K-ras mutations in human adenocarcinoma of the lung: association with smoking and occupational exposure to asbestos.
We investigated point mutational activation of the ras genes (K-ras codons 12, 13 and 61; N-ras codons 12, 13 and 61; H-ras codons 12 and 61) in primary, resected lung cancer by dot blotting and oligonucleotide hybridization. K-ras mutations were found in 14 (29%) of the 48 lung tumour specimens examined, but no N-ras or H-ras mutations were found. The highest frequency of K-ras mutation was observed in adenocarcinoma: 12 of the 21 samples studied (57%) had a mutation, which is one of the highest frequencies reported for lung adenocarcinoma. The commonest type of mutation in these lung tumour samples consisted of transversions: we observed 11, of which 8 (57% of all mutations) were G to T transversions. Most of the 48 patients studied had a history of heavy smoking, either with or without evidence of occupational exposure to asbestos. Statistical analysis revealed--in addition to the highly significant association between the adenocarcinoma type of lung cancer and K-ras mutation--a clear association of K-ras mutations with heavy life-time smoking (> or = 50 pack-years of cigarette smoking; odds ratio (OR) 4.9, 90% CI 1.2-19.5, multivariate analysis). In addition, occupational asbestos exposure showed an elevated, but non-significant, OR of 2.2 (90% CI 0.6-8.7) with the presence of K-ras mutation. We conclude that the occurrence of K-ras mutations in adenocarcinoma of the lung is frequent, and that such mutations are associated with heavy life-time exposure to tobacco smoke, possibly in combination with occupational exposure to asbestos fibres.
Husgafvel-Pursiainen
K
K
Institute of Occupational Health, Helsinki, Finland.
Hackman
P
P
Ridanpää
M
M
Anttila
S
S
Karjalainen
A
A
Partanen
T
T
Taikina-Aho
O
O
Heikkilä
L
L
Vainio
H
H
D000230:Adenocarcinoma / Q000235:genetics*; D000328:Adult; D000368:Aged; D001194:Asbestos / Q000009:adverse effects*; D001483:Base Sequence; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016273:Occupational Exposure / Q000009:adverse effects; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012907:Smoking / Q000235:genetics*
D001194:Asbestos