Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
DNA fragmentation in cultured cells exposed to high linear energy transfer radiation
Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
2000 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The DNA double-strand break (DSB) is a critical lesion which, if not completely restored, can have serious biological consequences. The relative biological effectiveness (RBE) of many severe end-points are closely related to radiation quality, with increased effectiveness at elevated ionization density. Data presented provide information about the influence of radiation quality on the initial processes causing DNA damage, and the mechanisms leading to its restoration. Such information will increase the understanding of radiation action mechanisms in mammalian cells.

Human cells were irradiated with accelerated ions having linear energy transfer (LET) values in the range 40-225 keV/μm, and 60Co-photons. Detailed analyses of the DNA fragment distributions were performed in the size-range 5 kilobasepairs to 6 megabasepairs by pulsed-field gel electrophoresis.

A non-random fragmentation of DNA was evident, with an elevated number of small and medium-sized fragments for ion irradiation, and the total number of breaks increased by 80-110% when these fragments were included in the analyses. The RBE for DSB induction was 1.2-1.5. A two-fold increase of the number of breaks induced per nitrogen ion passing the cell nuclues was found when LET was increased from 80 to 225 keV/μm, indicating a possible role of particle track structure in DSB induction. Furthermore, the ability to repair DNA was closely related to radiation quality, with an increased proportion of unrejoined breaks for densely ionizing radiation. Surprisingly, the majority of breaks were rapidly rejoined even following exposure to high-LET radiation. The proportion of breaks restored by the slow phase showed a five-fold increase for the highest LET tested, compared with photons. The results presented nominates the complexity of breaks as one determining factor for reduced reparability reported following high-LET exposure.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2000. , p. 58
Series
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 0282-7476 ; 960
Keyword [en]
Oncology
Keyword [sv]
Onkologi
National Category
Cancer and Oncology
Research subject
Biomedical Radiation Science
Identifiers
URN: urn:nbn:se:uu:diva-1254ISBN: 91-554-4822-4 (print)OAI: oai:DiVA.org:uu-1254DiVA, id: diva2:160815
Public defence
2000-10-21, Rudbecksalen, Rudbecklaboratoriet, Uppsala, 09:15
Available from: 2000-09-30 Created: 2000-09-30Bibliographically approved

Open Access in DiVA

fulltext(488 kB)1607 downloads
File information
File name FULLTEXT01.pdfFile size 488 kBChecksum SHA-1
128012011573a89ace1a2ca28c42174e991e35f629f8aeb0285a8a4ff56d8b4e0d764a64
Type fulltextMimetype application/pdf
Buy this publication >>

By organisation
Department of Oncology, Radiology and Clinical Immunology
Cancer and Oncology

Search outside of DiVA

GoogleGoogle Scholar
Total: 1607 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 735 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf