Analysis of benzo[a]pyrene diolepoxide mutagenesis in a mammalian in vitro DNA replication system

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Environmental and Molecular Mutagenesis

OSTI ID:115152

Vasunia, K; Cheng, L; Carty, M ^[1]

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1. Univ. of Cincinnati, OH (United States); and others

Chemicals that interact with DNA and cause mutations, thereby activating protooncogenes or inactivating tumor suppressor genes, are thought to initiate the process of carcinogenesis. To elucidate the molecular mechanisms involved in mutagenesis of bulky adducts, we used an in vitro DNA replication system. An SV40-based shuttle vector, PZ189, was treated with anti-benzo[a]pyrene-7,8- dihydrodiol-9,10-epoxide (BPDE) and then replicated in vitro using hypotonic extracts of human HeLa cells. The replication efficiency was monitored by the incorporation of a radiolabelled nucleotide into DNA. The products of the replication reaction were then digested with Dpn-1 to inactivate the unreplicated plasmid and the mutation frequency was evaluated by transfection into E. coli MBM7070. Our results show that BPDE-damaged plasmids undergo replication in the in vitro system. The efficiency of replication and the mutant frequency is dose-dependent, such that the replication efficiency decreases and mutation frequency increases with increasing BPDE dose to the plasmid. This study further validates the in vitro DNA replication system by demonstrating the mutagenicity of bulky adducts of BPDE.

• OSTI ID: 115152
• Report Number(s): CONF-9503160--; CNN: Grant ES05400; Grant ES04908
• Journal Information: Environmental and Molecular Mutagenesis, Journal Name: Environmental and Molecular Mutagenesis Journal Issue: Suppl.25 Vol. 25; ISSN 0893-6692; ISSN EMMUEG
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
DNA REPLICATION
EVALUATION
GENETIC EFFECTS
HELA CELLS
IN VITRO
MAN
MUTATIONS
PYRENE