6 isoforms have been characterized for the first time, and show a greatly reduced transcriptional potential. We have shown that these isoforms are unable to recognize the consensus response element of HNF4α. The α1 and α2 isoforms are the most potent regulators of gene expression, while the α3 isoform exhibits significantly reduced activity. Several transcription factors and coregulators have been identified as potential specific partners for certain HFH4α isoforms. The IRF-2BP2 co-repressor interacts specifically with isoforms which include the long form of the F domain of HNF4α. This specific interaction could explain the large number of genes modulated negatively by α1 and α2 compared to α3. The analysis integrating the vast amount of transcriptomic and proteomic data allows the identification of transcriptional regulatory mechanisms specific to certain isoforms, demonstrating the importance of considering all isoforms which can have diverse functions.
Project description:Background & Aims: The role of HNF4α has been extensively studied in hepatocytes and pancreatic β cells, but emerging evidence indicates that HNF4α is a key regulator of intestinal epithelial cell differentiation as well. The aim of the present work is to identify HNF4α target genes in the intestine in order to elucidate the role of HNF4α in differentiation of the intestinal epithelial cells. Results: One thousand one hundred and seventy-six genes were identified as HNF4α targets, many of which have not previously been described as being regulated by HNF4α. The 1,176 genes contributed significantly to gene ontology (GO) pathways categorized by lipid and amino acid transport and metabolism. A thorough analysis of Cdx-2, trehalase, and cingulin promoters verified that these genes are regulated by HNF4α. In each case we were able to identify a functional HNF4α binding site in their promoters. Conclusions: HNF4α regulation of the Cdx-2 promoter unravels a transcription factor network also including HNF1α and β, all of which are transcription factors involved in intestinal development and gene expression. Keywords: ChIP-CHIP and expression data
Project description:Background Worldwide, gastric cancer is the fourth most common malignancy and the most common cancer in East Asia. Development of targeted therapies for this disease has focused on a few known oncogenes but has had limited effects. Objective To determine oncogenic mechanisms and novel therapeutic targets specific for gastric cancer by identifying commonly dys-regulated genes from the tumors of both Asian-Pacific and Caucasian patients. Design We generated transcriptomic profiles of 22 Caucasian gastric cancer tumors and their matched non-cancerous samples, and performed an integrative analysis across different gastric cancer gene expression datasets. We examined the inhibition of commonly overexpressed oncogenes and their constituent signaling pathways by RNAi and/or pharmacologic inhibition. Results We found that HNF4α upregulation was a key signaling event in gastric tumors from both Caucasian and Asian patients, and HNF4α antagonism was antineoplastic. Perturbation experiments in GC tumor cell lines and xenograft models further demonstrated that HNF4α is downregulated by AMPKα signaling and the AMPK agonist metformin; blockade of HNF4α activity resulted in cyclin downregulation, cell cycle arrest, and tumor growth inhibition. HNF4α also regulated WNT signaling through its target gene WNT5A, a potential prognostic marker of diffuse type gastric tumors. Conclusions Our results indicate that HNF4α is a targetable oncoprotein in gastric cancer, is regulated by AMPK signaling through AMPKα, and resides upstream of WNT signaling. HNF4α may regulate “metabolic switch” characteristic of a general malignant phenotype and its target WNT5A has potential prognostic values. The AMPKα-HNF4α-WNT5A signaling cascade represents a potentially targetable pathway for drug development. Integrative analysis of Caucasian and Asian-Pacific gastric tumor expression datasets (including newly generated transcriptomic profiling of 22 tumors in this study) revealed a relatively small common sets of highly overexpressed genes.
Project description:β-catenin signaling can be both a physiological and an oncogenic pathway in the liver. It controls compartmentalized gene expression, allowing the liver to ensure its essential metabolic function. It is activated by mutations in 20 to 40% of hepatocellular carcinomas with specific metabolic features. We decipher the molecular determinants of β-catenin-dependent zonal transcription using mice with β-catenin-activated or -inactivated hepatocytes, characterizing in vivo their chromatin occupancy by Tcf4 and β-catenin, their transcriptome and their metabolome. We find that Tcf4 DNA-bindings depend on β-catenin. Tcf4/β-catenin binds Wnt-responsive elements preferentially around β-catenin-induced genes. In contrast, genes repressed by β-catenin bind Tcf4 on Hnf4-responsive elements. β-catenin, Tcf4 and Hnf4α interact, dictating β-catenin transcription which is antagonistic to that elicited by Hnf4α. Finally, we find the drug/bile metabolism pathway to be the one most heavily targeted by β-catenin, partly through xenobiotic nuclear receptors. We conclude that β-catenin patterns the zonal liver together with Tcf4, Hnf4α and xenobiotic nuclear receptors. This network represses lipid metabolism, and exacerbates glutamine, drug and bile metabolism, mirroring hepatocellular carcinomas with β-catenin mutational activation.
Project description:HNF4α is a transcription factor that plays a critical role in terminal hepatocyte failure. HNF4α-based reprogramming therapy can correct terminal liver failure in rats and humans. As liver disease progresses, HNF4α expression decreases in the nuclei of hepatocytes, leading to impaired regulation and hepatic function. Post-translational modifications (PTMs) are a fundamental regulatory mechanism of protein function and localization. In this study, we analyzed HNF4α localization and pathways involved in HNF4α PTMs in human hepatocytes at different stages of decompensated liver function upon Child-Pugh classification. RNA-seq analysis revealed that HNF4α and the PTMs-pathway related to AKT are down-regulation in cirrhotic hepatocytes with terminal failure. These findings were confirmed by protein expression, where the HNF4α nuclear levels are significantly reduced in Child‐Pugh B and C hepatocytes, whereas cytoplasmic expression of HNF4α was increased. Moreover, cMET and phospho-AKT were significantly reduced in Child‐Pugh B and C hepatocytes. The association and statistical contribution of cMET and phospho-AKT to the nuclear localization of HNF4α were confirmed by Spearman’s rank correlation test and pathway analysis. Principal component analysis was used to characterize the protein profiles related to the degree of liver dysfunction. Additionally, HNF4α acetylation was significantly reduced in failing human hepatocytes when compared to normal controls, demonstrating a significant correlation to the degree of hepatic function. Conclusion: These results suggest that the alterations in the cMET-AKT pathway directly correlate to HNF4α localization and the level of hepatic dysfunction. In conclusion, this study has therapeutic implications and suggests that manipulation of these pathways may restore hepatocyte function in terminal liver failure.
Project description:Hepatocyte nuclear factor 4alpha (HNF4α) is a nuclear receptor with an emerging role in the gut. While HNF4α has been implicated in colitis and colon cancer in humans, deciphering its functional role is complicated by the existence of two promoters (P1 and P2) in theHNF4A gene that drive the expression of multiple isoforms in the adult intestine. In this study we investigate the roles of P1- and P2-driven HNF4α under conditions of homeostasis, colitis and colitis-associated colon cancer (CAC). P1- and P2-HNF4α are differentially expressed in the differentiated and proliferative compartments of the normal colonic crypt, respectively. Expression profiling of untreated exon swap mice suggests distinct functions of the isoforms that were corroborated in migration and ion transport assays.