Detection of dibenzo[a,l]pyrene-induced H-ras codon 61 mutant genes in preneoplastic SENCAR mouse skin using a new PCR-RFLP method.

Abstract

One of the key events in tumor initiation in mouse skin is mutational activation of the H-ras gene. Papillomas induced by the most carcinogenic environmental polycyclic aromatic hydrocarbon (PAH), dibenzo[a,l]pyrene (DB[a,l]P), in SENCAR mouse skin contain a specific H-ras codon 61 (CAA-->CTA) mutation. We describe here detection of these mutations in preneoplastic skin by measuring the frequency of an induced XbaI RFLP, created by the mutation. Development of the PCR-XbaI RFLP method, sensitive enough to detect 1 codon 61 mutant allele among 10,000 wild-type genes, is described. The results indicate that codon 61 mutations are induced 1 day (0.1%) after DB[a,l]P treatment on mouse skin, reach a high value (5%) by day 3, rapidly decline between days 7-9 and increase again during the clonal expansion of pre-papillomas into tumors. The detection of codon 61 mutations 1 day after DB[a,l]P exposure suggests that mutations occurred by pre-replication misrepair.

• Authors: D Chakravarti, P Mailander, J Franzen, S Higginbotham, E L Cavalieri, E G Rogan
• Journal: Oncogene (Oncogene) Vol. 16 Issue 24 Pg. 3203-10 (Jun 18 1998) ISSN: 0950-9232 [Print] England
• PMID: 9671400 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Benzopyrenes
• Carcinogens
• Codon
• DNA Primers
• dibenzo(a,l)pyrene
• Tetradecanoylphorbol Acetate

Topics

• Animals
• Base Sequence
• Benzopyrenes (toxicity)
• Carcinogens (toxicity)
• Codon
• DNA Primers
• Female
• Genes, ras
• Mice
• Mutation
• Polymerase Chain Reaction (methods)
• Polymorphism, Restriction Fragment Length
• Precancerous Conditions (chemically induced, genetics)
• Skin Neoplasms (chemically induced, genetics)
• Tetradecanoylphorbol Acetate (toxicity)