| First Author | Shimada Y | Year | 2001 |
| Journal | Int J Radiat Biol | Volume | 77 |
| Issue | 4 | Pages | 465-73 |
| PubMed ID | 11304438 | Mgi Jnum | J:69234 |
| Mgi Id | MGI:1934322 | Doi | 10.1080/09553000010022643 |
| Citation | Shimada Y, et al. (2001) Characteristic association between K-ras gene mutation with loss of heterozygosity in X-ray-induced thymic lymphomas of the B6C3F1 mouse. Int J Radiat Biol 77(4):465-73 |
| abstractText | PURPOSE: To elucidate the characteristics of radiation carcinogenesis, the spectra of K- and N-ras oncogene mutations, loss of heterozygosity (LOH) and their association in X-ray-induced thymic lymphomas (TL) were determined by comparing with those of N-ethyl-N-nitrosourea (ENU)-induced and spontaneously occurring TL. MATERIALS AND METHODS: TL that arose in untreated, X-ray-irradiated and ENU-treated B6C3F1 mice were examined both for K- and N-ras mutations by PCR-SSCP and DNA sequencing and for LOH by PCR with polymorphic microsatellite markers. RESULTS: (1) ras gene mutations were found in a proportion of TL from X-ray-exposed (approximately 20%) and ENU-treated (30-40%) mice while no ras gene mutations were found in spontaneous TL. N-ras mutations were rare. (2) The spectrum of ras gene mutations was diverse and seemed to differ little between X-ray-induced and ENU-induced TL, even though there was a higher frequency of ras mutations in ENU-induced TL that clustered to K-ras codon 12. (3) The X-ray-induced TL showing K-ras mutation were associated with LOH on chromosome 6, while those showing no K-ras mutation were associated with high frequency of LOH on chromosomes 4, 11 and 12. CONCLUSION: These results demonstrate that, in the B6C3F1 mouse TL, X-ray-induced lymphomagenesis showed both the co-expression, yet low occurrence of allelic imbalance on chromosome 6 and K-ras mutation, and exclusive expression of frequent allelic imbalance on chromosomes 4, 11 and 12 and K-ras mutation. |
