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Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses

This study was carried out in 2 parts: 1. Genome analysis of human adenovirus species 7; 2. Search for a possible viral aetiology in oesophageal carcinoma. Sixteen laboratory isolates of adenovirus species 7, isolated in South Africa between 1975 and 1986, were characterized by restriction endonucle...

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Main Author: Brooks, Louise Alexandra
Other Authors: Steyn, Lafras M
Format: Thesis
Language:English
Published: Department of Medicine 2017
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access_status_str Open Access
author Brooks, Louise Alexandra
author2 Steyn, Lafras M
author_browse Brooks, Louise Alexandra
Steyn, Lafras M
author_facet Steyn, Lafras M
Brooks, Louise Alexandra
author_sort Brooks, Louise Alexandra
collection Thesis
description This study was carried out in 2 parts: 1. Genome analysis of human adenovirus species 7; 2. Search for a possible viral aetiology in oesophageal carcinoma. Sixteen laboratory isolates of adenovirus species 7, isolated in South Africa between 1975 and 1986, were characterized by restriction endonuclease analysis of their DNA genomes. Virus was propagated in human embryo fibroblast cells; genomic DNA, extracted and purified from cellular DNA extracts, was analyzed using 9 different restriction enzymes. Results of this study have demonstrated 2 new genome types of adenovirus 7c which have not previously been identified. The 2 novel strains, designated as genome types Ad7c1 and Ad7c2, were shown to differ from prototype Ad7 c according to restriction profiles with EcoRI; 2 new EcoRI sites were demonstrated in Ad7c1 and 1 in Ad7c2. The restriction sites were mapped on the viral genomes (at 3.68kb and 5.32kb from the left terminus) by double enzyme digestions, cloning of viral DNA, and nucleic acid hybridization using a cloned Ad7 probe. Strains resembling the prototype Ad7c and Ad7p (Gomen) genome types were also identified in the 1985 and 1986 Ad7 isolates. In order to investigate the possible role of a viral co-factor in the aetiology of oesophageal carcinoma, 18 probes, derived from potentially oncogenic viruses, were used to screen 3 human oesophageal carcinoma cell lines for the possible presence of integrated viral DNA. One of these, an Ad7 recombinant plasmid probe, was developed by cloning DNA from the transforming region of the Ad7cl strain into the plasmid vector pUC19. Cellular DNA, extracted from the 3 tumor lines HCU18, HCU33 and HCU39, was tested by means of both DNA dot hybridization and Southern blot hybridization for the presence of Epstein-Barr virus, human papillomavirus (types 1, 5, 6, 8, 11, 16, 18), human adenovirus (strains 5, 7, 12, 31) and human T-lymphotropic virus type I DNA. Both assays were demonstrated to be sensitive enough to detect 1 copy of viral DNA per cell. No hybridization between HPV, EBV, HTLV-I or adenovirus DNA probes, and the cellular DNA was detected. These findings indicate that the stable integration of these tumor viruses in host chromosomes did not play a role in the maintenance of the malignant phenotype of the 3 extensively passaged cell lines. Cells of the 3 oesophageal tumor lines were further examined by transmission electron microscopy, but the presence of virus particles in these cells was not observed.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:33:15.376Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2017
publishDateRange 2017
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publisher Department of Medicine
publisherStr Department of Medicine
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/25889 Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses Brooks, Louise Alexandra Steyn, Lafras M Renan, M J Dumbell, K R Adenoviruses Esophagus - Cancer This study was carried out in 2 parts: 1. Genome analysis of human adenovirus species 7; 2. Search for a possible viral aetiology in oesophageal carcinoma. Sixteen laboratory isolates of adenovirus species 7, isolated in South Africa between 1975 and 1986, were characterized by restriction endonuclease analysis of their DNA genomes. Virus was propagated in human embryo fibroblast cells; genomic DNA, extracted and purified from cellular DNA extracts, was analyzed using 9 different restriction enzymes. Results of this study have demonstrated 2 new genome types of adenovirus 7c which have not previously been identified. The 2 novel strains, designated as genome types Ad7c1 and Ad7c2, were shown to differ from prototype Ad7 c according to restriction profiles with EcoRI; 2 new EcoRI sites were demonstrated in Ad7c1 and 1 in Ad7c2. The restriction sites were mapped on the viral genomes (at 3.68kb and 5.32kb from the left terminus) by double enzyme digestions, cloning of viral DNA, and nucleic acid hybridization using a cloned Ad7 probe. Strains resembling the prototype Ad7c and Ad7p (Gomen) genome types were also identified in the 1985 and 1986 Ad7 isolates. In order to investigate the possible role of a viral co-factor in the aetiology of oesophageal carcinoma, 18 probes, derived from potentially oncogenic viruses, were used to screen 3 human oesophageal carcinoma cell lines for the possible presence of integrated viral DNA. One of these, an Ad7 recombinant plasmid probe, was developed by cloning DNA from the transforming region of the Ad7cl strain into the plasmid vector pUC19. Cellular DNA, extracted from the 3 tumor lines HCU18, HCU33 and HCU39, was tested by means of both DNA dot hybridization and Southern blot hybridization for the presence of Epstein-Barr virus, human papillomavirus (types 1, 5, 6, 8, 11, 16, 18), human adenovirus (strains 5, 7, 12, 31) and human T-lymphotropic virus type I DNA. Both assays were demonstrated to be sensitive enough to detect 1 copy of viral DNA per cell. No hybridization between HPV, EBV, HTLV-I or adenovirus DNA probes, and the cellular DNA was detected. These findings indicate that the stable integration of these tumor viruses in host chromosomes did not play a role in the maintenance of the malignant phenotype of the 3 extensively passaged cell lines. Cells of the 3 oesophageal tumor lines were further examined by transmission electron microscopy, but the presence of virus particles in these cells was not observed. 2017-10-30T07:01:38Z 2017-10-30T07:01:38Z 1987 2017-04-06T07:43:03Z Master Thesis Masters MSc http://hdl.handle.net/11427/25889 eng application/pdf Department of Medicine Faculty of Health Sciences University of Cape Town
spellingShingle Adenoviruses
Esophagus - Cancer
Brooks, Louise Alexandra
Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
thesis_degree_str Master's
title Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
title_full Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
title_fullStr Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
title_full_unstemmed Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
title_short Demonstration of new subtypes of adenovirus 7 in South Africa, and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
title_sort demonstration of new subtypes of adenovirus 7 in south africa and probing oesophageal carcinoma cell lines for evidence of adenovirus or of other oncogenic viruses
topic Adenoviruses
Esophagus - Cancer
url http://hdl.handle.net/11427/25889
work_keys_str_mv AT brookslouisealexandra demonstrationofnewsubtypesofadenovirus7insouthafricaandprobingoesophagealcarcinomacelllinesforevidenceofadenovirusorofotheroncogenicviruses