Table 2.
Effect of dominant-negative Ras on transformation of Rat-2 cells by v-Src
| Cells | Zn2+/Cd2+ | Src virus | Focus formation,* % | Soft agar colony formation,† % |
|---|---|---|---|---|
| Rat-2/pM2N-1 | − | + | 100 ± 12 | |
| Rat-2/pM2N-1 | + | + | 103 ± 6 | |
| Rat-2/pM2N-2 | − | + | 112 ± 6 | |
| Rat-2/pM2N-2 | + | + | 135 ± 3 | |
| Rat-2/N17Ras-1 | − | + | 124 ± 9 | |
| Rat-2/N17Ras-1 | + | + | 159 ± 18 | |
| Rat-2/N17Ras-2 | − | + | 126 ± 15 | |
| Rat-2/N17Ras-2 | + | + | 132 ± 18 | |
| Rat-2/N17Ras-3 | − | + | 88 ± 3 | |
| Rat-2/N17Ras-3 | + | + | 82 ± 3 | |
| Rat-2/pM2N-1 | − | 0 | ||
| Rat-2/pM2N-1 | + | 0 | ||
| Rat-2/pM2NSrc | − | 100 ± 3 | ||
| Rat-2/pM2NSrc | + | 99 ± 7 | ||
| Rat-2/N17Ras-2 | − | 0 | ||
| Rat-2/N17Ras-2 | + | 0 | ||
| Rat-2/N17RasSrc | − | 151 ± 8 | ||
| Rat-2/N17RasSrc | + | 164 ± 1 |
The data are expressed as the mean ± SEM (percent of control) of three replicate plates in a single experiment, and are representative of two independent experiments.
Focus assays with Rat-2-derived cell lines were conducted with two independent clones carrying the empty metal-inducible expression vector (Rat-2/pM2N-1 and -2) and three independent clones carrying metal-inducible N17Ras (Rat-2/N17Ras-1, -2, and -3), and were corrected for efficiency of infection by normalizing to hygromycin-resistant colony forming units.
Soft agar colony assays with Rat-2-derived cell lines were conducted with one clone transfected with the empty vector (Rat-2/pM2N-1), one clone transfected with the metal-inducible N17Ras (Rat-2/N17Ras-2), and single clones of these cells expressing v-Src (Rat-2/pM2NSrc and Rat-2/N17RasSrc).