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Hu B, Liu T, Wu Z, Phan SH. P53 regulates CCAAT/Enhancer binding protein β gene expression. Gene 2023; 884:147675. [PMID: 37541559 DOI: 10.1016/j.gene.2023.147675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/13/2023] [Accepted: 07/28/2023] [Indexed: 08/06/2023]
Abstract
BACKGROUND The transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) is implicated in diverse processes and diseases. Its two isoforms, namely liver-enriched activator protein (LAP) and liver-enriched inhibitor protein (LIP) are translated from the same mRNA. They share the same C-terminal DNA binding domain except LAP has an extra N-terminal activation domain. Probably due to its higher affinity for its DNA cognate sequences, LIP can inhibit LAP transcriptional activity even at substoichiometric levels. However, the regulatory mechanism of C/EBPβ gene expression and the LAP: LIP ratio is unclear. METHODS In this study, the C/EBPβ promoter sequence was scanned for conserved P53 response element (P53RE), and binding of P53 to the C/EBPβ promoter was tested by Electrophoretic Mobility Shift Assay (EMSA) and chromatin immunoprecipitation assay. P53 over-expression and dominant negative P53 expression plasmids were transfected into rat lung fibroblasts and tested for C/EBPβ gene transcription and expression. Western blot analysis was used to test the regulation of C/EBPβ LAP and LIP isoforms. Constructs containing the LAP 5'untranslated region (5'UTR) or the LIP 5'UTR region were used to test the importance of 5'UTR in the control of C/EBPβ LAP and LIP translation. RESULTS The C/EBPβ promoter sequence was found to contain a conserved P53 response element (P53RE), which binds P53 as demonstrated by Electrophoresis Mobility Shift Assay and chromatin immunoprecipitation assays. P53 over-expression suppressed while dominant negative P53 stimulated C/EBPβ gene transcription and expression. Western blot analysis showed that P53 differentially regulated the translation of the C/EBPβ LAP and LIP isoforms through the regulation of eIF4E and eIF4E-BP1. Further studies with constructs containing the LAP 5'untranslated region (5'UTR) or the LIP 5'UTR region showed that the 5'UTR is important in differential control of C/EBPβ LAP and LIP translation. CONCLUSION Analysis of the effects of P53 on C/EBPβ expression revealed a novel mechanism by which P53 could antagonize the effects of C/EBPβ on its target gene expression. For the first time, P53 is shown to be a repressor of C/EBPβ gene expression at both transcriptional and translational levels, with a differential effect in the magnitude of the effect on LAP vs. LIP isoforms.
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Affiliation(s)
- Biao Hu
- Department of Internal Medicine, University of Michigan Medical School, 1600 Huron Parkway, Ann Arbor, MI 48109 USA
| | - Tianju Liu
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA
| | - Zhe Wu
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA
| | - Sem H Phan
- Department of Pathology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109 USA.
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Samban SS, Hari A, Nair B, Kumar AR, Meyer BS, Valsan A, Vijayakurup V, Nath LR. An Insight Into the Role of Alpha-Fetoprotein (AFP) in the Development and Progression of Hepatocellular Carcinoma. Mol Biotechnol 2023:10.1007/s12033-023-00890-0. [PMID: 37782430 DOI: 10.1007/s12033-023-00890-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023]
Abstract
Hepatocellular carcinoma (HCC) is the primary malignancy of hepatocytes and the second most common cause of cancer-related mortality across the globe. Despite significant advancements in screening, diagnosis, and treatment modalities for HCC, the mortality-to-incidence ratio remain unacceptably high. A recent study indicates that a minor population of HCCs are AFP negative or express the normal range of AFP levels. Although it is a gold standard and a more reliable biomarker in the advanced stage of HCC and poorly differentiated tumors, it does not serve as a suitable means for screening HCC. AFP plays a significant role in the development and progression of HCC and understanding its role is crucial. By examining the molecular mechanisms involved in AFP-mediated tumorigenesis, we can better understand HCC pathogenesis and identify potential therapeutic targets. This article details the role of alpha-fetoprotein (AFP) in the carcinogenic transformation of hepatocytes. The article also focuses on information about the structure, biosynthesis, and regulation of AFP at the gene level. Additionally, it discusses the immune evasion, metastasis, and control of gene expression that AFP mediates during HCC.
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Affiliation(s)
- Swathy S Samban
- Department of Pharmacognosy, Amrita School of Pharmacy, AIMS Health Science Campus, Amrita Vishwa Vidyapeetham, Ponekkara P.O., Kochi, Kerala, India
| | - Aparna Hari
- Department of Pharmacognosy, Amrita School of Pharmacy, AIMS Health Science Campus, Amrita Vishwa Vidyapeetham, Ponekkara P.O., Kochi, Kerala, India
| | - Bhagyalakshmi Nair
- Department of Pharmacognosy, Amrita School of Pharmacy, AIMS Health Science Campus, Amrita Vishwa Vidyapeetham, Ponekkara P.O., Kochi, Kerala, India
| | - Ayana R Kumar
- Department of Pharmacognosy, Amrita School of Pharmacy, AIMS Health Science Campus, Amrita Vishwa Vidyapeetham, Ponekkara P.O., Kochi, Kerala, India
| | - Benjamin S Meyer
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL, 32610, USA
| | - Arun Valsan
- Department of Gastroenterology and Hepatology, Amrita Institute of Medical Science, AIMS Health Science Campus, Ponekkara P.O., Kochi, Kerala, India
| | - Vinod Vijayakurup
- Department of Anatomy and Cell Biology, University of Florida, Gainesville, FL, 32610, USA.
| | - Lekshmi R Nath
- Department of Pharmacognosy, Amrita School of Pharmacy, AIMS Health Science Campus, Amrita Vishwa Vidyapeetham, Ponekkara P.O., Kochi, Kerala, India.
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Kandhaya-Pillai R, Miro-Mur F, Alijotas-Reig J, Tchkonia T, Schwartz S, Kirkland JL, Oshima J. Key elements of cellular senescence involve transcriptional repression of mitotic and DNA repair genes through the p53-p16/RB-E2F-DREAM complex. Aging (Albany NY) 2023; 15:4012-4034. [PMID: 37219418 PMCID: PMC10258023 DOI: 10.18632/aging.204743] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 05/03/2023] [Indexed: 05/24/2023]
Abstract
Cellular senescence is a dynamic stress response process that contributes to aging. From initiation to maintenance, senescent cells continuously undergo complex molecular changes and develop an altered transcriptome. Understanding how the molecular architecture of these cells evolve to sustain their non-proliferative state will open new therapeutic avenues to alleviate or delay the consequences of aging. Seeking to understand these molecular changes, we studied the transcriptomic profiles of endothelial replication-induced senescence and senescence induced by the inflammatory cytokine, TNF-α. We previously reported gene expressional pattern, pathways, and the mechanisms associated with upregulated genes during TNF-α induced senescence. Here, we extend our work and find downregulated gene signatures of both replicative and TNF-α senescence were highly overlapped, involving the decreased expression of several genes associated with cell cycle regulation, DNA replication, recombination, repair, chromatin structure, cellular assembly, and organization. We identified multiple targets of p53/p16-RB-E2F-DREAM that are essential for proliferation, mitotic progression, resolving DNA damage, maintaining chromatin integrity, and DNA synthesis that were repressed in senescent cells. We show that repression of multiple target genes in the p53/p16-RB-E2F-DREAM pathway collectively contributes to the stability of the senescent arrest. Our findings show that the regulatory connection between DREAM and cellular senescence may play a potential role in the aging process.
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Affiliation(s)
- Renuka Kandhaya-Pillai
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
- Systemic Autoimmune Diseases Research Unit, Vall d’Hebron Research Institute (VHIR), Barcelona 08035, Spain
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
| | - Francesc Miro-Mur
- Systemic Autoimmune Diseases Research Unit, Vall d’Hebron Research Institute (VHIR), Barcelona 08035, Spain
| | - Jaume Alijotas-Reig
- Systemic Autoimmune Diseases Research Unit, Vall d’Hebron Research Institute (VHIR), Barcelona 08035, Spain
| | - Tamar Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physiology, Mayo Clinic, Rochester, MN 55905, USA
| | - Simo Schwartz
- Drug Delivery and Targeting Group, Clinical Biochemistry Department, Vall d’Hebron Hospital, Barcelona 08035, Spain
| | - James L. Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN 55905, USA
- Department of Physiology, Mayo Clinic, Rochester, MN 55905, USA
- Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Junko Oshima
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
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Zhang J, Zhang T, Guan G, Wen J, Chen CC, Liu J, Duan Y, Liu Y, Chen X. AUF1 promotes hepatocellular carcinoma progression and chemo-resistance by post-transcriptionally upregulating alpha-fetoprotein expression. Pathol Res Pract 2023; 245:154441. [PMID: 37060820 DOI: 10.1016/j.prp.2023.154441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/28/2023] [Accepted: 04/02/2023] [Indexed: 04/17/2023]
Abstract
BACKGROUND The target genes of AU-rich Element RNA-binding Protein 1 (AUF1), which is an RNA binding protein, and its role in the progression of hepatocellular carcinoma (HCC) is still elusive. This study aims to investigate the biological function and the underlying target genes of AUF1 in HCC. METHODS RNA sequencing data and the Liver Cancer Institute (LCI) database were used to screen candidate targets of AUF1. LCI database, TCGA database, and a retrospective HCC cohort were used to investigate the correlation between AUF1 and alpha-fetoprotein (AFP) and their prognostic values in HCC patients. Huh-7, HepG2, and HepAD38 cell lines were used to investigate the underlying mechanism of AUF1 regulating the AFP expression. Cell Counting Kit-8, colony formation, EdU incorporation, and flow cytometry assays were performed to detect the effect of AUF1-AFP axis on the progression and doxorubicin resistance of HCC cells. RESULTS A combined analysis of the transcriptome data from Huh-7 cells after knockdown of AUF1 and gene expression data from LCI database revealed that AFP was the most significantly downregulated gene after AUF1 depletion. AUF1 expression was positively associated with AFP expression in HCC tissues and the high expression of both AUF1 and AFP were correlated with a worse prognosis in HCC patients of LCI and TCGA databases, as well as our retrospective cohort. Mechanistically, AUF1 bound to the 3' untranslation region (UTR) of AFP mRNA to enhance the mRNA stability of AFP, thereby upregulating AFP. Functional tests showed that AFP knockdown inhibited tumor growth and doxorubicin resistance of HCC cells induced by AUF1. CONCLUSIONS AFP may be an important target gene of AUF1. AUF1 promoted HCC progression and doxorubicin resistance by upregulating AFP expression via increasing its mRNA stability.
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Affiliation(s)
- Jing Zhang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Ting Zhang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Guiwen Guan
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jiyun Wen
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Chia-Chen Chen
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jia Liu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yuan Duan
- School of Medicine, Shihezi University, Shihezi 832002, China
| | - Yanna Liu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Department of Gastroenterology and Hepatology, Beijing Youan Hospital, Capital Medical University, Beijing 100069, China.
| | - Xiangmei Chen
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; School of Medicine, Shihezi University, Shihezi 832002, China.
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Title: p53 alters intracellular Ca2+ signaling through regulation of TRPM4. Cell Calcium 2022; 104:102591. [DOI: 10.1016/j.ceca.2022.102591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/08/2022] [Accepted: 04/18/2022] [Indexed: 12/11/2022]
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Zhang C, Zhao HJ, Wang J, Zhou WY, Zhang TJ, Zhang CB. Structural Analysis of the 5'-Flanking Region of Human Alpha-Fetoprotein Encoding Gene. Mol Biol 2021. [DOI: 10.1134/s0026893321050174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Ahn KS, O'Brien DR, Kim YH, Kim TS, Yamada H, Park JW, Park SJ, Kim SH, Zhang C, Li H, Kang KJ, Roberts LR. Associations of Serum Tumor Biomarkers with Integrated Genomic and Clinical Characteristics of Hepatocellular Carcinoma. Liver Cancer 2021; 10:593-605. [PMID: 34950182 PMCID: PMC8647136 DOI: 10.1159/000516957] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/29/2021] [Indexed: 02/04/2023] Open
Abstract
INTRODUCTION Serum α-fetoprotein (AFP), Lens culinaris agglutinin-reactive AFP (AFP-L3), and des-γ-carboxy-pro-thrombin (DCP) are useful biomarkers of hepatocellular carcinoma (HCC). However, associations among molecular characteristics and serum biomarkers are unclear. We analyzed RNA expression and DNA variant data from The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) to examine their associations with serum biomarker levels and clinical data. METHODS From 371 TCGA-LIHC patients, we selected 91 seen at 3 institutions in Korea and the USA and measured AFP, AFP-L3, and DCP from preoperatively obtained serum. We conducted an integrative clinical and molecular analysis, focusing on biomarkers, and validated the findings with the remaining 280 patients in the TCGA-LIHC cohort. RESULTS Patients were categorized into 4 subgroups: elevated AFP or AFP-L3 alone (↑AFP&L3), elevated DCP alone (↑DCP), elevation of all 3 biomarkers (elevated levels of all 3 biomarkers [↑All]), and reference range values for all biomarkers (RR). CTNNB1 variants were frequently observed in ↑DCP patients (53.8%) and RR patients (38.5%), but ↑DCP patients with a CTNNB1 variant had worse survival than RR patients. TP53 sequence variants were associated with ↑AFP (30.8%) and ↑DCP (30.8%). The Wnt-β-catenin signaling pathway was activated in the ↑AFP&L3, whereas liver-related Wnt signaling was activated in the RR. TGF-β and VEGF signaling were activated in ↑AFP&L3, whereas dysregulated bile acid and fatty acid metabolism were dominant in ↑DCP. We validated these findings by showing similar results between the test cohort and the remainder of the TCGA-LIHC cohort. CONCLUSIONS Serum AFP, AFP-L3, and DCP levels can help predict variants in the genetic profile of HCC, especially for TP53 and CTNNB1. These findings may facilitate development of an evidence-based approach to treatment.
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Affiliation(s)
- Keun Soo Ahn
- Department of Surgery, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Daniel R. O'Brien
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Yong Hoon Kim
- Department of Surgery, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Tae-Seok Kim
- Department of Surgery, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Hiroyuki Yamada
- Global Clinical Research Management, FUJIFILM Wako Pure Chemical Corporation, Tokyo, Japan
| | - Joong-Won Park
- Center for Liver and Pancreatobiliary Cancer, National Cancer Center, Goyang, Republic of Korea
| | - Sang-Jae Park
- Department of Surgery, National Cancer Center, Goyang, Republic of Korea
| | - Seoung Hoon Kim
- Department of Surgery, National Cancer Center, Goyang, Republic of Korea
| | - Cheng Zhang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Hu Li
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota, USA
| | - Koo Jeong Kang
- Department of Surgery, Keimyung University Dongsan Hospital, Keimyung University School of Medicine, Daegu, Republic of Korea,*Koo Jeong Kang,
| | - Lewis R. Roberts
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA,**Lewis R. Roberts,
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FOXP1 and NDRG1 act differentially as downstream effectors of RAD9-mediated prostate cancer cell functions. Cell Signal 2021; 86:110091. [PMID: 34298089 DOI: 10.1016/j.cellsig.2021.110091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 11/21/2022]
Abstract
Metastatic progression is the key feature of prostate cancer primarily responsible for mortality caused by this disease. RAD9 is an oncogene for prostate cancer, and the encoded protein enhances metastasis-related phenotypes. RAD9 is a transcription factor with a limited set of regulated target genes, but the complete list of downstream genes critical for prostate carcinogenesis is unknown. We used microarray gene expression profiling and chromatin immunoprecipitation in parallel to identify genes transcriptionally controlled by RAD9 that contribute to this cancer. We found expression of 44 genes altered in human prostate cancer DU145 cells when RAD9 is knocked down by siRNA, and all of them bind RAD9 at their genomic location. FOXP1 and NDRG1 were down regulated when RAD9 expression was reduced, and we evaluated them further. We demonstrate that reduced RAD9, FOXP1 or NDGR1 expression decreases cell proliferation, rapid migration, anchorage-independent growth, anoikis resistance, and aerobic glycolysis. Ectopic expression of FOXP1 or NDRG1 partially restored aerobic glycolysis to prostate cancer cells with reduced RAD9 abundance, but only FOXP1 significantly complemented the other deficiencies. We thus show, for the first time, that RAD9 regulates FOXP1 and NDRG1 expression, and they function differently as downstream effectors for RAD9-mediated prostate cancer cell activities.
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Shen S, Feng H, Liu L, Su W, Yu L, Wu J. TCP10L negatively regulates alpha-fetoprotein expression in hepatocellular carcinoma. BMB Rep 2021. [PMID: 32438969 PMCID: PMC7473475 DOI: 10.5483/bmbrep.2020.53.8.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Alpha-fetoprotein (AFP) is one of the most commonly used and reliable biomarkers for Hepatocellular carcinoma(HCC). However, the underlying mechanism of AFP expression in HCC is poorly understood. In this study, we found that TCP10L, a gene specifically expressed in the liver, is down-regulated in HCC and that its expression inversely correlates with AFP expression. Moreover, overexpression of TCP10L suppresses AFP expression whereas knockdown of TCP10L increases AFP ex-pression, suggesting that TCP10L might be a negative regulator of AFP. We found that TCP10L is associated with the AFP promoter and inhibits AFP promoter-driven transcriptional acti-vity. Taken together, these results indicate that TCP10L nega-tively regulates AFP expression in HCC and that it could be a potential prognostic marker and therapeutic target for HCC.
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Affiliation(s)
- Suqin Shen
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
| | - Huan Feng
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
| | - Longjiang Liu
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
| | - Wei Su
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
| | - Long Yu
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
| | - Jiaxue Wu
- The State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Science, Fudan University, Shanghai 200438, China
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Li H, Liu Y, Jiang W, Xue J, Cheng Y, Wang J, Yang R, Zhang X. Icaritin promotes apoptosis and inhibits proliferation by down-regulating AFP gene expression in hepatocellular carcinoma. BMC Cancer 2021; 21:318. [PMID: 33765973 PMCID: PMC7992931 DOI: 10.1186/s12885-021-08043-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 03/15/2021] [Indexed: 11/10/2022] Open
Abstract
Background Icaritin, an active ingredient of the Chinese herb Epimedium, plays an anti-tumor role in liver cancer by inhibiting the proliferation of hepatocellular cells and promoting their apoptosis. In China, phase II and a large phase III clinical trial of icaritin reagent for the treatment of hepatocellular cancer is under-going, but the specific mechanism of icaritin action was unclear. Alpha-fetoprotein (AFP), an oncofetal protein, produced in the healthy fetal liver and yolk sac. Intracellular AFP promoted cellular proliferation and inhibited cellular apoptosis in hepatocellular carcinoma (HCC). The study was aimed to investigate the effect of icaritin on HCC through p53/AFP pathway. Methods Real-time RT PCR and western blot were used to detect p53 and AFP expression levels in HCC cells treated with icaritin. The mechanism of icaritin affecting p53 expression was verified by ubiquitination experiment, and the binding activity of icaritin on p53 in AFP promoter region was verified by luciferase experiment. EdU, MTT and flow cytometry were used to determine whether icaritin affected HCC cellular proliferation and apoptosis through p53/ AFP pathway. Expression levels of p53 and AFP in xenograft mouse model were determined by western blotting. Results Our results showed icaritin inhibited AFP expression at mRNA and protein level. AFP was also identified as the target gene of the p53 transcription factor. Icaritin abrogated murine double minute (Mdm) 2-mediated p53 ubiquitination degradation to improve the stability of p53. Up-regulated p53 protein levels then transcriptionally inhibited the AFP promoter. Icaritin-mediated decrease of AFP through Mdm2/p53 pathways inhibited HCC cellular proliferation and promoted HCC cellular apoptosis. Conclusion Our findings revealed the mechanism of icaritin in promoting apoptosis and inhibiting proliferation in liver cancer cells. The regulatory mechanism of icaritin in AFP protein down-regulation provides a theoretical and experimental basis for further research into new drugs for the treatment of liver cancer. Supplementary Information The online version contains supplementary material available at 10.1186/s12885-021-08043-9.
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Affiliation(s)
- Hui Li
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China.
| | - Yujuan Liu
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Wei Jiang
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Junhui Xue
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Yuning Cheng
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Jiyin Wang
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Ruixiang Yang
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
| | - Xiaowei Zhang
- Department of Biochemistry and Biophysics, School of Basic Medical Sciences, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Peking University Health Science Center, 100191, Beijing, People's Republic of China
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Guo L, Li H, Fan T, Ma Y, Wang L. Synergistic efficacy of curcumin and anti-programmed cell death-1 in hepatocellular carcinoma. Life Sci 2021; 279:119359. [PMID: 33753114 DOI: 10.1016/j.lfs.2021.119359] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/02/2021] [Accepted: 03/10/2021] [Indexed: 02/07/2023]
Abstract
Hepatocellular carcinoma (HCC) ranks near the top in the global list of malignancies causing cancer-related death. Recently, combination therapy has gained popularity in treating this cancer. We tried to investigate the efficacy of combined treatment with curcumin and anti-programmed cell death-1 (anti-PD-1) in HCC. Hep3B cells were treated with different concentrations of curcumin, followed by determination of Hep3B cell proliferation and programmed cell death ligand-1 (PD-L1) expression. Then, Hep3B cells were co-cultured with peripheral blood mononuclear cells (PBMCs), after which the Hep3B cell growth and immune activity were detected following treatment with curcumin and/or anti-PD-1. Besides, we investigated the effect of transforming growth factor beta 1 (TGF-β1) on lymphocyte activation and the interaction between E1A binding protein P300 (P300), histone acetylation, TGF-β1, and thrombin. Additionally, the synergistic role of curcumin and anti-PD-1 in mouse models of HCC was studied. Curcumin retarded Hep3B cell growth and reduced surface PD-L1 expression in Hep3B cells. After co-culture of Hep3B cells and PBMCs, curcumin had a synergistic effect with anti-PD-1 to slow Hep3B cell proliferation, activate lymphocytes, inhibit immune evasion, and down-regulate TGF-β1 expression. Functionally, curcumin inhibited thrombin to reduce P300-induced histone acetylation in the TGF-β1 promoter region, and anti-PD-1 suppressed binding of PD-1 and PD-L1 to promote immune activity; the combination of the two showed better in vitro anti-cancer effects. In vivo, curcumin combined with anti-PD-1 also lowered HCC growth rate and improved the tumor microenvironment. In conclusion, the combination of curcumin and anti-PD-1 is synergistically effective in the treatment of HCC treatment.
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Affiliation(s)
- Lei Guo
- Department of Infection, Qingdao No. 6 People's Hospital, Qingdao 266033, PR China
| | - Hongbo Li
- Department of Dermatology, Qingdao No. 6 People's Hospital, Qingdao 266033, PR China
| | - Tianli Fan
- Department of Infection, Qingdao No. 6 People's Hospital, Qingdao 266033, PR China
| | - Yanli Ma
- Department of Infection, Qingdao No. 6 People's Hospital, Qingdao 266033, PR China.
| | - Lili Wang
- Department of Hepatology, Qingdao No. 6 People's Hospital, Qingdao 266033, PR China.
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Regulation of Fetal Genes by Transitions among RNA-Binding Proteins during Liver Development. Int J Mol Sci 2020; 21:ijms21239319. [PMID: 33297405 PMCID: PMC7731027 DOI: 10.3390/ijms21239319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/05/2020] [Accepted: 12/05/2020] [Indexed: 12/12/2022] Open
Abstract
Transcripts of alpha-fetoprotein (Afp), H19, and insulin-like growth factor 2 (Igf2) genes are highly expressed in mouse fetal liver, but decrease drastically during maturation. While transcriptional regulation of these genes has been well studied, the post-transcriptional regulation of their developmental decrease is poorly understood. Here, we show that shortening of poly(A) tails and subsequent RNA decay are largely responsible for the postnatal decrease of Afp, H19, and Igf2 transcripts in mouse liver. IGF2 mRNA binding protein 1 (IMP1), which regulates stability and translation efficiency of target mRNAs, binds to these fetal liver transcripts. When IMP1 is exogenously expressed in mouse adult liver, fetal liver transcripts show higher expression and possess longer poly(A) tails, suggesting that IMP1 stabilizes them. IMP1 declines concomitantly with fetal liver transcripts as liver matures. Instead, RNA-binding proteins (RBPs) that promote RNA decay, such as cold shock domain containing protein E1 (CSDE1), K-homology domain splicing regulatory protein (KSRP), and CUG-BP1 and ETR3-like factors 1 (CELF1), bind to 3' regions of fetal liver transcripts. These data suggest that transitions among RBPs associated with fetal liver transcripts shift regulation from stabilization to decay, leading to a postnatal decrease in those fetal transcripts.
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Lin YH, Wu MH, Huang YH, Yeh CT, Lin KH. TUG1 Is a Regulator of AFP and Serves as Prognostic Marker in Non-Hepatitis B Non-Hepatitis C Hepatocellular Carcinoma. Cells 2020; 9:cells9020262. [PMID: 31973032 PMCID: PMC7072672 DOI: 10.3390/cells9020262] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 01/17/2020] [Accepted: 01/19/2020] [Indexed: 02/07/2023] Open
Abstract
Thyroid hormone (T3) and its receptor (TR) are involved in cell metabolism and cancer progression. Hypothyroidism is associated with significantly elevated risk of hepatocellular carcinoma (HCC). Levels of the glycoprotein alpha-fetoprotein (AFP) are increased in the majority of patients with HCC and may be useful in diagnosis and follow-up. However, the relationship between T3/TR and AFP levels in HCC is currently unclear. The expression profiles of long non-coding RNAs (lncRNAs) were compared in microarrays of HepG2-TRα1 cells treated with/without T3 and HCC specimens. The effects of T3 on taurine upregulated gene 1 (TUG1) and AFP expression were validated using qRT-PCR. A correlation between TUG1 and AFP was confirmed via RNAi and clustered regularly interspaced short palindromic repeats (CRISPR) strategies. Finally, overall and recurrence-free survival rates were analyzed using the Kaplan–Meier method and confirmed in online datasets. T3/TR treatment reduced TUG1 expression in vitro, resulting in the downregulation of AFP mRNA. Knockdown of TUG1 suppressed cell cycle progression and soft agar colony formation and induced cellular senescence. Our data support the involvement of TUG1 in the T3/TR-mediated suppression of cell growth. AFP mRNA levels showed strong positive correlations with TUG1 and unfavorable prognosis in patients with non-hepatitis B/non-hepatitis C HCC (NBNC-HCC). T3/TR, TUG1, and AFP may potentially serve as effective prognostic markers for NBNC-HCC.
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Affiliation(s)
- Yang-Hsiang Lin
- Liver Research Center, Chang Gung Memorial Hospital, 15 Wen-hwa 1 Road, Linkou, Taoyuan 333, Taiwan; (Y.-H.L.); (Y.-H.H.)
- Department of Biochemistry, College of Medicine, Chang Gung University, 259 Wen-hwa 1 Road, Taoyuan 333, Taiwan;
| | - Meng-Han Wu
- Department of Biochemistry, College of Medicine, Chang Gung University, 259 Wen-hwa 1 Road, Taoyuan 333, Taiwan;
| | - Ya-Hui Huang
- Liver Research Center, Chang Gung Memorial Hospital, 15 Wen-hwa 1 Road, Linkou, Taoyuan 333, Taiwan; (Y.-H.L.); (Y.-H.H.)
| | - Chau-Ting Yeh
- Liver Research Center, Chang Gung Memorial Hospital, 15 Wen-hwa 1 Road, Linkou, Taoyuan 333, Taiwan; (Y.-H.L.); (Y.-H.H.)
- Correspondence: (C.-T.Y.); (K.-H.L.); Tel./Fax: +886-3-2118263 (K.-H.L.)
| | - Kwang-Huei Lin
- Liver Research Center, Chang Gung Memorial Hospital, 15 Wen-hwa 1 Road, Linkou, Taoyuan 333, Taiwan; (Y.-H.L.); (Y.-H.H.)
- Department of Biochemistry, College of Medicine, Chang Gung University, 259 Wen-hwa 1 Road, Taoyuan 333, Taiwan;
- Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
- Correspondence: (C.-T.Y.); (K.-H.L.); Tel./Fax: +886-3-2118263 (K.-H.L.)
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Fezza M, Moussa M, Aoun R, Haber R, Hilal G. DKK1 promotes hepatocellular carcinoma inflammation, migration and invasion: Implication of TGF-β1. PLoS One 2019; 14:e0223252. [PMID: 31568519 PMCID: PMC6768474 DOI: 10.1371/journal.pone.0223252] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/17/2019] [Indexed: 12/24/2022] Open
Abstract
Dickkopf-1 (DKK1), an inhibitor of the most frequently impaired signaling pathway in hepatocellular carcinoma (HCC), the Wnt/beta-catenin pathway, seems to fulfill contradictory functions in the process of tumorigenesis, acting either as an oncogenic promoter of metastasis or as a tumor suppressor. Elevated serum levels of DKK1 have been reported in HCC; however, little is known about its functional significance. In the current study, we treated HepG2/C3A and PLC/PRF/5 with the recombinant protein DKK1. Cytotoxicity was first determined by the WST-8 assay. AFP expression was measured at both the mRNA and protein levels. Expression of the oncogenes MYC, CCND1, hTERT, and MDM2 and the tumor suppressor genes TP53, P21 and RB was assessed. Western blot analysis of non-phosphorylated ẞ-catenin and Sanger sequencing were performed to explain the functional differences between the two cell lines. Subsequently, inflammation, migration and invasion were evaluated by qPCR, ELISA, the Boyden chamber assay, zymography, and MMP-2 and MMP-9 western blot analysis. Knockdown of DKK1 and TGF-β1 were also performed. Our results suggest that DKK1 exerts an oncogenic effect on HepG2/C3A cell line by upregulating the expression of oncogenes and downregulating that of tumor suppressor genes, whereas the opposite effect was demonstrated in PLC/PRF/5 cells. This differential impact of DKK1 can be explained by the mutations that affect the canonical Wnt pathway that were detected in exon 3 of the CTNNB1 gene in the HepG2 cell line. We further confirmed that DKK1 promotes inflammation, tumor invasion and migration in both cell types. The canonical pathway was not responsible for the DKK1 proinvasive effect, as indicated by the active ẞ-catenin levels in the two cell lines upon DKK1 treatment. Interestingly, knockdown of TGF-β1 negatively affected the DKK1 proinvasive effect. Taken together, DKK1 appears to facilitate tumor invasion and migration through TGF- β1 by remodeling the tumor microenvironment and inducing inflammation. This finding endorses the relevance of TGF-β1 as a therapeutic target.
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Affiliation(s)
- Maha Fezza
- Cancer and Metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
| | - Mayssam Moussa
- Cancer and Metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
| | - Rita Aoun
- Cancer and Metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
| | - Rita Haber
- Cancer and Metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
| | - George Hilal
- Cancer and Metabolism Laboratory, Faculty of Medicine, Saint-Joseph University, Beirut, Lebanon
- * E-mail:
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15
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Wang S, Xiang C, Mou L, Yang Y, Zhong R, Wang L, Sun C, Qin Z, Yang J, Qian J, Zhao Y, Wang Y, Pan X, Qie J, Jiang Y, Wang X, Yang Y, Zhou WP, Miao X, He F, Jin L, Wang H. Trans-acting non-synonymous variant of FOXA1 predisposes to hepatocellular carcinoma through modulating FOXA1-ERα transcriptional program and may have undergone natural selection. Carcinogenesis 2019; 41:146-158. [DOI: 10.1093/carcin/bgz136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/26/2019] [Accepted: 07/30/2019] [Indexed: 12/18/2022] Open
Abstract
Abstract
Interplay of pioneer transcription factor forkhead box A1 (FOXA1) and estrogen receptor has been implicated in sexual dimorphism in hepatocellular carcinoma (HCC), but etiological relevance of its polymorphism was unknown. In the case control study (1152 patients versus1242 controls), we observed significant increase in HCC susceptibility in hepatitis B virus carriers associated with a non-synonymous Thr83Ala variant of FOXA1 (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.11−1.48, for Ala83-containing genotype, after validation in an independent population with 933 patients versus 1030 controls), a tightly linked (CGC)5/6or7 repeat polymorphism at its promoter (OR 1.32; 95% CI 1.10–1.60, for (CGC)6or7-repeat-containing genotype), and their combined haplotype (OR 1.50; 95% CI 1.24–1.81, for (CGC)6or7−Ala83 haplotype). The susceptible FOXA1-Ala83 impairs its interaction with ERα, attenuates transactivation toward some of their dual target genes, such as type 1 iodothyronine deiodinase, UDP glucuronosyltransferase 2 family, polypeptide B17 and sodium/taurocholate cotransporting polypeptide, but correlates with strengthened cellular expression of α-fetoprotein (AFP) and elevated AFP serum concentration in HCC patients (n = 1096). The susceptible FOXA1 cis-variant with (CGC)6or7 repeat strengthens the binding to transcription factor early growth response 1 and enhances promoter activity and gene expression. Evolutionary population genetics analyses with public datasets reveal significant population differentiation and unique haplotype structure of the derived protective FOXA1-Thr83 and suggest that it may have undergone positive natural selection in Chinese population. These findings epidemiologically highlight the functional significance of FOXA1-ERα transcriptional program and regulatory network in liver cancer development.
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Affiliation(s)
- Sheng Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chan Xiang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Pathology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Lin Mou
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yuan Yang
- The Third Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Rong Zhong
- Department of Epidemiology and Biostatistics and State Key Laboratory of Environment Health (Incubation), Ministry of Education Key Laboratory of Environment and Health, Ministry of Environmental Protection Key Laboratory of Environment and Health (Wuhan), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Liyan Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Chang Sun
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhaoyu Qin
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jingmin Yang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ji Qian
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Fudan-Taizhou Institute of Health Sciences, Taizhou, Jiangsu, China
| | - Yuanyuan Zhao
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yi Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xuedong Pan
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jingbo Qie
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yan Jiang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaofeng Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Fudan-Taizhou Institute of Health Sciences, Taizhou, Jiangsu, China
| | - Yajun Yang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Fudan-Taizhou Institute of Health Sciences, Taizhou, Jiangsu, China
| | - Wei-Ping Zhou
- The Third Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China
| | - Xiaoping Miao
- Department of Epidemiology and Biostatistics and State Key Laboratory of Environment Health (Incubation), Ministry of Education Key Laboratory of Environment and Health, Ministry of Environmental Protection Key Laboratory of Environment and Health (Wuhan), School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fuchu He
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences, Beijing Institute of Lifeomics, Beijing, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Fudan-Taizhou Institute of Health Sciences, Taizhou, Jiangsu, China
| | - Haijian Wang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center for Genetics and Development, School of Life Sciences; Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
- Fudan-Taizhou Institute of Health Sciences, Taizhou, Jiangsu, China
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16
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Jaramillo M, Yeh H, Yarmush ML, Uygun BE. Decellularized human liver extracellular matrix (hDLM)-mediated hepatic differentiation of human induced pluripotent stem cells (hIPSCs). J Tissue Eng Regen Med 2018; 12:e1962-e1973. [PMID: 29222839 DOI: 10.1002/term.2627] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/31/2017] [Accepted: 11/30/2017] [Indexed: 12/30/2022]
Abstract
Liver tissue engineering has emerged as a promising approach in organ transplantation but has been hampered by the lack of a reliable and readily available cell source. Human induced pluripotent stem cells hiPSCs have been highlighted as a desirable source, due to their differentiation potential, ability to self-renew, and the possibility of making patient-specific cells. We developed a decellularization protocol that efficiently removes cellular material while retaining extracellular matrix components. Subsequently, hiPSCs were differentiated on decellularized human liver extracellular matrix (hDLM) scaffolds using an established hepatic differentiation protocol. We demonstrate that using hDLM leads to upregulation markers of hepatic functions when compared with standard differentiation conditions. In addition, expression of a number of hepatic transcription and nuclear factors were found to be within levels comparable with those of primary human adult hepatocytes. Analysis of progression of differentiation on hDLM demonstrated that hepatic developmental marker expression was consistent with hepatic development. The hDLM-derived cells exhibited key hepatic characteristics that were comparable with those observed in primary neonatal human hepatocytes. We investigated the optimal timing of the introduction of hDLM into the differentiation protocol and found that the best results are obtained when cells are plated on hDLM since the earliest stages and accompanied by a progressive loss of sensitivity to substrate composition at later stages. The significance of this work is that it allows for the development of differentiation protocols that take into account signals from extracellular matrix, closely recapitulating of the in vivo micro-environment and resulting in cells that are phenotypically closer to mature hepatocytes.
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Affiliation(s)
- Maria Jaramillo
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Shriners Hospitals for Children, Boston, MA, USA.,Department of Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Heidi Yeh
- Department of Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Martin L Yarmush
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Shriners Hospitals for Children, Boston, MA, USA.,Department of Surgery, Massachusetts General Hospital, Boston, MA, USA.,Department of Biomedical Engineering, Rutgers University, Piscataway, NJ, USA
| | - Basak E Uygun
- Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Shriners Hospitals for Children, Boston, MA, USA.,Department of Surgery, Massachusetts General Hospital, Boston, MA, USA
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17
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Sullivan KD, Galbraith MD, Andrysik Z, Espinosa JM. Mechanisms of transcriptional regulation by p53. Cell Death Differ 2017; 25:133-143. [PMID: 29125602 PMCID: PMC5729533 DOI: 10.1038/cdd.2017.174] [Citation(s) in RCA: 288] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/25/2017] [Accepted: 08/31/2017] [Indexed: 12/19/2022] Open
Abstract
p53 is a transcription factor that suppresses tumor growth through regulation of dozens of target genes with diverse biological functions. The activity of this master transcription factor is inactivated in nearly all tumors, either by mutations in the TP53 locus or by oncogenic events that decrease the activity of the wild-type protein, such as overexpression of the p53 repressor MDM2. However, despite decades of intensive research, our collective understanding of the p53 signaling cascade remains incomplete. In this review, we focus on recent advances in our understanding of mechanisms of p53-dependent transcriptional control as they relate to five key areas: (1) the functionally distinct N-terminal transactivation domains, (2) the diverse regulatory roles of its C-terminal domain, (3) evidence that p53 is solely a direct transcriptional activator, not a direct repressor, (4) the ability of p53 to recognize many of its enhancers across diverse chromatin environments, and (5) mechanisms that modify the p53-dependent transcriptional program in a context-dependent manner.
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Affiliation(s)
- Kelly D Sullivan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Matthew D Galbraith
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Zdenek Andrysik
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Joaquin M Espinosa
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO 80203, USA
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18
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Mathai J, Mittal SPK, Alam A, Ranade P, Mogare D, Patel S, Saxena S, Ghorai S, Kulkarni AP, Chattopadhyay S. SMAR1 binds to T(C/G) repeat and inhibits tumor progression by regulating miR-371-373 cluster. Sci Rep 2016; 6:33779. [PMID: 27671416 PMCID: PMC5037395 DOI: 10.1038/srep33779] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 08/18/2016] [Indexed: 12/19/2022] Open
Abstract
Chromatin architecture and dynamics are regulated by various histone and non-histone proteins. The matrix attachment region binding proteins (MARBPs) play a central role in chromatin organization and function through numerous regulatory proteins. In the present study, we demonstrate that nuclear matrix protein SMAR1 orchestrates global gene regulation as determined by massively parallel ChIP-sequencing. The study revealed that SMAR1 binds to T(C/G) repeat and targets genes involved in diverse biological pathways. We observe that SMAR1 binds and targets distinctly different genes based on the availability of p53. Our data suggest that SMAR1 binds and regulates one of the imperative microRNA clusters in cancer and metastasis, miR-371-373. It negatively regulates miR-371-373 transcription as confirmed by SMAR1 overexpression and knockdown studies. Further, deletion studies indicate that a ~200 bp region in the miR-371-373 promoter is necessary for SMAR1 binding and transcriptional repression. Recruitment of HDAC1/mSin3A complex by SMAR1, concomitant with alteration of histone marks results in downregulation of the miRNA cluster. The regulation of miR-371-373 by SMAR1 inhibits breast cancer tumorigenesis and metastasis as determined by in vivo experiments. Overall, our study highlights the binding of SMAR1 to T(C/G) repeat and its role in cancer through miR-371-373.
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Affiliation(s)
- Jinumary Mathai
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Smriti P K Mittal
- Department of Zoology, Savitribai Phule Pune University Campus, Pune 411007, India
| | - Aftab Alam
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Payal Ranade
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Devraj Mogare
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Sonal Patel
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Smita Saxena
- Bioinformatics Centre, Savitribai Phule Pune University Campus, Pune 411007, India
| | - Suvankar Ghorai
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
| | - Abhijeet P Kulkarni
- Bioinformatics Centre, Savitribai Phule Pune University Campus, Pune 411007, India
| | - Samit Chattopadhyay
- Chromatin and Disease Biology Lab, National Centre for Cell Science, Savitribai Phule Pune University Campus, Ganeshkhind, Pune-411007, India
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19
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Abstract
The predominant function of the tumor suppressor p53 is transcriptional regulation. It is generally accepted that p53-dependent transcriptional activation occurs by binding to a specific recognition site in promoters of target genes. Additionally, several models for p53-dependent transcriptional repression have been postulated. Here, we evaluate these models based on a computational meta-analysis of genome-wide data. Surprisingly, several major models of p53-dependent gene regulation are implausible. Meta-analysis of large-scale data is unable to confirm reports on directly repressed p53 target genes and falsifies models of direct repression. This notion is supported by experimental re-analysis of representative genes reported as directly repressed by p53. Therefore, p53 is not a direct repressor of transcription, but solely activates its target genes. Moreover, models based on interference of p53 with activating transcription factors as well as models based on the function of ncRNAs are also not supported by the meta-analysis. As an alternative to models of direct repression, the meta-analysis leads to the conclusion that p53 represses transcription indirectly by activation of the p53-p21-DREAM/RB pathway.
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Key Words
- CDE, cell cycle-dependent element
- CDKN1A
- CHR, cell cycle genes homology region
- ChIP, chromatin immunoprecipitation
- DREAM complex
- DREAM, DP, RB-like, E2F4, and MuvB complex
- E2F/RB complex
- HPV, human papilloma virus
- NF-Y, Nuclear factor Y
- cdk, cyclin-dependent kinase
- genome-wide meta-analysis
- p53
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Affiliation(s)
- Martin Fischer
- a Molecular Oncology; Medical School ; University of Leipzig ; Leipzig , Germany
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20
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Murakami-Tonami Y, Ohtsuka H, Aiba H, Murakami H. Regulation of wee1(+) expression during meiosis in fission yeast. Cell Cycle 2015; 13:2853-8. [PMID: 25486473 PMCID: PMC4612672 DOI: 10.4161/15384101.2014.946807] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
In eukaryotes, the cyclin-dependent kinase Cdk1p (Cdc2p) plays a central role in entry into and progression through nuclear division during mitosis and meiosis. Cdk1p is activated during meiotic nuclear divisions by dephosphorylation of its tyrosine-15 residue. The phosphorylation status of this residue is largely determined by the Wee1p kinase and the Cdc25p phosphatase. In fission yeast, the forkhead-type transcription factor Mei4p is essential for entry into the first meiotic nuclear division. We recently identified cdc25+ as an essential target of Mei4p in the control of entry into meiosis I. Here, we show that wee1+ is another important target of Mei4p in the control of entry into meiosis I. Mei4p bound to the upstream region of wee1+ in vivo and in vitro and inhibited expression of wee1+, whereas Mei4p positively regulated expression of the adjacent pseudogene. Overexpression of Mei4p inhibited expression of wee1+ and induced that of the pseudogene. Conversely, deletion of Mei4p did not decrease expression of wee1+ but inhibited that of the pseudogene. In addition, deletion of Mei4p-binding regions delayed repression of wee1+ expression as well as induction of expression of the pseudogene. These results suggest that repression of wee1+ expression is primarily owing to Mei4p-mediated transcriptional interference.
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Affiliation(s)
- Yuko Murakami-Tonami
- a Aichi Cancer Center Research Institute ; Division of Molecular Oncology ; Nagoya , Japan
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21
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Zhang H, Cao D, Zhou L, Zhang Y, Guo X, Li H, Chen Y, Spear BT, Wu JW, Xie Z, Zhang WJ. ZBTB20 is a sequence-specific transcriptional repressor of alpha-fetoprotein gene. Sci Rep 2015; 5:11979. [PMID: 26173901 PMCID: PMC4648434 DOI: 10.1038/srep11979] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 06/12/2015] [Indexed: 02/07/2023] Open
Abstract
Alpha-fetoprotein (AFP) represents a classical model system to study developmental gene regulation in mammalian cells. We previously reported that liver ZBTB20 is developmentally regulated and plays a central role in AFP postnatal repression. Here we show that ZBTB20 is a sequence-specific transcriptional repressor of AFP. By ELISA-based DNA-protein binding assay and conventional gel shift assay, we successfully identified a ZBTB20-binding site at −104/−86 of mouse AFP gene, flanked by two HNF1 sites and two C/EBP sites in the proximal promoter. Importantly, mutation of the core sequence in this site fully abolished its binding to ZBTB20 in vitro, as well as the repression of AFP promoter activity by ZBTB20. The unique ZBTB20 site was highly conserved in rat and human AFP genes, but absent in albumin genes. These help to explain the autonomous regulation of albumin and AFP genes in the liver after birth. Furthermore, we demonstrated that transcriptional repression of AFP gene by ZBTB20 was liver-specific. ZBTB20 was dispensable for AFP silencing in other tissues outside liver. Our data define a cognate ZBTB20 site in AFP promoter which mediates the postnatal repression of AFP gene in the liver.
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Affiliation(s)
- Hai Zhang
- 1] Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China [2]
| | - Dongmei Cao
- 1] Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China [2]
| | - Luting Zhou
- 1] Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China [2]
| | - Ye Zhang
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | - Xiaoqin Guo
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | - Hui Li
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | - Yuxia Chen
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | - Brett T Spear
- Department of Microbiology, Immunology &Molecular Genetics, University of Kentucky College of Medicine, 800 Rose Street, Lexington, KY 40536, USA
| | - Jia-Wei Wu
- MOE Key Laboratory for Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhifang Xie
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
| | - Weiping J Zhang
- Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China
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Kadamb R, Mittal S, Bansal N, Saluja D. Stress-mediated Sin3B activation leads to negative regulation of subset of p53 target genes. Biosci Rep 2015; 35:e00234. [PMID: 26181367 PMCID: PMC4613689 DOI: 10.1042/bsr20150122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/03/2015] [Accepted: 06/19/2015] [Indexed: 11/28/2022] Open
Abstract
The multiprotein SWI-independent 3 (Sin3)-HDAC (histone deacetylase) corepressor complex mediates gene repression through its interaction with DNA-binding factors and recruitment of chromatin-modifying proteins on to the promoters of target gene. Previously, an increased expression of Sin3B and tumour suppressor protein, p53 has been established upon adriamycin treatment. We, now provide evidence that Sin3B expression is significantly up-regulated under variety of stress conditions and this response is not stress-type specific. We observed that Sin3B expression is significantly up-regulated both at transcript and at protein level upon DNA damage induced by bleomycin drug, a radiomimetic agent. This increase in Sin3B expression upon stress is found to be p53-dependent and is associated with enhanced interaction of Sin3B with Ser(15) phosphorylated p53. Binding of Sin3-HDAC repressor complex on to the promoters of p53 target genes influences gene regulation by altering histone modifications (H3K9me3 and H3K27me3) at target genes. Furthermore, knockdown of Sin3B by shRNA severely compromises p53-mediated gene repression under stress conditions. Taken together, these results suggest that stress-induced Sin3B activation is p53-dependent and is essential for p53-mediated repression of its selective target genes. The present study has an implication in understanding the transrepression mechanism of p53 under DNA damaging conditions.
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Affiliation(s)
- Rama Kadamb
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi-110007, India
| | - Shilpi Mittal
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi-110007, India
| | - Nidhi Bansal
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi-110007, India
| | - Daman Saluja
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi-110007, India
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El-Dahr S, Hilliard S, Aboudehen K, Saifudeen Z. The MDM2-p53 pathway: multiple roles in kidney development. Pediatr Nephrol 2014; 29:621-7. [PMID: 24077661 PMCID: PMC3969418 DOI: 10.1007/s00467-013-2629-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 08/21/2013] [Accepted: 08/30/2013] [Indexed: 01/02/2023]
Abstract
The molecular basis of nephron progenitor cell renewal and differentiation into nascent epithelial nephrons is an area of intense investigation. Defects in these early stages of nephrogenesis lead to renal hypoplasia, and eventually hypertension and chronic kidney disease. Terminal nephron differentiation, the process by which renal epithelial precursor cells exit the cell cycle and acquire physiological functions is equally important. Failure of terminal epithelial cell differentiation results in renal dysplasia and cystogenesis. Thus, a better understanding of the transcriptional frameworks that regulate early and late renal cell differentiation is of great clinical significance. In this review, we will discuss evidence implicating the MDM2-p53 pathway in cell fate determination during development. The emerging central theme from loss- and gain-of-function studies is that tight regulation of p53 levels and transcriptional activity is absolutely required for nephrogenesis. We will also discuss how post-translational modifications of p53 (e.g., acetylation and phosphorylation) alter the spatiotemporal and functional properties of p53 and thus cell fate during kidney development. Mutations and polymorphisms in the MDM2-p53 pathway are present in more than 50 % of cancers in humans. This raises the question of whether sequence variants in the MDM2-p53 pathway increase the susceptibility to renal dysgenesis, hypertension or chronic kidney disease. With the advent of whole exome sequencing and other high throughput technologies, this hypothesis is testable in cohorts of children with renal dysgenesis.
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Carvajal LA, Hamard PJ, Tonnessen C, Manfredi JJ. E2F7, a novel target, is up-regulated by p53 and mediates DNA damage-dependent transcriptional repression. Genes Dev 2012; 26:1533-45. [PMID: 22802528 DOI: 10.1101/gad.184911.111] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The p53 tumor suppressor protein is a transcription factor that exerts its effects on the cell cycle via regulation of gene expression. Although the mechanism of p53-dependent transcriptional activation has been well-studied, the molecular basis for p53-mediated repression has been elusive. The E2F family of transcription factors has been implicated in regulation of cell cycle-related genes, with E2F6, E2F7, and E2F8 playing key roles in repression. In response to cellular DNA damage, E2F7, but not E2F6 or E2F8, is up-regulated in a p53-dependent manner, with p53 being sufficient to increase expression of E2F7. Indeed, p53 occupies the promoter of the E2F7 gene after genotoxic stress, consistent with E2F7 being a novel p53 target. Ablation of E2F7 expression abrogates p53-dependent repression of a subset of its targets, including E2F1 and DHFR, in response to DNA damage. Furthermore, E2F7 occupancy of the E2F1 and DHFR promoters is detected, and expression of E2F7 is sufficient to inhibit cell proliferation. Taken together, these results show that p53-dependent transcriptional up-regulation of its target, E2F7, leads to repression of relevant gene expression. In turn, this E2F7-dependent mechanism contributes to p53-dependent cell cycle arrest in response to DNA damage.
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Affiliation(s)
- Luis A Carvajal
- Department of Oncological Sciences, Mount Sinai School of Medicine, New York, New York 10029, USA
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26
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p53 acts as a co-repressor to regulate keratin 14 expression during epidermal cell differentiation. PLoS One 2012; 7:e41742. [PMID: 22911849 PMCID: PMC3404013 DOI: 10.1371/journal.pone.0041742] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 06/27/2012] [Indexed: 11/22/2022] Open
Abstract
During epidermal cell differentiation, keratin 14 (K14) expression is down-regulated, p53 expression varies, and the expression of the p53 target genes, p21 and 14-3-3σ, increases. These trends suggest that the relative transcriptional activity of p53 is increased during epidermal cell differentiation. To determine the relationship between K14 and p53, we constructed K14 promoters of various sizes and found that wild-type p53 could repress the promoter activity of all of the K14 promoter constructs in H1299 cells. K14-p160 contains an SP1 binding site mutation that prevents p53 from repressing K14 expression. Using a DNA affinity precipitation assay, we confirmed that p53 forms a complex with SP1 at the SP1 binding site between nucleotides -48 and -43 on the K14 promoter. Thus, our data indicate that p53 acts as a co-repressor to down-regulate K14 expression by binding to SP1. Next, we used a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced epidermal cell differentiation model to examine the inhibition of K14 expression caused by increased p53 activity. Human ovarian teratocarcinoma C9 cells were treated with TPA to induce differentiation. Over-expression of the dominant negative p53 mutant ΔTAp53, which inhibits p53 activity, prevented the TPA-induced K14 down-regulation in C9 cells. Furthermore, treatment of normal primary human foreskin keratinocytes (PHFK) with the p53 inhibitor pifithrin-α (PFT-α) showed that the inhibition of p53 activity relieves K14 repression during epidermal cell differentiation. Finally, we found that TPA induces the phosphorylation of p53 at residue 378, which enhances the affinity of p53 to bind to Sp1 and repress K14 expression.
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Bochkis IM, Schug J, Ye DZ, Kurinna S, Stratton SA, Barton MC, Kaestner KH. Genome-wide location analysis reveals distinct transcriptional circuitry by paralogous regulators Foxa1 and Foxa2. PLoS Genet 2012; 8:e1002770. [PMID: 22737085 PMCID: PMC3380847 DOI: 10.1371/journal.pgen.1002770] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 05/02/2012] [Indexed: 01/04/2023] Open
Abstract
Gene duplication is a powerful driver of evolution. Newly duplicated genes acquire new roles that are relevant to fitness, or they will be lost over time. A potential path to functional relevance is mutation of the coding sequence leading to the acquisition of novel biochemical properties, as analyzed here for the highly homologous paralogs Foxa1 and Foxa2 transcriptional regulators. We determine by genome-wide location analysis (ChIP-Seq) that, although Foxa1 and Foxa2 share a large fraction of binding sites in the liver, each protein also occupies distinct regulatory elements in vivo. Foxa1-only sites are enriched for p53 binding sites and are frequently found near genes important to cell cycle regulation, while Foxa2-restricted sites show only a limited match to the forkhead consensus and are found in genes involved in steroid and lipid metabolism. Thus, Foxa1 and Foxa2, while redundant during development, have evolved divergent roles in the adult liver, ensuring the maintenance of both genes during evolution. The duplication of a gene from a common ancestor, resulting in two copies known as paralogs, plays an important role in evolution. Newly duplicated genes must acquire new functions in order to remain relevant, otherwise they are lost via mutation over time. We have performed genome-wide location analysis (ChIP–Seq) in adult liver to examine the differences between two paralogous DNA binding proteins, Foxa1 and Foxa2. While Foxa1 and Foxa2 bind a number of common genomic locations, each protein also localizes to distinct regulatory regions. Sites specific for Foxa1 also contain a DNA motif bound by tumor suppressor p53 and are found near genes important to cell cycle regulation, while Foxa2-only sites are found near genes essential to steroid and lipid metabolism. Hence, Foxa1 and Foxa2 have developed unique functions in adult liver, contributing to the maintenance of both genes during evolution.
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Affiliation(s)
- Irina M. Bochkis
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jonathan Schug
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Diana Z. Ye
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Svitlana Kurinna
- Center for Stem Cell and Developmental Biology, Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Sabrina A. Stratton
- Center for Stem Cell and Developmental Biology, Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Michelle C. Barton
- Center for Stem Cell and Developmental Biology, Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Klaus H. Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Yang HY, Liu HL, Tian LT, Song RP, Song X, Yin DL, Liang YJ, Qu LD, Jiang HC, Liu JR, Liu LX. Expression and prognostic value of ING3 in human primary hepatocellular carcinoma. Exp Biol Med (Maywood) 2012; 237:352-61. [PMID: 22550337 DOI: 10.1258/ebm.2011.011346] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The tumor-suppressor ING3 has been shown to be involved in tumor transcriptional regulation, apoptosis and the cell cycle. Some studies have demonstrated that ING3 is dysregulated in several types of cancers. However, the expression and function of ING3 in human hepatocellular carcinoma (HCC) remains unclear. The aim of this study is to investigate ING3 expression in hepatic tumors and its clinical relevance in hepatic cancer. The expression of ING3 protein was examined in 120 dissected HCC tissues and 47 liver tissues adjacent to the tumor by immunohistochemical assays and confirmed by Western blot analysis in 20 paired frozen tumor and non-tumor liver tissues. The relationship between ING3 staining and clinico-pathological characteristics of HCC was further analyzed. The mRNA expression of ING3 in the dissected tissues was also analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) and realtime PCR. Both mRNA and protein concentrations of ING3 were found to be downregulated in the majority of HCC tumors in comparison with matched non-tumor hepatic tissues. Analysis of the relationship between ING3 staining and clinico-pathological characteristics of HCC showed that the low expression of ING3 protein is correlated with more aggressive behavior of the tumor. Kaplan–Meier curves demonstrated that patients with a low expression of ING3 have a significantly increased risk of shortened survival time. In addition, multivariate analysis suggested that the level of ING3 expression may be an independent prognostic factor. Our findings indicate that ING3 may be an important marker for human hepatocellular carcinoma progression and prognosis, as well as a potential therapeutic target.
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Affiliation(s)
- Hai-Yan Yang
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Hao-Ling Liu
- Department of Endocrinology, The First Clinical College of Harbin Medical University, 23 Youzheng Street, Nangang District
| | - Lan-Tian Tian
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Rui-Peng Song
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Xuan Song
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Da-Long Yin
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Ying-Jian Liang
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Lian-Dong Qu
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Experimental Animal Center, 427 Ma Duan Street, Harbin 150001, PR China
| | - Hong-Chi Jiang
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
| | - Jia-Ren Liu
- Harvard Medical School, 300 Longwood Ave, Boston, MA 02115, USA
| | - Lian-Xin Liu
- Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Key Laboratory of Hepatosplenic Surgery, Ministry of Education
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Bansal N, Kadamb R, Mittal S, Vig L, Sharma R, Dwarakanath BS, Saluja D. Tumor suppressor protein p53 recruits human Sin3B/HDAC1 complex for down-regulation of its target promoters in response to genotoxic stress. PLoS One 2011; 6:e26156. [PMID: 22028823 PMCID: PMC3197607 DOI: 10.1371/journal.pone.0026156] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 09/21/2011] [Indexed: 11/18/2022] Open
Abstract
Master regulator protein p53, popularly known as the “guardian of genome” is the hub for regulation of diverse cellular pathways. Depending on the cell type and severity of DNA damage, p53 protein mediates cell cycle arrest or apoptosis, besides activating DNA repair, which is apparently achieved by regulation of its target genes, as well as direct interaction with other proteins. p53 is known to repress target genes via multiple mechanisms one of which is via recruitment of chromatin remodelling Sin3/HDAC1/2 complex. Sin3 proteins (Sin3A and Sin3B) regulate gene expression at the chromatin-level by serving as an anchor onto which the core Sin3/HDAC complex is assembled. The Sin3/HDAC co-repressor complex can be recruited by a large number of DNA-binding transcription factors. Sin3A has been closely linked to p53 while Sin3B is considered to be a close associate of E2Fs. The theme of this study was to establish the role of Sin3B in p53-mediated gene repression. We demonstrate a direct protein-protein interaction between human p53 and Sin3B (hSin3B). Amino acids 1–399 of hSin3B protein are involved in its interaction with N-terminal region (amino acids 1–108) of p53. Genotoxic stress induced by Adriamycin treatment increases the levels of hSin3B that is recruited to the promoters of p53-target genes (HSPA8, MAD1 and CRYZ). More importantly recruitment of hSin3B and repression of the three p53-target promoters upon Adriamycin treatment were observed only in p53+/+ cell lines. Additionally an increased tri-methylation of the H3K9 residue at the promoters of HSPA8 and CRYZ was also observed following Adriamycin treatment. The present study highlights for the first time the essential role of Sin3B as an important associate of p53 in mediating the cellular responses to stress and in the transcriptional repression of genes encoding for heat shock proteins or proteins involved in regulation of cell cycle and apoptosis.
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Affiliation(s)
- Nidhi Bansal
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Rama Kadamb
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Shilpi Mittal
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Leena Vig
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | - Raisha Sharma
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
| | | | - Daman Saluja
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
- * E-mail:
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Zhao L, Glazov EA, Pattabiraman DR, Al-Owaidi F, Zhang P, Brown MA, Leo PJ, Gonda TJ. Integrated genome-wide chromatin occupancy and expression analyses identify key myeloid pro-differentiation transcription factors repressed by Myb. Nucleic Acids Res 2011; 39:4664-79. [PMID: 21317192 PMCID: PMC3113568 DOI: 10.1093/nar/gkr024] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 01/11/2011] [Accepted: 01/12/2011] [Indexed: 12/28/2022] Open
Abstract
To gain insight into the mechanisms by which the Myb transcription factor controls normal hematopoiesis and particularly, how it contributes to leukemogenesis, we mapped the genome-wide occupancy of Myb by chromatin immunoprecipitation followed by massively parallel sequencing (ChIP-Seq) in ERMYB myeloid progenitor cells. By integrating the genome occupancy data with whole genome expression profiling data, we identified a Myb-regulated transcriptional program. Gene signatures for leukemia stem cells, normal hematopoietic stem/progenitor cells and myeloid development were overrepresented in 2368 Myb regulated genes. Of these, Myb bound directly near or within 793 genes. Myb directly activates some genes known critical in maintaining hematopoietic stem cells, such as Gfi1 and Cited2. Importantly, we also show that, despite being usually considered as a transactivator, Myb also functions to repress approximately half of its direct targets, including several key regulators of myeloid differentiation, such as Sfpi1 (also known as Pu.1), Runx1, Junb and Cebpb. Furthermore, our results demonstrate that interaction with p300, an established coactivator for Myb, is unexpectedly required for Myb-mediated transcriptional repression. We propose that the repression of the above mentioned key pro-differentiation factors may contribute essentially to Myb's ability to suppress differentiation and promote self-renewal, thus maintaining progenitor cells in an undifferentiated state and promoting leukemic transformation.
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Affiliation(s)
| | | | | | | | | | | | | | - Thomas J. Gonda
- The University of Queensland Diamantina Institute, Brisbane, Queensland 4102, Australia
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31
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Rinn JL, Huarte M. To repress or not to repress: this is the guardian's question. Trends Cell Biol 2011; 21:344-53. [PMID: 21601459 DOI: 10.1016/j.tcb.2011.04.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 04/11/2011] [Accepted: 04/13/2011] [Indexed: 10/18/2022]
Abstract
p53 is possibly the most central tumor suppressor gene of our cells, integrating stress signals to activate a transcriptional program responsible for maintaining cellular homeostasis. Many of the downstream effects of p53 are a consequence of its activity as a transcription factor, resulting in the induction of multiple target genes. In addition to gene activation, however, gene repression is an essential part of the p53 cellular response. Despite extensive research efforts towards the elucidation of p53 functions, the molecular mechanisms and biological consequences of gene repression by p53 have not been studied extensively. We review our current knowledge of the mechanisms and biological consequences of p53 repression, with special attention to recently discovered mechanisms of repression that involve non-coding RNA molecules, an emerging aspect of regulation in the p53 cellular network.
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Affiliation(s)
- John L Rinn
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, Massachusetts, USA
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32
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One function--multiple mechanisms: the manifold activities of p53 as a transcriptional repressor. J Biomed Biotechnol 2011; 2011:464916. [PMID: 21436991 PMCID: PMC3062963 DOI: 10.1155/2011/464916] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 01/17/2011] [Indexed: 12/31/2022] Open
Abstract
Maintenance of genome integrity is a dynamic process involving complex regulation systems. Defects in one or more of these pathways could result in cancer. The most important tumor-suppressor is the transcription factor p53, and its functional inactivation is frequently observed in many tumor types. The tumor suppressive function of p53 is mainly attributed to its ability to regulate numerous target genes at the transcriptional level. While the mechanism of transcriptional induction by p53 is well characterized, p53-dependent repression is not understood in detail. Here, we review the manifold mechanisms of p53 as a transcriptional repressor. We classify two different categories of repressed genes based on the underlying mechanism, and novel mechanisms which involve regulation through noncoding RNAs are discussed. The complete elucidation of p53 functions is important for our understanding of its tumor-suppressor activity and, therefore, represents the key for the development of novel therapeutic approaches.
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Peterson ML, Ma C, Spear BT. Zhx2 and Zbtb20: novel regulators of postnatal alpha-fetoprotein repression and their potential role in gene reactivation during liver cancer. Semin Cancer Biol 2011; 21:21-7. [PMID: 21216289 PMCID: PMC3313486 DOI: 10.1016/j.semcancer.2011.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 12/22/2010] [Accepted: 01/04/2011] [Indexed: 12/21/2022]
Abstract
The mouse alpha-fetoprotein (AFP) gene is abundantly expressed in the fetal liver, normally silent in the adult liver but is frequently reactivated in hepatocellular carcinoma. The basis for AFP expression in the fetal liver has been studied extensively. However, the basis for AFP reactivation during hepatocarcinogenesis is not well understood. Two novel factors that control postnatal AFP repression, Zhx2 and Zbtb20, were recently identified. Here, we review the transcription factors that regulate AFP in the fetal liver, as well as Zhx2 and Zbtb20, and raise the possibility that the loss of these postnatal repressors may be involved in AFP reactivation in liver cancer.
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Affiliation(s)
- Martha L Peterson
- Department of Microbiology, Immunology & Molecular Genetics and Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
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34
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McKenzie L, King S, Marcar L, Nicol S, Dias SS, Schumm K, Robertson P, Bourdon JC, Perkins N, Fuller-Pace F, Meek DW. p53-dependent repression of polo-like kinase-1 (PLK1). Cell Cycle 2010; 9:4200-12. [PMID: 20962589 PMCID: PMC3055203 DOI: 10.4161/cc.9.20.13532] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 08/26/2010] [Accepted: 09/04/2010] [Indexed: 02/06/2023] Open
Abstract
PLK1 is a critical mediator of G₂/M cell cycle transition that is inactivated and depleted as part of the DNA damage-induced G₂/M checkpoint. Here we show that downregulation of PLK1 expression occurs through a transcriptional repression mechanism and that p53 is both necessary and sufficient to mediate this effect. Repression of PLK1 by p53 occurs independently of p21 and of arrest at G₁/S where PLK1 levels are normally repressed in a cell cycle-dependent manner through a CDE/CHR element. Chromatin immunoprecipitation analysis indicates that p53 is present on the PLK1 promoter at two distinct sites termed p53RE1 and p53RE2. Recruitment of p53 to p53RE2, but not to p53RE1, is stimulated in response to DNA damage and/or p53 activation and is coincident with repression-associated changes in the chromatin. Downregulation of PLK1 expression by p53 is relieved by the histone deacetylase inhibitor, trichostatin A, and involves recruitment of histone deacetylase to the vicinity of p53RE2, further supporting a transcriptional repression mechanism. Additionally, wild type, but not mutant, p53 represses expression of the PLK1 promoter when fused upstream of a reporter gene. Silencing of PLK1 expression by RNAi interferes with cell cycle progression consistent with a role in the p53-mediated checkpoint. These data establish PLK1 as a direct transcriptional target of p53, independently of p21, that is required for efficient G₂/M arrest.
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Affiliation(s)
- Lynsey McKenzie
- Biomedical Research Institute, University of Dundee, Dundee, UK
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35
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Islam MR, Jimenez T, Pelham C, Rodova M, Puri S, Magenheimer BS, Maser RL, Widmann C, Calvet JP. MAP/ERK kinase kinase 1 (MEKK1) mediates transcriptional repression by interacting with polycystic kidney disease-1 (PKD1) promoter-bound p53 tumor suppressor protein. J Biol Chem 2010; 285:38818-31. [PMID: 20923779 DOI: 10.1074/jbc.m110.145284] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) cascades regulate a wide variety of cellular processes that ultimately depend on changes in gene expression. We have found a novel mechanism whereby one of the key MAP3 kinases, Mekk1, regulates transcriptional activity through an interaction with p53. The tumor suppressor protein p53 down-regulates a number of genes, including the gene most frequently mutated in autosomal dominant polycystic kidney disease (PKD1). We have discovered that Mekk1 translocates to the nucleus and acts as a co-repressor with p53 to down-regulate PKD1 transcriptional activity. This repression does not require Mekk1 kinase activity, excluding the need for an Mekk1 phosphorylation cascade. However, this PKD1 repression can also be induced by the stress-pathway stimuli, including TNFα, suggesting that Mekk1 activation induces both JNK-dependent and JNK-independent pathways that target the PKD1 gene. An Mekk1-p53 interaction at the PKD1 promoter suggests a new mechanism by which abnormally elevated stress-pathway stimuli might directly down-regulate the PKD1 gene, possibly causing haploinsufficiency and cyst formation.
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Affiliation(s)
- M Rafiq Islam
- Department of Chemistry/Physics, Northwest Missouri State University, Maryville, Missouri 64468, USA.
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36
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Kurinna S, Stratton SA, Tsai WW, Akdemir KC, Gu W, Singh P, Goode T, Darlington GJ, Barton MC. Direct activation of forkhead box O3 by tumor suppressors p53 and p73 is disrupted during liver regeneration in mice. Hepatology 2010; 52:1023-32. [PMID: 20564353 PMCID: PMC3741038 DOI: 10.1002/hep.23746] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
UNLABELLED The p53 family of proteins regulates the expression of target genes that promote cell cycle arrest and apoptosis, which may be linked to cellular growth control as well as tumor suppression. Within the p53 family, p53 and the transactivating p73 isoform (TA-p73) have hepatic-specific functions in development and tumor suppression. Here, we determined TA-p73 interactions with chromatin in the adult mouse liver and found forkhead box O3 (Foxo3) to be one of 158 gene targets. Global profiling of hepatic gene expression in the regenerating liver versus the quiescent liver revealed specific, functional categories of genes regulated over the time of regeneration. Foxo3 is the most responsive gene among transcription factors with altered expression during regenerative cellular proliferation. p53 and TA-p73 bind a Foxo3 p53 response element (p53RE) and maintain active expression in the quiescent liver. During regeneration of the liver, the binding of p53 and TA-p73, the recruitment of acetyltransferase p300, and the active chromatin structure of Foxo3 are disrupted along with a loss of Foxo3 expression. In agreement with the loss of Foxo3 transcriptional activation, a decrease in histone activation marks (dimethylated histone H3 at lysine 4, acetylated histone H3 at lysine 14, and acetylated H4) at the Foxo3 p53RE was detected after partial hepatectomy in mice. These parameters of Foxo3 regulation are reestablished with the completion of liver growth and regeneration and support a temporary suspension of p53 and TA-p73 regulatory functions in normal cells during tissue regeneration. p53-dependent and TA-p73-dependent activation of Foxo3 was also observed in mouse embryonic fibroblasts and in mouse hepatoma cells overexpressing p53, TA-p73alpha, and TA-p73beta isoforms. CONCLUSION p53 and p73 directly bind and activate the expression of the Foxo3 gene in the adult mouse liver and murine cell lines. p53, TA-p73, and p300 binding and Foxo3 expression decrease during liver regeneration, and this suggests a critical growth control mechanism mediated by these transcription factors in vivo.
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Affiliation(s)
- Svitlana Kurinna
- Graduate program in Genes and Development, University of Texas Graduate School of Biomedical Sciences, Houston, TX,Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology
| | - Sabrina A. Stratton
- Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology
| | - Wen-Wei Tsai
- Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology
| | - Kadir C. Akdemir
- Department of Biostatistics and Bioinformatics, UT MD Anderson Cancer Center, Houston, TX
| | | | - Pallavi Singh
- Columbia University College of Physicians and Surgeons, New York, NY
| | - Triona Goode
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX
| | | | - Michelle Craig Barton
- Graduate program in Genes and Development, University of Texas Graduate School of Biomedical Sciences, Houston, TX,Department of Biochemistry and Molecular Biology, Center for Stem Cell and Developmental Biology
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Abstract
Inactivation of p53 is critical for the formation of most tumors. Illumination of the key function(s) of p53 protein in protecting cells from becoming cancerous is therefore a worthy goal. Arguably p53's most important function is to act as a transcription factor that directly regulates perhaps several hundred of the cell's RNA polymerase II (RNAP II)-transcribed genes, and indirectly regulates thousands of others. Indeed p53 is the most well studied mammalian transcription factor. The p53 tetramer binds to its response element where it can recruit diverse transcriptional coregulators such as histone modifying enzymes, chromatin remodeling factors, subunits of the mediator complex, and components of general transcription machinery and preinitiation complex (PIC) to modulate RNAPII activity at target loci (Laptenko and Prives 2006). The p53 transcriptional program is regulated in a stimulus-specific fashion (Murray-Zmijewski et al. 2008; Vousden and Prives 2009), whereby distinct subsets of p53 target genes are induced in response to different p53-activating agents, likely allowing cells to tailor their response to different types of stress. How p53 is able to discriminate between these different loci is the subject of intense research. Here, we describe key aspects of the fundamentals of p53-mediated transcriptional regulation and target gene promoter selectivity.
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Affiliation(s)
- Rachel Beckerman
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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38
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Taube JH, Allton K, Duncan SA, Shen L, Barton MC. Foxa1 functions as a pioneer transcription factor at transposable elements to activate Afp during differentiation of embryonic stem cells. J Biol Chem 2010; 285:16135-44. [PMID: 20348100 DOI: 10.1074/jbc.m109.088096] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Epigenetic control of genes that are silent in embryonic stem cells, but destined for expression during differentiation, includes distinctive hallmarks, such as simultaneous activating/repressing (bivalent) modifications of chromatin and DNA hypomethylation at enhancers of gene expression. Although alpha-fetoprotein (Afp) falls into this class of genes, as it is silent in pluripotent stem cells and activated during differentiation of endoderm, we find that Afp chromatin lacks bivalent histone modifications. However, critical regulatory sites for Afp activation, overlapping Foxa1/p53/Smad-binding elements, are located within a 300-bp region lacking DNA methylation, due to transposed elements underrepresented in CpG sequences: a short interspersed transposable element and a medium reiterated sequence 1 element. Forkhead family member Foxa1 is activated by retinoic acid treatment of embryonic stem cells, binds its DNA consensus site within the short interspersed transposable/medium reiterated sequence 1 elements, and displaces linker histone H1 from silent Afp chromatin. Small interfering RNA depletion of Foxa1 showed that Foxa1 is essential in providing chromatin access to transforming growth factor beta-activated Smad2 and Smad4 and their subsequent DNA binding. Together these transcription factors establish highly acetylated chromatin and promote expression of Afp. Foxa1 acts as a pioneer transcription factor in de novo activation of Afp, by exploiting a lack of methylation at juxtaposed transposed elements, to bind and poise chromatin for intersection with transforming growth factor beta signaling during differentiation of embryonic stem cells.
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Affiliation(s)
- Joseph H Taube
- Department of Biochemistry and Molecular Biology, Graduate School of Biomedical Sciences, Center for Stem Cell and Developmental Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Dhar SK, Xu Y, St Clair DK. Nuclear factor kappaB- and specificity protein 1-dependent p53-mediated bi-directional regulation of the human manganese superoxide dismutase gene. J Biol Chem 2010; 285:9835-9846. [PMID: 20061391 PMCID: PMC2843232 DOI: 10.1074/jbc.m109.060715] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/29/2009] [Indexed: 01/12/2023] Open
Abstract
Tumor suppressor p53 is known to activate certain sets of genes while suppressing others. However, whether p53 can both activate and suppress the same gene is unclear. To address this question, concentration-dependent p53 effect on the manganese superoxide dismutase (MnSOD) gene was investigated. By transfecting p53 in PC-3 cells, we demonstrate that low concentrations of p53 increase while high concentrations suppress MnSOD expression. The physiological relevance of this effect was determined in vitro and in vivo using combined UVB-mediated activation and small interference RNA-mediated suppression of p53. Results were consistent with the bi-directional effect of p53 on MnSOD expression. MnSOD-promoter/enhancer analysis demonstrates that p53 is suppressive to the promoter activity regardless of the presence or absence of putative p53 binding sites. However, a low level of p53 increases MnSOD gene transcription in the presence of the intronic-enhancer element, and this effect is dependent on nuclear-factor kappaB (NF-kappaB) binding sites. Expression of p53 enhances nuclear levels of p65 with corresponding increase in the DNA-binding activity of NF-kappaB as detected by electrophoretic mobility shift and chromatin immunoprecipitation assays. Transfection of p65 small interference RNA reduces the positive effect of p53 on MnSOD gene transcription. These data suggest that p65 can overcome the negative effect of p53 on MnSOD expression. However, when the level of p53 was further increased, the suppressive effect of p53 outweighed the positive effect of p65 and led to the suppression of MnSOD gene transcription. These results demonstrated that p53 can both suppress and induce MnSOD expression depending on the balance of promoter and enhancer binding transcription factors.
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Affiliation(s)
- Sanjit K Dhar
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536
| | - Yong Xu
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536
| | - Daret K St Clair
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536.
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40
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Abstract
Roscovitine and flavopiridol suppress cyclin-dependent kinase 7 (CDK7) and CDK9 activity resulting in transcription inhibition, thus providing an alternative mechanism to traditional genotoxic chemotherapy. These agents have been effective in slow or nonreplicative cell types. 8-Amino-adenosine is a transcription inhibitor that has proved very effective in multiple myeloma cell lines and primary indolent leukemia cells. The objective of the current work was to define mechanisms of action that lead to transcription inhibition by 8-amino-adenosine. 8-Amino-adenosine is metabolized into the active triphosphate (8-amino-ATP) in cells. This accumulation resulted in a simultaneous decrease of intracellular ATP and RNA synthesis. When the effects of established ATP synthesis inhibitors and transcription inhibitors on intracellular ATP concentrations and RNA synthesis were studied, there was a strong correlation between ATP decline and RNA synthesis. This correlation substantiated the hypothesis that the loss of ATP in 8-amino-adenosine-treated cells contributes to the decrease in transcription due to the lack of substrate needed for mRNA body and polyadenylation tail synthesis. RNA polymerase II COOH terminal domain phosphorylation declined sharply in 8-amino-adenosine-treated cells, which may have been due to the lack of an ATP phosphate donor or competitive inhibition with 8-amino-ATP at CDK7 and CDK9. Furthermore, 8-amino-ATP was incorporated into nascent RNA in a dose-dependent manner at the 3'-end resulting in transcription termination. Finally, in vitro transcription assays showed that 8-amino-ATP competes with ATP for incorporation into mRNA. Collectively, we have concluded that 8-amino-adenosine elicits effects on multiple mechanisms of transcription, providing a new class of transcription inhibitors.
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Affiliation(s)
- Jennifer Ann Frey
- Department of Experimental Therapeutics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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41
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Iguchi T, Aishima S, Umeda K, Sanefuji K, Fujita N, Sugimachi K, Gion T, Taketomi A, Maehara Y, Tsuneyoshi M. Fascin expression in progression and prognosis of hepatocellular carcinoma. J Surg Oncol 2009; 100:575-9. [PMID: 19697358 DOI: 10.1002/jso.21377] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND OBJECTIVES Fascin is an actin-bundling protein and induces membrane protrusions and cell motility after the formation of lamellipodia or filopodia. Fascin expression has been reported to be associated with progression or prognosis in various neoplasms, but the role of fascin in hepatocellular carcinoma (HCC) remains unknown. The aim of this study was to investigate the clinicopathological and prognostic relevance of fascin by immunohistochemistry. METHODS A total of 137 patients with HCC were stained with anti-fascin antibody. The tumor cells having unequivocal cytoplasmic and/or membranous fascin immunoreactivity were defined as fascin-positive. RESULTS Immunohistochemically, 23 (16.8%) HCCs having unequivocal fascin immunoreactivity were found. Tumors showing fascin expression were larger and less differentiated than those showing no fascin expression (P = 0.0239 and 0.0018, respectively). Portal venous invasion, bile duct invasion, and intrahepatic metastasis were detected significantly more frequently in fascin-positive group (P = 0.0029, 0.0333, and 0.0403, respectively). In addition, high alpha-fetoprotein (AFP) levels were significantly associated with the fascin expression in HCC (P = 0.0116). Fascin-positive group had significantly poorer outcomes than fascin-negative group and was an independent prognostic factor for disease-free survival. CONCLUSIONS Fascin might become a novel marker of progression in HCC and a significant indicator of a poor prognosis for patients with HCC.
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Affiliation(s)
- Tomohiro Iguchi
- Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
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42
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Suriapranata IM, Sudania WM, Tjong WY, Suciptan AA, Gani RA, Hasan I, Sanityoso A, Budihusodo U, Miskad UA, Akil F, Lelosutan SAR, Martamala R, Yusuf I, Lesmana LA, Sulaiman A, Tai S. Alpha-fetoprotein gene polymorphisms and risk of HCC and cirrhosis. Clin Chim Acta 2009; 411:351-8. [PMID: 19968979 DOI: 10.1016/j.cca.2009.11.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 11/25/2009] [Accepted: 11/29/2009] [Indexed: 11/19/2022]
Abstract
BACKGROUND Elevated level of alpha fetoprotein (AFP) is found in approximately 60% of hepatocellular carcinoma (HCC) cases. Other liver diseases including cirrhosis and chronic hepatitis are related with an increased level of AFP. The regulation of AFP gene expression has been relatively less studied although the gene has been suggested to play a role in HCC development. This study aimed at identifying genetic variations in AFP that might be associated with the presence of HCC and cirrhosis among ethnic Indonesians. METHODS Direct DNA sequencing was carried out to sequence AFP promoter, exons, and 3' untranslated region (UTR) in DNA samples isolated from 119 HCC, 119 cirrhosis and 105 control subjects. For each sample serum AFP level was determined and association studies with single nucleotide polymorphisms (SNPs) and haplotypes were performed. RESULTS In this study we identified 47 SNPs in the AFP gene. Statistically significant associations with HCC and cirrhosis were detected for six individual SNPs in the AFP promoter, AFP intron 1 and intron 2 (rs6834059, rs3796678, rs3796677, rs3796676, rs28532518 and rs4646038). Furthermore, we identified two SNPs in AFP intron 7 and 3'UTR, rs2298839 and rs10020432, which are associated with increased risk of cirrhosis. CONCLUSION Genetic variants in the AFP gene may be associated with HCC and cirrhosis risk for ethnic Indonesians.
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Affiliation(s)
- Ivet M Suriapranata
- Mochtar Riady Institute for Nanotechnology, Lippo Karawaci, Tangerang, Indonesia
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Guerriero G, Martin N, Golovko A, Sundström JF, Rask L, Ezcurra I. The RY/Sph element mediates transcriptional repression of maturation genes from late maturation to early seedling growth. THE NEW PHYTOLOGIST 2009; 184:552-565. [PMID: 19659659 DOI: 10.1111/j.1469-8137.2009.02977.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In orthodox seeds, the transcriptional activator ABI3 regulates two major stages in embryo maturation: a mid-maturation (MAT) stage leading to accumulation of storage compounds, and a late maturation (LEA) stage leading to quiescence and desiccation tolerance. Our aim was to elucidate mechanisms for transcriptional shutdown of MAT genes during late maturation, to better understand phase transition between MAT and LEA stages. Using transgenic and transient approaches in Nicotiana, we examined activities of two ABI3-dependent reporter genes driven by multimeric RY and abscisic acid response elements (ABREs) from a Brassica napus napin gene, termed RY and ABRE, where the RY reporter requires ABI3 DNA binding. Expression of RY peaks during mid-maturation and drops during late maturation, mimicking the MAT gene program, and in Arabidopsis thaliana RY elements are over-represented in MAT, but not in LEA, genes. The ABI3 transactivation of RY is inhibited by staurosporine, by a PP2C phosphatase, and by a repressor of maturation genes, VAL1/HSI2. The RY element mediates repression of MAT genes, and we propose that transcriptional shutdown of the MAT program during late maturation involves inhibition of ABI3 DNA binding by dephosphorylation. Later, during seedling growth, VAL1/HSI2 family repressors silence MAT genes by binding RY elements.
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Affiliation(s)
- Gea Guerriero
- KTH Biotechnology, Swedish Center of Biomimetic Fiber Engineering, AlbaNova, SE-106 91, Stockholm, Sweden
| | - Nathalie Martin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, SE-751 23, Uppsala; Sweden
| | - Anna Golovko
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, SE-751 23, Uppsala; Sweden
| | - Jens F Sundström
- Department of Plant Biology and Forest Genetics, SLU, Box 7080, SE-750 07, Uppsala, Sweden
| | - Lars Rask
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, SE-751 23, Uppsala; Sweden
| | - Ines Ezcurra
- KTH Biotechnology, Swedish Center of Biomimetic Fiber Engineering, AlbaNova, SE-106 91, Stockholm, Sweden
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44
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Abstract
Long interspersed nuclear elements-1 (L1s) are highly repetitive DNA elements that are capable of altering the human genome through retrotransposition. To protect against L1 retroposition, the cell downregulates the expression of L1 proteins by various mechanisms, including high-density cytosine methylation of L1 promoters and DICER-dependent destruction of L1 mRNAs. In this report, a large number of p53 responsive elements, or p53 DNA binding sites, were detected in L1 elements within the human genome. At least some of these p53 responsive elements are functional and can act to increase the levels of L1 mRNA expression. The p53 protein can directly bind to a short 15-nucleotide sequence within the L1 promoter. This p53 responsive element within L1 is a recent addition to evolution, appearing approximately 20 million years ago. This suggests an interplay between L1 elements, which have a rich history of causing changes in the genome, and the p53 protein, the function of which is to protect against genomic changes. To understand these observations, a model is proposed in which the increased expression of L1 mRNAs by p53 actually increases, rather than decreases, the genomic stability through amplification of p53-dependent processes for genomic protection.
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45
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Banerjee T, Nath S, Roychoudhury S. DNA damage induced p53 downregulates Cdc20 by direct binding to its promoter causing chromatin remodeling. Nucleic Acids Res 2009; 37:2688-98. [PMID: 19273532 PMCID: PMC2677870 DOI: 10.1093/nar/gkp110] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
CDC20 is a critical molecule in the Spindle Assembly Checkpoint (SAC). It activates the Anaphase promoting complex and helps a dividing cell to proceed towards Anaphase. CDC20 is overexpressed in many tumor cells which cause chromosomal instability. There have been limited reports on the mechanism of SAC's response to genotoxic stress. We show that ectopically expressed p53 or DNA damage induced endogenous p53 can downregulate Cdc20 transcriptionally. We have identified a consensus p53-binding site on the Cdc20 promoter and have shown that it is being used by p53 to bind the promoter and bring about chromatin remodeling thereby repressing Cdc20. Additionally, p53 also downregulates Cdc20 promoter through CDE/CHR element, but in a p21 independent manner. This CDE/CHR element-mediated downregulation occurs only under p53 overexpressed condition but not in the context of DNA damage. The present results suggest that the two CCAAT elements in the Cdc20 promoter are not used by p53 to downregulate its activity, as reported earlier.
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Affiliation(s)
- Taraswi Banerjee
- Molecular and Human Genetics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata 700032, India
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46
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Atta MM, El-Masry SA, Abdel-Hameed M, Baiomy HA, Ramadan NE. Value of serum anti-p53 antibodies as a prognostic factor in Egyptian patients with hepatocellular carcinoma. Clin Biochem 2008; 41:1131-9. [DOI: 10.1016/j.clinbiochem.2008.06.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Revised: 05/15/2008] [Accepted: 06/04/2008] [Indexed: 12/26/2022]
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47
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Tsai WW, Nguyen TT, Shi Y, Barton MC. p53-targeted LSD1 functions in repression of chromatin structure and transcription in vivo. Mol Cell Biol 2008; 28:5139-46. [PMID: 18573881 PMCID: PMC2519740 DOI: 10.1128/mcb.00287-08] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite years of study focused on the tumor suppressor p53, little is understood about its functions in normal, differentiated cells. We found that p53 directly interacts with lysine-specific demethylase 1 (LSD1) to alter chromatin structure and confer developmental repression of the tumor marker alpha-fetoprotein (AFP). Chromatin immunoprecipitation (ChIP) and sequential ChIP of developmentally staged liver showed that p53 and LSD1 cooccupy a p53 response element, concomitant with dimethylated histone H3 lysine 4 (H3K4me2) demethylation and postnatal repression of AFP transcription. In p53-null mice, LSD1 binding is depleted, H3K4me2 is increased, and H3K9me2 remains unchanged compared to those of the wild type, underscoring the specificity of p53-LSD1 complexes in demethylation of H3K4me2. We performed partial hepatectomy of wild-type mouse liver and induced a regenerative response, which led to a loss of p53, increased H3K4me2, and decreased LSD1 interaction at AFP chromatin, in parallel with reactivation of AFP expression. In contrast, nuclear translocation of p53 in mouse embryonic fibroblasts led to p53 interaction with p21/CIP1 chromatin, without recruitment of LSD1, and to activation of p21/CIP1. These findings reveal that LSD1 is targeted to chromatin by p53, likely in a gene-specific manner, and define a molecular mechanism by which p53 mediates transcription repression in vivo during differentiation.
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Affiliation(s)
- Wen-Wei Tsai
- Dept. of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Box 1000, Houston, TX 77030, USA
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Zinc finger protein ZBTB20 is a key repressor of alpha-fetoprotein gene transcription in liver. Proc Natl Acad Sci U S A 2008; 105:10859-64. [PMID: 18669658 DOI: 10.1073/pnas.0800647105] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The alpha-fetoprotein (AFP) gene is highly activated in fetal liver but is dramatically repressed shortly after birth. The mechanisms that underlie AFP transcriptional repression in postpartum liver are not well understood. AFP enhancer, repressor region, and promoter are implicated to be involved in AFP postnatal repression, but the major transcriptional repressor remains undefined. We previously identified a zinc finger protein gene ZBTB20. To determine its physiological functions in vivo, we have generated hepatocyte-specific ZBTB20 knockout mice by the Cre/loxP approach and demonstrated here that ZBTB20 ablation in liver led to dramatic derepression of the AFP gene in entire liver throughout adult life, although the hepatocytes were normally under nonproliferating status. Furthermore, we found that ZBTB20 was a transcriptional repressor capable of specifically inhibiting AFP promoter-driven transcriptional activity. Liver chromatin immunoprecipitation and mobility shift assays showed that ZBTB20 bound to AFP promoter directly. ZBTB20 was developmentally activated in liver after birth and inversely correlated with its AFP gene expression, suggesting that activated ZBTB20 expression in liver mediated AFP gene repression. Our data point to ZBTB20 as a key regulator governing AFP gene transcription and postulate a new model for the postnatal gene repression of AFP in liver.
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Yang X, Zhang Y, Zhang L, Zhang L, Mao J. Silencing alpha-fetoprotein expression induces growth arrest and apoptosis in human hepatocellular cancer cell. Cancer Lett 2008; 271:281-93. [PMID: 18657899 DOI: 10.1016/j.canlet.2008.06.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 04/14/2008] [Accepted: 06/12/2008] [Indexed: 12/13/2022]
Abstract
The expression of alpha-fetoprotein (AFP), a tumor-associated antigen, is silenced in normal adult hepatocyte but reactivated in human hepatocellular carcinoma (HCC). To investigate the roles of AFP in the regulation of cell growth, we silenced AFP expression in the HCC cell line Huh7 by transfection of specific Stealth RNAi. After the transfection for 48 h, the expression of AFP gene was almost abolished, the cell proliferation was inhibited by 46.15%, and the number of cells undergoing early apoptosis was significantly increased to 63.93%. Inhibition of AFP expression also resulted in an increased in Bax/Bcl-2 ratio, the release of cytochrome c from mitochondria and activation of caspase-3. The results suggest that AFP may positively regulate cell proliferation by enhancing the apoptosis resistance via dysfunction of the p53/Bax/cytochrome c/caspase-3 signaling pathway in AFP-producing HCC cell line. As such, the knockdown of AFP gene should be further investigated in vivo as a novel approach to HCC treatment.
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Affiliation(s)
- Xiaojun Yang
- Department of General Surgery, Lanzhou University Second Hospital, Lanzhou, 730030, Gansu, China
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50
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Abstract
The p53 protein regulates the transcription of many different genes in response to a wide variety of stress signals. Following DNA damage, p53 regulates key processes, including DNA repair, cell-cycle arrest, senescence and apoptosis, in order to suppress cancer. This Analysis article provides an overview of the current knowledge of p53-regulated genes in these pathways and others, and the mechanisms of their regulation. In addition, we present the most comprehensive list so far of human p53-regulated genes and their experimentally validated, functional binding sites that confer p53 regulation.
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