Activated Ki-ras genes in bladder epithelial cell lines transformed by treatment of primary mouse bladder explant cultures with 7,12-dimethylbenz[a]anthracene
✍ Scribed by Peter Brookes; Colin S. Cooper; Moira V. Ellis; William Warren; Emily Gardner; Ian C. Summerhayes
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 739 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0899-1987
No coin nor oath required. For personal study only.
✦ Synopsis
DNA from five lines of transformed bladder epithelial cells derived from cultures of primary cells that had been treated with 7,12-dimethylbenz[a]anthracene (DMBA) can transform NIH 3T3 mouse fibroblasts in DNA transfection experiments. Southern analysis of DNA from NIH 3T3 primary and secondary transformants established that four of the DMBA-transformed cell lines contained activated cellular Ki-ras, while the remaining cell line contained a transforming gene that is unrelated to Ki-ras, N-ras, and Ha-ras. The point mutations responsible for Ki-ras activation were detected using oligonucleotide probes following selective amplification of Ki-ras specific sequences using the polymerase chain reaction. The results showed that activation of Ki-ras invariably involved a GC----AT transition mutation of the first position of codon 12. Surprisingly, a Ki-ras gene that was activated by a GC----AT transition mutation at the same position was also detected in a single transformed bladder urothelial cell line derived from control cultures of mouse bladder cells. Together, our results indicate that Ki-ras activation in the DMBA-transformed bladder cell lines may not be a direct consequence of interaction of activated DMBA metabolites with the Ki-ras gene.