Table 5.
Metastatic Potential of TS/A-IFN-α, TS/A-IFN-β, and TS/A-IFN-γ Cells Injected i.v.
| Challenging TS/A cells (IFN) | Lung colonies | ||
|---|---|---|---|
| Incidence | Median | Range | |
| TS/A parental (none) | 5 /5 | 34 | 26–51 |
| I/A.4.60 (α) | 5 /5 | 13† | 4–23 |
| I/A.2.1000 (α) | 5 /5 | 5† | 1–8 |
| TS/A-IFN-β-4 (β) | 5 /5 | 38‡ | 3–76 |
| TS/A-IFN-β-6 (β) | 5 /5 | 12† | 8–26 |
| TS/A-IFN-β-10 (β) | 5 /5 | 6† | 3–11 |
| I.3.500 (γ) | 5 /5 | 117† | 41–168 |
Six- to seven-week-old BALB/c mice were injected i.v. with 5 × 104 cells of the indicated cell lines. After 20 days, all of the mice in each group were sacrificed for evaluation of lung metastases, which was performed as described elsewhere. 11 The lung metastatic nodules formed by both TS/A-IFN-β and TS/A-IFN-α tumor cells appeared, at a gross examination, smaller in size and flatter as compared with the metastases developed in mice injected with parental or IFN-γ-producing TS/A tumor cells.
†P < 0.05 versus TS/A parental cell-injected mice.
‡Not significant versus TS/A parental cell-injected mice.