Mutation Research, 271 (1992) 115-200
115
© 1992 Elsevier Science Publishers B.V. All rights reserved 0165-1161/92/$05.00
MUTENV 08816
European Environmental Mutagen Society
Selected Poster Abstracts of the 21st Annual Meeting of the European Environmental Mutagen Society, 25-31 August 1991, Prague (Czechoslovakia) Edited by: A.T. Natarajan and R. Sram (Received 18 October 1991) (Accepted 18 October 1991)
Keywords: European Environmental Mutagen Society; Abstracts; Annual Meeting 1991, EEMS
I. DNA repair mechanisms of mutagenesis
1 Arnsdorff-Roubicek, D. ~, and A.T. Natarajan 2, Dept. Biologia, Inst. Bioci&ncias, USP, Sao Paulo (Brasil) and Dept. Radiat. Genet. and Chem. Mutag., Univ. Leiden, Leiden (The Netherlands) Induction of SCEs by mono- and bifunctional psoralens in repair proficient and deficient CHO cells
The induction of sister-chromatid exchanges (SCEs) by near UV light (UVA, 365 nm) and 8-methoxypsoralen (8-MOP), which is able to form bulky monoadducts and interstrand crosslinks in DNA, or angelicin, which can form only monoadducts, was studied. In order to understand the relative importance of these two DNA lesions in the formation of SCEs, we used four different Chinese hamster ovary (CHO) cell lines: CHO-9 (wild type); its mutant 43-3B, which is repair deficient and hypersensitive to UV and crosslinking agents; and
Correspondence: Prof. A.T. Natarajan, Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Wassenaarseweg 72, P.O. Box 9503, 2300 AR Leiden (The Netherlands).
two of its derivatives, namely, 43IIIMMC and 62E3, in which few or many copies of the human ERCC-1 repair gene have been integrated, correcting the defect. All cell lines responded with an increase in the frequencies of SCEs following treatment with both agents, CHO-9, 43IIIMMC and 62E3 to a very similar extent. 43-3B cells were more sensitive than the other cell lines to both psoralens, susceptibility to angelicin being greatest.
2 Basic-Zaninovic, T., F. Palombo, M. Nignami and E. Dogliotti, Istituto Superiore di SanitY, Rome (Italy) Effect of direction of DNA replication on mutagenesis by N-methyl-N-nitrosourea in human cells
In a previous study we reported that Nmethyl-N-nitrosourea-induced mutations are preferentially located in the non-transcribed strand of the gpt gene carried by the EBV-derived shuttle vector, pF1-EBV, stably replicating in human cells. The strand specificity was shown to be independent of the transcriptional activity of the target gene. Strand specificity was also reported for UV-induced mutations at the HPRT gene in hamster ceils. In this case the phe-
115
© 1992 Elsevier Science Publishers B.V. All rights reserved 0165-1161/92/$05.00
MUTENV 08816
European Environmental Mutagen Society
Selected Poster Abstracts of the 21st Annual Meeting of the European Environmental Mutagen Society, 25-31 August 1991, Prague (Czechoslovakia) Edited by: A.T. Natarajan and R. Sram (Received 18 October 1991) (Accepted 18 October 1991)
Keywords: European Environmental Mutagen Society; Abstracts; Annual Meeting 1991, EEMS
I. DNA repair mechanisms of mutagenesis
1 Arnsdorff-Roubicek, D. ~, and A.T. Natarajan 2, Dept. Biologia, Inst. Bioci&ncias, USP, Sao Paulo (Brasil) and Dept. Radiat. Genet. and Chem. Mutag., Univ. Leiden, Leiden (The Netherlands) Induction of SCEs by mono- and bifunctional psoralens in repair proficient and deficient CHO cells
The induction of sister-chromatid exchanges (SCEs) by near UV light (UVA, 365 nm) and 8-methoxypsoralen (8-MOP), which is able to form bulky monoadducts and interstrand crosslinks in DNA, or angelicin, which can form only monoadducts, was studied. In order to understand the relative importance of these two DNA lesions in the formation of SCEs, we used four different Chinese hamster ovary (CHO) cell lines: CHO-9 (wild type); its mutant 43-3B, which is repair deficient and hypersensitive to UV and crosslinking agents; and
Correspondence: Prof. A.T. Natarajan, Department of Radiation Genetics and Chemical Mutagenesis, State University of Leiden, Wassenaarseweg 72, P.O. Box 9503, 2300 AR Leiden (The Netherlands).
two of its derivatives, namely, 43IIIMMC and 62E3, in which few or many copies of the human ERCC-1 repair gene have been integrated, correcting the defect. All cell lines responded with an increase in the frequencies of SCEs following treatment with both agents, CHO-9, 43IIIMMC and 62E3 to a very similar extent. 43-3B cells were more sensitive than the other cell lines to both psoralens, susceptibility to angelicin being greatest.
2 Basic-Zaninovic, T., F. Palombo, M. Nignami and E. Dogliotti, Istituto Superiore di SanitY, Rome (Italy) Effect of direction of DNA replication on mutagenesis by N-methyl-N-nitrosourea in human cells
In a previous study we reported that Nmethyl-N-nitrosourea-induced mutations are preferentially located in the non-transcribed strand of the gpt gene carried by the EBV-derived shuttle vector, pF1-EBV, stably replicating in human cells. The strand specificity was shown to be independent of the transcriptional activity of the target gene. Strand specificity was also reported for UV-induced mutations at the HPRT gene in hamster ceils. In this case the phe-
