of Work: Cobalt sulfate induced a higher incidence of alveolar/bronchiolar adenomas and carcinomas in male and female mice exposed to various concentrations of cobalt sulfate compared to controls. DNA samples from lung neoplasms were sequenced for point mutations in the K-ras gene. Unique point mutations were detected in K-ras exon 2. Future work on this project includes determining the mechanism for the unique mutations and characterizing genetic alterations in potential tumor suppressor genes which may be relevant to human exposure. The findings for the first part of these studies were presented to the Peer Review Board in December 1996.
| Sills, R C; Hong, H L; Boorman, G A et al. (2001) Point mutations of K-ras and H-ras genes in forestomach neoplasms from control B6C3F1 mice and following exposure to 1,3-butadiene, isoprene or chloroprene for up to 2-years. Chem Biol Interact 135-136:373-86 |
| Hayashi, S; Hong, H H; Toyoda, K et al. (2001) High frequency of ras mutations in forestomach and lung tumors of B6C3F1 mice exposed to 1-amino-2,4-dibromoanthraquinone for 2 years. Toxicol Pathol 29:422-9 |
