Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-5-19
pubmed:abstractText
SR 4233 (3-amino-1,2,4-benzotriazine 1,4-dioxide) is a bioreductive agent which exhibits highly selective killing of hypoxic cells in a variety of mammalian cell lines in vitro and in murine tumors in vivo. The selective toxicity of the drug results from its one-electron reduction under hypoxic conditions to form a free radical intermediate capable of damaging DNA, through the formation of strand breaks. Using the neutral filter elution assay, SR 4233 was found to be more efficient at producing DNA double strand breaks in Chinese hamster ovary (CHO) cells than an equitoxic dose of gamma-rays. Drug and radiation sequencing experiments were also performed, with both cell survival and DNA strand break rejoining used as endpoints. As a result of these studies, we now describe two additional properties of SR 4233: (a) radiosensitization of aerobic cells in culture produced by hypoxic incubation with drug either before or after irradiation, and (b) the inhibition of subsequent rejoining of radiation-induced DNA double strand breaks after hypoxic pretreatment with drug. The magnitude of the radiosensitization produced did not vary for drug treatments which, when given alone, reduced cell survival over a range from 30% to 2%. The extent of DNA repair inhibition increased with increasing severity of the SR 4233 pretreatment, but was quite small for non-lethal drug exposures.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0360-3016
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
967-71
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Pre- and post-irradiation radiosensitization by SR 4233.
pubmed:affiliation
Department of Radiation Oncology, Stanford University Medical Center, CA 94305.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.