Detection of codon 12 point mutations of K-ras gene from mouse lung adenocarcinoma by "enriched" PCR.
PURPOSE: Recent studies have shown that chemical carcinogens induce a high frequency of point mutations in the K-ras oncogene from mouse lung tumors at codons 12, 13 and 61. These experiments were performed to identify K-ras mutations in tissues from control and radiation-exposed mice. MATERIALS AND METHODS: By modifying the technique of the 'enriched' polymerase chain reaction (PCR), it was possible to detect point mutations at codon 12 of the K-ras oncogene from 25-year-old paraffin-embedded normal lungs and lung adenocarcinomas from mice exposed to radiation. Together, a total of 120 lung tissues were screened for point mutations at codon 12 of the K-ras oncogene in this study. RESULTS: A significant increase in K-ras codon 12 point mutations was observed in the normal lungs from mice exposed to 24 once-weekly neutron irradiations (100%), compared with normal lungs from mice with sham-irradiation (50%) (p<0.05). Lung adenocarcinomas from mice receiving 24 once-weekly neutron irradiations also had a significantly higher frequency of K-ras codon 12 point mutations (100%) than the lung adenocarcinomas of mice receiving 24 or 60 once-weekly gamma-ray irradiations (50%), but the higher frequency was not significantly different from that in spontaneous lung adenocarcinomas from mice (75%; p > 0.05). The validity of the technique was confirmed by sequencing two of the mutants. In doing so, a K-ras 13(Asp) point mutation was observed. CONCLUSIONS: The data suggest that high-linear energy transfer (LET) neutron radiation was more effective than low-LET gamma-rays in inducing K-ras point mutations at codon 12 in the lungs of B6CF1 mice.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 938192
- Report Number(s):
- ANL/CMB/JA-28105; TRN: US200908%%227
- Journal Information:
- Int. J. Radiat. Biol., Vol. 74, Issue 1 ; Jul. 1998
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Rb and p53 gene deletions in lung adenocarcinomas from irradiated and control mice
Analysis of the K-ras and p53 pathways in x-ray-induced lung tumors in the rat