Please use this identifier to cite or link to this item: http://dx.doi.org/10.18419/opus-7780
|Authors:||Rajewsky, Manfred F.|
Laerum, Ole D.
Hülser, Dieter F.
|Title:||Molecular and cellular mechanisms in nervous system-specific carcinogenesis by N-ethyl-N-nitrosourea|
|metadata.ubs.publikation.source:||Magee, Peter N. (Hrsg.): Fundamentals in cancer prevention : proc.of the 6th intern. Symp. of the Princess Takamatsu Cancer Res. Fund, Tokyo, 1975. Baltimore : University Park Press, 1976. - ISBN 0-8391-0965-2, S. 313-334|
|Abstract:||A single pulse of N-ethyl-N-nitrosourea (ENU), applied to BDIX rats during the perinatal age, specifically results in a high incidence of neuroectodermal neoplasms in the central and peripheral nervous system (NS). The pronounced sensitivity of the developing NS suggests a dependence of the carcinogenic effect on the proliferative and/or differentiative state of the target cells at the time of the ENU pulse. The specificity of ENU for the NS cannot be due to tissue variations in the degree of carcinogen-cell interactions, since the reactive, electrophilic ethyl cation is produced by rapid, nonenzymatic decomposition of ENU indiscriminately in all tissues. Correspondingly, the initial molar fractions of ethylated purine bases are similar in the DNA of "high-risk" (perinatal brain) and "low-risk" tissues (e.g., liver; adult brain). However, while the respective half lives in DNA of N7-ethylguanine and N3-ethyladenine show only minor differences for both types of tissues, the mutagenic ethylation product 06-ethylguanine is removed from brain DNA very much more slowly than from the DNA of other tissues. Together with their high rate of DNA replication during the perinatal age, the incapacity of rat brain cells for enzymatic elimination of 06-alkylguanine from their DNA could account for an increased probability of neoplastic conversion, and hence for the NS specificity of ENU in the rat.|
|Appears in Collections:||15 Fakultätsübergreifend / Sonstige Einrichtung|
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