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Zhang H, Liu B, Cheng J, Li Z, Jia M, Li M, Zhao L, Wang L, Xi Y. Characterization and integrated analysis of extrachromosomal DNA amplification in hematological malignancies. Neoplasia 2024; 56:101025. [PMID: 38996538 PMCID: PMC11301242 DOI: 10.1016/j.neo.2024.101025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024]
Abstract
The study of extrachromosomal DNA (ecDNA), an element existing beyond classical chromosomes, contributes to creating a more comprehensive map of the cancer genome. In hematological malignancies, research on ecDNA has lacked comprehensive investigation into its frequency, structure, function, and mechanisms of formation. We re-analyzed WGS data from 208 hematological cancer samples across 11 types, focusing on ecDNA characteristics. Amplification of ecDNA was observed in 7 of these cancer types, with no instances found in normal blood cells. Patients with leukemia carrying ecDNA showed a low induction therapy remission rate (<30 %), a high relapse rate (75 %) among those who achieved complete remission, and a significantly lower survival rate compared to the general leukemia population, even those with complex chromosomal karyotypes. Among the 55 identified ecDNA amplicons, 268 genes were detected, of which 38 are known cancer-related genes exhibiting significantly increased copy numbers. By integrating RNA-Seq data, we discovered that the increased copy number, resulting in a higher amount of available DNA templates, indeed leads to the elevated expression of genes encoded on ecDNA. Additionally, through the integration of H3K4me3/H3K27ac chromatin immunoprecipitation sequencing, assay for transposase-accessible chromatin with sequencing, and high-throughput chromosome conformation capture data, we identified that ecDNA amplifications can also facilitate efficient, copy number-independent amplification of oncogenes. This process is linked to active histone modifications, improved chromatin accessibility, and enhancer hijacking, all of which are effects of ecDNA amplification. Mechanistically, chromothripsis and dysfunction of the DNA repair pathway can, to some extent, explain the origin of ecDNA.
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Affiliation(s)
- Hao Zhang
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Bei Liu
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Juan Cheng
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Zijian Li
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Mingfeng Jia
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Ming Li
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Long Zhao
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Lina Wang
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China
| | - Yaming Xi
- Department of Hematology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, China.
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2
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Dehkordi SR, Wong ITL, Ni J, Luebeck J, Zhu K, Prasad G, Krockenberger L, Xu G, Chowdhury B, Rajkumar U, Caplin A, Muliaditan D, Coruh C, Jin Q, Turner K, Teo SX, Pang AWC, Alexandrov LB, Chua CEL, Furnari FB, Paulson TG, Law JA, Chang HY, Yue F, DasGupta R, Zhao J, Mischel PS, Bafna V. Breakage fusion bridge cycles drive high oncogene copy number, but not intratumoral genetic heterogeneity or rapid cancer genome change. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571349. [PMID: 38168210 PMCID: PMC10760206 DOI: 10.1101/2023.12.12.571349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Oncogene amplification is a major driver of cancer pathogenesis. Breakage fusion bridge (BFB) cycles, like extrachromosomal DNA (ecDNA), can lead to high copy numbers of oncogenes, but their impact on intratumoral heterogeneity, treatment response, and patient survival are not well understood due to difficulty in detecting them by DNA sequencing. We describe a novel algorithm that detects and reconstructs BFB amplifications using optical genome maps (OGMs), called OM2BFB. OM2BFB showed high precision (>93%) and recall (92%) in detecting BFB amplifications in cancer cell lines, PDX models and primary tumors. OM-based comparisons demonstrated that short-read BFB detection using our AmpliconSuite (AS) toolkit also achieved high precision, albeit with reduced sensitivity. We detected 371 BFB events using whole genome sequences from 2,557 primary tumors and cancer lines. BFB amplifications were preferentially found in cervical, head and neck, lung, and esophageal cancers, but rarely in brain cancers. BFB amplified genes show lower variance of gene expression, with fewer options for regulatory rewiring relative to ecDNA amplified genes. BFB positive (BFB (+)) tumors showed reduced heterogeneity of amplicon structures, and delayed onset of resistance, relative to ecDNA(+) tumors. EcDNA and BFB amplifications represent contrasting mechanisms to increase the copy numbers of oncogene with markedly different characteristics that suggest different routes for intervention.
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Affiliation(s)
- Siavash Raeisi Dehkordi
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Ivy Tsz-Lo Wong
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Jing Ni
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215 USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 USA
| | - Jens Luebeck
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, San Diego, CA, USA
| | - Kaiyuan Zhu
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Gino Prasad
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Lena Krockenberger
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Guanghui Xu
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Biswanath Chowdhury
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Utkrisht Rajkumar
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Ann Caplin
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
| | - Daniel Muliaditan
- Laboratory of Precision Oncology and Cancer Evolution, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Ceyda Coruh
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- ClearNote Health, San Diego, CA 92121 USA
| | - Qiushi Jin
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine Northwestern University, Chicago, IL, USA
| | | | - Shu Xian Teo
- Singapore Nuclear Research and Safety Initiative, National University of Singapore
| | | | - Ludmil B Alexandrov
- Moores Cancer Center, UC San Diego Health, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
- Department of Bioengineering, University of California at San Diego, La Jolla, CA, USA
| | | | - Frank B Furnari
- Department of Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Thomas G Paulson
- Translational Science and Therapeutics Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Julie A Law
- Plant Molecular and Cellular Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Feng Yue
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine Northwestern University, Chicago, IL, USA
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL, USA
| | - Ramanuj DasGupta
- Laboratory of Precision Oncology and Cancer Evolution, Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Jean Zhao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215 USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 USA
| | - Paul S Mischel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
| | - Vineet Bafna
- Department of Computer Science and Engineering, University of California San Diego, San Diego, CA, USA
- Halıcıoğlu Data Science Institute, University of California at San Diego, La Jolla, CA, USA
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3
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Dong Y, He Q, Chen X, Yang F, He L, Zheng Y. Extrachromosomal DNA (ecDNA) in cancer: mechanisms, functions, and clinical implications. Front Oncol 2023; 13:1194405. [PMID: 37448518 PMCID: PMC10338009 DOI: 10.3389/fonc.2023.1194405] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/05/2023] [Indexed: 07/15/2023] Open
Abstract
Extrachromosomal DNA (ecDNA) is circular DNA that plays an important role in the development and heterogeneity of cancer. The rapid evolution of methods to detect ecDNA, including microscopic and sequencing approaches, has greatly enhanced our knowledge of the role of ecDNA in cancer development and evolution. Here, we review the molecular characteristics, functions, mechanisms of formation, and detection methods of ecDNA, with a focus on the potential clinical implications of ecDNA in cancer. Specifically, we consider the role of ecDNA in acquired drug resistance, as a diagnostic and prognostic biomarker, and as a therapeutic target in the context of cancer. As the pathological and clinical significance of ecDNA continues to be explored, it is anticipated that ecDNA will have broad applications in the diagnosis, prognosis, and treatment of patients with cancer.
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Affiliation(s)
- Yucheng Dong
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qi He
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Xinyu Chen
- Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Fan Yang
- Department of Liver Surgery, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Li He
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma, OK, United States
| | - Yongchang Zheng
- Department of Liver Surgery, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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4
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Luo J, Li Y, Zhang T, Xv T, Chen C, Li M, Qiu Q, Song Y, Wan S. Extrachromosomal circular DNA in cancer drug resistance and its potential clinical implications. Front Oncol 2023; 12:1092705. [PMID: 36793345 PMCID: PMC9923117 DOI: 10.3389/fonc.2022.1092705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 12/28/2022] [Indexed: 01/31/2023] Open
Abstract
Chemotherapy is widely used to treat patients with cancer. However, resistance to chemotherapeutic drugs remains a major clinical concern. The mechanisms of cancer drug resistance are extremely complex and involve such factors such as genomic instability, DNA repair, and chromothripsis. A recently emerging area of interest is extrachromosomal circular DNA (eccDNA), which forms owing to genomic instability and chromothripsis. eccDNA exists widely in physiologically healthy individuals but also arises during tumorigenesis and/or treatment as a drug resistance mechanism. In this review, we summarize the recent progress in research regarding the role of eccDNA in the development of cancer drug resistance as well as the mechanisms thereof. Furthermore, we discuss the clinical applications of eccDNA and propose some novel strategies for characterizing drug-resistant biomarkers and developing potential targeted cancer therapies.
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Affiliation(s)
- Juanjuan Luo
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China,China Medical University, Shenyang, China, Ganzhou, China
| | - Ying Li
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Tangxuan Zhang
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Tianhan Xv
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Chao Chen
- Department of Interventional Radiology, The People’s Hospital of Ganzhou City, Ganzhou, China
| | - Mengting Li
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Qixiang Qiu
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China
| | - Yusheng Song
- Department of Interventional Radiology, The People’s Hospital of Ganzhou City, Ganzhou, China,*Correspondence: Shaogui Wan, ; Yusheng Song,
| | - Shaogui Wan
- Center for Molecular Pathology, Department of Basic Medicine, Gannan Medical University, Ganzhou, China,China Medical University, Shenyang, China, Ganzhou, China,*Correspondence: Shaogui Wan, ; Yusheng Song,
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5
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Ilić M, Zaalberg IC, Raaijmakers JA, Medema RH. Life of double minutes: generation, maintenance, and elimination. Chromosoma 2022; 131:107-125. [PMID: 35487993 PMCID: PMC9470669 DOI: 10.1007/s00412-022-00773-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/17/2022] [Accepted: 03/24/2022] [Indexed: 12/20/2022]
Abstract
Advances in genome sequencing have revealed a type of extrachromosomal DNA, historically named double minutes (also referred to as ecDNA), to be common in a wide range of cancer types, but not in healthy tissues. These cancer-associated circular DNA molecules contain one or a few genes that are amplified when double minutes accumulate. Double minutes harbor oncogenes or drug resistance genes that contribute to tumor aggressiveness through copy number amplification in combination with favorable epigenetic properties. Unequal distribution of double minutes over daughter cells contributes to intratumoral heterogeneity, thereby increasing tumor adaptability. In this review, we discuss various models delineating the mechanism of generation of double minutes. Furthermore, we highlight how double minutes are maintained, how they evolve, and discuss possible mechanisms driving their elimination.
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Affiliation(s)
- Mila Ilić
- Division of Cell Biology, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - Irene C Zaalberg
- Division of Cell Biology, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
- Center for Molecular Medicine, University Medical Center Utrecht, Utrecht University, Universiteitsweg, 100, 3584, CG Utrecht, The Netherlands
| | - Jonne A Raaijmakers
- Division of Cell Biology, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands
| | - René H Medema
- Division of Cell Biology, Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
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6
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Abstract
In cancer, complex genome rearrangements and other structural alterations, including the amplification of oncogenes on circular extrachromosomal DNA (ecDNA) elements, drive the formation and progression of tumors. ecDNA is a particularly challenging structural alteration. By untethering oncogenes from chromosomal constraints, it elevates oncogene copy number, drives intratumoral genetic heterogeneity, promotes rapid tumor evolution, and results in treatment resistance. The profound changes in DNA shape and nuclear architecture generated by ecDNA alter the transcriptional landscape of tumors by catalyzing new types of regulatory interactions that do not occur on chromosomes. The current suite of tools for interrogating cancer genomes is well suited for deciphering sequence but has limited ability to resolve the complex changes in DNA structure and dynamics that ecDNA generates. Here, we review the challenges of resolving ecDNA form and function and discuss the emerging tool kit for deciphering ecDNA architecture and spatial organization, including what has been learned to date about how this dramatic change in shape alters tumor development, progression, and drug resistance.
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Affiliation(s)
- Vineet Bafna
- Department of Computer Science and Engineering and Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, California, USA;
| | - Paul S Mischel
- Department of Pathology and ChEM-H, Stanford University School of Medicine, Stanford, California, USA;
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7
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Arrey G, Keating ST, Regenberg B. A unifying model for extrachromosomal circular DNA load in eukaryotic cells. Semin Cell Dev Biol 2022; 128:40-50. [PMID: 35292190 DOI: 10.1016/j.semcdb.2022.03.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 02/06/2023]
Abstract
Extrachromosomal circular DNA (eccDNA) with exons and whole genes are common features of eukaryotic cells. Work from especially tumours and the yeast Saccharomyces cerevisiae has revealed that eccDNA can provide large selective advantages and disadvantages. Besides the phenotypic effect due to expression of an eccDNA fragment, eccDNA is different from other mutations in that it is released from 1:1 segregation during cell division. This means that eccDNA can quickly change copy number, pickup secondary mutations and reintegrate into a chromosome to establish substantial genetic variation that could not have evolved via canonical mechanisms. We propose a unifying 5-factor model for conceptualizing the eccDNA load of a eukaryotic cell, emphasizing formation, replication, segregation, selection and elimination. We suggest that the magnitude of these sequential events and their interactions determine the copy number of eccDNA in mitotically dividing cells. We believe that our model will provide a coherent framework for eccDNA research, to understand its biology and the factors that can be manipulated to modulate eccDNA load in eukaryotic cells.
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Affiliation(s)
- Gerard Arrey
- Section for Ecology and Evolution, University of Copenhagen, Copenhagen, Denmark
| | - Samuel T Keating
- Section for Ecology and Evolution, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte Regenberg
- Section for Ecology and Evolution, University of Copenhagen, Copenhagen, Denmark.
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8
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Song K, Minami JK, Huang A, Dehkordi SR, Lomeli SH, Luebeck J, Goodman MH, Moriceau G, Krijgsman O, Dharanipragada P, Ridgley T, Crosson WP, Salazar J, Pazol E, Karin G, Jayaraman R, Balanis NG, Alhani S, Sheu K, Hoeve JT, Palermo A, Motika SE, Senaratne TN, Paraiso KH, Hergenrother PJ, Rao PN, Multani AS, Peeper DS, Bafna V, Lo RS, Graeber TG. Plasticity of Extrachromosomal and Intrachromosomal BRAF Amplifications in Overcoming Targeted Therapy Dosage Challenges. Cancer Discov 2022; 12:1046-1069. [PMID: 34930786 PMCID: PMC9192483 DOI: 10.1158/2159-8290.cd-20-0936] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/06/2021] [Accepted: 12/15/2021] [Indexed: 11/16/2022]
Abstract
Focal amplifications (FA) can mediate targeted therapy resistance in cancer. Understanding the structure and dynamics of FAs is critical for designing treatments that overcome plasticity-mediated resistance. We developed a melanoma model of dual MAPK inhibitor (MAPKi) resistance that bears BRAFV600 amplifications through either extrachromosomal DNA (ecDNA)/double minutes (DM) or intrachromosomal homogenously staining regions (HSR). Cells harboring BRAFV600E FAs displayed mode switching between DMs and HSRs, from both de novo genetic changes and selection of preexisting subpopulations. Plasticity is not exclusive to ecDNAs, as cells harboring HSRs exhibit drug addiction-driven structural loss of BRAF amplicons upon dose reduction. FA mechanisms can couple with kinase domain duplications and alternative splicing to enhance resistance. Drug-responsive amplicon plasticity is observed in the clinic and can involve other MAPK pathway genes, such as RAF1 and NRAS. BRAF FA-mediated dual MAPKi-resistant cells are more sensitive to proferroptotic drugs, extending the spectrum of ferroptosis sensitivity in MAPKi resistance beyond cases of dedifferentiation. SIGNIFICANCE Understanding the structure and dynamics of oncogene amplifications is critical for overcoming tumor relapse. BRAF amplifications are highly plastic under MAPKi dosage challenges in melanoma, through involvement of de novo genomic alterations, even in the HSR mode. Moreover, BRAF FA-driven, dual MAPKi-resistant cells extend the spectrum of resistance-linked ferroptosis sensitivity. This article is highlighted in the In This Issue feature, p. 873.
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Affiliation(s)
- Kai Song
- Department of Bioengineering, UCLA, Los Angeles, CA 90095, USA
| | - Jenna K. Minami
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- Department of Integrative Biology and Physiology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Arthur Huang
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Siavash R. Dehkordi
- Department of Computer Science and Engineering, University of California at San Diego, La Jolla, CA 92093, USA
| | - Shirley H. Lomeli
- Division of Dermatology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Jens Luebeck
- Department of Computer Science and Engineering, University of California at San Diego, La Jolla, CA 92093, USA
| | - Mark H. Goodman
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Gatien Moriceau
- Division of Dermatology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Oscar Krijgsman
- Division of Molecular Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Prashanthi Dharanipragada
- Division of Dermatology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Trevor Ridgley
- Bioinformatics Interdepartmental Program, UCLA, Los Angeles, CA, 90095, USA
| | - William P. Crosson
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Jesus Salazar
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Eli Pazol
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Gabriel Karin
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Rachana Jayaraman
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Nikolas G. Balanis
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Salwan Alhani
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Kyle Sheu
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Johanna ten Hoeve
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- UCLA Metabolomics Center, Los Angeles, CA, 90095, USA
| | - Amelia Palermo
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- UCLA Metabolomics Center, Los Angeles, CA, 90095, USA
| | - Stephen E. Motika
- Department of Chemistry, Institute for Genomic Biology, Cancer Center at Illinois, University of Illinois, Urbana-Champaign, USA
| | - T. Niroshi Senaratne
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Kim H. Paraiso
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Paul J. Hergenrother
- Department of Chemistry, Institute for Genomic Biology, Cancer Center at Illinois, University of Illinois, Urbana-Champaign, USA
| | - P. Nagesh Rao
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Asha S. Multani
- Department of Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77030
| | - Daniel S. Peeper
- Division of Molecular Oncology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands
| | - Vineet Bafna
- Department of Computer Science and Engineering, University of California at San Diego, La Jolla, CA 92093, USA
| | - Roger S. Lo
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- Division of Dermatology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA 90095, USA
| | - Thomas G. Graeber
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA 90095, USA
- Crump Institute for Molecular Imaging, UCLA, Los Angeles, CA 90095, USA
- California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, UCLA, Los Angeles, CA 90095, USA
- UCLA Metabolomics Center, Los Angeles, CA, 90095, USA
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9
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Mouse embryonic stem cells maintain differentiation potency into somatic lineage despite alternation of ploidy. ZYGOTE 2022; 30:480-486. [PMID: 35357291 DOI: 10.1017/s0967199421000800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Vertebrates, including mammals, are considered to have evolved by whole genome duplications. Although some fish have been reported to be polyploids that have undergone additional genome duplication, there have been no reports of polyploid mammals due to abnormal development after implantation. Furthermore, as the number of physiologically existing tetraploid somatic cells is small, details of the functions of these ploidy-altered cells are not fully understood. In this present study, we aimed to clarify the details of the differentiation potency of tetraploids using tetraploid embryonic stem cells. To clarify the differentiation potency, we used mouse tetraploid embryonic stem cells derived from tetraploid embryos. We presented tetraploid embryonic stem cells differentiated into neural and osteocyte lineage in vitro and tetraploid cells that contributed to various tissues of chimeric embryos ubiquitously in vivo. These results revealed that mouse embryonic stem cells maintain differentiation potency after altering the ploidy. Our results provide an important basis for the differentiation dynamics of germ layers in mammalian polyploid embryogenesis.
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10
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Noer JB, Hørsdal OK, Xiang X, Luo Y, Regenberg B. Extrachromosomal circular DNA in cancer: history, current knowledge, and methods. Trends Genet 2022; 38:766-781. [PMID: 35277298 DOI: 10.1016/j.tig.2022.02.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022]
Abstract
Extrachromosomal circular DNA (eccDNA) is a closed-circle, nuclear, nonplasmid DNA molecule found in all tested eukaryotes. eccDNA plays important roles in cancer pathogenesis, evolution of tumor heterogeneity, and therapeutic resistance. It is known under many names, including very large cancer-specific circular extrachromosomal DNA (ecDNA), which carries oncogenes and is often amplified in cancer cells. Our understanding of eccDNA has historically been limited and fragmented. To provide better a context of new and previous research on eccDNA, in this review we give an overview of the various names given to eccDNA at different times. We describe the different mechanisms for formation of eccDNA and the methods used to study eccDNA thus far. Finally, we explore the potential clinical value of eccDNA.
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Affiliation(s)
- Julie B Noer
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Oskar K Hørsdal
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Xi Xiang
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Lars Bolund Institute of Regenerative Medicine, Qingdao-Europe Advanced Institute for Life Sciences, BGI-Shenzhen, Qingdao, China
| | - Yonglun Luo
- Department of Biomedicine, Aarhus University, Aarhus, Denmark; Lars Bolund Institute of Regenerative Medicine, Qingdao-Europe Advanced Institute for Life Sciences, BGI-Shenzhen, Qingdao, China; Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.
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11
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Gene Amplification and the Extrachromosomal Circular DNA. Genes (Basel) 2021; 12:genes12101533. [PMID: 34680928 PMCID: PMC8535887 DOI: 10.3390/genes12101533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/09/2021] [Accepted: 09/23/2021] [Indexed: 12/12/2022] Open
Abstract
Oncogene amplification is closely linked to the pathogenesis of a broad spectrum of human malignant tumors. The amplified genes localize either to the extrachromosomal circular DNA, which has been referred to as cytogenetically visible double minutes (DMs), or submicroscopic episome, or to the chromosomal homogeneously staining region (HSR). The extrachromosomal circle from a chromosome arm can initiate gene amplification, resulting in the formation of DMs or HSR, if it had a sequence element required for replication initiation (the replication initiation region/matrix attachment region; the IR/MAR), under a genetic background that permits gene amplification. In this article, the nature, intracellular behavior, generation, and contribution to cancer genome plasticity of such extrachromosomal circles are summarized and discussed by reviewing recent articles on these topics. Such studies are critical in the understanding and treating human cancer, and also for the production of recombinant proteins such as biopharmaceuticals by increasing the recombinant genes in the cells.
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12
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Karami Fath M, Akbari Oryani M, Ramezani A, Barjoie Mojarad F, Khalesi B, Delazar S, Anjomrooz M, Taghizadeh A, Taghizadeh S, Payandeh Z, Pourzardosht N. Extra chromosomal DNA in different cancers: Individual genome with important biological functions. Crit Rev Oncol Hematol 2021; 166:103477. [PMID: 34534658 DOI: 10.1016/j.critrevonc.2021.103477] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/30/2021] [Accepted: 09/03/2021] [Indexed: 12/21/2022] Open
Abstract
Cancer can be caused by various factors, including the malfunction of tumor suppressor genes and the hyper-activation of proto-oncogenes. Tumor-associated extrachromosomal circular DNA (eccDNA) has been shown to adversely affect human health and accelerate malignant actions. Whole-genome sequencing (WGS) on different cancer types suggested that the amplification of ecDNA has increased the oncogene copy number in various cancers. The unique structure and function of ecDNA, its profound significance in cancer, and its help in the comprehension of current cancer genome maps, renders it as a hotspot to explore the tumor pathogenesis and evolution. Illumination of the basic mechanisms of ecDNA may provide more insights into cancer therapeutics. Despite the recent advances, different features of ecDNA require further elucidation. In the present review, we primarily discussed the characteristics, biogenesis, genesis, and origin of ecDNA and later highlighted its functions in both tumorigenesis and therapeutic resistance of different cancers.
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Affiliation(s)
- Mohsen Karami Fath
- Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Mahsa Akbari Oryani
- Department of Pathology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Arefeh Ramezani
- Department of Microbiology and Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Barjoie Mojarad
- Department of Radiology, Faculty of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Bahman Khalesi
- Department of Research and Production of Poultry Viral Vaccine, Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran
| | - Sina Delazar
- Department of Radiology, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehran Anjomrooz
- Department of Radiology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Arvin Taghizadeh
- School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahin Taghizadeh
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Payandeh
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Navid Pourzardosht
- Biochemistry Department, Guilan University of Medical Sciences, Rasht, Iran.
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13
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Wang M, Chen X, Yu F, Ding H, Zhang Y, Wang K. Extrachromosomal Circular DNAs: Origin, formation and emerging function in Cancer. Int J Biol Sci 2021; 17:1010-1025. [PMID: 33867825 PMCID: PMC8040306 DOI: 10.7150/ijbs.54614] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
The majority of cellular DNAs in eukaryotes are organized into linear chromosomes. In addition to chromosome DNAs, genes also reside on extrachromosomal elements. The extrachromosomal DNAs are commonly found to be circular, and they are referred to as extrachromosomal circular DNAs (eccDNAs). Recent technological advances have enriched our knowledge of eccDNA biology. There is currently increasing concern about the connection between eccDNA and cancer. Gene amplification on eccDNAs is prevalent in cancer. Moreover, eccDNAs commonly harbor oncogenes or drug resistance genes, hence providing a growth or survival advantage to cancer cells. eccDNAs play an important role in tumor heterogeneity and evolution, facilitating tumor adaptation to challenging circumstances. In addition, eccDNAs have recently been identified as cell-free DNAs in circulating system. The altered level of eccDNAs is observed in cancer patients relative to healthy controls. Particularly, eccDNAs are associated with cancer progression and poor outcomes. Thus, eccDNAs could be useful as novel biomarkers for the diagnosis and prognosis of cancer. In this review, we summarize current knowledge regarding the formation, characteristics and biological importance of eccDNAs, with a focus on the molecular mechanisms associated with their roles in cancer progression. We also discuss their potential applications in the detection and treatment of cancer. A better understanding of the functional role of eccDNAs in cancer would facilitate the comprehensive analysis of molecular mechanisms involved in cancer pathogenesis.
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Affiliation(s)
- Man Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Xinzhe Chen
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Fei Yu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Han Ding
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Yuan Zhang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
| | - Kun Wang
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, College of Medicine, Qingdao University, Qingdao 266021, China
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14
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Blanter M, Gouwy M, Struyf S. Studying Neutrophil Function in vitro: Cell Models and Environmental Factors. J Inflamm Res 2021; 14:141-162. [PMID: 33505167 PMCID: PMC7829132 DOI: 10.2147/jir.s284941] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/04/2020] [Indexed: 01/21/2023] Open
Abstract
Neutrophils are the most abundant immune cell type in the blood and constitute the first line of defense against invading pathogens. Despite their important role in many diseases, they are challenging to study due to their short life span and the inability to cryopreserve or expand them in vitro. Thus, research into neutrophils has to rely on cells freshly isolated from peripheral blood of human donors, introducing donor-dependent variation in the experimental data. To counteract these problems, researchers tried to develop adequate cell models, such as cell lines. For those functional studies that cannot rely on cell models, a standardization of protocols regarding neutrophil purification and culturing could be a solution. In this review, we provide an overview of the most commonly used models for neutrophil function (HL-60, PLB-985, NB4, Kasumi-1 and induced pluripotent stem cells). In addition, we describe the effects of glucose concentration, pH, oxygen tension and temperature on neutrophil function.
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Affiliation(s)
- Marfa Blanter
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
| | - Mieke Gouwy
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
| | - Sofie Struyf
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven 3000, Belgium
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15
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Wei J, Wu C, Meng H, Li M, Niu W, Zhan Y, Jin L, Duan Y, Zeng Z, Xiong W, Li G, Zhou M. The biogenesis and roles of extrachromosomal oncogene involved in carcinogenesis and evolution. Am J Cancer Res 2020; 10:3532-3550. [PMID: 33294253 PMCID: PMC7716155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023] Open
Abstract
More and more extrachromosomal DNA (ecDNA) was found in human tumor cells in recent years, which has a high copy number in tumors and changes the expression of oncogenes, thus different from normal chromosomal DNA. These circular structures were identified to originate from chromosomes, and play critical roles in rapid carcinogenesis, tumor evolution and multidrug resistance. Therefore, this review mostly focuses on the biogenesis and regulation of extrachromosomal oncogene in ecDNA as well as its function and mechanism in tumors, which are of great significance for our comprehensive understanding of the role of ecDNA in tumor carcinogenic mechanism and are expected to provide ecDNA with the potential to be a new molecular target for the diagnosis and treatment of tumors.
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Affiliation(s)
- Jianxia Wei
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
- Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
| | - Chunchun Wu
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Hanbing Meng
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Mengna Li
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
- Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
| | - Weihong Niu
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Yuting Zhan
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
- Department of Pathology, The Second Xiangya Hospital, Central South UniversityChangsha 410011, Hunan, China
| | - Long Jin
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Yumei Duan
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Zhaoyang Zeng
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Guiyuan Li
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
| | - Ming Zhou
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
- Cancer Research Institute and School of Basic Medical Sciences, Central South UniversityChangsha 410078, Hunan, China
- The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South UniversityChangsha 410078, Hunan, China
- Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South UniversityChangsha 410013, Hunan, China
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16
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Yan Y, Guo G, Huang J, Gao M, Zhu Q, Zeng S, Gong Z, Xu Z. Current understanding of extrachromosomal circular DNA in cancer pathogenesis and therapeutic resistance. J Hematol Oncol 2020; 13:124. [PMID: 32928268 PMCID: PMC7491193 DOI: 10.1186/s13045-020-00960-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/03/2020] [Indexed: 02/08/2023] Open
Abstract
Extrachromosomal circular DNA was recently found to be particularly abundant in multiple human cancer cells, although its frequency varies among different tumor types. Elevated levels of extrachromosomal circular DNA have been considered an effective biomarker of cancer pathogenesis. Multiple reports have demonstrated that the amplification of oncogenes and therapeutic resistance genes located on extrachromosomal DNA is a frequent event that drives intratumoral genetic heterogeneity and provides a potential evolutionary advantage. This review highlights the current understanding of the extrachromosomal circular DNA present in the tissues and circulation of patients with advanced cancers and provides a detailed discussion of their substantial roles in tumor regulation. Confirming the presence of cancer-related extrachromosomal circular DNA would provide a putative testing strategy for the precision diagnosis and treatment of human malignancies in clinical practice.
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Affiliation(s)
- Yuanliang Yan
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.,Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Guijie Guo
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jinzhou Huang
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Ming Gao
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Qian Zhu
- Department of Oncology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Shuangshuang Zeng
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Zhicheng Gong
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Zhijie Xu
- Department of Pathology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China. .,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
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17
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The adaptive potential of circular DNA accumulation in ageing cells. Curr Genet 2020; 66:889-894. [PMID: 32296868 PMCID: PMC7497353 DOI: 10.1007/s00294-020-01069-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/12/2020] [Accepted: 03/14/2020] [Indexed: 12/20/2022]
Abstract
Carefully maintained and precisely inherited chromosomal DNA provides long-term genetic stability, but eukaryotic cells facing environmental challenges can benefit from the accumulation of less stable DNA species. Circular DNA molecules lacking centromeres segregate randomly or asymmetrically during cell division, following non-Mendelian inheritance patterns that result in high copy number instability and massive heterogeneity across populations. Such circular DNA species, variously known as extrachromosomal circular DNA (eccDNA), microDNA, double minutes or extrachromosomal DNA (ecDNA), are becoming recognised as a major source of the genetic variation exploited by cancer cells and pathogenic eukaryotes to acquire drug resistance. In budding yeast, circular DNA molecules derived from the ribosomal DNA (ERCs) have been long known to accumulate with age, but it is now clear that aged yeast also accumulate other high-copy protein-coding circular DNAs acquired through both random and environmentally-stimulated recombination processes. Here, we argue that accumulation of circular DNA provides a reservoir of heterogeneous genetic material that can allow rapid adaptation of aged cells to environmental insults, but avoids the negative fitness impacts on normal growth of unsolicited gene amplification in the young population.
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18
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Hull RM, King M, Pizza G, Krueger F, Vergara X, Houseley J. Transcription-induced formation of extrachromosomal DNA during yeast ageing. PLoS Biol 2019; 17:e3000471. [PMID: 31794573 PMCID: PMC6890164 DOI: 10.1371/journal.pbio.3000471] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/31/2019] [Indexed: 12/22/2022] Open
Abstract
Extrachromosomal circular DNA (eccDNA) facilitates adaptive evolution by allowing rapid and extensive gene copy number variation and is implicated in the pathology of cancer and ageing. Here, we demonstrate that yeast aged under environmental copper accumulate high levels of eccDNA containing the copper-resistance gene CUP1. Transcription of the tandemly repeated CUP1 gene causes CUP1 eccDNA accumulation, which occurs in the absence of phenotypic selection. We have developed a sensitive and quantitative eccDNA sequencing pipeline that reveals CUP1 eccDNA accumulation on copper exposure to be exquisitely site specific, with no other detectable changes across the eccDNA complement. eccDNA forms de novo from the CUP1 locus through processing of DNA double-strand breaks (DSBs) by Sae2, Mre11 and Mus81, and genome-wide analyses show that other protein coding eccDNA species in aged yeast share a similar biogenesis pathway. Although abundant, we find that CUP1 eccDNA does not replicate efficiently, and high-copy numbers in aged cells arise through frequent formation events combined with asymmetric DNA segregation. The transcriptional stimulation of CUP1 eccDNA formation shows that age-linked genetic change varies with transcription pattern, resulting in gene copy number profiles tailored by environment. Transcription can cause the de novo formation of protein-coding extrachromosomal DNA that accumulates in ageing yeast cells; these extrachromosomal circular DNA molecules form frequently by a DNA double strand break repair mechanism.
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Affiliation(s)
- Ryan M. Hull
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Michelle King
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Grazia Pizza
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Felix Krueger
- Babraham Bioinformatics, Babraham Institute, Cambridge, United Kingdom
| | - Xabier Vergara
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
| | - Jonathan Houseley
- Epigenetics Programme, Babraham Institute, Cambridge, United Kingdom
- * E-mail:
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19
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Jacobson EC, Grand RS, Perry JK, Vickers MH, Olins AL, Olins DE, O'Sullivan JM. Hi-C detects novel structural variants in HL-60 and HL-60/S4 cell lines. Genomics 2019; 112:151-162. [PMID: 31095996 DOI: 10.1016/j.ygeno.2019.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 12/29/2022]
Abstract
Cancer cell lines often have large structural variants (SVs) that evolve over time. There are many reported differences in large scale SVs between HL-60 and HL-60/S4, two cell lines derived from the same acute myeloid leukemia sample. However, the stability and variability of inter- and intra-chromosomal structural variants between different sources of the same cell line is unknown. Here, we used Hi-C and RNA-seq to identify and compare large SVs in HL-60 and HL-60/S4 cell lines. Comparisons with previously published karyotypes identified novel SVs in both cell lines. Hi-C was used to characterize the known expansion centered on the MYC locus. The MYC expansion was integrated into known locations in HL-60/S4, and a novel location (chr4) in HL-60. The HL-60 cell line has more within-line structural variation than the HL-60/S4 derivative cell line. Collectively we demonstrate the usefulness of Hi-C and with RNA-seq data for the identification and characterization of SVs.
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Affiliation(s)
- Elsie C Jacobson
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Ralph S Grand
- Liggins Institute, University of Auckland, Auckland, New Zealand; Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jo K Perry
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Mark H Vickers
- Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Ada L Olins
- University of New England, Portland, ME, USA
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20
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Mack EKM, Marquardt A, Langer D, Ross P, Ultsch A, Kiehl MG, Mack HID, Haferlach T, Neubauer A, Brendel C. Comprehensive genetic diagnosis of acute myeloid leukemia by next-generation sequencing. Haematologica 2018; 104:277-287. [PMID: 30190345 PMCID: PMC6355503 DOI: 10.3324/haematol.2018.194258] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022] Open
Abstract
Differential induction therapy of all subtypes of acute myeloid leukemia other than acute promyelocytic leukemia is impeded by the long time required to complete complex and diverse cytogenetic and molecular genetic analyses for risk stratification or targeted treatment decisions. Here, we describe a reliable, rapid and sensitive diagnostic approach that combines karyotyping and mutational screening in a single, integrated, next-generation sequencing assay. Numerical karyotyping was performed by low coverage whole genome sequencing followed by copy number variation analysis using a novel algorithm based on in silico-generated reference karyotypes. Translocations and DNA variants were examined by targeted resequencing of fusion transcripts and mutational hotspot regions using commercially available kits and analysis pipelines. For the identification of FLT3 internal tandem duplications and KMT2A partial tandem duplications, we adapted previously described tools. In a validation cohort including 22 primary patients’ samples, 9/9 numerically normal karyotypes were classified correctly and 30/31 (97%) copy number variations reported by classical cytogenetics and fluorescence in situ hybridization analysis were uncovered by our next-generation sequencing karyotyping approach. Predesigned fusion and mutation panels were validated exemplarily on leukemia cell lines and a subset of patients’ samples and identified all expected genomic alterations. Finally, blinded analysis of eight additional patients’ samples using our comprehensive assay accurately reproduced reference results. Therefore, calculated karyotyping by low coverage whole genome sequencing enables fast and reliable detection of numerical chromosomal changes and, in combination with panel-based fusion-and mutation screening, will greatly facilitate implementation of subtype-specific induction therapies in acute myeloid leukemia.
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Affiliation(s)
- Elisabeth K M Mack
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
| | - André Marquardt
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
| | - Danny Langer
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
| | - Petra Ross
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
| | - Alfred Ultsch
- Databionics, Department of Mathematics and Informatics, Philipps-University Marburg, Germany
| | - Michael G Kiehl
- Department of Internal Medicine, Frankfurt (Oder) General Hospital, Frankfurt/Oder, Germany
| | - Hildegard I D Mack
- Institute for Biomedical Aging Research, Leopold-Franzens-University Innsbruck, Austria
| | | | - Andreas Neubauer
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
| | - Cornelia Brendel
- Department of Hematology, Oncology and Immunology, Philipps-University Marburg, and University Hospital Gießen and Marburg, Marburg, Germany
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21
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Mourier T. Potential movement of transposable elements through DNA circularization. Curr Genet 2016; 62:697-700. [PMID: 26979517 DOI: 10.1007/s00294-016-0592-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 03/05/2016] [Accepted: 03/07/2016] [Indexed: 01/09/2023]
Abstract
The generation of circular DNAs is a relatively unrecognized type of genomic structural variation, but recent findings point to a possible role of circular DNAs in the movement of transposable elements. Circularization of genomic DNA is observed across eukaryotic species, in a range of different cell types, and from all parts of the genome. A recent study on circular DNAs in yeast found that transposable element sequence residing in circular structures mostly corresponded to full-length transposable elements. Transposable elements are mobile genetic elements scattered across eukaryotic genomes. Different classes of transposable elements move either through a copy-and-paste or a cut-and-paste. As circular DNA structures may recombine with the genome and re-integrate into a novel genomic locus, transposable elements could move through circularization. In yeast, the predominant type of transposable element is a so-called LTR (long terminal repeats) retrotransposable element that moves through a copy-and-paste mechanism. The observed circularization of this element means it potentially could move through a cut-and-paste mechanism as well. Although further experimental evidence is needed to establish the extent to which movement of transposable elements through DNA circularization takes place, such movement is likely to have a functional impact on the genomic context.
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Affiliation(s)
- Tobias Mourier
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Oester Voldgade 5-7, 1350, Copenhagen K, Denmark.
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22
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Rao PH, Zhao S, Zhao YJ, Yu A, Rainusso N, Trucco M, Allen-Rhoades W, Satterfield L, Fuja D, Borra VJ, Man TK, Donehower LA, Yustein JT. Coamplification ofMyc/Pvt1and homozygous deletion ofNlrp1locus are frequent genetics changes in mouse osteosarcoma. Genes Chromosomes Cancer 2015; 54:796-808. [DOI: 10.1002/gcc.22291] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 07/19/2015] [Accepted: 07/29/2015] [Indexed: 01/10/2023] Open
Affiliation(s)
- Pulivarthi H. Rao
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Shuying Zhao
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Yi-Jue Zhao
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Alexander Yu
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Nino Rainusso
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Matteo Trucco
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Wendy Allen-Rhoades
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Laura Satterfield
- Integrative Molecular and Biological Sciences Program; Baylor College of Medicine; Houston TX 77030
| | - Daniel Fuja
- Integrative Molecular and Biological Sciences Program; Baylor College of Medicine; Houston TX 77030
| | - Vishnupriya J. Borra
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Tsz-Kwong Man
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
| | - Lawrence A. Donehower
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
- Department of Molecular & Cellular Biology; Baylor College of Medicine; Houston TX 77030
- Department of Molecular Virology & Microbiology; Baylor College of Medicine; Houston TX 77030
- Integrative Molecular and Biological Sciences Program; Baylor College of Medicine; Houston TX 77030
| | - Jason T. Yustein
- Texas Children's Cancer and Hematology Centers, Department of Pediatrics; Baylor College of Medicine; Houston TX 77030
- Department of Molecular & Cellular Biology; Baylor College of Medicine; Houston TX 77030
- Integrative Molecular and Biological Sciences Program; Baylor College of Medicine; Houston TX 77030
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23
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Coleman AE, McNeil N, Kovalchuck AL, Wangsa D, Ried T, Wang H. Cellular exposure to muscle relaxants and propofol could lead to genomic instability in vitro. J Biomed Res 2013; 26:117-24. [PMID: 23554740 PMCID: PMC3597328 DOI: 10.1016/s1674-8301(12)60021-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 01/05/2012] [Accepted: 01/28/2012] [Indexed: 11/25/2022] Open
Abstract
Anesthesia is widely used in several medical settings and accepted as safe. However, there is some evidence that anesthetic agents can induce genomic changes leading to neural degeneration or apoptosis. Although chromosomal changes have not been observed in vivo, this is most likely due to DNA repair mechanisms, apoptosis, or cellular senescence. Potential chromosomal alterations after exposure to common anesthetic agents may be relevant in patients with genomic instability syndromes or with aggressive treatment of malignancies. In this study, the P388 murine B cells were cultured in vitro, and spectral karyotyping (SKY) was utilized to uncover genome-wide changes. Clinically relevant doses of cisatracurium and propofol increased structural and numerical chromosomal instability. These results may be relevant in patients with underlying chromosomal instability syndromes or concurrently being exposed to chemotherapeutic agents. Future studies may include utilization of stimulated peripheral blood lymphocytes to further confirm the significance of these results.
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Affiliation(s)
- Allen Edward Coleman
- Department of Anesthesiology, Wayne State University, Detroit Medical Center, Detroit, Michigan 48201, USA
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24
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Mukherjee K, Storici F. A mechanism of gene amplification driven by small DNA fragments. PLoS Genet 2012; 8:e1003119. [PMID: 23271978 PMCID: PMC3521702 DOI: 10.1371/journal.pgen.1003119] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/11/2012] [Indexed: 11/19/2022] Open
Abstract
DNA amplification is a molecular process that increases the copy number of a chromosomal tract and often causes elevated expression of the amplified gene(s). Although gene amplification is frequently observed in cancer and other degenerative disorders, the molecular mechanisms involved in the process of DNA copy number increase remain largely unknown. We hypothesized that small DNA fragments could be the trigger of DNA amplification events. Following our findings that small fragments of DNA in the form of DNA oligonucleotides can be highly recombinogenic, we have developed a system in the yeast Saccharomyces cerevisiae to capture events of chromosomal DNA amplification initiated by small DNA fragments. Here we demonstrate that small DNAs can amplify a chromosomal region, generating either tandem duplications or acentric extrachromosomal DNA circles. Small fragment-driven DNA amplification (SFDA) occurs with a frequency that increases with the length of homology between the small DNAs and the target chromosomal regions. SFDA events are triggered even by small single-stranded molecules with as little as 20-nt homology with the genomic target. A double-strand break (DSB) external to the chromosomal amplicon region stimulates the amplification event up to a factor of 20 and favors formation of extrachromosomal circles. SFDA is dependent on Rad52 and Rad59, partially dependent on Rad1, Rad10, and Pol32, and independent of Rad51, suggesting a single-strand annealing mechanism. Our results reveal a novel molecular model for gene amplification, in which small DNA fragments drive DNA amplification and define the boundaries of the amplicon region. As DNA fragments are frequently found both inside cells and in the extracellular environment, such as the serum of patients with cancer or other degenerative disorders, we propose that SFDA may be a common mechanism for DNA amplification in cancer cells, as well as a more general cause of DNA copy number variation in nature.
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Affiliation(s)
- Kuntal Mukherjee
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Francesca Storici
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- * E-mail:
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25
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Pereira ELR, Lima PDL, Khayat AS, Bahia MO, Bezerra FS, Andrade-Neto M, Montenegro RC, Pessoa C, Costa-Lotufo LV, Moraes MO, Yoshioka FKN, Pinto GR, Burbano RR. Inhibitory effect of pisosterol on human glioblastoma cell lines with C-MYC amplification. J Appl Toxicol 2010; 31:554-60. [DOI: 10.1002/jat.1596] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 08/21/2010] [Accepted: 08/24/2010] [Indexed: 11/08/2022]
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26
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Lachish-Zalait A, Lau CK, Fichtman B, Zimmerman E, Harel A, Gaylord MR, Forbes DJ, Elbaum M. Transportin mediates nuclear entry of DNA in vertebrate systems. Traffic 2010; 10:1414-28. [PMID: 19761539 DOI: 10.1111/j.1600-0854.2009.00968.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Delivery of DNA to the cell nucleus is an essential step in many types of viral infection, transfection, gene transfer by the plant pathogen Agrobacterium tumefaciens and in strategies for gene therapy. Thus, the mechanism by which DNA crosses the nuclear pore complex (NPC) is of great interest. Using nuclei reconstituted in vitro in Xenopus egg extracts, we previously studied DNA passage through the nuclear pores using a single-molecule approach based on optical tweezers. Fluorescently labeled DNA molecules were also seen to accumulate within nuclei. Here we find that this import of DNA relies on a soluble protein receptor of the importin family. To identify this receptor, we used different pathway-specific cargoes in competition studies as well as pathway-specific dominant negative inhibitors derived from the nucleoporin Nup153. We found that inhibition of the receptor transportin suppresses DNA import. In contrast, inhibition of importin beta has little effect on the nuclear accumulation of DNA. The dependence on transportin was fully confirmed in assays using permeabilized HeLa cells and a mammalian cell extract. We conclude that the nuclear import of DNA observed in these different vertebrate systems is largely mediated by the receptor transportin. We further report that histones, a known cargo of transportin, can act as an adaptor for the binding of transportin to DNA.
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Affiliation(s)
- Aurelie Lachish-Zalait
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
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27
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Silva TCR, Lima PDL, Bahia MO, Khayat AS, Bezerra FS, Andrade-Neto M, Seabra AD, Pontes TB, Moraes MO, Montenegro RC, Costa-Lotufo LV, Pessoa C, Pinto GR, Burbano RR. Pisosterol induces interphase arrest in HL60 cells with c-MYC amplification. Hum Exp Toxicol 2010; 29:235-40. [PMID: 20071475 DOI: 10.1177/0960327109359637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion mechanisms in cancer cells. One marked characteristic of HL60 cells is the c-MYC proto-oncogene amplification, resulting in the formation of homogeneously staining regions (HSRs) at 8p24. We conducted a fluorescence in situ hybridization study in an HL60 cell line, using a locus-specific probe for c-MYC, before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 microg/mL), a triterpene isolated from the fungus Pisolithus tinctorius. Before treatment, 87.5% of the cells showed HSRs. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 microg/mL). However, at 1.8 microg/mL only 15% of the cells presented HSRs, and 39.5% presented few fluorescent signals (3 or 4 alleles), suggesting that pisosterol probably blocks the cells with HSRs at interphase. This result is particularly interesting because cells that do not show a high degree of c-MYC gene amplification have a less aggressive and invasive behaviour and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.
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Affiliation(s)
- T C R Silva
- Human Cytogenetics Laboratory, Institute of Biological Sciences, Federal University of Pará, Belém/PA, Brazil
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28
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Abstract
OBJECTIVE CYP2D6 is a polymorphic gene. It has been observed to be deleted, to be duplicated and to undergo recombination events involving the CYP2D7 pseudogene and surrounding sequences. The objective of this study was to discover the genomic structure of CYP2D6 recombinants that interfere with clinical genotyping platforms that are available today. METHODS Clinical samples containing rare homozygous CYP2D6 alleles, ambiguous readouts, and those with duplication signals and two different alleles were analyzed by long-range PCR amplification of individual genes, PCR fragment analysis, allele-specific primer extension assay, and DNA sequencing to characterize alleles and genomic structure. RESULTS Novel alleles, genomic structures, and the DNA sequence of these structures are described. Interestingly, in 49 of 50 DNA samples that had CYP2D6 gene duplications or multiplications where two alleles were detected, the chromosome containing the duplication or multiplication had identical tandem alleles. CONCLUSION Several new CYP2D6 alleles and genomic structures are described which will be useful for CYP2D6 genotyping. The findings suggest that the recombination events responsible for CYP2D6 duplications and multiplications are because of mechanisms other than interchromosomal crossover during meiosis.
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29
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Burbano RR, Lima PDL, Bahia MO, Khayat AS, Silva TCR, Bezerra FS, Andrade Neto M, de Moraes MO, Montenegro RC, Costa-Lotufo LV, Pessoa C. Cell cycle arrest induced by Pisosterol in HL60 cells with gene amplification. Cell Biol Toxicol 2008; 25:245-51. [DOI: 10.1007/s10565-008-9074-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2007] [Accepted: 03/28/2008] [Indexed: 11/24/2022]
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30
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Hirano T, Ike F, Murata T, Obata Y, Utiyama H, Yokoyama KK. Genes encoded within 8q24 on the amplicon of a large extrachromosomal element are selectively repressed during the terminal differentiation of HL-60 cells. Mutat Res 2007; 640:97-106. [PMID: 18243251 DOI: 10.1016/j.mrfmmm.2007.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/12/2007] [Accepted: 12/13/2007] [Indexed: 10/22/2022]
Abstract
Human acute myeloblastic leukemia HL-60 cells become resistant to differentiation during long-term cultivation. After 150 passages, double minute chromosomes (dmins) found in early-passaged cells are replaced by large extrachromosomal elements (LEEs). In a DNA library derived from a purified fraction of LEEs, 12.6% (23/183) of clones were assigned to 8q24 and 9.2% (17/183) were assigned to 14q11 in the human genome. Fluorescence in situ hybridization (FISH) revealed a small aberrant chromosome, which had not been found in early-passaged cells, in addition to the purified LEEs. We determined that each LEE consisted of six discontinuous segments in a region that extended for 4.4Mb over the 8q24 locus. Five genes, namely, Myc (a proto-oncogene), NSMCE2 (for a SUMO ligase), CCDC26 (for a retinoic acid-dependent modulator of myeloid differentiation), TRIB1 (for a regulator of MAPK kinase) and LOC389637 (for a protein of unknown function), were encoded by the amplicon. Breaks in the chromosomal DNA within the amplicon were found in the NSMCE2 and CCDC26 genes. The discontinuous structure of the amplicon unit of the LEEs was identical with that of dmins in HL-60 early-passaged cells. The difference between them seemed, predominantly, to be the number (10-15 copies per LEE versus 2 or 3 copies per dmin) of constituent units. Expression of the Myc, NSMCE2, CCDC26 and LOC389637 and TRIB1 genes was constitutive in all lines of HL-60 cells and that of the first four genes was repressed during the terminal differentiation of early-passaged HL-60 cells. We also detected abnormal transcripts of CCDC26. Our results suggest that these genes were selected during the development of amplicons. They might be amplified and, sometimes, truncated to contribute to the maintenance of HL-60 cells in an undifferentiated state.
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Affiliation(s)
- Tetsuo Hirano
- Life Science Group, Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8521, Japan.
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31
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Kuttler F, Mai S. Formation of non-random extrachromosomal elements during development, differentiation and oncogenesis. Semin Cancer Biol 2006; 17:56-64. [PMID: 17116402 DOI: 10.1016/j.semcancer.2006.10.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Accepted: 10/17/2006] [Indexed: 11/25/2022]
Abstract
Extrachromosomal elements (EEs) were first discovered as minute chromatin bodies [Cox et al. Minute chromatin bodies in malignant tumors of childhood. Lancet 1965;62:55-8], and subsequently characterized as small circular DNA molecules physically separated from chromosomes. They include episomes, minichromosomes, small polydispersed DNAs or double minutes. This review focuses on eukaryotic EEs generated by genome rearrangements under physiological or pathological conditions. Some of those rearrangements occur randomly, but others are strictly non-random, highly regulated, and involve specific chromosomal locations (V(D)J-recombination, telomere maintenance mechanisms, c-myc deregulation). The multiple mechanisms of EEs formation are strongly interconnected and frequently linked to gene amplification. Identification of genes located on EEs will undoubtedly allow a better understanding of genome dynamics and oncogenic pathways.
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Affiliation(s)
- Fabien Kuttler
- Manitoba Institute of Cell Biology, CancerCare Manitoba, University of Manitoba, 675 McDermot Avenue, Winnipeg, Man. R3E 0V9, Canada.
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32
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Myllykangas S, Knuutila S. Manifestation, mechanisms and mysteries of gene amplifications. Cancer Lett 2005; 232:79-89. [PMID: 16288831 DOI: 10.1016/j.canlet.2005.07.045] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2005] [Accepted: 07/30/2005] [Indexed: 12/31/2022]
Abstract
Gene amplifications are essential features of advanced cancers and have prognostic as well as therapeutic significance in clinical cancer treatment. Models explaining the amplification process, such as breakage-fusion-bridge cycle and excision and unequal segregation of extrachromosomal DNA fragments, predict that independent DNA double-stranded breaks must occur to induce amplification formation. Many cellular, tissue and environmental factors induce DNA damage and amplifications. Also labile DNA sequence features like fragile sites facilitate amplifications. Although, databases and data mining tools of various genomic attributes are already available, extra-large scale systems biology endeavors to decipher dynamics, interactions and dependencies between different factors contributing to amplification process fail, because current databases of DNA copy number aberrations and fragile sites comprise conventional cytogenetics results obtained at far too coarse chromosome band resolution. Array comparative genomic hybridization (aCGH) enables genome-wide gene copy number measurements and amplification detection at molecular genetic resolution. Similarly, cloning and sequencing of fragile sites produce mapping information of vastly improved resolution. In conclusion, databases of aCGH and sequenced fragile sites are needed to resolve the mechanisms of gene amplifications in systems biology configuration.
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Affiliation(s)
- Samuel Myllykangas
- Department of Pathology, Haartman Institute and HUSLAB, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
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33
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Santoni-Rugiu E, Duro D, Farkas T, Mathiasen IS, Jäättelä M, Bartek J, Lukas J. E2F activity is essential for survival of Myc-overexpressing human cancer cells. Oncogene 2002; 21:6498-509. [PMID: 12226753 DOI: 10.1038/sj.onc.1205828] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2002] [Revised: 06/18/2002] [Accepted: 06/28/2002] [Indexed: 12/22/2022]
Abstract
Effective cell cycle completion requires both Myc and E2F activities. However, whether these two activities interact to regulate cell survival remains to be tested. Here we have analysed survival of inducible c-Myc-overexpressing cell lines derived from U2OS human osteosarcoma cells, which carry wild-type pRb and p53 and are deficient for p16 and ARF expression. Induced U2OS-Myc cells neither underwent apoptosis spontaneously nor upon reconstitution of the ARF-p53 axis and/or serum-starvation. However, they died massively when concomitantly exposed to inhibitors of E2F activity, including a constitutively active pRb (RbDeltacdk) mutant, p16, a stable p27 (p27T187A) mutant, a dominant-negative (dn) CDK2, or dnDP-1. Similar apoptotic effect was observed upon down-modulation of endogenous E2Fs through overexpression of E2F binding site oligonucleotides in U2OS-Myc cells, upon expression of RbDeltacdk or dnDP-1 in the Myc-amplified HL-60 (ARF-; p53-) human leukemia cells, and upon co-transfection of Myc and RbDeltacdk in SAOS-2 (ARF+; p53-) human osteosarcoma cells but not in human primary fibroblasts. Consistent with these results, a dnp53 mutant did not abrogate the Myc-induced apoptotic phenotype, which instead strictly depended on caspase-3-like proteases and on Myc transcriptional activity. Our data indicate that in contrast to normal cells, Myc-overexpressing human cancer cells need E2F activity for their survival, regardless of their ARF and p53 status, a notion that may have important implications for antineoplastic treatment strategies.
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Affiliation(s)
- Eric Santoni-Rugiu
- Department of Cell Cycle and Cancer, Institute of Cancer Biology, Danish Cancer Society, 2100 Copenhagen E., Denmark.
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34
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Haque MM, Hirano T, Itoh N, Utiyama H. Evolution of large extrachromosomal elements in HL-60 cells during culture and the associated phenotype alterations. Biochem Biophys Res Commun 2001; 288:592-6. [PMID: 11676484 DOI: 10.1006/bbrc.2001.5797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the HL-60 sublines that were isolated after a long-term continuous culture, abnormally stained or abnormally banded regions on chromosomes replaced extrachromosomal double minutes. The c-MYC gene is amplified in these structures. We followed the c-MYC gene loci during a consecutive passage by using FISH, and have found a large extrachromosomal element (LEE) that preexisted at the earliest passage in a very small fraction of cells. No chromosomal integration of c-MYC sequences was observed in up to 225 passages. The LEEs persistently evolved during culture and were not excluded from the nucleus. In the LEE-positive cells, the spontaneous differentiation was blocked and the granulocytic differentiation that was induced by treatment with dimethyl sulfoxide was reversed by withdrawal of the drug. The c-MYC gene integration into LEEs is unlikely to lead to these phenotypes. The reversibility might be related to the reversible c-MYC down-regulation during the early phase of the drug treatment of HL-60 cells at early cell passages.
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Affiliation(s)
- M M Haque
- Life Science Group, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8521, Japan
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35
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Ogino H, Nakabayashi K, Suzuki M, Takahashi E, Fujii M, Suzuki T, Ayusawa D. Release of telomeric DNA from chromosomes in immortal human cells lacking telomerase activity. Biochem Biophys Res Commun 1998; 248:223-7. [PMID: 9675117 DOI: 10.1006/bbrc.1998.8875] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Some immortal human cell lines lack telomerase activity. These cell lines were found to contain small dispersed DNA hybridizing to TTAGGG repeats. Such DNA was located in their cytoplasm and nuclei. Normal human fibroblasts or telomerase-positive cell lines did not contain such DNA. Upon cloning and sequencing, it was shown to consist of TTAGGG repeats. When electrophoresed on neutral and alkaline agarose gels, it behaved as double-stranded and linear DNA. These results suggest that telomeric DNA is released from chromosomes in association with maintenance of telomeres in telomerase-negative cell lines.
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Affiliation(s)
- H Ogino
- Kihara Institute for Biological Research and Graduate School of Integrated Science, Yokohama City University, Totsuka-ku, Maioka-cho, Yokohama, 244-0813, Japan
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36
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Stewart DJ, Tomiak EM, Goss G, Gertler SZ, Logan D, Huan S, Yau J, Dulude H, Evans WK. Paclitaxel plus hydroxyurea as second line therapy for non-small cell lung cancer. Lung Cancer 1996; 15:115-23. [PMID: 8865129 DOI: 10.1016/0169-5002(96)00576-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We tested paclitaxel (Taxol) and low dose hydroxyurea as second line therapy in 30 patients with non-small cell lung cancer since both drugs are active against non-small cell lung cancer in other settings, and since hydroxyurea may reverse chemotherapy resistance by disrupting double minute chromosomes. Hydroxyurea 500 mg was given orally each Monday, Wednesday, Friday starting 1 week before paclitaxel, and continuing until removal from study. Paclitaxel 135 mg/m2 was given i.v. over > or = 1 h every 3 weeks with dexamethasone, diphenhydramine, and ranitidine. Patients could have paclitaxel doses escalated to 175 mg/m2 in course 2 and to 200 mg/m2 in course 3, where tolerated. Sixteen males and 14 females were treated. All patients had previously received a single cisplatin-based chemotherapy regimen and 23 had previously received radiotherapy. Twelve patients had adenocarcinomas, six had squamous cell carcinomas, and 12 had large cell carcinomas. Eight patients had Stage IIIb cancers and 22 had Stage IV. Paclitaxel doses were 135 mg/m2 in 56 courses, 175 mg/m2 in 24, and 200 mg/m2 in 15. Treatment was well tolerated. Median granulocyte nadirs were 2.5 (x 10(9)/l) for paclitaxel 135 mg/m2, 1.8 for 175 mg/m2, and 1.3 for 200 mg/m2. No patient developed febrile neutropenia, and none required a dose reduction. Two patients had reversible anaphylaxis. Other toxicities were quite tolerable. They included fatigue, myalgias, dizziness, paresthesias, diarrhea, alopecia, mucositis, flushing, headache, swollen red hands, and anxiety. One patient had a partial remission and 15 had stable disease (including six with minor responses). Median survival was 20 (95% CI, 12-34) weeks, with 19% of patients remaining alive at 1 year from initiation of treatment. This is a well-tolerated regimen with modest activity as second line chemotherapy for patients with non-small cell lung cancer previously treated with cisplatin regimens. Higher doses would be feasible and other strategies are now being explored.
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Affiliation(s)
- D J Stewart
- Ontario Cancer Treatment and Research Foundation, University of Ottawa Faculty of Medicine, Ontario, Canada
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37
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Cohen S, Lavi S. Induction of circles of heterogeneous sizes in carcinogen-treated cells: two-dimensional gel analysis of circular DNA molecules. Mol Cell Biol 1996; 16:2002-14. [PMID: 8628266 PMCID: PMC231187 DOI: 10.1128/mcb.16.5.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Extrachromosomal circular DNA molecules are associated with genomic instability, and circles containing inverted repeats were suggested to be the early amplification products. Here we present for the first time the use of neutral-neutral two-dimensional (2D) gel electrophoresis as a technique for the identification, isolation, and characterization of heterogeneous populations of circular molecules. Using this technique, we demonstrated that in N-methyl-N'-nitro-N-nitrosoguanidine-treated simian virus 40-transformed Chinese hamster cells (CO60 cells), the viral sequences are amplified as circular molecules of various sizes. The supercoiled circular fraction was isolated and was shown to contain molecules with inverted repeats. 2D gel analysis of extrachromosomal DNA from CHO cells revealed circular molecules containing highly repetitive DNA which are similar in size to the simian virus 40-amplified molecules. Moreover, enhancement of the amount of circular DNA was observed upon N-methyl-N'-nitro-N-nitrosoguanidine treatment of CHO cells. The implications of these findings regarding the processes of gene amplification and genomic instability and the possible use of the 2D gel technique to study these phenomena are discussed.
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MESH Headings
- Animals
- CHO Cells
- Carcinogens/toxicity
- Cell Line
- Cell Line, Transformed
- Cell Transformation, Viral
- Cricetinae
- DNA Replication/drug effects
- DNA, Circular/biosynthesis
- DNA, Circular/chemistry
- DNA, Circular/ultrastructure
- DNA, Viral/biosynthesis
- DNA, Viral/chemistry
- DNA, Viral/ultrastructure
- Methylnitronitrosoguanidine/toxicity
- Microscopy, Electron
- Models, Structural
- Nucleic Acid Conformation
- Repetitive Sequences, Nucleic Acid
- Simian virus 40/genetics
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Affiliation(s)
- S Cohen
- Department of Cell Research and Immunology, Tel Aviv University, Israel
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38
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Volpi EV, Vatcheva R, Labella T, Gan SU. More detailed characterization of some of the HL60 karyotypic features by fluorescence in situ hybridization. CANCER GENETICS AND CYTOGENETICS 1996; 87:103-6. [PMID: 8625253 DOI: 10.1016/0165-4608(95)00214-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We performed a focused chromosome analysis on the HL60 cell line by multicolor fluorescence in situ hybridization (FISH), using probes for the unequivocal identification of specific chromosome regions and subregions. The purpose of this karyotypic re-evaluation was to confirm and to characterize in more detail chromosome rearrangements already identified by means of classic cytogenetic approaches and recurrently detected from the initial establishment of the cell line. The observations reported may help reassess the potential of the HL60 cell line in understanding the molecular events underlying the non-random karyotype alterations associated with acute myeloid leukemias (AML).
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Affiliation(s)
- E V Volpi
- Istituto di Genetica Molecolare del CNR, Alghero, Italy
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39
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VanDevanter DR, Tseng JC, Yirdaw G. Electrophoretic isolation of extrachromosomal DNA from tumor cells. Genes Chromosomes Cancer 1995; 12:262-71. [PMID: 7539280 DOI: 10.1002/gcc.2870120405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Gene amplification allows transformed cells to overexpress specific genes and gain a survival advantage. For this reason, cloning and characterization of amplified genes can improve our understanding of the biology of transformed cells. The techniques of in-gel renaturation and chromosome microdissection can enrich for amplified DNA sequences, but both are labor intensive and have other drawbacks. We have developed an alternative strategy of enriching for amplified DNA sequences that involves two-directional agarose gel electrophoresis of extrachromosomal circular DNA. Extrachromosomal circles can be detected with repetitive DNA probes and can be used to produce DNA probes suitable for fluorescence in situ hybridization for location of genomic origin. The ability to enrich for amplified DNA without specialized equipment or transformed cell metaphases should prove useful in the search for new genes which are important in tumor cell progression.
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Affiliation(s)
- D R VanDevanter
- Tumor Institute, Swedish Medical Center, Seattle, Washington, USA
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van Loon N, Miller D, Murnane JP. Formation of extrachromosomal circular DNA in HeLa cells by nonhomologous recombination. Nucleic Acids Res 1994; 22:2447-52. [PMID: 8041604 PMCID: PMC308194 DOI: 10.1093/nar/22.13.2447] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Extrachromosomal circular DNA (eccDNA) generated from chromosomal DNA is found in all mammalian cells and increases with cell stress or aging. Studies of eccDNA structure and mode of formation provide insight into mechanisms of instability of the mammalian genome. Previous studies have suggested that eccDNA is generated through a process involving recombination between repetitive sequences. However, we observed that approximately one half of the small eccDNA fragments cloned from HeLa S3 cells were composed entirely of nonrepetitive or low-copy DNA sequences. We analyzed four of these fragments by polymerase chain reaction and nucleotide sequencing and found that they were complete eccDNAs. We then screened a human genomic library with the eccDNAs to isolate the complementary chromosomal sequences. Comparing the recombination junctions within the eccDNAs with the chromosomal sequences from which they were derived revealed that nonhomologous recombination was involved in their formation. One of the eccDNAs was composed of two separate sequences from different parts of the genome. These results suggest that rejoining of ends of fragmented DNA is responsible for the generation of a substantial portion of the eccDNAs found in HeLa S3 cells.
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Affiliation(s)
- N van Loon
- Laboratory of Radiobiology and Environmental Health, University of California, San Francisco 94143-0750
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41
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Abstract
We have determined the structure and organization of a 630-kb extrachromosomal element (amplisome) containing the dihydrofolate reductase-encoding gene (DHFR) in a methotrexate (MTX)-resistant human cell line, HeLa-Bu25-10B3. The size and copy number of amplisomes have previously been found to remain remarkably stable with or without selection. Both linear and open circular 630-kb amplisomes are present in these cells. We have been able to isolate the linear amplisomes after pulsed-field gel electrophoresis (PFGE), and transfect the amplisomes into MTX-sensitive recipient cells by electroporation, thus demonstrating that DNA as large as 630 kb can be transfected into mammalian cells. The NotI restriction site immediately upstream from DHFR on the circular amplisome is devoid of methylation, suggesting that it is transcriptionally active. Restriction mapping by PFGE reveals that there is only one copy of DHFR per amplisome and no repetitive structure is observed. The small size of the amplisomes, their stability and our ability to transfect large DNA molecules provide the necessary ingredients for the development of mammalian cloning vectors for large DNA fragments.
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Affiliation(s)
- C Esnault
- Department of Pharmacology, University of North Carolina at Chapel Hill 27599-7365
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42
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Eckhardt SG, Dai A, Davidson KK, Forseth BJ, Wahl GM, Von Hoff DD. Induction of differentiation in HL60 cells by the reduction of extrachromosomally amplified c-myc. Proc Natl Acad Sci U S A 1994; 91:6674-8. [PMID: 8022834 PMCID: PMC44265 DOI: 10.1073/pnas.91.14.6674] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Oncogene amplification in tumor cells results in the overexpression of proteins that confer a growth advantage in vitro and in vivo. Amplified oncogenes can reside intrachromosomally, within homogeneously staining regions (HSRs), or extrachromosomally, within double minute chromosomes (DMs). Since previous studies have shown that low concentrations of hydroxyurea (HU) can eliminate DMs, we studied the use of HU as a gene-targeting agent in tumor cells containing extrachromosomally amplified oncogenes. In a neuroendocrine cell line (COLO 320), we have shown that HU can eliminate amplified copies of c-myc located on DMs, leading to a reduction in tumorigenicity in vitro and in vivo. To determine whether the observed reduction in tumorigenicity was due to differentiation, we next investigated whether HU could induce differentiation in HL60 cells containing extrachromosomally amplified c-myc. We compared the effects of HU, as well as two other known differentiating agents (dimethyl sulfoxide and retinoic acid), on c-myc gene copy number, c-myc expression, and differentiation in HL60 cells containing amplified c-myc genes either on DMs or HSRs. We discovered that HU and dimethyl sulfoxide reduced both c-myc gene copy number and expression and induced differentiation in cells containing c-myc amplified on DMs. These agents failed to have similar effects on HL60 cells with amplified c-myc in HSRs. By contrast, retinoic acid induced differentiation independent of the localization of amplified c-myc. These data illustrate the utility of targeting extrachromosomal DNA to modulate tumor phenotype and reveal that both HU and dimethyl sulfoxide induce differentiation in HL60 cells through DM elimination.
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Affiliation(s)
- S G Eckhardt
- Cancer Therapy and Research Center of South Texas, San Antonio 78229
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Hammond DW, Hancock BW, Goyns MH. Identification of a subclass of double minute chromosomes containing centromere-associated DNA. Genes Chromosomes Cancer 1994; 10:139-42. [PMID: 7520268 DOI: 10.1002/gcc.2870100210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In a study of abnormal chromosomes in non-Hodgkin's lymphoma (NHL) cells we have identified one case which contained extrachromosomal chromatin bodies that, on the basis of their morphology and negative C-banding, appeared to be double minute chromosomes (dmin). However, fluorescence in-situ hybridization (FISH) analysis using an X-specific centromeric alphoid repeat probe and a pan-centromere probe, clearly demonstrated the presence of centromere-associated DNA in these dmin. FISH analysis with the pan-centromere probe of the dmin in neuroblastoma and sarcoma cells failed to reveal the presence of centromere-associated DNA, but analysis of two cases of acute myeloid leukemia cells revealed centromere-associated DNA in 25% of their dmin. These data indicate the existence of dmin that contain centromere-associated DNA and suggest that such dmin might represent a new class of extrachromosomal chromatin bodies.
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Affiliation(s)
- D W Hammond
- Department of Clinical Oncology, University Medical School, Sheffield, United Kingdom
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/physiology
- Antineoplastic Agents/pharmacology
- Cloning, Molecular
- Colchicine/pharmacology
- DNA, Circular/genetics
- Drug Resistance, Multiple/genetics
- Gene Amplification
- Gene Expression Regulation, Neoplastic
- Humans
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Neoplasms/genetics
- Neoplasms/metabolism
- Tumor Cells, Cultured/drug effects
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Affiliation(s)
- P V Schoenlein
- Medical College of Georgia, Department of Cell and Molecular Biology, Augusta 30912
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Slovak ML, Ho JP, Pettenati MJ, Khan A, Douer D, Lal S, Traweek ST. Localization of amplified MYC gene sequences to double minute chromosomes in acute myelogenous leukemia. Genes Chromosomes Cancer 1994; 9:62-7. [PMID: 7507702 DOI: 10.1002/gcc.2870090111] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cytogenetic and molecular studies were performed on two dmin-bearing acute myelogenous leukemia (FAB-M2) samples. Both cases were characterized by complex karyotypes containing interstitial deletions of the long arm of chromosome 8 altering band 8q24.1, aberrations affecting the short arm of chromosome 17, and multiple double minute chromosomes (dmin). Using a 1.4 kb cDNA probe coding for the third exon of the MYC oncogene, DNA slot blots indicated MYC gene sequences were amplified in both samples. Fluorescence in situ hybridization using a 9.0 kb genomic probe for MYC was performed in one case and localized the amplified MYC gene sequences to the dmin. Neither patient achieved a complete remission using traditional induction chemotherapy. The complex karyology with amplification of MYC gene sequences appears to represent a poor prognostic subgroup of acute myelogenous leukemia.
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Affiliation(s)
- M L Slovak
- Department of Cytogenetics, City of Hope National Medical Center, Duarte, CA 91010
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Fan D, Poste G, Seid C, Earnest LE, Bull T, Clyne RK, Fidler IJ. Reversal of multidrug resistance in murine fibrosarcoma cells by thioxanthene flupentixol. Invest New Drugs 1994; 12:185-95. [PMID: 7896537 DOI: 10.1007/bf00873959] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The purpose of this study was to identify calcium channel and calmodulin antagonists effective in increasing the cytotoxic effects of several chemotherapeutic drugs against UV-2237 murine fibrosarcoma MDR cells. Among 8 compounds tested at nontoxic concentrations, flupentixol, a piperazine-substituted thioxanthene, was the most potent in enhancing the cytotoxicity of anticancer drugs commonly associated with the multidrug resistant (MDR) phenotype, such as Adriamycin, actinomycin D, vinblastine, and vincristine, but not 5-fluorouracil, a drug usually unaffected by MDR. The chemosensitizing effects of flupentixol were produced by increasing intracellular drug accumulation via a mechanism unrelated to the binding of the plasma membrane P-glycoprotein.
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Affiliation(s)
- D Fan
- Department of Cell Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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47
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McGill JR, Beitzel BF, Nielsen JL, Walsh JT, Drabek SM, Meador RJ, Von Hoff DD. Double minutes are frequently found in ovarian carcinomas. CANCER GENETICS AND CYTOGENETICS 1993; 71:125-31. [PMID: 8281515 DOI: 10.1016/0165-4608(93)90017-g] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Double minutes (dmins) are acentric chromosomal-like entities that are important in the etiology of cancer because they are known to harbor amplified oncogenes and drug resistance genes. Because dmins can be unequally partitioned at mitosis they have the ability to confer genetic diversification rapidly. Selective pressures operative in vitro may be quite different than those in vivo; therefore, tumor cells which harbor dmins could be selected against during short-term in vitro propagation. We wanted to determine the incidence of dmins in human ovarian cancer cells obtained from fresh ovarian specimens with an absolute minimum of culture time (6-24 hours). In "direct" chromosomal preparations obtained from these clinical specimens we found dmins present in 88% of these samples. This remarkable finding that dmins are found so frequently in ovarian cancers underscores the importance of gene amplification in human tumor biology. Therefore, the presence of dmins in patient specimens indicates that these unstable genetic elements may play a significant role in the maintenance or progression of malignancy.
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Affiliation(s)
- J R McGill
- Cancer Therapy and Research Center, San Antonio, Texas
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48
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Abstract
The development of double-minute chromosomes (DMs) and subsequent gene amplification are important genomic alterations resulting in increased oncogene expression in a variety of tumors. The molecular mechanisms mediating the development of these acentric extrachromosomal elements have not been completely defined. To elucidate the mechanisms involved in DM formation, we have developed strategies to map amplified circular DM DNA. In this study, we present a long-range restriction map of a 980-kb DM. A cell line cloned from mouse EMT-6 cells was developed by stepwise selection for resistance to methotrexate. This cloned cell line contains multiple copies of the 980-kb DM carrying the dihydrofolate reductase (DHFR) gene. A long-range restriction map was developed in which a hypomethylated CpG-rich region near the DHFR gene served as a landmark. This strategy was combined with plasmid-like analysis of ethidium bromide-stained pulsed-field gels and indicated that a single copy of the DHFR gene was located near a hypomethylated region containing SsII and NotI sites. At least 490 kb of this DM appears to be composed of unrearranged chromosomal DNA.
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49
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Abstract
The development of double-minute chromosomes (DMs) and subsequent gene amplification are important genomic alterations resulting in increased oncogene expression in a variety of tumors. The molecular mechanisms mediating the development of these acentric extrachromosomal elements have not been completely defined. To elucidate the mechanisms involved in DM formation, we have developed strategies to map amplified circular DM DNA. In this study, we present a long-range restriction map of a 980-kb DM. A cell line cloned from mouse EMT-6 cells was developed by stepwise selection for resistance to methotrexate. This cloned cell line contains multiple copies of the 980-kb DM carrying the dihydrofolate reductase (DHFR) gene. A long-range restriction map was developed in which a hypomethylated CpG-rich region near the DHFR gene served as a landmark. This strategy was combined with plasmid-like analysis of ethidium bromide-stained pulsed-field gels and indicated that a single copy of the DHFR gene was located near a hypomethylated region containing SsII and NotI sites. At least 490 kb of this DM appears to be composed of unrearranged chromosomal DNA.
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Affiliation(s)
- J L Beland
- Department of Radiology, State University of New York, Syracuse 13210
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50
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Roelofs H, Schuuring E, Wiegant J, Michalides R, Giphart-Gassler M. Amplification of the 11q13 region in human carcinoma cell lines: a mechanistic view. Genes Chromosomes Cancer 1993; 7:74-84. [PMID: 7687456 DOI: 10.1002/gcc.2870070203] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We previously proposed that a local duplication, not the loss of the subsequently amplified marker from its original site, might be the first step in gene amplification in human cells. It is important to investigate this issue in naturally occurring amplification and when copy numbers are relatively low. We have examined the location of single-copy and amplified 11q13 sequences in cell lines from human breast cancers and squamous cell carcinomas using fluorescence in situ hybridization both with a probe specific for the 11q13 amplifying region and with a chromosome 11-specific library. We show that in most cell lines the 11q13 amplicons are physically linked to chromosome 11 or to a chromosome derived from chromosome 11 by various rearrangements near the 11q13 region. In none of the cell lines were interstitial deletions of 11q13 detected. These results indicate that 11q13 amplification in human tumor cells generally does not involve deletion as the initial step. One cell line with chromosomally located amplified 11q13 sequences contained double minutes that harbored the MYC gene but no 11q13 sequences. This suggests that the genetic outcome and the mechanism of gene amplification are probably dependent on specific DNA sequences rather than on the origin of the cells.
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Affiliation(s)
- H Roelofs
- Department of Molecular Genetics, Gorlaeus Laboratories, University of Leiden, The Netherlands
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