Table 1.
Summary of soft agar colony formation assay and xenograft propagation experiment: NHA and NIH3T3 cells infected with retroviral vectors expressing hTERT (T), SV40ER (S), H-RasV12 (R), myrAKT (A), and/or MGMT as well as parental NHA cells were subjected to the soft-agar colony formation and xenograft propagation assays.
| Cell types | Colony numbers a | % Tumor incidence (n) b |
| NHA (parental) | 0 | ND |
| NHA/TS | 0 | 0 (3) |
| NHA/TSR | 664 ± 19 | 100 (3) |
| NHA/TSRA | 736 ± 51 | 100 (3) |
| NHA/TSR + MGMT | 649 ± 34 | ND |
| NIH3T3/R | 1440 ± 56 | ND |
| NIH3T3/R + MGMT | 1344 ± 88 | ND |
aNHA (2 × 104) and NIH3T3 cells (1 × 104) were plated in soft-agar (0.36% top agar containing 5% fetal calf serum in 60-mm dishes) and incubated for 21 days and 14 days, respectively. Colonies were stained with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and the numbers of stained colonies were counted. Results represent mean ± SD from two independent triplicate experiments.
b3 × 106 cells were injected s.c. into nude mice. n, number of animals treated. ND, not done.