Early detection of 2-amino-1-methyl-6-phenylimidazo (4,5-b)pyridine(PhIP)-induced mutations within the Apc gene of rat colon.
A large proportion of human cancers result from exposure of individuals to environmental or occupational carcinogens. The early detection of carcinogen-induced mutations is a prerequisite for the identification of individuals at risk for developing cancer. Short G-rich repetitive sequences have been previously identified as hot-spots for frameshift mutagenesis induced by a large variety of carcinogens belonging to several families of widespread environmental pollutants. In order to test if these sequences, when mutated, might serve as biomarkers for carcinogen exposure, we designed a sensitive PCR-based strategy that allows the detection of rare mutational events within a whole genome. 2-Amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), the most abundant carcinogenic heterocyclic amine generated in cooked meat, induces mammary and colon carcinoma in F344 rats. About 25% of male rats exposed to 400 p.p.m. PhIP in the diet for >43 weeks present colon tumors with specific -1G mutations within 5'-GGGA-3' sequences of the APC: gene. Using our PCR assay we have assessed the occurrence of such specific events in rats exposed to PhIP for only 1, 2, 4 and 6 weeks. A specific amplification signal was already observed in the 1 week-treated population and increases in a treatment time-dependent manner. These data validate this approach for the early detection of mutations and demonstrate its usefulness for molecular epidemiology and early diagnosis.
Burnouf
D
D
Groupe d'Epidémiologie Moléculaire du Cancer, UPR 9003, Centre National de la Recherche Scientifique, Institut de Recherche sur les Cancers de l'Appareil Digestif, 1 Place de l'Hopital, 67097 Strasbourg,France. dominique.burnouf@ircad.u-strasbg.fr
Miturski
R
R
Nagao
M
M
Nakagama
H
H
Nothisen
M
M
Wagner
J
J
Fuchs
R P
RP
D000818:Animals; D020137:Base Pair Mismatch; D002273:Carcinogens / Q000633:toxicity*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000175:diagnosis* / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D004273:DNA, Neoplasm / Q000032:analysis; D004587:Electrophoresis, Agar Gel; D017353:Gene Deletion; D017491:Genes, APC / Q000235:genetics*; D006801:Humans; D007093:Imidazoles / Q000633:toxicity*; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D051381:Rats; D011916:Rats, Inbred F344; D012680:Sensitivity and Specificity
D002273:Carcinogens; D017931:DNA Primers; D004273:DNA, Neoplasm; D007093:Imidazoles; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine