c-N-ras is activated infrequently in canine malignant lymphoma.
Activated c-N-ras alleles have been detected in human lymphoma specimens. The aim of the present study was to determine the frequency of c-N-ras mutational activation in canine malignant lymphoma. DNA was isolated from 28 canine malignant lymphoma specimens collected from 28 separate dogs and examined for c-N-ras mutations by polymerase chain reaction amplification and direct sequencing. The tumors were naturally occurring and derived from 20 dogs with known exposures to the phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and from 8 dogs with no known exposure to the herbicide. An oncogenically activating mutation was found in 1 dog without known 2,4-D exposure. The mutation was a 13th codon, second position transition that would result in a glycine-to-aspartate amino acid substitution. The results of this study demonstrate that, similar to the human, c-N-ras mutations are uncommon in dogs with malignant lymphoma and that there is no association between 2,4-D exposure and activation of c-N-ras in the dog.
Edwards
M D
MD
Department of Surgery, School of Veterinary Medicine, University of California, Davis 95616-8745.
Pazzi
K A
KA
Gumerlock
P H
PH
Madewell
B R
BR
D015084:2,4-Dichlorophenoxyacetic Acid; D000818:Animals; D001483:Base Sequence; D002273:Carcinogens; D004273:DNA, Neoplasm / Q000096:biosynthesis; D004283:Dog Diseases / Q000235:genetics*; D004285:Dogs; D005091:Exons; D011905:Genes, ras; D006651:Histocytochemistry; D008223:Lymphoma / Q000139:chemically induced / Q000235:genetics / Q000662:veterinary*; D009154:Mutation; D016133:Polymerase Chain Reaction
D002273:Carcinogens; D004273:DNA, Neoplasm; D015084:2,4-Dichlorophenoxyacetic Acid