Multiple functions of the Kras2 oncogene

Active proto-oncogenes, such as Kras2, are generally perceived to be genes that promote cancer development. But, in August 27 Nature Genetics advanced online publication, Zhongqiu Zhang and colleagues at The Ohio State University show for the first time that the presence of a non-activated Kras2 oncogene induces suppression of lung tumor formation and progression in mice.

Zhang et al. performed a lung tumor bioassay on heterozygous Kras2-deficient mice and found that they were highly susceptible to chemically induced lung tumors, compared to wildtype mice. All tumors displayed an activated Kras2 because of a chemically induced mutation. Addition of a non-mutated wildtype Kras2 inhibited colony formation and tumor development in a murine lung tumor cell line containing an activated Kras2 allele. The loss of wildtype Kras2 was found in 67–100% of chemically induced mouse lung adenocarcinomas harboring a mutant Kras2 allele (Nat Genet 2001, 10.1038/ng721).

The authors suggest that Kras2 has ...