Environmental and Molecular Mutagenesis (EMM) Editor's Choice - June 2011
The Editor's Choice for June is “Accumulation of K-Ras codon 12 mutations in the F344 rat distal colon following azoxymethane exposure” by Page B. McKinzie and Barbara L. Parsons.
The earliest events in chemically-induced carcinogenesis have been inferred from data on tumor response and characterization of tumor-associated mutations, generally observed many months after carcinogen exposure. The research article by Drs. McKinzie and Parsons is unique, in that it directly measures induction of a mutation with established importance in the azoxymethane rat colon cancer model (K-Ras codon 12 GAT mutation) only one week after exposure. The successful detection of a statistically-significant change in K-Ras codon 12 GAT mutation, after such a short “expression time,” provides evidence that their Allele-specific Competitive Blocker (ACB-PCR) method is a very sensitive approach for measuring chemical induction of specific hotspot oncomutations. In addition, McKinzie and Parsons described the accumulation of the chemically-induced GAT mutation over time. Finally, they demonstrated that significant induction of the K-Ras codon 12 GAT mutation takes place in the saline-treated, control animals as they reach adulthood. Their data suggests the ACB-PCR measurement of somatic oncomutations may become a useful approach for evaluating the potential carcinogenic potency of chemicals. Environ. Mol. Mutagen. 52:409-418, 2011 Published 2010 Wiley-Liss, Inc.