Fig. 4
Impact of leptin on melanoma progression and on the outcome of DTIC therapy in ob/ob and db/db mice. a Layout of the in vivo experiments. b–d ob-WT mice were injected with B16F10 cells (2 × 105 cells/mouse in 100 μl PBS). After the tumor formation, vehicle or DTIC treatment (N = 6 per each group) was given as per the experimental layout shown in a. b Tumor progression, c tumor volume, and d tumor weight. e–g ob/ob mice were divided into two major groups. One group was fed ad libitum on normal diet. In the second group, caloric intake was restricted to 50% by providing half the quantity of feed in normal before inoculating B16F10 cells. After 15 days, mice of all groups were injected subcutaneously with B16F10 cells (2 × 105 cells/mouse in 100 μl PBS). After tumor formation, vehicle or DTIC treatment (N = 6 per each group) was given as per the experimental layout shown in a. e Trend of tumor progression, f tumor volume, and g tumor weight. h–j db-WT mice were injected with B16F10 cells (2 × 105 cells/mouse in 100 μl PBS). After tumor formation, vehicle or DTIC treatment (N = 6 per each group) was given as per the experimental layout shown in a. h Trend of tumor progression, i tumor volume, and j tumor weight. k–m db/db mice were divided into two major groups. One group was fed ad libitum on normal diet. In the second group, caloric intake was restricted to 50% by providing half the quantity of feed in normal before inoculating B16F10 cells. After 15 days, mice of all groups were injected subcutaneously with B16F10 cells (2 × 105 cells/mouse in 100 μl PBS). After tumor formation, vehicle or DTIC treatment (N = 6 per each group) was given as per the experimental layout shown in a. At the end of the experiment, mice were sacrificed and tumors were collected. k Trend of tumor progression, l tumor volume, and m tumor weight. The results are given as means ± standard error of the mean. Statistical analysis was performed using two-tailed unpaired Student’s t test (b, h), whereas one-way ANOVA, followed by the Tukey multiple comparison test was used for e and k. *p < 0.05, when compared to respective controls