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Di Girolamo D, Di Iorio E, Missero C. Molecular and Cellular Function of p63 in Skin Development and Genetic Diseases. J Invest Dermatol 2024:S0022-202X(24)02076-1. [PMID: 39340489 DOI: 10.1016/j.jid.2024.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 08/02/2024] [Accepted: 08/16/2024] [Indexed: 09/30/2024]
Abstract
The transcription factor p63 is a master regulator of multiple ectodermal derivatives. During epidermal commitment, p63 interacts with several chromatin remodeling complexes to transactivate epidermal-specific genes and repress transcription of simple epithelial and nonepithelial genes. In the postnatal epidermis, p63 is required to control the proliferative potential of progenitor cells, maintain epidermal integrity, and contribute to epidermal differentiation. Autosomal dominant sequence variant in p63 cause a spectrum of syndromic disorders that affect several tissues, including or derived from stratified epithelia. In this review, we describe the recent studies that have provided novel insights into disease pathogenesis and potential therapeutic targets.
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Affiliation(s)
- Daniela Di Girolamo
- CEINGE Biotecnologie Avanzate Franco Salvatore, Naples, Italy; Biology Department, University of Naples Federico II, Naples, Italy
| | - Enzo Di Iorio
- Clinical Genetics Unit, University Hospital of Padua, Padua, Italy; Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Caterina Missero
- CEINGE Biotecnologie Avanzate Franco Salvatore, Naples, Italy; Biology Department, University of Naples Federico II, Naples, Italy.
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2
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Abstract
Keratinocyte senescence contributes to skin ageing and epidermal dysfunction. According to the existing knowledge, the transcription factor ΔNp63α plays pivotal roles in differentiation and proliferation of keratinocytes. It is traditionally accepted that ΔNp63α exerts its functions via binding to promoter regions to activate or repress gene transcription. However, accumulating evidence demonstrates that ΔNp63α can bind to elements away from promoter regions of its target genes, mediating epigenetic regulation. On the other hand, several epigenetic alterations, including DNA methylation, histone modification and variation, chromatin remodelling, as well as enhancer-promoter looping, are found to be related to cell senescence. To systematically elucidate how ΔNp63α affects keratinocyte senescence via epigenetic regulation, we comprehensively compiled the literatures on the roles of ΔNp63α in keratinocyte senescence, epigenetics in cellular senescence, and the relation between ΔNp63α-mediated epigenetic regulation and keratinocyte senescence. Based on the published data, we conclude that ΔNp63α mediates epigenetic regulation via multiple mechanisms: recruiting epigenetic enzymes to modify DNA or histones, coordinating chromatin remodelling complexes (CRCs) or regulating their expression, and mediating enhancer-promoter looping. Consequently, the expression of genes related to cell cycle is modulated, and proliferation of keratinocytes and renewal of stem cells are maintained, by ΔNp63α. During skin inflammaging, the decline of ΔNp63α may lead to epigenetic dysregulation, resultantly deteriorating keratinocyte senescence.
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Affiliation(s)
- Linghan Kuang
- Department of Laboratory Medicine, West China Second University Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu 610041, China
| | - Chenghua Li
- Center of Growth, Metabolism and Aging, Key Laboratory of Biological Resources and Ecological Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, China
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3
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Chen CW, Zhang L, Dutta R, Niroula A, Miller PG, Gibson CJ, Bick AG, Reyes JM, Lee YT, Tovy A, Gu T, Waldvogel S, Chen YH, Venters BJ, Estève PO, Pradhan S, Keogh MC, Natarajan P, Takahashi K, Sperling AS, Goodell MA. SRCAP mutations drive clonal hematopoiesis through epigenetic and DNA repair dysregulation. Cell Stem Cell 2023; 30:1503-1519.e8. [PMID: 37863054 PMCID: PMC10841682 DOI: 10.1016/j.stem.2023.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/25/2023] [Accepted: 09/27/2023] [Indexed: 10/22/2023]
Abstract
Somatic mutations accumulate in all cells with age and can confer a selective advantage, leading to clonal expansion over time. In hematopoietic cells, mutations in a subset of genes regulating DNA repair or epigenetics frequently lead to clonal hematopoiesis (CH). Here, we describe the context and mechanisms that lead to enrichment of hematopoietic stem cells (HSCs) with mutations in SRCAP, which encodes a chromatin remodeler that also influences DNA repair. We show that SRCAP mutations confer a selective advantage in human cells and in mice upon treatment with the anthracycline-class chemotherapeutic doxorubicin and bone marrow transplantation. Furthermore, Srcap mutations lead to a lymphoid-biased expansion, driven by loss of SRCAP-regulated H2A.Z deposition and increased DNA repair. Altogether, we demonstrate that SRCAP operates at the intersection of multiple pathways in stem and progenitor cells, offering a new perspective on the functional impact of genetic variants that promote stem cell competition in the hematopoietic system.
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Affiliation(s)
- Chun-Wei Chen
- Interdepartmental Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Linda Zhang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA; Program in Translational Biology and Molecular Medicine, Houston, TX, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Ravi Dutta
- Division of Hematology, Brigham and Women's Hospital, Boston, MA, USA
| | - Abhishek Niroula
- Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Peter G Miller
- Division of Hematology, Brigham and Women's Hospital, Boston, MA, USA; Center for Cancer Research and Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | | - Alexander G Bick
- Division of Hematology, Brigham and Women's Hospital, Boston, MA, USA; Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jaime M Reyes
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Yi-Tang Lee
- Interdepartmental Program in Integrative Molecular and Biomedical Sciences, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ayala Tovy
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Tianpeng Gu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA
| | - Sarah Waldvogel
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Yi-Hung Chen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | | | | | | | | | - Pradeep Natarajan
- Division of Hematology, Brigham and Women's Hospital, Boston, MA, USA; Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Koichi Takahashi
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Adam S Sperling
- Division of Hematology, Brigham and Women's Hospital, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Margaret A Goodell
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, TX, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA.
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4
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Oyelakin A, Sosa J, Nayak K, Glathar A, Gluck C, Sethi I, Tsompana M, Nowak N, Buck M, Romano RA, Sinha S. An integrated genomic approach identifies follistatin as a target of the p63-epidermal growth factor receptor oncogenic network in head and neck squamous cell carcinoma. NAR Cancer 2023; 5:zcad038. [PMID: 37492374 PMCID: PMC10365026 DOI: 10.1093/narcan/zcad038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/27/2023] Open
Abstract
Although numerous putative oncogenes have been associated with the etiology of head and neck squamous cell carcinoma (HNSCC), the mechanisms by which these oncogenes and their downstream targets mediate tumor progression have not been fully elucidated. We performed an integrative analysis to identify a crucial set of targets of the oncogenic transcription factor p63 that are common across multiple transcriptomic datasets obtained from HNSCC patients, and representative cell line models. Notably, our analysis revealed FST which encodes follistatin, a secreted glycoprotein that inhibits the transforming growth factor TGFβ/activin signaling pathways, to be a direct transcriptional target of p63. In addition, we found that FST expression is also driven by epidermal growth factor receptor EGFR signaling, thus mediating a functional link between the TGF-β and EGFR pathways. We show through loss- and gain-of-function studies that FST predominantly imparts a tumor-growth and migratory phenotype in HNSCC cells. Furthermore, analysis of single-cell RNA sequencing data from HNSCC patients unveiled cancer cells as the dominant source of FST within the tumor microenvironment and exposed a correlation between the expression of FST and its regulators with immune infiltrates. We propose FST as a prognostic biomarker for patient survival and a compelling candidate mediating the broad effects of p63 on the tumor and its associated microenvironment.
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Affiliation(s)
- Akinsola Oyelakin
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Jennifer Sosa
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Kasturi Bala Nayak
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Alexandra Glathar
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Christian Gluck
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Isha Sethi
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Maria Tsompana
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Norma Nowak
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Michael Buck
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
- Department of Biomedical Informatics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Rose-Anne Romano
- Department of Oral Biology, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA
| | - Satrajit Sinha
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
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Yang K, Wang Q, Wu L, Gao QC, Tang S. Development and verification of a combined diagnostic model for primary Sjögren's syndrome by integrated bioinformatics analysis and machine learning. Sci Rep 2023; 13:8641. [PMID: 37244954 DOI: 10.1038/s41598-023-35864-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/25/2023] [Indexed: 05/29/2023] Open
Abstract
Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease mostly affecting the exocrine glands. This debilitating condition is complex and specific treatments remain unavailable. There is a need for the development of novel diagnostic models for early screening. Four gene profiling datasets were downloaded from the Gene Expression Omnibus database. The 'limma' software package was used to identify differentially expressed genes (DEGs). A random forest-supervised classification algorithm was used to screen disease-specific genes, and three machine learning algorithms, including artificial neural networks (ANN), random forest (RF), and support vector machines (SVM), were used to build a pSS diagnostic model. The performance of the model was measured using its area under the receiver operating characteristic curve. Immune cell infiltration was investigated using the CIBERSORT algorithm. A total of 96 DEGs were identified. By utilizing a RF classifier, a set of 14 signature genes that are pivotal in transcription regulation and disease progression in pSS were identified. Through the utilization of training and testing datasets, diagnostic models for pSS were successfully designed using ANN, RF, and SVM, resulting in AUCs of 0.972, 1.00, and 0.9742, respectively. The validation set yielded AUCs of 0.766, 0.8321, and 0.8223. It was the RF model that produced the best prediction performance out of the three models tested. As a result, an early predictive model for pSS was successfully developed with high diagnostic performance, providing a valuable resource for the screening and early diagnosis of pSS.
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Affiliation(s)
- Kun Yang
- School of Humanities and Social Sciences, Shanxi Medical University, Taiyuan, China
| | - Qi Wang
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
- Shanxi Key Laboratory of Big Data for Clinical Decision Research, Taiyuan, China
- Key Laboratory of Cellular Physiology at Shanxi Medical University, Ministry of Education, Taiyuan, China
| | - Li Wu
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
- Department of Anesthesiology, Shanxi Provincial People's Hospital (Fifth Hospital) of Shanxi Medical University, Taiyuan, China
| | - Qi-Chao Gao
- School of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
- Shanxi Key Laboratory of Big Data for Clinical Decision Research, Taiyuan, China
- Key Laboratory of Cellular Physiology at Shanxi Medical University, Ministry of Education, Taiyuan, China
| | - Shan Tang
- The First Hospital of Shanxi Medical University, Taiyuan, China.
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Kudo KI, Tsuyama N, Nagata K, Imaoka T, Iizuka D, Sugai-Takahashi M, Muramatsu M, Sakai A. ΔNp63α transcriptionally represses p53 target genes involved in the radiation-induced DNA damage response : ΔNp63α may cause genomic instability in epithelial stem cells. Radiat Oncol 2022; 17:183. [PMID: 36380314 PMCID: PMC9667649 DOI: 10.1186/s13014-022-02139-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/05/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The DNA damage response (DDR) is a mechanism that protects cells against radiation-induced oxidative DNA damage by causing cell cycle arrest and apoptosis. TP63 is a member of the tumour suppressor TP53 gene family, and ΔNp63α, a TP63 splicing variant, is constitutively expressed in the stem cell-containing basal layer of stratified epithelial tissues, including the mammary gland, where it plays a critical role in stemness and tissue development. ΔNp63α has been reported to transcriptionally inhibit the tumour suppression protein p53. This p53-repressive activity may cause genomic instability in epithelial stem cells exposed to radiation. In this study, we analysed the inhibitory effect of ΔNp63α on radiation-induced DDR. METHODS To elucidate the role of the p53-repressive effect of ΔNp63α in radiation response, we performed a p63-siRNA knockdown experiment using human mammary epithelial cells (HMECs) expressing ΔNp63α and then performed ectopic and entopic expression experiments using human induced pluripotent stem cells (hiPSCs). After irradiation, the expression of DDR-related genes and proteins in ΔNp63α-expressing and control cells was analysed by RT-qPCR, Western blotting, and flow cytometry. RESULTS The mRNA/protein expression levels of BAX and p21 were significantly increased in p63-siRNA-treated HMECs (sip63) after X-ray irradiation (4 Gy, 0.7 Gy/min) but not in scramble-siRNA treated HMECs (scr). Transcriptomic analysis showed decreased RNA expression of cell cycle-related genes and increased expression of programmed cell death-related genes in sip63 cells compared to scr cells. Furthermore, flow cytometric analysis revealed an increase in apoptotic cells and a decrease in 5-ethynyl-2´-deoxyuridine uptake in sip63 cells compared to scr cells. On the other hand, both the ectopic and entopic expression of ΔNp63α in apoptosis-sensitive hiPSCs reduced the expression levels of BAX after irradiation and significantly decreased the number of apoptotic cells induced by radiation. CONCLUSION Taken together, these results indicate that ΔNp63α represses p53-related radiation-induced DDR, thereby potentially causing genomic instability in epithelial stem cells.
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Affiliation(s)
- Ken-Ichi Kudo
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan.
| | - Naohiro Tsuyama
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Kento Nagata
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Tatsuhiko Imaoka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Daisuke Iizuka
- Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Misaki Sugai-Takahashi
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Moe Muramatsu
- Department of Diagnostic Pathology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Akira Sakai
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
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Distinct interactors define the p63 transcriptional signature in epithelial development or cancer. Biochem J 2022; 479:1375-1392. [PMID: 35748701 PMCID: PMC9250260 DOI: 10.1042/bcj20210737] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/01/2022] [Accepted: 06/06/2022] [Indexed: 11/24/2022]
Abstract
The TP63 is an indispensable transcription factor for development and homeostasis of epithelia and its derived glandular tissue. It is also involved in female germline cell quality control, muscle and thymus development. It is expressed as multiple isoforms transcribed by two independent promoters, in addition to alternative splicing occurring at the mRNA 3′-UTR. Expression of the TP63 gene, specifically the amino-deleted p63 isoform, ΔNp63, is required to regulate numerous biological activities, including lineage specification, self-renewal capacity of epithelial stem cells, proliferation/expansion of basal keratinocytes, differentiation of stratified epithelia. In cancer, ΔNp63 is implicated in squamous cancers pathogenesis of different origin including skin, head and neck and lung and in sustaining self-renewal of cancer stem cells. How this transcription factor can control such a diverse set of biological pathways is central to the understanding of the molecular mechanisms through which p63 acquires oncogenic activity, profoundly changing its down-stream transcriptional signature. Here, we highlight how different proteins interacting with p63 allow it to regulate the transcription of several central genes. The interacting proteins include transcription factors/regulators, epigenetic modifiers, and post-transcriptional modifiers. Moreover, as p63 depends on its interactome, we discuss the hypothesis to target the protein interactors to directly affect p63 oncogenic activities and p63-related diseases.
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A novel SNF2 ATPase complex in Trypanosoma brucei with a role in H2A.Z-mediated chromatin remodelling. PLoS Pathog 2022; 18:e1010514. [PMID: 35675371 PMCID: PMC9236257 DOI: 10.1371/journal.ppat.1010514] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/27/2022] [Accepted: 04/08/2022] [Indexed: 11/25/2022] Open
Abstract
A cascade of histone acetylation events with subsequent incorporation of a histone H2A variant plays an essential part in transcription regulation in various model organisms. A key player in this cascade is the chromatin remodelling complex SWR1, which replaces the canonical histone H2A with its variant H2A.Z. Transcriptional regulation of polycistronic transcription units in the unicellular parasite Trypanosoma brucei has been shown to be highly dependent on acetylation of H2A.Z, which is mediated by the histone-acetyltransferase HAT2. The chromatin remodelling complex which mediates H2A.Z incorporation is not known and an SWR1 orthologue in trypanosomes has not yet been reported. In this study, we identified and characterised an SWR1-like remodeller complex in T. brucei that is responsible for Pol II-dependent transcriptional regulation. Bioinformatic analysis of potential SNF2 DEAD/Box helicases, the key component of SWR1 complexes, identified a 1211 amino acids-long protein that exhibits key structural characteristics of the SWR1 subfamily. Systematic protein-protein interaction analysis revealed the existence of a novel complex exhibiting key features of an SWR1-like chromatin remodeller. RNAi-mediated depletion of the ATPase subunit of this complex resulted in a significant reduction of H2A.Z incorporation at transcription start sites and a subsequent decrease of steady-state mRNA levels. Furthermore, depletion of SWR1 and RNA-polymerase II (Pol II) caused massive chromatin condensation. The potential function of several proteins associated with the SWR1-like complex and with HAT2, the key factor of H2A.Z incorporation, is discussed. Trypanosoma brucei is the causative agent of African trypanosomiasis (sleeping sickness) in humans and nagana in cattle. Its unusual genomic organisation featuring large polycistronic units requires a general mechanism of transcription initiation, because individual gene promoters are mostly absent. Despite the fact that the histone variant H2A.Z has previously been identified as a key player of transcription regulation, the complex responsible for correct H2A.Z incorporation at transcription start sites (TSS) remains elusive. In other eukaryotes, SWR1, a SNF2 ATPase-associated chromatin remodelling complex, is responsible for correct incorporation of this histone variant. This study identified a SWR1-like complex in T. brucei. Depletion of the SNF2 ATPase resulted in a reduction of H2A.Z incorporation at the TSS and decreased steady-state mRNA levels accompanied by chromatin condensation. In addition to the SWR1-like complex, we also identified a trypanosome-specific HAT2 complex that includes the histone acetyltransferases HAT2, a key player in the H2A.Z incorporation process. This complex has a trypanosome-specific composition that is different from the NuA4/TIP60 complex in Saccharomyces cerevisiae.
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Prieto-Garcia C, Tomašković I, Shah VJ, Dikic I, Diefenbacher M. USP28: Oncogene or Tumor Suppressor? A Unifying Paradigm for Squamous Cell Carcinoma. Cells 2021; 10:2652. [PMID: 34685632 PMCID: PMC8534253 DOI: 10.3390/cells10102652] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/22/2021] [Accepted: 09/27/2021] [Indexed: 01/03/2023] Open
Abstract
Squamous cell carcinomas are therapeutically challenging tumor entities. Low response rates to radiotherapy and chemotherapy are commonly observed in squamous patients and, accordingly, the mortality rate is relatively high compared to other tumor entities. Recently, targeting USP28 has been emerged as a potential alternative to improve the therapeutic response and clinical outcomes of squamous patients. USP28 is a catalytically active deubiquitinase that governs a plethora of biological processes, including cellular proliferation, DNA damage repair, apoptosis and oncogenesis. In squamous cell carcinoma, USP28 is strongly expressed and stabilizes the essential squamous transcription factor ΔNp63, together with important oncogenic factors, such as NOTCH1, c-MYC and c-JUN. It is presumed that USP28 is an oncoprotein; however, recent data suggest that the deubiquitinase also has an antineoplastic effect regulating important tumor suppressor proteins, such as p53 and CHK2. In this review, we discuss: (1) The emerging role of USP28 in cancer. (2) The complexity and mutational landscape of squamous tumors. (3) The genetic alterations and cellular pathways that determine the function of USP28 in squamous cancer. (4) The development and current state of novel USP28 inhibitors.
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Affiliation(s)
- Cristian Prieto-Garcia
- Protein Stability and Cancer Group, Department of Biochemistry and Molecular Biology, University of Würzburg, 97074 Würzburg, Germany
- Comprehensive Cancer Centre Mainfranken, 97074 Würzburg, Germany
- Molecular Signaling Group, Institute of Biochemistry II, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany; (I.T.); (V.J.S.); (I.D.)
| | - Ines Tomašković
- Molecular Signaling Group, Institute of Biochemistry II, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany; (I.T.); (V.J.S.); (I.D.)
| | - Varun Jayeshkumar Shah
- Molecular Signaling Group, Institute of Biochemistry II, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany; (I.T.); (V.J.S.); (I.D.)
| | - Ivan Dikic
- Molecular Signaling Group, Institute of Biochemistry II, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany; (I.T.); (V.J.S.); (I.D.)
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany
| | - Markus Diefenbacher
- Protein Stability and Cancer Group, Department of Biochemistry and Molecular Biology, University of Würzburg, 97074 Würzburg, Germany
- Comprehensive Cancer Centre Mainfranken, 97074 Würzburg, Germany
- Mildred Scheel Early Career Center, 97074 Würzburg, Germany
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10
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Woodstock DL, Sammons MA, Fischer M. p63 and p53: Collaborative Partners or Dueling Rivals? Front Cell Dev Biol 2021; 9:701986. [PMID: 34291055 PMCID: PMC8287303 DOI: 10.3389/fcell.2021.701986] [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: 04/28/2021] [Accepted: 06/14/2021] [Indexed: 11/27/2022] Open
Abstract
The tumor suppressor p53 and its oncogenic sibling p63 (ΔNp63) direct opposing fates in tumor development. These paralog proteins are transcription factors that elicit their tumor suppressive and oncogenic capacity through the regulation of both shared and unique target genes. Both proteins predominantly function as activators of transcription, leading to a paradigm shift away from ΔNp63 as a dominant negative to p53 activity. The discovery of p53 and p63 as pioneer transcription factors regulating chromatin structure revealed new insights into how these paralogs can both positively and negatively influence each other to direct cell fate. The previous view of a strict rivalry between the siblings needs to be revisited, as p53 and p63 can also work together toward a common goal.
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Affiliation(s)
- Dana L Woodstock
- Department of Biological Sciences, The State University of New York at Albany, Albany, NY, United States
| | - Morgan A Sammons
- Department of Biological Sciences, The State University of New York at Albany, Albany, NY, United States
| | - Martin Fischer
- Computational Biology Group, Leibniz Institute on Aging - Fritz Lipmann Institute (FLI), Jena, Germany
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11
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Pokorná Z, Vysloužil J, Hrabal V, Vojtěšek B, Coates PJ. The foggy world(s) of p63 isoform regulation in normal cells and cancer. J Pathol 2021; 254:454-473. [PMID: 33638205 DOI: 10.1002/path.5656] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/10/2021] [Accepted: 02/24/2021] [Indexed: 12/19/2022]
Abstract
The p53 family member p63 exists as two major protein variants (TAp63 and ΔNp63) with distinct expression patterns and functional properties. Whilst downstream target genes of p63 have been studied intensively, how p63 variants are themselves controlled has been relatively neglected. Here, we review advances in understanding ΔNp63 and TAp63 regulation, highlighting their distinct pathways. TAp63 has roles in senescence and metabolism, and in germ cell genome maintenance, where it is activated post-transcriptionally by phosphorylation cascades after DNA damage. The function and regulation of TAp63 in mesenchymal and haematopoietic cells is less clear but may involve epigenetic control through DNA methylation. ΔNp63 functions to maintain stem/progenitor cells in various epithelia and is overexpressed in squamous and certain other cancers. ΔNp63 is transcriptionally regulated through multiple enhancers in concert with chromatin modifying proteins. Many signalling pathways including growth factors, morphogens, inflammation, and the extracellular matrix influence ΔNp63 levels, with inconsistent results reported. There is also evidence for reciprocal regulation, including ΔNp63 activating its own transcription. ΔNp63 is downregulated during cell differentiation through transcriptional regulation, while post-transcriptional events cause proteasomal degradation. Throughout the review, we identify knowledge gaps and highlight discordances, providing potential explanations including cell-context and cell-matrix interactions. Identifying individual p63 variants has roles in differential diagnosis and prognosis, and understanding their regulation suggests clinically approved agents for targeting p63 that may be useful combination therapies for selected cancer patients. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Zuzana Pokorná
- Research Centre of Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Jan Vysloužil
- Research Centre of Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Václav Hrabal
- Research Centre of Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic.,Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Borˇivoj Vojtěšek
- Research Centre of Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Philip J Coates
- Research Centre of Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic
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12
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Reichrath J, Reichrath S. The Impact of Notch Signaling for Carcinogenesis and Progression of Nonmelanoma Skin Cancer: Lessons Learned from Cancer Stem Cells, Tumor Angiogenesis, and Beyond. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1287:123-154. [PMID: 33034030 DOI: 10.1007/978-3-030-55031-8_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since many decades, nonmelanoma skin cancer (NMSCs) is the most common malignancy worldwide. Basal cell carcinomas (BCC) and squamous cell carcinomas (SCC) are the major types of NMSCs, representing approximately 70% and 25% of these neoplasias, respectively. Because of their continuously rising incidence rates, NMSCs represent a constantly increasing global challenge for healthcare, although they are in most cases nonlethal and curable (e.g., by surgery). While at present, carcinogenesis of NMSC is still not fully understood, the relevance of genetic and molecular alterations in several pathways, including evolutionary highly conserved Notch signaling, has now been shown convincingly. The Notch pathway, which was first developed during evolution in metazoans and that was first discovered in fruit flies (Drosophila melanogaster), governs cell fate decisions and many other fundamental processes that are of high relevance not only for embryonic development, but also for initiation, promotion, and progression of cancer. Choosing NMSC as a model, we give in this review a brief overview on the interaction of Notch signaling with important oncogenic and tumor suppressor pathways and on its role for several hallmarks of carcinogenesis and cancer progression, including the regulation of cancer stem cells, tumor angiogenesis, and senescence.
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Affiliation(s)
- Jörg Reichrath
- Department of Dermatology, Saarland University Medical Center, Homburg, Germany.
| | - Sandra Reichrath
- Department of Dermatology, Saarland University Medical Center, Homburg, Germany.,School of Health Professions, Saarland University Medical Center, Homburg, Germany
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13
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Riege K, Kretzmer H, Sahm A, McDade SS, Hoffmann S, Fischer M. Dissecting the DNA binding landscape and gene regulatory network of p63 and p53. eLife 2020; 9:e63266. [PMID: 33263276 PMCID: PMC7735755 DOI: 10.7554/elife.63266] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
The transcription factor p53 is the best-known tumor suppressor, but its sibling p63 is a master regulator of epidermis development and a key oncogenic driver in squamous cell carcinomas (SCC). Despite multiple gene expression studies becoming available, the limited overlap of reported p63-dependent genes has made it difficult to decipher the p63 gene regulatory network. Particularly, analyses of p63 response elements differed substantially among the studies. To address this intricate data situation, we provide an integrated resource that enables assessing the p63-dependent regulation of any human gene of interest. We use a novel iterative de novo motif search approach in conjunction with extensive ChIP-seq data to achieve a precise global distinction between p53-and p63-binding sites, recognition motifs, and potential co-factors. We integrate these data with enhancer:gene associations to predict p63 target genes and identify those that are commonly de-regulated in SCC representing candidates for prognosis and therapeutic interventions.
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Affiliation(s)
- Konstantin Riege
- Computational Biology Group, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI)JenaGermany
| | - Helene Kretzmer
- Department of Genome Regulation, Max Planck Institute for Molecular GeneticsBerlinGermany
| | - Arne Sahm
- Computational Biology Group, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI)JenaGermany
| | - Simon S McDade
- Patrick G Johnston Centre for Cancer Research, Queen's University BelfastBelfastUnited Kingdom
| | - Steve Hoffmann
- Computational Biology Group, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI)JenaGermany
| | - Martin Fischer
- Computational Biology Group, Leibniz Institute on Aging – Fritz Lipmann Institute (FLI)JenaGermany
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14
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Yi M, Tan Y, Wang L, Cai J, Li X, Zeng Z, Xiong W, Li G, Li X, Tan P, Xiang B. TP63 links chromatin remodeling and enhancer reprogramming to epidermal differentiation and squamous cell carcinoma development. Cell Mol Life Sci 2020; 77:4325-4346. [PMID: 32447427 PMCID: PMC7588389 DOI: 10.1007/s00018-020-03539-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/21/2020] [Accepted: 04/24/2020] [Indexed: 12/19/2022]
Abstract
Squamous cell carcinoma (SCC) is an aggressive malignancy that can originate from various organs. TP63 is a master regulator that plays an essential role in epidermal differentiation. It is also a lineage-dependent oncogene in SCC. ΔNp63α is the prominent isoform of TP63 expressed in epidermal cells and SCC, and overexpression promotes SCC development through a variety of mechanisms. Recently, ΔNp63α was highlighted to act as an epidermal-specific pioneer factor that binds closed chromatin and enhances chromatin accessibility at epidermal enhancers. ΔNp63α coordinates chromatin-remodeling enzymes to orchestrate the tissue-specific enhancer landscape and three-dimensional high-order architecture of chromatin. Moreover, ΔNp63α establishes squamous-like enhancer landscapes to drive oncogenic target expression during SCC development. Importantly, ΔNp63α acts as an upstream regulator of super enhancers to activate a number of oncogenic transcripts linked to poor prognosis in SCC. Mechanistically, ΔNp63α activates genes transcription through physically interacting with a number of epigenetic modulators to establish enhancers and enhance chromatin accessibility. In contrast, ΔNp63α also represses gene transcription via interacting with repressive epigenetic regulators. ΔNp63α expression is regulated at multiple levels, including transcriptional, post-transcriptional, and post-translational levels. In this review, we summarize recent advances of p63 in epigenomic and transcriptional control, as well as the mechanistic regulation of p63.
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Affiliation(s)
- Mei Yi
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Yixin Tan
- Department of Dermatology, The Second Xiangya Hospital, The Central South University, Changsha, 410011, Hunan, China
| | - Li Wang
- Department of Thoracic Surgery, The Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Jing Cai
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Xiaoling Li
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Zhaoyang Zeng
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Guiyuan Li
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China
| | - Xiayu Li
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China.
| | - Pingqing Tan
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.
- Department of Head and Neck Surgery, Hunan Provincial Cancer Hospital and Cancer Hospital Affiliated to Xiangya Medical School, Central South University, Changsha, 410013, Hunan, China.
| | - Bo Xiang
- NHC Key Laboratory of Carcinogenesis, Hunan Provincial Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, Hunan, China.
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, The Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China.
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute and School of Basic Medical Sciences, Central South University, Changsha, 410078, Hunan, China.
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15
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Lin D, Lin B, Bhanot H, Riou R, Abt NB, Rajagopal J, Saladi SV. RUVBL1 is an amplified epigenetic factor promoting proliferation and inhibiting differentiation program in head and neck squamous cancers. Oral Oncol 2020; 111:104930. [PMID: 32745900 DOI: 10.1016/j.oraloncology.2020.104930] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/24/2020] [Accepted: 07/22/2020] [Indexed: 12/14/2022]
Abstract
Mutations in histone modifying enzymes and histone variants were identified in multiple cancers in The Cancer Genome Atlas (TCGA) studies. However, very little progress and understanding has been made in identifying the contribution of epigenetic factors in head and neck squamous cell carcinoma (HNSCC). Here, we report the identification of RUVBL1 (TIP49a), a component of the TIP60 histone modifying complex as being amplified and overexpressed in HNSCC. RUVBL1 plays a key role in incorporating histone variant H2AZ in chromatin thereby regulating transcription of key genes involved in differentiation, cancer cell proliferation and invasion. H2AZ is also overexpressed in HNSCC tumors thereby regulating RUVBL1/H2AZ dependent transcriptional programs. Patient data analysis of multiple cohorts including TCGA and single cell HNSCC data indicated RUVBL1 overexpression as a poor prognostic marker and predicts poor survival. In vitro experiments indicate a pro-proliferative role for RUVBL1/H2AZ in HNSCC cells. RUVBL1 inversely correlates with differentiation program and positively correlates with oncogenic programs, making it a key contributor to tumorigenesis and a vulnerable therapeutic target in HNSCC patients.
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Affiliation(s)
- Derrick Lin
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, United States; Massachusetts General Hospital Cancer Center, United States
| | - Brian Lin
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, United States
| | - Haymanti Bhanot
- Dana Farber Cancer Institute, Harvard Medical School, United States
| | - Rozenn Riou
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, United States
| | - Nicholas B Abt
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, United States; Massachusetts General Hospital Cancer Center, United States
| | - Jayaraj Rajagopal
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, United States; Broad Institute of MIT and Harvard, United States
| | - Srinivas Vinod Saladi
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, United States; Massachusetts General Hospital Cancer Center, United States; Broad Institute of MIT and Harvard, United States.
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16
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Klein K, Habiger C, Iftner T, Stubenrauch F. A TGF-β– and p63-Responsive Enhancer Regulates IFN-κ Expression in Human Keratinocytes. THE JOURNAL OF IMMUNOLOGY 2020; 204:1825-1835. [DOI: 10.4049/jimmunol.1901178] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 01/19/2020] [Indexed: 12/31/2022]
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17
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Abraham CG, Ludwig MP, Andrysik Z, Pandey A, Joshi M, Galbraith MD, Sullivan KD, Espinosa JM. ΔNp63α Suppresses TGFB2 Expression and RHOA Activity to Drive Cell Proliferation in Squamous Cell Carcinomas. Cell Rep 2019; 24:3224-3236. [PMID: 30232004 DOI: 10.1016/j.celrep.2018.08.058] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 08/07/2018] [Accepted: 08/21/2018] [Indexed: 02/08/2023] Open
Abstract
The transcriptional repressor ΔNp63α is a potent oncogene widely overexpressed in squamous cell carcinomas (SCCs) of diverse tissue origins, where it promotes malignant cell proliferation and survival. We report here the results of a genome-wide CRISPR screen to identify pathways controlling ΔNp63α-dependent cell proliferation, which revealed that the small GTPase RHOA blocks cell division upon ΔNp63α knockdown. After ΔNp63α depletion, RHOA activity is increased, and cells undergo RHOA-dependent proliferation arrest along with transcriptome changes indicative of increased TGF-β signaling. Mechanistically, ΔNp63α represses transcription of TGFB2, which induces a cell cycle arrest that is partially dependent on RHOA. Ectopic TGFB2 activates RHOA and impairs SCC proliferation, and TGFB2 neutralization restores cell proliferation during ΔNp63α depletion. Genomic data from tumors demonstrate inactivation of RHOA and the TGFBR2 receptor and ΔNp63α overexpression in more than 80% of lung SCCs. These results reveal a signaling pathway controlling SCC proliferation that is potentially amenable to pharmacological intervention.
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Affiliation(s)
- Christopher G Abraham
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Michael P Ludwig
- Department of Pharmacology, 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
| | - Ahwan Pandey
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Molishree Joshi
- Functional Genomics Facility, 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
| | - Kelly D Sullivan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA; Functional Genomics Facility, 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; Functional Genomics Facility, 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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Giaimo BD, Ferrante F, Herchenröther A, Hake SB, Borggrefe T. The histone variant H2A.Z in gene regulation. Epigenetics Chromatin 2019; 12:37. [PMID: 31200754 PMCID: PMC6570943 DOI: 10.1186/s13072-019-0274-9] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 04/23/2019] [Indexed: 01/04/2023] Open
Abstract
The histone variant H2A.Z is involved in several processes such as transcriptional control, DNA repair, regulation of centromeric heterochromatin and, not surprisingly, is implicated in diseases such as cancer. Here, we review the recent developments on H2A.Z focusing on its role in transcriptional activation and repression. H2A.Z, as a replication-independent histone, has been studied in several model organisms and inducible mammalian model systems. Its loading machinery and several modifying enzymes have been recently identified, and some of the long-standing discrepancies in transcriptional activation and/or repression are about to be resolved. The buffering functions of H2A.Z, as supported by genome-wide localization and analyzed in several dynamic systems, are an excellent example of transcriptional control. Posttranslational modifications such as acetylation and ubiquitination of H2A.Z, as well as its specific binding partners, are in our view central players in the control of gene expression. Understanding the key-mechanisms in either turnover or stabilization of H2A.Z-containing nucleosomes as well as defining the H2A.Z interactome will pave the way for therapeutic applications in the future.
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Affiliation(s)
| | - Francesca Ferrante
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany
| | - Andreas Herchenröther
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Sandra B Hake
- Institute for Genetics, University of Giessen, Heinrich-Buff-Ring 58-62, 35392, Giessen, Germany
| | - Tilman Borggrefe
- Institute of Biochemistry, University of Giessen, Friedrichstrasse 24, 35392, Giessen, Germany.
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19
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Gatti V, Bongiorno-Borbone L, Fierro C, Annicchiarico-Petruzzelli M, Melino G, Peschiaroli A. p63 at the Crossroads between Stemness and Metastasis in Breast Cancer. Int J Mol Sci 2019; 20:E2683. [PMID: 31159154 PMCID: PMC6600246 DOI: 10.3390/ijms20112683] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 05/27/2019] [Accepted: 05/29/2019] [Indexed: 12/20/2022] Open
Abstract
After lung cancer, breast cancer (BC) is the most frequent cause of cancer death among women, worldwide. Although advances in screening approaches and targeted therapeutic agents have decreased BC incidence and mortality, over the past five years, triple-negative breast cancer (TNBC) remains the breast cancer subtype that displays the worst prognosis, mainly due to the lack of clinically actionable targets. Genetic and molecular profiling has unveiled the high intrinsic heterogeneity of TNBC, with the basal-like molecular subtypes representing the most diffuse TNBC subtypes, characterized by the expression of basal epithelial markers, such as the transcription factor p63. In this review, we will provide a broad picture on the physiological role of p63, in maintaining the basal epithelial identity, as well as its involvement in breast cancer progression, emphasizing its relevance in tumor cell invasion and stemness.
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Affiliation(s)
- Veronica Gatti
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, 00133 Rome, Italy.
| | | | - Claudia Fierro
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, 00133 Rome, Italy.
| | | | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome Tor Vergata, 00133 Rome, Italy.
- Medical Research Council, Toxicology Unit, University of Cambridge, Cambridge CB2 1PZ, UK.
| | - Angelo Peschiaroli
- National Research Council of Italy, Institute of Translational Pharmacology, 00133 Rome, Italy.
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20
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The base pair-scale diffusion of nucleosomes modulates binding of transcription factors. Proc Natl Acad Sci U S A 2019; 116:12161-12166. [PMID: 31147470 DOI: 10.1073/pnas.1815424116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The structure of promoter chromatin determines the ability of transcription factors (TFs) to bind to DNA and therefore has a profound effect on the expression levels of genes. However, the role of spontaneous nucleosome movements in this process is not fully understood. Here, we developed a single-molecule optical tweezers assay capable of simultaneously characterizing the base pair-scale diffusion of a nucleosome on DNA and the binding of a TF, using the luteinizing hormone β subunit gene (Lhb) promoter and Egr-1 as a model system. Our results demonstrate that nucleosomes undergo confined diffusion, and that the incorporation of the histone variant H2A.Z serves to partially relieve this confinement, inducing a different type of nucleosome repositioning. The increase in diffusion leads to exposure of a TF's binding site and facilitates its association with the DNA, which, in turn, biases the subsequent movement of the nucleosome. Our findings suggest the use of mobile nucleosomes as a general transcriptional regulatory mechanism.
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21
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Karsli Uzunbas G, Ahmed F, Sammons MA. Control of p53-dependent transcription and enhancer activity by the p53 family member p63. J Biol Chem 2019; 294:10720-10736. [PMID: 31113863 DOI: 10.1074/jbc.ra119.007965] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/15/2019] [Indexed: 01/20/2023] Open
Abstract
Transcriptional activation by p53 provides powerful, organism-wide tumor suppression. We hypothesized that the local chromatin environment, including differential enhancer activities, contributes to various p53-dependent transcriptional activities in different cell types during stress-induced signaling. In this work, using ChIP-sequencing, immunoblotting, quantitative PCR, and computational analyses across various mammalian cell lines, we demonstrate that the p53-induced transcriptome varies by cell type, reflects cell type-specific activities, and is considerably broader than previously anticipated. We found that these molecular events are strongly influenced by p53's engagement with differentially active cell type-specific enhancers and promoters. We also observed that p53 activity depends on the p53 family member tumor protein p63 in epithelial cell types. Notably, we demonstrate that p63 is required for epithelial enhancer identity, including enhancers used by p53 during stress-dependent signaling. Loss of p63, but not p53, caused site-specific depletion of enhancer-associated chromatin modifications, suggesting that p63 functions as an enhancer maintenance factor in epithelial cells. Additionally, a subset of epithelial-specific enhancers depends on the activity of p63 providing a direct link between lineage determination and enhancer structure. These results suggest that a broad, cell-intrinsic mechanism controls p53-dependent cellular stress response through differential regulation of cis-regulatory elements.
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Affiliation(s)
- Gizem Karsli Uzunbas
- From the Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222
| | - Faraz Ahmed
- From the Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222
| | - Morgan A Sammons
- From the Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222
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22
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Gatti V, Fierro C, Annicchiarico-Petruzzelli M, Melino G, Peschiaroli A. ΔNp63 in squamous cell carcinoma: defining the oncogenic routes affecting epigenetic landscape and tumour microenvironment. Mol Oncol 2019; 13:981-1001. [PMID: 30845357 PMCID: PMC6487733 DOI: 10.1002/1878-0261.12473] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 02/21/2019] [Accepted: 02/22/2019] [Indexed: 12/20/2022] Open
Abstract
Squamous cell carcinoma (SCC) is a treatment‐refractory tumour which arises from the epithelium of diverse anatomical sites such as oesophagus, head and neck, lung and skin. Accumulating evidence has revealed a number of genomic, clinical and molecular features commonly observed in SCC of distinct origins. Some of these genetic events culminate in fostering the activity of ΔNp63, a potent oncogene which exerts its pro‐tumourigenic effects by regulating specific transcriptional programmes to sustain malignant cell proliferation and survival. In this review, we will describe the genetic and epigenetic determinants underlying ΔNp63 oncogenic activities in SCC, and discuss some relevant transcriptional effectors of ΔNp63, emphasizing their impact in modulating the crosstalk between tumour cells and tumour microenvironment (TME).
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Affiliation(s)
- Veronica Gatti
- Department of Experimental Medicine, TOR, University of Rome, Tor Vergata, Italy
| | - Claudia Fierro
- Department of Experimental Medicine, TOR, University of Rome, Tor Vergata, Italy
| | | | - Gerry Melino
- Department of Experimental Medicine, TOR, University of Rome, Tor Vergata, Italy.,Medical Research Council, Toxicology Unit, University of Cambridge, UK
| | - Angelo Peschiaroli
- National Research Council of Italy, Institute of Translational Pharmacology, Rome, Italy
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23
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Gatti V, Fierro C, Compagnone M, Giangrazi F, Markert EK, Bongiorno-Borbone L, Melino G, Peschiaroli A. ΔNp63 regulates the expression of hyaluronic acid-related genes in breast cancer cells. Oncogenesis 2018; 7:65. [PMID: 30139970 PMCID: PMC6107578 DOI: 10.1038/s41389-018-0073-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/20/2018] [Accepted: 07/10/2018] [Indexed: 12/16/2022] Open
Abstract
Triple negative breast cancers (TNBC) represent the most aggressive and clinically relevant breast carcinomas. On the basis of specific molecular signature, the majority of TNBC can be classified as basal-like breast carcinoma. Here, we report data showing that in basal-like breast carcinoma cells ΔNp63 is capable of sustaining the production of the hyaluronic acid (HA), one of the major component of the extracellular matrix (ECM). At molecular level, we found that ΔNp63 regulates the expression of HA-related genes, such as the HA synthase HAS3, the hyaluronidase HYAL-1 and CD44, the major HA cell membrane receptor. By controlling this pathway, ∆Np63 contributes to maintain the self-renewal of breast cancer stem cells. Importantly, high HAS3 expression is a negative prognostic factor of TNBC patients. Our data suggest that in basal-type breast carcinoma ∆Np63 might favor a HA-rich microenviroment, which can sustain tumor proliferation and stemness.
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Affiliation(s)
- Veronica Gatti
- National Research Council of Italy, (CNR), Institute of Cell Biology and Neurobiology (IBCN), CNR, Monterotondo, Rome, Italy
| | - Claudia Fierro
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy
| | - Mirco Compagnone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.,Paediatric Haematology/Oncology Department, Bambino Gesù Children's Hospital IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy
| | - Federica Giangrazi
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.,Molecular Cell Biology Laboratory, Department of Genetics, The Smurfit Institute, Trinity College, The University of Dublin, Dublin 2, Ireland
| | - Elke Katrin Markert
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Lucilla Bongiorno-Borbone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy
| | - Gerry Melino
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy. .,Medical Research Council, Toxicology Unit, Hodgkin Building, Leicester University, Lancaster Road, P.O. Box 138, Leicester, LE1 9HN, UK.
| | - Angelo Peschiaroli
- National Research Council of Italy, (CNR), Institute of Translational Pharmacology (IFT), Via Fosso del Cavaliere 100, Rome, 00133, Italy.
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24
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Dong Q, Wang Y, Qi S, Gai K, He Q, Wang Y. Histone variant H2A.Z antagonizes the positive effect of the transcriptional activator CPC1 to regulate catalase-3 expression under normal and oxidative stress conditions. Free Radic Biol Med 2018; 121:136-148. [PMID: 29738831 DOI: 10.1016/j.freeradbiomed.2018.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 05/01/2018] [Accepted: 05/03/2018] [Indexed: 10/17/2022]
Abstract
In eukaryotes, deposition of the histone variant H2A.Z into nucleosomes through the chromatin remodeling complex, SWR1, is a crucial step in modulating gene transcription. Recently, H2A.Z has been shown to control the expression of responsive genes, but the underlying mechanism of how H2A.Z responds to physiological stimuli is not well understood. Here, we reveal that, in Neurospora crassa, H2A.Z is a negative regulator of catalase-3 gene, which is responsible for resistance to oxidative stress. H2A.Z represses cat-3 gene expression through direct incorporation at cat-3 locus in a SWR1 complex dependent pathway. Notably, loss of H2A.Z or SWR1 subunits leads to increased binding of a transcription factor, CPC1, at cat-3 locus. Additionally, introduction of plasmids containing gene encoding H2A.Z or SWR1 complex subunits into wild-type strains decreased CAT-3 expression, indicating that H2A.Z counteracts the positive effect of CPC1 to achieve low level cat-3 expression under non-inductive condition. Furthermore, upon oxidative stress, H2A.Z is rapidly evicted from cat-3 locus for the recruitment of CPC1, resulting in robust and full cat-3 gene expression in response to external stimuli. Collectively, this study strongly demonstrates that H2A.Z antagonizes the function of transcription factor to regulate responsive gene transcription under normal conditions and to poise for gene full activation under oxidative stress.
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Affiliation(s)
- Qing Dong
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yajun Wang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shaohua Qi
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Kexin Gai
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Ying Wang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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25
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Mikesch JH, Schwammbach D, Hartmann W, Schmidt L, Schliemann C, Angenendt L, Wiewrodt R, Marra A, Thoennissen NH, Wardelmann E, Köhler G, Lenz G, Müller-Tidow C, Berdel WE, Arteaga MF. Reptin drives tumour progression and resistance to chemotherapy in nonsmall cell lung cancer. Eur Respir J 2018; 52:13993003.01637-2017. [DOI: 10.1183/13993003.01637-2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 05/19/2018] [Indexed: 11/05/2022]
Abstract
While targeted nonsmall cell lung cancer (NSCLC) therapies have improved the outcome of defined disease subtypes, prognosis for most patients remains poor. We found the AAA+ ATPase Reptin to be highly expressed in the vast majority of 278 NSCLC tumour samples. Thus, the objective of the study was to assess the role of Reptin in NSCLC.Survival analyses of 1145 NSCLC patients revealed that high RNA expression levels of Reptin are associated with adverse outcome. Knockdown of Reptin in human NSCLC cells impaired growth ex vivo and eliminated engraftment in a xenograft model. Reptin directly interacted with histone deacetylase 1 (HDAC1) as the critical mechanism driving NSCLC tumour progression. Pharmacological disruption of the Reptin/HDAC1 complex resulted in a substantial decrease in NSCLC cell proliferation and induced significant sensitisation to cisplatin.Our results identify Reptin as a novel independent prognostic factor and as a key regulator mediating proliferation and clonal growth of human NSCLC cells ex vivo and in vivo. We unveil a Reptin/HDAC1 protein complex whose pharmacological disruption sensitises NSCLC cells to cisplatin, suggesting this approach for application in clinical trials.
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26
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Regina C, Compagnone M, Peschiaroli A, Lena A, Annicchiarico-Petruzzelli M, Piro MC, Melino G, Candi E. Setdb1, a novel interactor of ΔNp63, is involved in breast tumorigenesis. Oncotarget 2018; 7:28836-48. [PMID: 26840455 PMCID: PMC5045360 DOI: 10.18632/oncotarget.7089] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 01/13/2016] [Indexed: 01/05/2023] Open
Abstract
ΔNp63 has been recently involved in self-renewal potential of breast cancer stem cells. Although the p63 transcriptional profile has been extensively characterized, our knowledge of the p63-binding partners potentially involved in the regulation of breast tumour progression is limited. Here, we performed the yeast two hybrid approach to identify p63α interactors involved in breast tumorigenesis and we found that SETDB1, a histone lysine methyl transferases, interacts with ΔNp63α and that this interaction contributes to p63 protein stability. SETDB1 is often amplified in primary breast tumours, and its depletion confers to breast cancer cells growth disadvantage. We identified a list of thirty genes repressed by ΔNp63 in a SETDB1-dependent manner, whose expression is positively correlated to survival of breast cancer patients. These results suggest that p63 and SETDB1 expression, together with the repressed genes, may have diagnostic and prognostic potential.
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Affiliation(s)
- Carla Regina
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Mirco Compagnone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | | | - AnnaMaria Lena
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | | | - Maria Cristina Piro
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Gerry Melino
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Eleonora Candi
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy.,IDI-IRCCS, Rome, Italy
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27
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Compagnone M, Gatti V, Presutti D, Ruberti G, Fierro C, Markert EK, Vousden KH, Zhou H, Mauriello A, Anemone L, Bongiorno-Borbone L, Melino G, Peschiaroli A. ΔNp63-mediated regulation of hyaluronic acid metabolism and signaling supports HNSCC tumorigenesis. Proc Natl Acad Sci U S A 2017; 114:13254-13259. [PMID: 29162693 PMCID: PMC5740608 DOI: 10.1073/pnas.1711777114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, and several molecular pathways that underlie the molecular tumorigenesis of HNSCC have been identified. Among them, amplification or overexpression of ΔNp63 isoforms is observed in the majority of HNSCCs. Here, we unveiled a ΔNp63-dependent transcriptional program able to regulate the metabolism and the signaling of hyaluronic acid (HA), the major component of the extracellular matrix (ECM). We found that ∆Np63 is capable of sustaining the production of HA levels in cell culture and in vivo by regulating the expression of the HA synthase HAS3 and two hyaluronidase genes, HYAL-1 and HYAL-3. In addition, ∆Np63 directly regulates the expression of CD44, the major HA cell membrane receptor. By controlling this transcriptional program, ∆Np63 sustains the epithelial growth factor receptor (EGF-R) activation and the expression of ABCC1 multidrug transporter gene, thus contributing to tumor cell proliferation and chemoresistance. Importantly, p63 expression is positively correlated with CD44, HAS3, and ABCC1 expression in squamous cell carcinoma datasets and p63-HA pathway is a negative prognostic factor of HNSCC patient survival. Altogether, our data shed light on a ∆Np63-dependent pathway functionally important to the regulation of HNSCC progression.
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Affiliation(s)
- Mirco Compagnone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Veronica Gatti
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00015 Monterotondo (Rome), Italy
| | - Dario Presutti
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00015 Monterotondo (Rome), Italy
| | - Giovina Ruberti
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00015 Monterotondo (Rome), Italy
| | - Claudia Fierro
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Elke Katrin Markert
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1BD United Kingdom
| | | | - Huiqing Zhou
- Radboud Institute for Molecular Life Sciences, Department of Human Genetics 855, Radboud University Medical Centre, 6525 GA Nijmegen, The Netherlands
- Faculty of Science, Radboud Institute for Molecular Life Sciences, Department of Molecular Developmental Biology, Radboud University, 6525 GA Nijmegen, The Netherlands
| | - Alessandro Mauriello
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Lucia Anemone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Lucilla Bongiorno-Borbone
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Gerry Melino
- Department of Experimental Medicine and Surgery, University of Rome "Tor Vergata", 00133 Rome, Italy;
- Medical Research Council, Toxicology Unit, Leicester University, Leicester LE1 9HN, United Kingdom
| | - Angelo Peschiaroli
- Institute of Cell Biology and Neurobiology, National Research Council of Italy (CNR), 00015 Monterotondo (Rome), Italy;
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28
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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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29
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Thomsen LN, Thomsen PD, Downing A, Talbot R, Berg LC. FOXO1, PXK, PYCARD and SAMD9L are differentially expressed by fibroblast-like cells in equine synovial membrane compared to joint capsule. BMC Vet Res 2017; 13:106. [PMID: 28410619 PMCID: PMC5391632 DOI: 10.1186/s12917-017-1003-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 03/28/2017] [Indexed: 11/11/2022] Open
Abstract
Background The synovial membrane lines the luminal side of the joint capsule in synovial joints. It maintains joint homeostasis and plays a crucial role in equine joint pathology. When trauma or inflammation is induced in a joint, the synovial membrane influences progression of joint damage. Equine synovial membrane research is hampered by a lack of markers of fibroblast-like synoviocytes (FLS) to distinguish FLS from other fibroblast-like cells in musculoskeletal connective tissues. The aim of this study is to identify potential FLS markers of the equine synovial membrane using microarray to compare between gene expression in equine synovial membrane and the joint capsule in metacarpophalangeal joints. Results Microarray analysis of tissues from 6 horses resulted in 1167 up-regulated genes in synovial membrane compared with joint capsule. Pathway analysis resulted in 241 candidate genes. Of these, 15 genes were selected for further confirmation as genes potentially expressed by fibroblast-like synoviocytes. Four genes: FOXO1, PXK, PYCARD and SAMD9L were confirmed in 9 horses by qPCR as differentially expressed in synovial membrane compared to joint capsule. Conclusions In conclusion, FOXO1, PXK, PYCARD and SAMD9L were confirmed as differentially expressed in synovial membrane compared to joint capsule. These four genes are potential markers of fibroblast-like synoviocytes of the synovial membrane. As these genes are overexpressed in synovial membrane compared to joint capsule, these genes could shed light on synovial membrane physiology and its role in joint disease.
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Affiliation(s)
- Line Nymann Thomsen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Hoejbakkegaards alle 5, 2630, Taastrup, Denmark
| | - Preben Dybdahl Thomsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Groennegaardsvej 7, 1870, Frederiksberg C, Denmark
| | - Alison Downing
- Edinburgh Genomics, Ashworth Laboratories, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Richard Talbot
- Edinburgh Genomics, Ashworth Laboratories, University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Lise Charlotte Berg
- Department of Veterinary Clinical Sciences, University of Copenhagen, Hoejbakkegaards alle 5, 2630, Taastrup, Denmark.
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30
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Saladi SV, Ross K, Karaayvaz M, Tata PR, Mou H, Rajagopal J, Ramaswamy S, Ellisen LW. ACTL6A Is Co-Amplified with p63 in Squamous Cell Carcinoma to Drive YAP Activation, Regenerative Proliferation, and Poor Prognosis. Cancer Cell 2017; 31:35-49. [PMID: 28041841 PMCID: PMC5225026 DOI: 10.1016/j.ccell.2016.12.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 08/18/2016] [Accepted: 11/30/2016] [Indexed: 12/16/2022]
Abstract
Loss-of-function mutations in SWI/SNF chromatin-remodeling subunit genes are observed in many cancers, but an oncogenic role for SWI/SNF is not well established. Here, we reveal that ACTL6A, encoding an SWI/SNF subunit linked to stem cell and progenitor cell function, is frequently co-amplified and highly expressed together with the p53 family member p63 in head and neck squamous cell carcinoma (HNSCC). ACTL6A and p63 physically interact, cooperatively controlling a transcriptional program that promotes proliferation and suppresses differentiation, in part through activation of the Hippo-YAP pathway via regulators including WWC1. Ectopic ACTL6A/p63 expression promotes tumorigenesis, while ACTL6A expression and YAP activation are highly correlated in primary HNSCC and predict poor patient survival. Thus, ACTL6A and p63 collaborate as oncogenic drivers in HNSCC.
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Affiliation(s)
- Srinivas Vinod Saladi
- Massachusetts General Hospital Cancer Center, GRJ-904, 55 Fruit Street, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Kenneth Ross
- Massachusetts General Hospital Cancer Center, GRJ-904, 55 Fruit Street, Boston, MA 02114, USA
| | - Mihriban Karaayvaz
- Massachusetts General Hospital Cancer Center, GRJ-904, 55 Fruit Street, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Purushothama R Tata
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Hongmei Mou
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Jayaraj Rajagopal
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Internal Medicine, Pulmonary and Critical Care Unit, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Sridhar Ramaswamy
- Massachusetts General Hospital Cancer Center, GRJ-904, 55 Fruit Street, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02138, USA
| | - Leif W Ellisen
- Massachusetts General Hospital Cancer Center, GRJ-904, 55 Fruit Street, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA.
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31
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A Chromatin-Focused siRNA Screen for Regulators of p53-Dependent Transcription. G3-GENES GENOMES GENETICS 2016; 6:2671-8. [PMID: 27334938 PMCID: PMC4978920 DOI: 10.1534/g3.116.031534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The protein product of the Homo sapiens TP53 gene is a transcription factor (p53) that regulates the expression of genes critical for the response to DNA damage and tumor suppression, including genes involved in cell cycle arrest, apoptosis, DNA repair, metabolism, and a number of other tumorigenesis-related pathways. Differential transcriptional regulation of these genes is believed to alter the balance between two p53-dependent cell fates: cell cycle arrest or apoptosis. A number of previously identified p53 cofactors covalently modify and alter the function of both the p53 protein and histone proteins. Both gain- and loss-of-function mutations in chromatin modifiers have been strongly implicated in cancer development; thus, we sought to identify novel chromatin regulatory proteins that affect p53-dependent transcription and the balance between the expression of pro-cell cycle arrest and proapoptotic genes. We utilized an siRNA library designed against predicted chromatin regulatory proteins, and identified known and novel chromatin-related factors that affect both global p53-dependent transcription and gene-specific regulators of p53 transcriptional activation. The results from this screen will serve as a comprehensive resource for those interested in further characterizing chromatin and epigenetic factors that regulate p53 transcription.
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32
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Liu Y, Xiong Z, Beasley A, D'Amico T, Chen XL. Personalized and targeted therapy of esophageal squamous cell carcinoma: an update. Ann N Y Acad Sci 2016; 1381:66-73. [PMID: 27399176 DOI: 10.1111/nyas.13144] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 05/16/2016] [Accepted: 05/23/2016] [Indexed: 12/20/2022]
Abstract
Esophageal squamous cell carcinoma (ESCC) is a deadly disease that requires extensive research. In this review, we update recent progress in the research area of targeted therapy for ESCC. SOX2 and its associated proteins (e.g., ΔNP63α), which regulate lineage survival of ESCC cells, are proposed as therapeutic targets. It is believed that targeting the lineage-survival mechanism may be more effective than targeting other mechanisms. With the advent of a new era of personalized targeted therapy, there is a need to move from the tumor-centric model into an organismic model.
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Affiliation(s)
- Yongjing Liu
- Department of Cardiothoracic Surgery, 105th Hospital of PLA, Hefei, Anhui Province, China.,Division of Thoracic Surgery, Duke University Medical Center, Durham, North Carolina.,Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina
| | - Zhaohui Xiong
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina
| | - Andrea Beasley
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina
| | - Thomas D'Amico
- Division of Thoracic Surgery, Duke University Medical Center, Durham, North Carolina
| | - Xiaoxin Luke Chen
- Cancer Research Program, Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University, Durham, North Carolina. .,Division of Gastroenterology and Hepatology, Department of Medicine, Center for Esophageal Disease and Swallowing, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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33
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Chen DH, Below JE, Shimamura A, Keel SB, Matsushita M, Wolff J, Sul Y, Bonkowski E, Castella M, Taniguchi T, Nickerson D, Papayannopoulou T, Bird TD, Raskind WH. Ataxia-Pancytopenia Syndrome Is Caused by Missense Mutations in SAMD9L. Am J Hum Genet 2016; 98:1146-1158. [PMID: 27259050 DOI: 10.1016/j.ajhg.2016.04.009] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/14/2016] [Indexed: 11/25/2022] Open
Abstract
Ataxia-pancytopenia (AP) syndrome is characterized by cerebellar ataxia, variable hematologic cytopenias, and predisposition to marrow failure and myeloid leukemia, sometimes associated with monosomy 7. Here, in the four-generation family UW-AP, linkage analysis revealed four regions that provided the maximal LOD scores possible, one of which was in a commonly microdeleted chromosome 7q region. Exome sequencing identified a missense mutation (c.2640C>A, p.His880Gln) in the sterile alpha motif domain containing 9-like gene (SAMD9L) that completely cosegregated with disease. By targeted sequencing of SAMD9L, we subsequently identified a different missense mutation (c.3587G>C, p.Cys1196Ser) in affected members of the first described family with AP syndrome, Li-AP. Neither variant is reported in the public databases, both affect highly conserved amino acid residues, and both are predicted to be damaging. With time in culture, lymphoblastic cell lines (LCLs) from two affected individuals in family UW-AP exhibited copy-neutral loss of heterozygosity for large portions of the long arm of chromosome 7, resulting in retention of only the wild-type SAMD9L allele. Newly established LCLs from both individuals demonstrated the same phenomenon. In addition, targeted capture and sequencing of SAMD9L in uncultured blood DNA from both individuals showed bias toward the wild-type allele. These observations indicate in vivo hematopoietic mosaicism. The hematopoietic cytopenias that characterize AP syndrome and the selective advantage for clones that have lost the mutant allele support the postulated role of SAMD9L in the regulation of cell proliferation. Furthermore, we show that AP syndrome is distinct from the dyskeratoses congenita telomeropathies, with which it shares some clinical characteristics.
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34
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Bretz AC, Gittler MP, Charles JP, Gremke N, Eckhardt I, Mernberger M, Mandic R, Thomale J, Nist A, Wanzel M, Stiewe T. ΔNp63 activates the Fanconi anemia DNA repair pathway and limits the efficacy of cisplatin treatment in squamous cell carcinoma. Nucleic Acids Res 2016; 44:3204-18. [PMID: 26819410 PMCID: PMC4838363 DOI: 10.1093/nar/gkw036] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/18/2015] [Accepted: 01/12/2016] [Indexed: 12/30/2022] Open
Abstract
TP63, a member of the p53 gene family gene, encodes the ΔNp63 protein and is one of the most frequently amplified genes in squamous cell carcinomas (SCC) of the head and neck (HNSCC) and lungs (LUSC). Using an epiallelic series of siRNAs with intrinsically different knockdown abilities, we show that the complete loss of ΔNp63 strongly impaired cell proliferation, whereas partial ΔNp63 depletion rendered cells hypersensitive to cisplatin accompanied by an accumulation of DNA damage. Expression profiling revealed wide-spread transcriptional regulation of DNA repair genes and in particular Fanconi anemia (FA) pathway components such as FANCD2 and RAD18 - known to be crucial for the repair of cisplatin-induced interstrand crosslinks. In SCC patients ΔNp63 levels significantly correlate with FANCD2 and RAD18 expression confirming ΔNp63 as a key activator of the FA pathway in vivo Mechanistically, ΔNp63 bound an upstream enhancer of FANCD2 inactive in primary keratinocytes but aberrantly activated by ΔNp63 in SCC. Consistently, depletion of FANCD2 sensitized to cisplatin similar to depletion of ΔNp63. Together, our results demonstrate that ΔNp63 directly activates the FA pathway in SCC and limits the efficacy of cisplatin treatment. Targeting ΔNp63 therefore would not only inhibit SCC proliferation but also sensitize tumors to chemotherapy.
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Affiliation(s)
- Anne Catherine Bretz
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Miriam P Gittler
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Joël P Charles
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Niklas Gremke
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Ines Eckhardt
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Marco Mernberger
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany
| | - Robert Mandic
- Department of Otorhinolaryngology, Head & Neck Surgery, University Hospital Giessen and Marburg, Philipps-University, 35033 Marburg, Germany
| | - Jürgen Thomale
- Institute of Cell Biology, University Duisburg-Essen, 45122 Essen, Germany
| | - Andrea Nist
- Genomics Core Facility, Philipps-University Marburg, 35043 Marburg, Germany
| | - Michael Wanzel
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany Universities of Giessen and Marburg Lung Center, member of the German Center for Lung Research (DZL), 35043 Marburg, Germany
| | - Thorsten Stiewe
- Institute of Molecular Oncology, Philipps-University Marburg, 35043 Marburg, Germany Genomics Core Facility, Philipps-University Marburg, 35043 Marburg, Germany Universities of Giessen and Marburg Lung Center, member of the German Center for Lung Research (DZL), 35043 Marburg, Germany
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ΔNp63α modulates histone methyl transferase SETDB1 to transcriptionally repress target genes in cancers. Cell Death Discov 2016; 2:16015. [PMID: 27551509 PMCID: PMC4979509 DOI: 10.1038/cddiscovery.2016.15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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The actin family protein ARP6 contributes to the structure and the function of the nucleolus. Biochem Biophys Res Commun 2015; 464:554-60. [PMID: 26164235 DOI: 10.1016/j.bbrc.2015.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/01/2015] [Indexed: 12/22/2022]
Abstract
The actin family members, consisting of actin and actin-related proteins (ARPs), are essential components of chromatin remodeling complexes. ARP6, one of the nuclear ARPs, is part of the Snf-2-related CREB-binding protein activator protein (SRCAP) chromatin remodeling complex, which promotes the deposition of the histone variant H2A.Z into the chromatin. In this study, we showed that ARP6 influences the structure and the function of the nucleolus. ARP6 is localized in the central region of the nucleolus, and its knockdown induced a morphological change in the nucleolus. We also found that in the presence of high concentrations of glucose ARP6 contributed to the maintenance of active ribosomal DNA (rDNA) transcription by placing H2A.Z into the chromatin. In contrast, under starvation, ARP6 was required for cell survival through the repression of rDNA transcription independently of H2A.Z. These findings reveal novel pleiotropic roles for the actin family in nuclear organization and metabolic homeostasis.
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Scavenger receptor class A member 5 (SCARA5) and suprabasin (SBSN) are hub genes of coexpression network modules associated with peripheral vein graft patency. J Vasc Surg 2015; 64:202-209.e6. [PMID: 25935274 DOI: 10.1016/j.jvs.2014.12.052] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 12/18/2014] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Approximately 30% of autogenous vein grafts develop luminal narrowing and fail because of intimal hyperplasia or negative remodeling. We previously found that vein graft cells from patients who later develop stenosis proliferate more in vitro in response to growth factors than cells from patients who maintain patent grafts. To discover novel determinants of vein graft outcome, we have analyzed gene expression profiles of these cells using a systems biology approach to cluster the genes into modules by their coexpression patterns and to correlate the results with growth data from our prior study and with new studies of migration and matrix remodeling. METHODS RNA from 4-hour serum- or platelet-derived growth factor (PDGF)-BB-stimulated human saphenous vein cells obtained from the outer vein wall (20 cell lines) was used for microarray analysis of gene expression, followed by weighted gene coexpression network analysis. Cell migration in microchemotaxis chambers in response to PDGF-BB and cell-mediated collagen gel contraction in response to serum were also determined. Gene function was determined using short-interfering RNA to inhibit gene expression before subjecting cells to growth or collagen gel contraction assays. These cells were derived from samples of the vein grafts obtained at surgery, and the long-term fate of these bypass grafts was known. RESULTS Neither migration nor cell-mediated collagen gel contraction showed a correlation with graft outcome. Although 1188 and 1340 genes were differentially expressed in response to treatment with serum and PDGF, respectively, no single gene was differentially expressed in cells isolated from patients whose grafts stenosed compared with those that remained patent. Network analysis revealed four unique groups of genes, which we term modules, associated with PDGF responses, and 20 unique modules associated with serum responses. The "yellow" and "skyblue" modules, from PDGF and serum analyses, respectively, correlated with later graft stenosis (P = .005 and P = .02, respectively). In response to PDGF, yellow was also associated with increased cell growth. For serum, skyblue was also associated with inhibition of collagen gel contraction. The hub genes for yellow and skyblue (ie, the gene most connected to other genes in the module), scavenger receptor class A member 5 (SCARA5) and suprabasin (SBSN), respectively, were tested for effects on proliferation and collagen contraction. Knockdown of SCARA5 increased proliferation by 29.9% ± 7.8% (P < .01), whereas knockdown of SBSN had no effect. Knockdown of SBSN increased collagen gel contraction by 24.2% ± 8.6% (P < .05), whereas knockdown of SCARA5 had no effect. CONCLUSIONS Using weighted gene coexpression network analysis of cultured vein graft cell gene expression, we have discovered two small gene modules, which comprise 42 genes, that are associated with vein graft failure. Further experiments are needed to delineate the venous cells that express these genes in vivo and the roles these genes play in vein graft healing, starting with the module hub genes SCARA5 and SBSN, which have been shown to have modest effects on cell proliferation or collagen gel contraction.
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Suarez-Carmona M, Hubert P, Gonzalez A, Duray A, Roncarati P, Erpicum C, Boniver J, Castronovo V, Noel A, Saussez S, Peulen O, Delvenne P, Herfs M. ΔNp63 isoform-mediated β-defensin family up-regulation is associated with (lymph)angiogenesis and poor prognosis in patients with squamous cell carcinoma. Oncotarget 2015; 5:1856-68. [PMID: 24732135 PMCID: PMC4039122 DOI: 10.18632/oncotarget.1819] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Beside a role in normal development/differentiation, high p63 immunoreactivity is also frequently observed in squamous cell carcinoma (SCC). Due to the complexity of the gene, the role of each p63 isotype in tumorigenesis is still confusing. Constitutively produced or induced in inflammatory conditions, human beta-defensins (HβDs) are cationic peptides involved in host defenses against bacteria, viruses and fungi. Here, we investigated both the role of p63 proteins in the regulation of HβDs and the implication of these antimicrobial peptides in tumor (lymph)angiogenesis. Thus, in contrast to TAp63 isotypes, we observed that ΔNp63 proteins (α, β, γ) induce HβD1, 2 and 4 expression. Similar results were observed in cancer tissues and cell lines. We next demonstrated that ΔNp63-overexpressing SCC are associated with both a poor prognosis and a high tumor vascularisation and lymphangiogenesis. Moreover, we showed that HβDs exert a chemotactic activity for (lymphatic) endothelial cells in a CCR6-dependent manner. The ability of HβDs to enhance (lymph)angiogenesis in vivo was also evaluated. We observed that HβDs increase the vessel number and induce a significant increase in relative vascular area compared to negative control. Taken together, the results of this study suggest that ΔNp63-regulated HβD could promote tumor (lymph)angiogenesis in SCC microenvironment.
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Affiliation(s)
- Meggy Suarez-Carmona
- Laboratory of Experimental Pathology, GIGA-Cancer, University of Liege, Liege, Belgium
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Antonini D, Sirico A, Aberdam E, Ambrosio R, Campanile C, Fagoonee S, Altruda F, Aberdam D, Brissette JL, Missero C. A composite enhancer regulates p63 gene expression in epidermal morphogenesis and in keratinocyte differentiation by multiple mechanisms. Nucleic Acids Res 2015; 43:862-74. [PMID: 25567987 PMCID: PMC4333422 DOI: 10.1093/nar/gku1396] [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] [Indexed: 12/22/2022] Open
Abstract
p63 is a crucial regulator of epidermal development, but its transcriptional control has remained elusive. Here, we report the identification of a long-range enhancer (p63LRE) that is composed of two evolutionary conserved modules (C38 and C40), acting in concert to control tissue- and layer-specific expression of the p63 gene. Both modules are in an open and active chromatin state in human and mouse keratinocytes and in embryonic epidermis, and are strongly bound by p63. p63LRE activity is dependent on p63 expression in embryonic skin, and also in the commitment of human induced pluripotent stem cells toward an epithelial cell fate. A search for other transcription factors involved in p63LRE regulation revealed that the CAAT enhancer binding proteins Cebpa and Cebpb and the POU domain-containing protein Pou3f1 repress p63 expression during keratinocyte differentiation by binding the p63LRE enhancer. Collectively, our data indicate that p63LRE is composed of additive and partly redundant enhancer modules that act to direct robust p63 expression selectively in the basal layer of the epidermis.
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Affiliation(s)
| | - Anna Sirico
- CEINGE Biotecnologie Avanzate, Napoli, Italy
| | - Edith Aberdam
- INSERM UMR-S 976, Paris, France Université Paris-Diderot, Hopital St-Louis, Paris, France
| | | | | | - Sharmila Fagoonee
- Institute for Biostructures and Bioimages (CNR), c/o Molecular Biotechnology Center, University of Turin, Torino, Italy
| | - Fiorella Altruda
- Molecular Biotechnology Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Torino, Italy
| | - Daniel Aberdam
- INSERM UMR-S 976, Paris, France Université Paris-Diderot, Hopital St-Louis, Paris, France
| | - Janice L Brissette
- Department of Cell Biology, State University of New York Downstate Medical Center, NY, USA
| | - Caterina Missero
- CEINGE Biotecnologie Avanzate, Napoli, Italy Department of Biology, University of Naples Federico II, Napoli, Italy
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Missero C, Antonini D. Crosstalk among p53 family members in cutaneous carcinoma. Exp Dermatol 2014; 23:143-6. [PMID: 24417641 DOI: 10.1111/exd.12320] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2014] [Indexed: 12/27/2022]
Abstract
Cutaneous squamous cell carcinoma (cSCC) is the second most common human cancer with a frequency increasing worldwide. The risk of developing cSCC has been strongly associated with chronic sun exposure, especially in light skin people. The aim of this viewpoint is to discuss the contribution of the tumor suppressor p53 and its homologues p63 and p73 in the formation and progression of cSCC. Mutations in the p53 gene are early and frequent events in skin carcinogenesis mainly as a consequence of UV light exposure, often followed by loss of function of the second allele. Although rarely mutated in cancer, p63 and p73 play key roles in human cancers, with their truncated isoforms lacking the N-terminal transactivating domain (∆N) being often upregulated as compared to normal tissues. ∆Np63 is abundantly expressed in cSCC, and it is likely to favour tumor initiation and progression. The function of p73 in cSCC is more enigmatic and awaits further studies. Interestingly, an intimate interplay exists between both p53 and p63, and the Notch signalling pathway, often inactivated in cSCC. Here, we summarize our current knowledge about the biological activities of p53 family members in cSCC and propose that integration of their signalling with Notch is key to cSCC formation and progression.
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McDade SS, Patel D, Moran M, Campbell J, Fenwick K, Kozarewa I, Orr NJ, Lord CJ, Ashworth AA, McCance DJ. Genome-wide characterization reveals complex interplay between TP53 and TP63 in response to genotoxic stress. Nucleic Acids Res 2014; 42:6270-85. [PMID: 24823795 PMCID: PMC4041465 DOI: 10.1093/nar/gku299] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 02/18/2014] [Accepted: 03/29/2014] [Indexed: 01/07/2023] Open
Abstract
In response to genotoxic stress the TP53 tumour suppressor activates target gene expression to induce cell cycle arrest or apoptosis depending on the extent of DNA damage. These canonical activities can be repressed by TP63 in normal stratifying epithelia to maintain proliferative capacity or drive proliferation of squamous cell carcinomas, where TP63 is frequently overexpressed/amplified. Here we use ChIP-sequencing, integrated with microarray analysis, to define the genome-wide interplay between TP53 and TP63 in response to genotoxic stress in normal cells. We reveal that TP53 and TP63 bind to overlapping, but distinct cistromes of sites through utilization of distinctive consensus motifs and that TP53 is constitutively bound to a number of sites. We demonstrate that cisplatin and adriamycin elicit distinct effects on TP53 and TP63 binding events, through which TP53 can induce or repress transcription of an extensive network of genes by direct binding and/or modulation of TP63 activity. Collectively, this results in a global TP53-dependent repression of cell cycle progression, mitosis and DNA damage repair concomitant with activation of anti-proliferative and pro-apoptotic canonical target genes. Further analyses reveal that in the absence of genotoxic stress TP63 plays an important role in maintaining expression of DNA repair genes, loss of which results in defective repair.
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Affiliation(s)
- Simon S McDade
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Daksha Patel
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Michael Moran
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast BT9 7BL, UK
| | - James Campbell
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Kerry Fenwick
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Iwanka Kozarewa
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Nicholas J Orr
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Christopher J Lord
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Alan A Ashworth
- The Breakthrough Breast Cancer Research Centre, Institute for Cancer Research, Chelsea, London SW3 6JB, UK
| | - Dennis J McCance
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast BT9 7BL, UK
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Abstract
Eukaryotic gene regulation involves a balance between packaging of the genome into nucleosomes and enabling access to regulatory proteins and RNA polymerase. Nucleosomes, consisting of DNA wrapped around a core of histone proteins, are integral components of gene regulation that restrict access to both regulatory sequences and the underlying template. In this review, Weber and Henikoff consider how histone variants and their interacting partners are involved in transcriptional regulation through the creation of unique chromatin states. Eukaryotic gene regulation involves a balance between packaging of the genome into nucleosomes and enabling access to regulatory proteins and RNA polymerase. Nucleosomes are integral components of gene regulation that restrict access to both regulatory sequences and the underlying template. Whereas canonical histones package the newly replicated genome, they can be replaced with histone variants that alter nucleosome structure, stability, dynamics, and, ultimately, DNA accessibility. Here we consider how histone variants and their interacting partners are involved in transcriptional regulation through the creation of unique chromatin states.
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Affiliation(s)
- Christopher M Weber
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
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Soboleva TA, Nekrasov M, Ryan DP, Tremethick DJ. Histone variants at the transcription start-site. Trends Genet 2014; 30:199-209. [DOI: 10.1016/j.tig.2014.03.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 01/30/2023]
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Ng WL, Chen G, Wang M, Wang H, Story M, Shay JW, Zhang X, Wang J, Amin ARMR, Hu B, Cucinotta FA, Wang Y. OCT4 as a target of miR-34a stimulates p63 but inhibits p53 to promote human cell transformation. Cell Death Dis 2014; 5:e1024. [PMID: 24457968 PMCID: PMC4040665 DOI: 10.1038/cddis.2013.563] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 12/14/2013] [Accepted: 12/17/2013] [Indexed: 01/07/2023]
Abstract
Human cell transformation is a key step for oncogenic development, which involves multiple pathways; however, the mechanism remains unclear. To test our hypothesis whether cell oncogenic transformation shares some mechanisms with the process of reprogramming non-stem cells to induced pluripotent stem cells (iPSC), we studied the relationship among the key factors for promoting or inhibiting iPSC in radiation-transformed human epithelial cell lines derived from different tissues (lung, breast and colon). We unexpectedly found that p63 and OCT4 were highly expressed (accompanied by low expressed p53 and miR-34a) in all transformed cell lines examined when compared with their non-transformed counterparts. We further elucidated the relationship of these factors: the 3p strand of miR-34a directly targeted OCT4 by binding to the 3′ untranslated region (3′-UTR) of OCT4 and, OCT4, in turn, stimulated p63 but inhibited p53 expression by binding to a specific region of the p63 or p53 promoter. Moreover, we revealed that the effects of OCT4 on promoting cell oncogenic transformation were by affecting p63 and p53. These results support that a positive loop exists in human cells: OCT4 upregulation as a consequence of inhibition of miR-34a, promotes p63 but suppresses p53 expression, which further stimulates OCT4 upregulation by downregulating miR-34a. This functional loop contributes significantly to cell transformation and, most likely, also to the iPSC process.
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Affiliation(s)
- W L Ng
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - G Chen
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - M Wang
- Division of Space Life Sciences, Universities Space Research Association, Houston, TX, USA
| | - H Wang
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - M Story
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - J W Shay
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX, USA
| | - X Zhang
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - J Wang
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - A R M R Amin
- Department of Hematology and Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
| | - B Hu
- 1] Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA [2] Department of Medical Molecular Biology, Beijing Institute of Biotechnology, Beijing, China
| | - F A Cucinotta
- Department of Health Physics and Diagnostic Sciences, University of Nevada, Las Vegas, NV, USA
| | - Y Wang
- Department of Radiation Oncology, Emory University School of Medicine, Winship Cancer Institute of Emory University, Atlanta, GA, USA
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Ranjan A, Mizuguchi G, FitzGerald PC, Wei D, Wang F, Huang Y, Luk E, Woodcock CL, Wu C. Nucleosome-free region dominates histone acetylation in targeting SWR1 to promoters for H2A.Z replacement. Cell 2013; 154:1232-45. [PMID: 24034247 DOI: 10.1016/j.cell.2013.08.005] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 06/04/2013] [Accepted: 08/05/2013] [Indexed: 01/31/2023]
Abstract
The histone variant H2A.Z is a genome-wide signature of nucleosomes proximal to eukaryotic regulatory DNA. Whereas the multisubunit chromatin remodeler SWR1 is known to catalyze ATP-dependent deposition of H2A.Z, the mechanism of SWR1 recruitment to S. cerevisiae promoters has been unclear. A sensitive assay for competitive binding of dinucleosome substrates revealed that SWR1 preferentially binds long nucleosome-free DNA and the adjoining nucleosome core particle, allowing discrimination of gene promoters over gene bodies. Analysis of mutants indicates that the conserved Swc2/YL1 subunit and the adenosine triphosphatase domain of Swr1 are mainly responsible for binding to substrate. SWR1 binding is enhanced on nucleosomes acetylated by the NuA4 histone acetyltransferase, but recognition of nucleosome-free and nucleosomal DNA is dominant over interaction with acetylated histones. Such hierarchical cooperation between DNA and histone signals expands the dynamic range of genetic switches, unifying classical gene regulation by DNA-binding factors with ATP-dependent nucleosome remodeling and posttranslational histone modifications.
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Affiliation(s)
- Anand Ranjan
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Ratovitski EA. Tumor Protein p63/microRNA Network in Epithelial Cancer Cells. Curr Genomics 2013; 14:441-52. [PMID: 24396276 PMCID: PMC3867720 DOI: 10.2174/13892029113146660011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 09/09/2013] [Accepted: 09/09/2013] [Indexed: 02/07/2023] Open
Abstract
Non-coding microRNAs are involved in multiple regulatory mechanisms underlying response of cancer cells to stress leading to apoptosis, cell cycle arrest and autophagy. Many molecular layers are implicated in such cellular response including epigenetic regulation of transcription, RNA processing, metabolism, signaling. The molecular interrelationship between tumor protein (TP)-p53 family members and specific microRNAs is a key functional network supporting tumor cell response to chemotherapy and potentially playing a decisive role in chemoresistance of human epithelial cancers. TP63 was shown to modulate the expression of numerous microRNAs involved in regulation of epithelial cell proliferation, differentiation, senescence, "stemness" and skin maintenance, epithelial/ mesenchymal transition, and tumorigenesis in several types of epithelial cancers (e.g. squamous cell carcinoma, ovarian carcinoma, prostate carcinoma, gastric cancer, bladder cancer, and breast tumors), as well as in chemoresistance of cancer cells. TP63/microRNA network was shown to be involved in cell cycle arrest, apoptosis, autophagy, metabolism and epigenetic transcriptional regulation, thereby providing the groundwork for novel chemotherapeutic venues.
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Affiliation(s)
- Edward A. Ratovitski
- Department of Otolaryngology/Head and Neck Surgery, Head and Neck Cancer Research Division, The Johns Hopkins University School of Medicine, Cancer Research Building II, 1550 Orleans Street, Baltimore, MD 21231, U.S.A
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Kim K, Punj V, Choi J, Heo K, Kim JM, Laird PW, An W. Gene dysregulation by histone variant H2A.Z in bladder cancer. Epigenetics Chromatin 2013; 6:34. [PMID: 24279307 PMCID: PMC3853418 DOI: 10.1186/1756-8935-6-34] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 09/27/2013] [Indexed: 12/20/2022] Open
Abstract
Background The incorporation of histone variants into nucleosomes is one of the main strategies that the cell uses to regulate the structure and function of chromatin. Histone H2A.Z is an evolutionarily conserved histone H2A variant that is preferentially localized within nucleosomes at the transcriptional start site (TSS). H2A.Z reorganizes the local chromatin structure and recruits the transcriptional machinery for gene activation. High expression of H2A.Z has been reported in several types of cancers and is causally linked to genomic instability and tumorigenesis. However, it is not entirely clear how H2A.Z overexpression in cancer cells establishes aberrant chromatin states and promotes gene expression. Results Through integration of genome-wide H2A.Z ChIP-seq data with microarray data, we demonstrate that H2A.Z is enriched around the TSS of cell cycle regulatory genes in bladder cancer cells, and this enrichment is correlated with the elevated expression of cancer-promoting genes. RNAi-mediated knockdown of H2A.Z in the cancer cells causes transcriptional suppression of multiple cell cycle regulatory genes with a distinct decrease in cell proliferation. H2A.Z nucleosomes around the TSS have higher levels of H3K4me2/me3, which coincides with the recruitment of two chromatin factors, WDR5 and BPTF. The observed recruitment is functional, as the active states of H2A.Z target genes are largely erased by suppressing the expression of WDR5 or BPTF, effects resembling H2A.Z knockdown. Conclusions We conclude that H2A.Z is overexpressed in bladder cancer cells and contributes to cancer-related transcription pathways. We also provide evidence in support of the engagement of H3K4me2/me3 and WDR5/BPTF in H2A.Z-induced cancer pathogenesis. Further studies are warranted to understand how H2A.Z overexpression contributes to the recruitment of the full repertoire of transcription machinery to target genes in bladder cancer cells.
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Abstract
Chromatin acts as an organizer and indexer of genomic DNA and is a highly dynamic and regulated structure with properties directly related to its constituent parts. Histone variants are abundant components of chromatin that replace canonical histones in a subset of nucleosomes, thereby altering nucleosomal characteristics. The present review focuses on the H2A variant histones, summarizing current knowledge of how H2A variants can introduce chemical and functional heterogeneity into chromatin, the positions that nucleosomes containing H2A variants occupy in eukaryotic genomes, and the regulation of these localization patterns.
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Gallant-Behm CL, Espinosa JM. ΔNp63α utilizes multiple mechanisms to repress transcription in squamous cell carcinoma cells. Cell Cycle 2013; 12:409-16. [PMID: 23324337 PMCID: PMC3587441 DOI: 10.4161/cc.23593] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
ΔNp63α is a potent oncogene in squamous cell carcinomas (SCCs) and a pro-proliferative factor expressed by basal epithelial cells. ΔNp63α functions both as a transcriptional repressor and activator, but it is not clear how these activities contribute to its oncogenic potential. ΔNp63α was proposed to function as a dominant negative of the related factor p53. Additionally, ΔNp63α was shown to inactivate its family member TAp73 and mediate recruitment of repressive histone deacetylase (HDAC) complexes to chromatin. Recently, we identified a new mechanism of repression involving recruitment of histone H2A/H2A.Z exchange complexes and H2A.Z deposition at ΔNp63α target genes. Here, we aimed to define the possible co-occurrence of the various repressive mechanisms. In lung SCC cells expressing ΔNp63α, p53 and TAp73, we found that ΔNp63α exerts its pro-proliferative and transcriptional repressive effects in a manner independent of p53, TAp73 and histone H3 and H4 deacetylation. Instead, ΔNp63α target genes are differentiated from non-target genes within the p53 network by incorporation and accumulation of acetylated H2A.Z. These results indicate that ΔNp63α utilizes multiple mechanisms of repression in diverse epithelial and SCC cells.
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Affiliation(s)
- Corrie L Gallant-Behm
- Howard Hughes Medical Institute and Department of Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder, CO, USA
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