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Duong MT, Akli S, Macalou S, Biernacka A, Debeb BG, Yi M, Hunt KK, Keyomarsi K. Hbo1 is a cyclin E/CDK2 substrate that enriches breast cancer stem-like cells. Cancer Res 2013; 73:5556-68. [PMID: 23955388 DOI: 10.1158/0008-5472.can-13-0013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Expression of cyclin E proteolytic cleavage products, low-molecular weight cyclin E (LMW-E), is associated with poor clinical outcome in patients with breast cancer and it enhances tumorigenecity in mouse models. Here we report that LMW-E expression in human mammary epithelial cells induces an epithelial-to-mesenchymal transition phenotype, increases the CD44(hi)/CD24(lo) population, enhances mammosphere formation, and upregulates aldehyde dehydrogenase expression and activity. We also report that breast tumors expressing LMW-E have a higher proportion of CD44(hi)/CD24(lo) tumor cells as compared with tumors expressing only full-length cyclin E. In order to explore how LMW-E enriches cancer stem cells in breast tumors, we conducted a protein microarray analysis that identified the histone acetyltransferase (HAT) Hbo1 as a novel cyclin E/CDK2 substrate. The LMW-E/CDK2 complex phosphorylated Hbo1 at T88 without affecting its HAT activity. When coexpressed with LMW-E/CDK2, wild-type Hbo1 promoted enrichment of cancer stem-like cells (CSC), whereas the T88 Hbo1 mutant reversed the CSC phenotype. Finally, doxorubicin and salinomycin (a CSC-selective cytotoxic agent) synergized to kill cells expressing LMW-E, but not full-length cyclin E. Collectively, our results suggest that the heightened oncogenecity of LMW-E relates to its ability to promote CSC properties, supporting the design of therapeutic strategies to target this unique function.
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Affiliation(s)
- Mylinh T Duong
- Departments of Experimental Radiation Oncology, Radiation Oncology, and Surgical Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 0066, Houston, TX77030, USA
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52
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Abstract
Although distinct chromatin types have been long known to replicate at different timepoints of S phase, fine replication control has only recently become considered as an epigenetic phenomenon. It is now clear that in course of differentiation significant changes in genome replication timing occur, and these changes are intimately linked with the changes in transcriptional activity and nuclear architecture. Temporally coordinate replication is organized spatially into discrete units having specific chromosomal organization and function. Even though the functional aspects of such tight control of replication timing remain to be explored, one can confidently consider the replication program as yet another fundamental feature characteristic of the given differentiation state. The present review touches upon the molecular mechanisms of spatial and temporal control of replication timing, involving individual replication origins as well as large chromatin domains.
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53
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Song B, Liu XS, Rice S, Kuang S, Elzey BD, Konieczny SF, Ratliff TL, Hazbun T, Chiorean EG, Liu X. Plk1 phosphorylation of orc2 and hbo1 contributes to gemcitabine resistance in pancreatic cancer. Mol Cancer Ther 2013; 12:58-68. [PMID: 23188630 PMCID: PMC3732037 DOI: 10.1158/1535-7163.mct-12-0632] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although gemcitabine is the standard chemotherapeutic drug for treatment of pancreatic cancer, almost all patients eventually develop resistance to this agent. Previous studies identified Polo-like kinase 1 (Plk1) as the mediator of gemcitabine resistance, but the molecular mechanism remains unknown. In this study, we show that Plk1 phosphorylation of Orc2 and Hbo1 mediates the resistance to gemcitabine. We show that the level of Plk1 expression positively correlates with gemcitabine resistance, both in pancreatic cancer cells and xenograft tumors. Overexpression of Plk1 increases gemcitabine resistance, while inhibition of Plk1 sensitizes pancreatic cancer cells to gemcitabine treatment. To validate our findings, we show that inhibition of Plk1 sensitizes tumors to gemcitabine treatment in a mouse xenograft study. Mechanistically, we find that Plk1 phosphorylation of Orc2 maintains DNA replication on gemcitabine treatment. Furthermore, Plk1 phosphorylation of Hbo1 transcriptionally increases cFos expression and consequently elevates its target multidrug resistance 1 (MDR1), which was previously reported to confer chemotherapeutic drug resistance. Knockdown of cFos or MDR1 sensitizes gemcitabine-resistant cells to gemcitabine treatment. Finally, pancreatic cancer cells expressing Plk1-unphosphorylatable mutants of Orc2 or Hbo1 are more sensitive to gemcitabine than cells expressing wild-type Orc2 or Hbo1. In short, our study provides a mechanism for Plk1-mediated gemcitabine resistance, suggesting that Plk1 is a promising target for treatment of gemcitabine-resistant pancreatic cancer.
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Affiliation(s)
- Bing Song
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | - X. Shawn Liu
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907
| | - Steven Rice
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Bennett D. Elzey
- Department of Comparative Pathology, Purdue University, West Lafayette, IN 47907
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Stephen F. Konieczny
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Timothy L. Ratliff
- Department of Comparative Pathology, Purdue University, West Lafayette, IN 47907
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
| | - Tony Hazbun
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Elena G. Chiorean
- Indiana University Melvin and Bren Simon Cancer Center, Indianapolis, IN 46202
| | - Xiaoqi Liu
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907
- Purdue Center for Cancer Research, Purdue University, West Lafayette, IN 47907
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54
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Havasi A, Haegele JA, Gall JM, Blackmon S, Ichimura T, Bonegio RG, Panchenko MV. Histone acetyl transferase (HAT) HBO1 and JADE1 in epithelial cell regeneration. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 182:152-62. [PMID: 23159946 DOI: 10.1016/j.ajpath.2012.09.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/09/2012] [Accepted: 09/20/2012] [Indexed: 12/31/2022]
Abstract
HBO1 acetylates lysine residues of histones and is involved in DNA replication and gene transcription. Two isoforms of JADE1, JADE1S and JADE1L, bind HBO1 and promote acetylation of histones in chromatin context. We characterized the role of JADE1-HBO1 complexes in vitro and in vivo during epithelial cell replication. Down-regulation of JADE1 by siRNA diminished the rate of DNA synthesis in cultured cells, decreased endogenous HBO1 protein expression, and prevented chromatin recruitment of replication factor Mcm7, demonstrating that JADE1 is required for cell proliferation. We used a murine model of acute kidney injury to examine expression of HBO1-JADE1S/L in injured and regenerating epithelial tissue. In control kidneys, JADE1S, JADE1L, and HBO1 were expressed in nuclei of proximal and distal tubular epithelial cells. Ischemia and reperfusion injury resulted in an initial decrease in JADE1S, JADE1L, and HBO1 protein levels, which returned to baseline during renal recovery. HBO1 and JADE1S recovered as cell proliferation reached its maximum, whereas JADE1L recovered after bulk proliferation had ceased. The temporal expression of JADE1S correlated with the acetylation of histone H4 on lysines 5 and 12, but not with acetylation of histone H3 on lysine 14, demonstrating that the JADE1S-HBO1 complex specifically marks H4 during epithelial cell proliferation. These data implicate JADE1-HBO1 complex in acute kidney injury and suggest distinct roles for JADE1 isoforms during epithelial cell recovery.
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Affiliation(s)
- Andrea Havasi
- Department of Pathology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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55
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Abstract
Lysine acetylation refers to transfer of the acetyl moiety from acetyl-CoA to the ε-amino group of a lysine residue on a protein. This has recently emerged as a major covalent modification and interplays with other modifications, such as phosphorylation, methylation, ubiquitination (addition of a small protein called ubiquitin) and SUMOylation [addition of a ubiquitin-like protein known as SUMO (small ubiquitin-related modifier)], to form multisite modification programmes for cellular regulation in diverse organisms. This modification is post-translational (i.e. after synthesis of a protein) and reversible, with its level being dynamically balanced by two groups of enzymes known as lysine acetyltransferases and deacetylases. The acetyltransferases belong to three major families, whereas deacetylases have been divided into the classical and sirtuin [Sir-tu-in, for Sir2 (silent information regulator 2)-like protein; named after the yeast protein Sir2] families. In addition to these enzymes, proteins containing the bromodomain, a protein module named after the fly protein Brahma (God of creation in Hindu), are relevant to lysine acetylation biology due to their ability to recognize acetyl-lysine-containing peptides. Importantly, recent studies have made intimate links between these three different groups of proteins to different pathological conditions. In this chapter, we provide a brief overview of these proteins and emphasize their direct links to related human diseases.
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56
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Gigek CO, Chen ES, Calcagno DQ, Wisnieski F, Burbano RR, Smith MAC. Epigenetic mechanisms in gastric cancer. Epigenomics 2012; 4:279-94. [PMID: 22690664 DOI: 10.2217/epi.12.22] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cancer is considered one of the major health issues worldwide, and gastric cancer accounted for 8% of total cases and 10% of total deaths in 2008. Gastric cancer is considered an age-related disease, and the total number of newly diagnosed cases has been increasing as a result of the higher life expectancy. Therefore, the basic mechanisms underlying gastric tumorigenesis is worth investigation. This review provides an overview of the epigenetic mechanisms, such as DNA methylation, histone modifications, chromatin remodeling complex and miRNA, involved in gastric cancer. As the studies in gastric cancer continue, the mapping of an epigenome code is not far for this disease. In conclusion, an epigenetic therapy might appear in the not too distant future.
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Affiliation(s)
- Carolina Oliveira Gigek
- Disciplina de Genética, Departamento de Morfologia e Genética, Escola Paulista de Medicina/Universidade Federal de São Paulo, Rua Botucatu 740, São Paulo, SP, Brazil.
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57
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Abstract
Breast cancer is caused by progressive genetic alterations and epigenetic changes that trigger tumor development. Among the epigenetic alterations descried in breast cancer, DNA promoter methylation has been extensively studied and observed in genes involved in several critical signaling pathways that initiate and promote breast tumorigenesis. In addition to DNA hypermethylation, global methylation levels have been observed to decrease with breast cancer progression. In close connection with DNA methylation changes, histone modifications, especially the acetylation and methylation of histone lysines, play an essential role in the nucleosomes remodeling and gene expression regulation in breast cancer.
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Affiliation(s)
- Ramona G Dumitrescu
- Saba University School of Medicine, Saba Island and Georgetown University Medical School, Washington, DC, USA.
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58
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Sun WJ, Zhou X, Zheng JH, Lu MD, Nie JY, Yang XJ, Zheng ZQ. Histone acetyltransferases and deacetylases: molecular and clinical implications to gastrointestinal carcinogenesis. Acta Biochim Biophys Sin (Shanghai) 2012; 44:80-91. [PMID: 22194016 DOI: 10.1093/abbs/gmr113] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Histone acetyltransferases and deacetylases are two groups of enzymes whose opposing activities govern the dynamic levels of reversible acetylation on specific lysine residues of histones and many other proteins. Gastrointestinal (GI) carcinogenesis is a major cause of morbidity and mortality worldwide. In addition to genetic and environmental factors, the role of epigenetic abnormalities such as aberrant histone acetylation has been recognized to be pivotal in regulating benign tumorigenesis and eventual malignant transformation. Here we provide an overview of histone acetylation, list the major groups of histone acetyltransferases and deacetylases, and cover in relatively more details the recent studies that suggest the links of these enzymes to GI carcinogenesis. As potential novel therapeutics for GI and other cancers, histone deacetylase inhibitors are also discussed.
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Affiliation(s)
- Wei-Jian Sun
- The 2nd Affiliated Hospital, Wenzhou Medical College, China
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59
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Miotto B, Struhl K. JNK1 phosphorylation of Cdt1 inhibits recruitment of HBO1 histone acetylase and blocks replication licensing in response to stress. Mol Cell 2011; 44:62-71. [PMID: 21856198 DOI: 10.1016/j.molcel.2011.06.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 02/08/2011] [Accepted: 06/23/2011] [Indexed: 10/17/2022]
Abstract
In response to environmental stresses, cells activate stress-response genes and inhibit DNA replication. HBO1 histone acetylase is a coactivator both for AP-1 transcription factors responding to stress-activated JNK kinases and also for the Cdt1 licensing factor that ensures that DNA is replicated exactly once per cell cycle. In response to nongenotoxic stress, JNK phosphorylates Jun, an AP-1 transcription factor, leading to increased recruitment of HBO1 and increased transcription of target genes. In addition, JNK phosphorylates Cdt1 on threonine 29, leading to rapid dissociation of HBO1 from replication origins, thereby blocking initiation of DNA replication. Upon relief of stress, HBO1 reassociates with replication origins. Thus, regulated and reciprocal recruitment of the HBO1 coactivator to target genes and replication origins via JNK-mediated phosphorylation of the recruiting transcription and replication licensing factors coordinates the transcriptional and DNA replication response to cellular stress.
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Affiliation(s)
- Benoit Miotto
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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60
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Liu J, McConnell K, Dixon M, Calvi BR. Analysis of model replication origins in Drosophila reveals new aspects of the chromatin landscape and its relationship to origin activity and the prereplicative complex. Mol Biol Cell 2011; 23:200-12. [PMID: 22049023 PMCID: PMC3248898 DOI: 10.1091/mbc.e11-05-0409] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
A study of model DNA replication origins in Drosophila reveals a codependence between histone acetylation and pre-RC assembly and leads to a chromatin switch model for the coordination of origin and promoter activity during development. Epigenetic regulation exerts a major influence on origins of DNA replication during development. The mechanisms for this regulation, however, are poorly defined. We showed previously that acetylation of nucleosomes regulates the origins that mediate developmental gene amplification during Drosophila oogenesis. Here we show that developmental activation of these origins is associated with acetylation of multiple histone lysines. Although these modifications are not unique to origin loci, we find that the level of acetylation is higher at the active origins and quantitatively correlated with the number of times these origins initiate replication. All of these acetylation marks were developmentally dynamic, rapidly increasing with origin activation and rapidly declining when the origins shut off and neighboring promoters turn on. Fine-scale analysis of the origins revealed that both hyperacetylation of nucleosomes and binding of the origin recognition complex (ORC) occur in a broad domain and that acetylation is highest on nucleosomes adjacent to one side of the major site of replication initiation. It was surprising to find that acetylation of some lysines depends on binding of ORC to the origin, suggesting that multiple histone acetyltransferases may be recruited during origin licensing. Our results reveal new insights into the origin epigenetic landscape and lead us to propose a chromatin switch model to explain the coordination of origin and promoter activity during development.
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Affiliation(s)
- Jun Liu
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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61
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The Hbo1-Brd1/Brpf2 complex is responsible for global acetylation of H3K14 and required for fetal liver erythropoiesis. Blood 2011; 118:2443-53. [DOI: 10.1182/blood-2011-01-331892] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Abstract
The histone acetyltransferases (HATs) of the MYST family include TIP60, HBO1, MOZ/MORF, and MOF and function in multisubunit protein complexes. Bromodomain-containing protein 1 (BRD1), also known as BRPF2, has been considered a subunit of the MOZ/MORF H3 HAT complex based on analogy with BRPF1 and BRPF3. However, its physiologic function remains obscure. Here we show that BRD1 forms a novel HAT complex with HBO1 and regulates erythropoiesis. Brd1-deficient embryos showed severe anemia because of impaired fetal liver erythropoiesis. Biochemical analyses revealed that BRD1 bridges HBO1 and its activator protein, ING4. Genome-wide mapping in erythroblasts demonstrated that BRD1 and HBO1 largely colocalize in the genome and target key developmental regulator genes. Of note, levels of global acetylation of histone H3 at lysine 14 (H3K14) were profoundly decreased in Brd1-deficient erythroblasts and depletion of Hbo1 similarly affected H3K14 acetylation. Impaired erythropoiesis in the absence of Brd1 accompanied reduced expression of key erythroid regulator genes, including Gata1, and was partially restored by forced expression of Gata1. Our findings suggest that the Hbo1-Brd1 complex is the major H3K14 HAT required for transcriptional activation of erythroid developmental regulator genes.
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Arnold KM, Lee S, Denu JM. Processing mechanism and substrate selectivity of the core NuA4 histone acetyltransferase complex. Biochemistry 2011; 50:727-37. [PMID: 21182309 DOI: 10.1021/bi101355a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Esa1, an essential MYST histone acetyltransferase found in the yeast piccolo NuA4 complex (picNuA4), is responsible for genome-wide histone H4 and histone H2A acetylation. picNuA4 uniquely catalyzes the rapid tetra-acetylation of nucleosomal H4, though the molecular determinants driving picNuA4 efficiency and specificity have not been defined. Here, we show through rapid substrate trapping experiments that picNuA4 utilizes a nonprocessive mechanism in which picNuA4 dissociates from the substrate after each acetylation event. Quantitative mass spectral analyses indicate that picNuA4 randomly acetylates free and nucleosomal H4, with a small preference for lysines 5, 8, and 12 over lysine 16. Using a series of 24 histone mutants of H4 and H2A, we investigated the parameters affecting catalytic efficiency. Most strikingly, removal of lysine residues did not substantially affect the ability of picNuA4 to acetylate remaining sites, and insertion of an additional lysine into the H4 tail led to rapid quintuple acetylation. Conversion of the native H2A tail to an H4-like sequence resulted in enhanced multisite acetylation. Collectively, the results suggest picNuA4's site selectivity is dictated by accessibility on the nucleosome surface, the relative proximity from the histone fold domain, and a preference for intervening glycine residues with a minimal (n + 2) spacing between lysines. Functionally distinct from other HAT families, the proposed model for picNuA4 represents a unique mechanism of substrate recognition and multisite acetylation.
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Affiliation(s)
- Kevin M Arnold
- Department of Biomolecular Chemistry, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, United States
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63
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HBO1 is required for H3K14 acetylation and normal transcriptional activity during embryonic development. Mol Cell Biol 2010; 31:845-60. [PMID: 21149574 DOI: 10.1128/mcb.00159-10] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We report here that the MYST histone acetyltransferase HBO1 (histone acetyltransferase bound to ORC; MYST2/KAT7) is essential for postgastrulation mammalian development. Lack of HBO1 led to a more than 90% reduction of histone 3 lysine 14 (H3K14) acetylation, whereas no reduction of acetylation was detected at other histone residues. The decrease in H3K14 acetylation was accompanied by a decrease in expression of the majority of genes studied. However, some genes, in particular genes regulating embryonic patterning, were more severely affected than "housekeeping" genes. Development of HBO1-deficient embryos was arrested at the 10-somite stage. Blood vessels, mesenchyme, and somites were disorganized. In contrast to previous studies that reported cell cycle arrest in HBO1-depleted cultured cells, no defects in DNA replication or cell proliferation were seen in Hbo1 mutant embryo primary fibroblasts or immortalized fibroblasts. Rather, a high rate of cell death and DNA fragmentation was observed in Hbo1 mutant embryos, resulting initially in the degeneration of mesenchymal tissues and ultimately in embryonic lethality. In conclusion, the primary role of HBO1 in development is that of a transcriptional activator, which is indispensable for H3K14 acetylation and for the normal expression of essential genes regulating embryonic development.
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64
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Wang WZ, Liu HO, Wu YH, Hong Y, Yang JW, Liu YH, Wu WB, Zhou L, Sun LL, Xu JJ, Yun XJ, Gu JX. Estrogen receptor α (ERα) mediates 17β-estradiol (E2)-activated expression of HBO1. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2010; 29:140. [PMID: 21040551 PMCID: PMC2989947 DOI: 10.1186/1756-9966-29-140] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 11/01/2010] [Indexed: 12/21/2022]
Abstract
BACKGROUND HBO1 (histone acetyltransferase binding to ORC1) is a histone acetyltransferase (HAT) which could exert oncogenic function in breast cancer. However, the biological role and underlying mechanism of HBO1 in breast cancer remains largely unknown. In the current study, we aimed to investigate the role of HBO1 in breast cancer and uncover the underlying molecular mechanism. METHODS Immunohistochemistry was applied to detect HBO1 protein expression in breast cancer specimens (n=112). The expression of protein level was scored by integral optical density (IOD) for further statistical analyses using SPSS. Real-time PCR was used to simultaneously measure mRNA levels of HBO1. The HBO1 protein expression in breast cancer cells was confirmed by western blot. RESULTS HBO1 was highly expressed in breast cancer tissues and significantly correlated with estrogen receptor α (ERα) (p<0.001) and progestational hormone (PR) (p=0.002). HBO1 protein level also correlated positively with histology grade in ERα positive tumors (p=0.016) rather than ERα negative tumors. 17β-estradiol (E2) could upregulate HBO1 gene expression which was significantly inhibited by ICI 182,780 or ERα RNAi. E2-increased HBO1 protein expression was significantly suppressed by treatment with inhibitor of MEK1/2 (U0126) in T47 D and MCF-7 cells. CONCLUSIONS HBO1 was an important downstream molecule of ERα, and ERK1/2 signaling pathway may involved in the expression of HBO1 increased by E2.
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Affiliation(s)
- Wen-zhong Wang
- Department of Biochemistry and Molecular Biology, Shanghai Medical College of Fudan University, Shanghai, 200032, China
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65
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Abstract
In this issue of Molecular Cell, Miotto and Struhl (2010) suggest that replication licensing, the loading of Mcm2-7 onto DNA, is promoted by HBO1 acetylating histone H4 at replication origins, providing a molecular view of how chromatin status influences origin usage.
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Affiliation(s)
- Gaganmeet Singh Chadha
- Wellcome Trust Centre for Gene Regulation & Expression, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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66
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Dalvai M, Bystricky K. The role of histone modifications and variants in regulating gene expression in breast cancer. J Mammary Gland Biol Neoplasia 2010; 15:19-33. [PMID: 20131086 DOI: 10.1007/s10911-010-9167-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 01/08/2010] [Indexed: 02/03/2023] Open
Abstract
The role of epigenetic phenomena in cancer biology is increasingly being recognized. Here we focus on the mechanisms and enzymes involved in regulating histone methylation and acetylation, and the modulation of histone variant expression and deposition. Implications of these epigenetic marks for tumor development, progression and invasiveness are discussed with a particular emphasis on breast cancer progression.
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Affiliation(s)
- Mathieu Dalvai
- Université de Toulouse, LBME, 118 route de Narbonne, 31062, Toulouse, France.
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