Dm. Demarini et al., MUTATION SPECTRUM OF CIGARETTE-SMOKE CONDENSATE IN SALMONELLA - COMPARISON TO MUTATIONS IN SMOKING-ASSOCIATED TUMORS, Carcinogenesis, 16(10), 1995, pp. 2535-2542
We used colony probe hybridization and polymerase chain reaction/DNA s
equence analysis to determine the mutations in similar to 1600 reverta
nts of Salmonella induced by cigarette smoke condensate (CSC) in the p
resence of S9, CSC induced similar to 80% GC --> TA transversions and
similar to 20% GC --> AT transitions at the base-substitution allele (
hisG46) in strain TA100. This spectrum was similar to those of the pol
ycyclic aromatic hydrocarbon (PAD) benzo[a]pyrene and various aromatic
amines such as 4-aminobiphenyl and Glu-P-1, all of which are present
in CSC, This spectrum was also similar to that produced by PAHs in oth
er bacteria, mammalian cells, and rodents as well as to that of the p5
3 gene in lung tumors from smokers. The results in Salmonella are cons
istent with a role for the PAH component of cigarette smoke in the bas
e-substitution specificity found in the p53 gene of smoking-associated
lung tumors, At the frameshift allele in strains TA1538 and TA98, CSC
induced only a hotspot 2-base deletion, which is a mutation spectrum
that is identical to that induced by the heterocyclic amine pyrolysate
products of amino acids, such as Glu-P-1. This is consistent with bio
assay-directed fractionation studies showing that aromatic amines acco
unt for most of the frameshift specificity of CSC in Salmonella. Roden
t and human studies indicate that aromatic amines are responsible for
smoking-associated bladder cancer, Repeated freezing and thawing of th
e CSC samples changed the chemical composition of the mixtures as evid
enced by the production of an altered mutation spectrum, This emphasiz
es the necessity of proper storage and handling of labile complex mixt
ures, This study (i) confirms our previous studies showing that the mu
tation spectrum of a complex mixture reflects the dominance of one or
a few classes of chemical mutagens within the mixture, and (ii) illust
rates the potential of bioassay-directed molecular analysis for identi
fying the chemical classes in a complex mixture that are responsible f
or specific classes of mutation and tumor types produced by the mixtur
e.