Figure 5.

The role of CD137L reverse or direct signalling in osteosarcoma. (a) SaOS2 cells were cultured with 10 or 20 μg/ml CD137-Fc or mock-Fc. Cell proliferation was assessed at 48 h. Error bars represent SD (n = 3). *P < 0.05, **P < 0.001, Student’s t-test. (b) p53 ^+/+ calvarial osteoblasts were cultured with 40 μg/ml Cd137-Fc or mock-Fc protein. Cell proliferation was assessed at 48 h. Error bars represent SD (n = 3). *P < 0.05, Student’s t-test. (c,d) IL2 production (c) and proliferation (d) of CD4⁺ or CD8⁺ T cells were assessed 48 h after stimulation with Cd137l-Fc. **P < 0.001, Student’s t-test. (e) C3H/HeJ mice (each group, n = 3) were subcutaneously injected into the left flank with 0.1 ml of PBS containing 1 × 10⁶ LM8 cells. After tumours reached 0.5 cm in diameter, each of the mice was treated with Cd137l-Fc fusion protein or control mock-Fc by intraperitoneal injection for 3 days. The tumour volume was calculated every 2 or 3 days. Arrow shows the days of injection. *P < 0.05, Wilcoxon rank-sum test.