Growth characteristics of K199R HRI NIH 3T3 cells
| NIH 3T3 cells . | Growth in monolayers* . | Tumorigenicity† (animals with tumors/animals injected) . | ||
|---|---|---|---|---|
| Doubling times (h) . | Saturation density (106 cells) . | Cloning efficiency (%)1-153 . | ||
| pLXSN | 28.5 ± 1.0 | 3.4 ± 0.4 | 0 | 0/3 |
| K199R HRI.1 | 28.8 ± 1.3 | 3.1 ± 0.3 | 0 | 0/3 |
| K199R HRI.2 | 28.5 ± 0.5 | 3.3 ± 0.3 | 0 | 0/3 |
| K199R HRI.3 | 29.3 ± 0.9 | 3.3 ± 0.5 | 0 | 0/3 |
| PKRΔ6-12 | 24.2 ± 1.1 | 4.5 ± 0.5 | 19.8 ± 0.9 | 3/3 (28-34 days) |
| NIH 3T3 cells . | Growth in monolayers* . | Tumorigenicity† (animals with tumors/animals injected) . | ||
|---|---|---|---|---|
| Doubling times (h) . | Saturation density (106 cells) . | Cloning efficiency (%)1-153 . | ||
| pLXSN | 28.5 ± 1.0 | 3.4 ± 0.4 | 0 | 0/3 |
| K199R HRI.1 | 28.8 ± 1.3 | 3.1 ± 0.3 | 0 | 0/3 |
| K199R HRI.2 | 28.5 ± 0.5 | 3.3 ± 0.3 | 0 | 0/3 |
| K199R HRI.3 | 29.3 ± 0.9 | 3.3 ± 0.5 | 0 | 0/3 |
| PKRΔ6-12 | 24.2 ± 1.1 | 4.5 ± 0.5 | 19.8 ± 0.9 | 3/3 (28-34 days) |
Cell growth in monolayers was measured by seeding 5 × 104 cells in 100-mm dishes in Dulbecco's modified Eagle's medium (DMEM) + 10% calf serum. The medium was changed every 3 days. The doubling times were determined by counting the cells every day for a 6-day period and calculating the growth rate of exponentially growing cells. The saturation density was determined by counting the number of cells in culture at 3 days post-confluence.
The ability of these cells to form tumors was examined in 6-week-old athymic mice (nu/nu); 1 × 106 cells in 100 μL of phosphate-buffered saline were injected subcutaneously.
For studies on cloning efficiency, cells (1 × 104) were suspended in a 0.35% agar solution in DMEM + 20% fetal calf serum (FCS) and overlaid onto a 0.5% agar matrix in DMEM + 20% FCS in 35-mm plates. One day after incubation at 37°C in 5% CO2, 2 mL DMEM + 20% FCS was added. Cells grown in soft agar were counted 10 days after plating. Cloning efficiency was determined by the number of colonies divided by the number of cells plated. The figures presented are the averages of 3 experiments with SD.