Dose-dependent inhibition of M109 lung carcinoma growth in mice by Dp44mT and 3-AP. (A) Dp44mT and, to a greater extent, 3-AP markedly decreased the growth of M109 lung carcinoma in mice after a 5-day treatment regimen. (B) Induction of apoptosis in tumors after injection of (i) vehicle control or (ii) Dp44mT, as determined using TUNEL assay. (A) 1 × 105 M109 cells were subcutaneously implanted in CD2F1 mice. The chelators Dp44mT and 3-AP were injected intravenously twice daily for 5 consecutive days starting on the fourth day after tumor implantation. Tumor weight was measured on the 12th day after implantation. n = 8 in each experimental group. Data were analyzed using the Student t test. *P < .05 compared with control. **P < .01 compared with control. ***P < .0001. (B) M109 lung carcinoma specimens from mice treated as for panel A with (i) vehicle control or (ii) Dp44mT were fixed in 10% (vol/vol) buffered formalin and embedded in paraffin. Sections were stained for apoptotic cells in situ using the TUNEL assay. Positive nuclei stained brown, and negative nuclei stained blue. Results in panel A are mean ± SEM for 3 experiments, whereas data in panel B are typical of results found in 3 separate experiments.
