Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive 

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-35868

Buterin, T; Hess, M T; Luneva, N; Geacintov, N E; Amin, S; Kroth, H; Seidel, A; Naegeli, H (2000). Unrepaired fjord region polycyclic aromatic hydrocarbon-DNA adducts in ras codon 61 mutational hot spots. Cancer Research, 60(7):1849-1856.

[img]PDF - Registered users only
873Kb

Abstract

The fjord region diol-epoxide metabolites of polycyclic aromatic hydrocarbons display stronger tumorigenic activities in rodent studies than comparable bay region diol-epoxides, but the molecular basis for this difference between fjord and bay region derivatives is not understood. Here we tested whether the variable effects of these genotoxic metabolites of polycyclic aromatic hydrocarbons may result from different DNA repair reactions. In particular, we compared the repairability of DNA adducts formed by bay region benzo[a]pyrene (B[a]P) diol-epoxides and the structurally similar but significantly more tumorigenic fjord region diol-epoxide metabolites of benzo[c]phenanthrene (B[c]Ph). For that purpose, we incorporated both types of polycyclic aromatic hydrocarbon adducts into known hot spot sites for carcinogen-induced proto-oncogene activation. Synthetic DNA substrates were assembled using a portion of human N-ras or H-ras that includes codon 61, and stereospecific B[a]P or B[c]Ph adducts were synthesized on adenine N6 at the second position of these two ras codon 61 sequences. DNA repair was determined by incubating the site-directed substrates in human cell extracts, followed by electrophoretic visualization of radiolabeled oligonucleotide excision products. These cell-free assays showed that all tested bay region B[a]P-N6-dA adducts are removed by the human nucleotide excision repair system, although excision efficiency varied with the particular stereochemical configuration of each B[a]P residue. In contrast, all fjord region B[c]Ph-N6-dA adducts located in the identical sequence context and with exactly the same stereochemical properties as the corresponding B[a]P lesions were refractory to the nucleotide excision repair process. These findings indicate that the exceptional tumorigenic potency of B[c]Ph or related fjord region diol-epoxides may be attributed, at least in part, to slow repair of the stable base adducts deriving from the reaction of these compounds with DNA.

Item Type:Journal Article, refereed, original work
Communities & Collections:05 Vetsuisse Faculty > Institute of Veterinary Pharmacology and Toxicology
DDC:570 Life sciences; biology
Language:English
Date:2000
Deposited On:09 Nov 2010 18:17
Last Modified:07 Dec 2013 02:06
Publisher:American Association for Cancer Research
ISSN:0008-5472
Free access at:Official URL. An embargo period may apply.
Official URL:http://cancerres.aacrjournals.org/content/60/7/1849.long
PubMed ID:10766171
Citations:Web of Science®. Times Cited: 83
Google Scholar™

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page