You are here:
ASSOCIATION BETWEEN MUTATION SPECTRUM AND PERSISTENT DNA ADDUCT PROFILE IN SALMONELLA FOR BENZO[A]PYRENE AND DIBENZO[A]PYRENE
Citation:
Ross, J A., G B. Nelson, M L. Shelton, S H. Warren, N. M. Hanley, G. HugginsClark, AND D M. DeMarini. ASSOCIATION BETWEEN MUTATION SPECTRUM AND PERSISTENT DNA ADDUCT PROFILE IN SALMONELLA FOR BENZO[A]PYRENE AND DIBENZO[A]PYRENE. Presented at American Association for Cancer Research, San Diego, CA, April 2, 2000.
Description:
Dibenzo[a,l]pyrene (DB[a1]P) is less prevalent in the environment but 100-200X more carcinogenic in rodents than benzo[a]pyrene (B[a]P) .B[a]P induces most of its adducts on G, whereas DB[a,1]P produces most its adducts on A. Using the Salmonella mutagenicity assay, we have examined the relationship between the DNA adduct profile and the mutation profile (i.e., the mutation spectrum) for both of these compounds. In the frameshift strain TA98, 69 and
94% of the mutations induced by B[a]P and DB[a,1]P, respectively, were the hotspot (2-base) deletion; 23 and 4%, respectively, were complex frameshifts. In the base-substitution strain TA100, 80 and 67% of the mutations induced by B[a]P and DB[a,1P, respectively, were GC -7 TA transversions; the remaining mutations were GC -7 AT transitions. In the base-substitution strain TA104, which, unlike the other tvlO strains, provides both GC and TA sites as targets for mutagenesis, 39 and 86% of the mutations induced by B[a]P and DB[a,l]P, respectively, were at AT sites. In this strain, 52 and 14% of the mutations induced by B[a]P and DB[a,1]P, respectively, were GC -7 TA transversions; 33 and 85%, respectively, were AT -7 TA transversions. Using 32p- postlabeling of DNA extracted from mutagenized Salmonella, 74% of the DB[a,l]P-induced adducts were at adenine, which compared favorably to the finding that 86% of the mutations induced by DB[a,1]P in TA104 were also at adenine.
This abstract does not necessarily represent policy of the US EPA.