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Nikitina E, Burk-Körner A, Wiesenfarth M, Alwers E, Heide D, Tessmer C, Ernst C, Krunic D, Schrotz-King P, Chang-Claude J, von Winterfeld M, Herpel E, Brobeil A, Brenner H, Heikenwalder M, Hoffmeister M, Kopp-Schneider A, Bund T. Bovine meat and milk factor protein expression in tumor-free mucosa of colorectal cancer patients coincides with macrophages and might interfere with patient survival. Mol Oncol 2023. [PMID: 36811271 DOI: 10.1002/1878-0261.13390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/05/2022] [Accepted: 02/03/2023] [Indexed: 02/24/2023] Open
Abstract
Bovine milk and meat factors (BMMFs) are plasmid-like DNA molecules isolated from bovine milk and serum, as well as the peritumor of colorectal cancer (CRC) patients. BMMFs have been proposed as zoonotic infectious agents and drivers of indirect carcinogenesis of CRC, inducing chronic tissue inflammation, radical formation and increased levels of DNA damage. Data on expression of BMMFs in large clinical cohorts to test an association with co-markers and clinical parameters were not previously available and were therefore assessed in this study. Tissue sections with paired tumor-adjacent mucosa and tumor tissues of CRC patients [individual cohorts and tissue microarrays (TMAs) (n = 246)], low-/high-grade dysplasia (LGD/HGD) and mucosa of healthy donors were used for immunohistochemical quantification of the expression of BMMF replication protein (Rep) and CD68/CD163 (macrophages) by co-immunofluorescence microscopy and immunohistochemical scoring (TMA). Rep was expressed in the tumor-adjacent mucosa of 99% of CRC patients (TMA), was histologically associated with CD68+ /CD163+ macrophages and was increased in CRC patients when compared to healthy controls. Tumor tissues showed only low stromal Rep expression. Rep was expressed in LGD and less in HGD but was strongly expressed in LGD/HGD-adjacent tissues. Albeit not reaching statistical significance, incidence curves for CRC-specific death were increased for higher Rep expression (TMA), with high tumor-adjacent Rep expression being linked to the highest incidence of death. BMMF Rep expression might represent a marker and early risk factor for CRC. The correlation between Rep and CD68 expression supports a previous hypothesis that BMMF-specific inflammatory regulations, including macrophages, are involved in the pathogenesis of CRC.
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Affiliation(s)
- Ekaterina Nikitina
- Division of Episomal-persistent DNA in Cancer- and Chronic Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Amelie Burk-Körner
- Division of Episomal-persistent DNA in Cancer- and Chronic Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Manuel Wiesenfarth
- Division of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Elizabeth Alwers
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Danijela Heide
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Claudia Tessmer
- Monoclonal Antibody Unit of the Genomics and Proteomics Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Claudia Ernst
- Division of Episomal-persistent DNA in Cancer- and Chronic Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Damir Krunic
- Light Microscopy Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Petra Schrotz-King
- Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Jenny Chang-Claude
- Unit of Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Cancer Epidemiology Group, University Medical Center Hamburg-Eppendorf, University Cancer Center Hamburg, Hamburg, Germany
| | - Moritz von Winterfeld
- Institute of Pathology, University Hospital Heidelberg, Germany
- Pathologie Rosenheim, Germany
| | - Esther Herpel
- Institute of Pathology, University Hospital Heidelberg, Germany
- Tissue Bank of the National Center for Tumor Diseases (NCT) Heidelberg, Germany
| | - Alexander Brobeil
- Institute of Pathology, University Hospital Heidelberg, Germany
- Tissue Bank of the National Center for Tumor Diseases (NCT) Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany
- German Cancer Consortium, German Cancer Research Center, Heidelberg, Germany
| | - Mathias Heikenwalder
- Division of Chronic Inflammation and Cancer, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Hoffmeister
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Timo Bund
- Division of Episomal-persistent DNA in Cancer- and Chronic Diseases, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Nikitina E, Alikhanyan K, Neßling M, Richter K, Kaden S, Ernst C, Seitz S, Chuprikova L, Häfele L, Gunst K, Rahbari N, Birgin E, Rasbach E, Rahbari M, Brobeil A, Schenk M, Büchler M, de Villiers E, Bund T, zur Hausen H. Structural Expression of BMMF in tissues of colorectal, lung and pancreatic cancer patients. Int J Cancer 2022; 153:173-182. [PMID: 36444499 DOI: 10.1002/ijc.34374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 10/19/2022] [Accepted: 11/10/2022] [Indexed: 11/30/2022]
Abstract
Chronic inflammation, linked to the presence of bovine milk and meat factors (BMMFs) and specific subsets of macrophages, results in oxygen radical synthesis and induction of mutations in DNA of actively replicating cells and replicating single stranded DNA. Cancers arising from this process have been characterized as indirect carcinogenesis by infectious agents (without persistence of genes of the agent in premalignant or cancers cells). Here, we investigate structural properties of pleomorphic vesicles, regularly identified by staining peritumor tissues of colorectal, lung and pancreatic cancer for expression of BMMF Rep. The latter represents a subgroup of BMMF1 proteins involved in replication of small single-stranded circular plasmids of BMMF, but most likely also contributing to pleomorphic vesicular structures found in the periphery of colorectal, lung and pancreatic cancers. Structurally dense regions are demonstrated in preselected areas of colorectal cancer, after staining with monoclonal antibodies against BMMF1 Rep. Similar structures were observed in human embryonic cells (HEK293TT) overexpressing Rep. These data suggest that Rep or Rep isoforms contribute to the structural formation of vesicles.
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Affiliation(s)
- Ekaterina Nikitina
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Kristina Alikhanyan
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Michelle Neßling
- Electron Microscopy Core Facility, German Cancer Research Centre Heidelberg Germany
| | - Karsten Richter
- Electron Microscopy Core Facility, German Cancer Research Centre Heidelberg Germany
| | - Sylvia Kaden
- Electron Microscopy Core Facility, German Cancer Research Centre Heidelberg Germany
| | - Claudia Ernst
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Stefan Seitz
- Division of Virus‐associated Carcinogenesis German Cancer Research Centre Heidelberg Germany
| | - Liubov Chuprikova
- Division of Virus‐associated Carcinogenesis German Cancer Research Centre Heidelberg Germany
| | - Lisa Häfele
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Karin Gunst
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Nuh Rahbari
- Department of Surgery, University Hospital Mannheim, Medical Faculty Mannheim University of Heidelberg Mannheim Germany
| | - Emrullah Birgin
- Department of Surgery, University Hospital Mannheim, Medical Faculty Mannheim University of Heidelberg Mannheim Germany
| | - Erik Rasbach
- Department of Surgery, University Hospital Mannheim, Medical Faculty Mannheim University of Heidelberg Mannheim Germany
| | - Mohammad Rahbari
- Department of Surgery, University Hospital Mannheim, Medical Faculty Mannheim University of Heidelberg Mannheim Germany
- Division of Chronic Inflammation and Cancer German Cancer Research Centre Heidelberg Germany
| | - Alexander Brobeil
- Tissue Bank of the National Centre for Tumour Diseases (NCT) Heidelberg Germany
- Institute of Pathology University Hospital Heidelberg Germany
| | - Miriam Schenk
- Department of General, Visceral and Transplantation Surgery University of Heidelberg Germany
| | - Markus Büchler
- Department of General, Visceral and Transplantation Surgery University of Heidelberg Germany
| | - Ethel‐Michele de Villiers
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Timo Bund
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
| | - Harald zur Hausen
- Division of Episomal‐Persistent DNA in Cancer‐ and Chronic Diseases German Cancer Research Centre Heidelberg Germany
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de Villiers EM, Gunst K, Chakraborty D, Ernst C, Bund T, Zur Hausen H. A specific class of infectious agents isolated from bovine serum and dairy products and peritumoral colon cancer tissue. Emerg Microbes Infect 2019; 8:1205-1218. [PMID: 31409221 PMCID: PMC6713099 DOI: 10.1080/22221751.2019.1651620] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The in silico analyses of 109 replication-competent genomic DNA sequences isolated from cow milk and its products (97 in the bovine meat and milk factors 2 group – BMMF2, and additional 4 in BMMF1) seems to place these in a specific class of infectious agents spanning between bacterial plasmid and circular ssDNA viruses. Satellite-type small plasmids with partial homology to larger genomes, were also isolated in both groups. A member of the BMMF1 group H1MBS.1 was recovered in a distinctly modified form from colon tissue by laser microdissection. Although the evolutionary origin is unknown, it draws the attention to the existence of a hitherto unrecognized, broad spectrum of potential pathogens. Indirect hints to the origin and structure of our isolates, as well as to their replicative behaviour, result from parallels drawn to the Hepatitis deltavirus genome structure and replication.
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Affiliation(s)
- Ethel-Michele de Villiers
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Karin Gunst
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Deblina Chakraborty
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Claudia Ernst
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Timo Bund
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
| | - Harald Zur Hausen
- a Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum , Heidelberg , Germany
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Zur Hausen H, Bund T, de Villiers EM. Infectious Agents in Bovine Red Meat and Milk and Their Potential Role in Cancer and Other Chronic Diseases. Curr Top Microbiol Immunol 2019; 407:83-116. [PMID: 28349283 DOI: 10.1007/82_2017_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Red meat and dairy products have frequently been suggested to represent risk factors for certain cancers, chronic neurodegenerative diseases, and autoimmune and cardiovascular disorders. This review summarizes the evidence and investigates the possible involvement of infectious factors in these diseases. The isolation of small circular single-stranded DNA molecules from serum and dairy products of Eurasian Aurochs (Bos taurus)-derived cattle, obviously persisting as episomes in infected cells, provides the basis for further investigations. Gene expression of these agents in human cells has been demonstrated, and frequent infection of humans is implicated by the detection of antibodies in a high percentage of healthy individuals. Epidemiological observations suggest their relationship to the development multiple sclerosis, to heterophile antibodies, and to N-glycolylneuraminic acid (Neu5Gc) containing cell surface receptors.
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Affiliation(s)
- Harald Zur Hausen
- Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
| | - Timo Bund
- Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
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Kilic T, Popov AN, Burk-Körner A, Koromyslova A, zur Hausen H, Bund T, Hansman GS. Structural analysis of a replication protein encoded by a plasmid isolated from a multiple sclerosis patient. Acta Crystallogr D Struct Biol 2019; 75:498-504. [PMID: 31063152 PMCID: PMC6503762 DOI: 10.1107/s2059798319003991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 03/23/2019] [Indexed: 12/15/2022] Open
Abstract
Bovine meat and milk factors (BMMFs) are circular, single-stranded episomal DNAs that have been detected in bovine meat and milk products. BMMFs are thought to have roles in human malignant and degenerative diseases. BMMFs encode a replication initiator protein (Rep) that is actively transcribed and translated in human cells. In this study, a Rep WH1 domain encoded on a BMMF (MSBI1.176) isolated from a multiple sclerosis human brain sample was determined to 1.53 Å resolution using X-ray crystallography. The overall structure of the MSBI1.176 WH1 domain was remarkably similar to other Rep structures, despite having a low (28%) amino-acid sequence identity. The MSBI1.176 WH1 domain contained elements common to other Reps, including five α-helices, five β-strands and a hydrophobic pocket. These new findings suggest that the MSBI1.176 Rep might have comparable roles and functions to other known Reps of different origins.
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Affiliation(s)
- Turgay Kilic
- Schaller Research Group at the University of Heidelberg, Heidelberg, Germany
- Department of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
| | - Alexander N. Popov
- Structural Biology Group, European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - Amelie Burk-Körner
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Biosciences Faculty, University of Heidelberg, Heidelberg, Germany
| | - Anna Koromyslova
- Schaller Research Group at the University of Heidelberg, Heidelberg, Germany
- Department of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
| | | | - Timo Bund
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Grant S. Hansman
- Schaller Research Group at the University of Heidelberg, Heidelberg, Germany
- Department of Infectious Diseases, Virology, University of Heidelberg, Heidelberg, Germany
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Zur Hausen H, Bund T, de Villiers EM. Specific nutritional infections early in life as risk factors for human colon and breast cancers several decades later. Int J Cancer 2018; 144:1574-1583. [PMID: 30246328 DOI: 10.1002/ijc.31882] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/06/2018] [Accepted: 09/17/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Harald Zur Hausen
- Division Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | - Timo Bund
- Division Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | - Ethel-Michele de Villiers
- Division Episomal-Persistent DNA in Cancer- and Chronic Diseases, Deutsches Krebsforschungszentrum, Heidelberg, Germany
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Bund T, Spoden GA, Koynov K, Hellmann N, Boukhallouk F, Arnold P, Hinderberger D, Florin L. An L2 SUMO interacting motif is important for PML localization and infection of human papillomavirus type 16. Cell Microbiol 2014; 16:1179-200. [PMID: 24444361 DOI: 10.1111/cmi.12271] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 01/08/2014] [Accepted: 01/14/2014] [Indexed: 11/27/2022]
Abstract
Human papillomaviruses (HPV) induce warts and cancers on skin and mucosa. The HPV16 capsid is composed of the proteins L1 and L2. After cell entry and virus disassembly, the L2 protein accompanies the viral DNA to promyelocytic leukaemia nuclear bodies (PML-NBs) within the host nuclei enabling viral transcription and replication. Multiple components of PML-NBs are regulated by small ubiquitin-like modifiers (SUMOs) either based on covalent SUMO modification (SUMOylation), or based on non-covalent SUMO interaction via SUMO interacting motifs (SIMs). We show here that the HPV16 L2 comprises at least one SIM, which is crucial for the L2 interaction with SUMO2 in immunoprecipitation and colocalization with SUMO2 in PML-NBs. Biophysical analysis confirmed a direct L2 interaction with SUMO substantiated by identification of potential L2-SUMO interaction structures in molecular dynamics simulations. Mutation of the SIM resulted in absence of the L2-DNA complex at PML-NB and in a loss of infectivity of mutant HPV16 pseudoviruses. In contrast, we found that L2 SUMOylation has no effect on L2 localization in PML-NBs and SUMO interaction. Our data suggest that the L2 SIM is important for L2 interaction with SUMO and/or SUMOylated proteins, which is indispensable for the delivery of viral DNA to PML-NBs and efficient HPV infection.
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Affiliation(s)
- Timo Bund
- Max Planck Institute for Polymer Research, Mainz, Germany; Department of Medical Microbiology and Hygiene, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
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8
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Kattnig DR, Bund T, Boggs JM, Harauz G, Hinderberger D. Lateral self-assembly of 18.5-kDa myelin basic protein (MBP) charge component-C1 on membranes. Biochimica et Biophysica Acta (BBA) - Biomembranes 2012; 1818:2636-47. [DOI: 10.1016/j.bbamem.2012.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/23/2012] [Accepted: 06/14/2012] [Indexed: 11/16/2022]
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Hüttinger K, Förster C, Bund T, Hinderberger D, Heinze K. Stereochemical Consequences of Oxygen Atom Transfer and Electron Transfer in Imido/Oxido Molybdenum(IV, V, VI) Complexes with Two Unsymmetric Bidentate Ligands. Inorg Chem 2012; 51:4180-92. [DOI: 10.1021/ic202588u] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Kristina Hüttinger
- Institute
of Inorganic Chemistry
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Christoph Förster
- Institute
of Inorganic Chemistry
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Timo Bund
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Dariush Hinderberger
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - Katja Heinze
- Institute
of Inorganic Chemistry
and Analytical Chemistry, Johannes Gutenberg-University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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Bund T, Boggs JM, Harauz G, Hellmann N, Hinderberger D. Copper uptake induces self-assembly of 18.5 kDa myelin basic protein (MBP). Biophys J 2011; 99:3020-8. [PMID: 21044600 DOI: 10.1016/j.bpj.2010.08.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 07/23/2010] [Accepted: 08/02/2010] [Indexed: 12/26/2022] Open
Abstract
Myelin basic protein (MBP) is predominantly found in the membranes of the myelin sheath of the central nervous system and is involved in important protein-protein and protein-lipid interactions in vivo and in vitro. Furthermore, divalent transition metal ions, especially Zn(2+) and Cu(2+), seem to directly affect the MBP-mediated formation and stabilization of the myelin sheath of the central nervous system. MBP belongs to the realm of intrinsically disordered proteins, and only fragmentary information is available regarding its partial structure(s) or supramolecular arrangements. Here, using standard continuous wave and modern pulse electron paramagnetic resonance methods, as well as dynamic light scattering, we demonstrate the uptake and specific coordination of two Cu(2+) atoms or one Zn(2+) atom per MBP molecule in solution. In the presence of phosphates, further addition of divalent metal ions above a characteristic threshold of four Cu(2+) atoms or two Zn(2+) atoms per MBP molecule leads to the formation of large MBP aggregates within the protein solution. In vivo, MBP-MBP interactions may thus be mediated by divalent cations.
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Affiliation(s)
- Timo Bund
- Max Planck Institute for Polymer Research, Mainz, Germany
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Volkov A, Dockter C, Bund T, Paulsen H, Jeschke G. Pulsed EPR determination of water accessibility to spin-labeled amino acid residues in LHCIIb. Biophys J 2009; 96:1124-41. [PMID: 19186148 PMCID: PMC2716639 DOI: 10.1016/j.bpj.2008.09.047] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 09/22/2008] [Indexed: 11/24/2022] Open
Abstract
Membrane proteins reside in a structured environment in which some of their residues are accessible to water, some are in contact with alkyl chains of lipid molecules, and some are buried in the protein. Water accessibility of residues may change during folding or function-related structural dynamics. Several techniques based on the combination of pulsed electron paramagnetic resonance (EPR) with site-directed spin labeling can be used to quantify such water accessibility. Accessibility parameters for different residues in major plant light-harvesting complex IIb are determined by electron spin echo envelope modulation spectroscopy in the presence of deuterated water, deuterium contrast in transversal relaxation rates, analysis of longitudinal relaxation rates, and line shape analysis of electron-spin-echo-detected EPR spectra as well as by the conventional techniques of measuring the maximum hyperfine splitting and progressive saturation in continuous-wave EPR. Systematic comparison of these parameters allows for a more detailed characterization of the environment of the spin-labeled residues. These techniques are applicable independently of protein size and require approximately 10-20 nmol of singly spin-labeled protein per sample. For a residue close to the N-terminus, in a domain unresolved in the existing x-ray structures of light-harvesting complex IIb, all methods indicate high water accessibility.
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Affiliation(s)
- A. Volkov
- Max-Planck Institute for Polymer Research, Mainz, Germany
| | - C. Dockter
- Institute of General Botany, Johannes Gutenberg University, Mainz, Germany
| | - T. Bund
- Institute of General Botany, Johannes Gutenberg University, Mainz, Germany
| | - H. Paulsen
- Institute of General Botany, Johannes Gutenberg University, Mainz, Germany
| | - G. Jeschke
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, Zürich, Switzerland
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Abstract
Cat-scratch disease is an infection by Bartonella henselea and resolves spontaneously. We present a case of untypical Bartonella infection which was misinterpreted by MRI as a soft-tissue sarcoma of the upper arm. The histological findings of an incision biopsy were unspecific, without signs of malignancy. The tumor was excised completely and the final histology, however, showed no evidence of malignant changes. The Bartonella henselae infection could be confirmed by polymerase chain reaction. The untypical presentation of cat-scratch disease should be considered in the differential diagnosis of clinically suspected soft tissue sarcoma.
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Affiliation(s)
- J Eichhorn-Sens
- Plastische Gesichtschirurgie, Marienhospital Stuttgart, Böheimstrabe 37, 70199, Stuttgart.
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13
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Rohde V, Sattler HP, Bund T, Bonkhoff H, Fixemer T, Bachmann C, Lensch R, Unteregger G, Stoeckle M, Wullich B. Expression of the human telomerase reverse transcriptase is not related to telomerase activity in normal and malignant renal tissue. Clin Cancer Res 2000; 6:4803-9. [PMID: 11156238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
In this study, the association between telomerase activity and the expression of the human telomerase subunits human telomerase RNA (hTR) and human telomerase reverse transcriptase (hTERT) in paired neoplastic and normal renal tissue samples was investigated. Reverse transcription (RT)-PCR on 20 tumor nephrectomy samples revealed that hTR was constitutively expressed both in cancer and normal tissue samples, independent of the telomerase activity status. Remarkably, using in situ hybridization, the expression levels of hTR were found to be markedly higher in the normal tissue than those in the tumors. Expression of hTERT mRNA by RT-PCR was observed in 90% of the cancer samples and, notably, also in 75% of the corresponding normal renal tissue samples. Because all of the normal tissue samples and some of the tumor samples were shown to be telomerase negative, our findings suggest that hTERT mRNA expression is not sufficient for telomerase enzyme activation. Furthermore, semiquantitative RT-PCR revealed equal or even higher hTERT mRNA expression levels in the telomerase-negative normal samples than in the corresponding cancer samples with telomerase activity, contradicting the assumption that a certain threshold level of hTERT mRNA is required for telomerase activation at least in renal tissue. It seems more likely, that other mechanisms, such as posttranscriptional modification of hTERT or inactivation of telomerase inhibitors, are involved in the acquisition of enzyme activity.
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Affiliation(s)
- V Rohde
- Clinic of Urology and Pediatric Urology, University of the Saarland, Homburg/Saar, Germany
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