Figure 5
Intrathecal TLR4 siRNA 439 attenuates bone cancer pain in the rat model. (A, B) In the siRNA-treated IBCP group, the PWTs were significantly higher and the ambulatory scores were significantly lower than those observed in mismatch siRNA- and vehicle-treated rats(n = 10, ANOVA2w, P < 0.01, pos-hoc Bonferroni, df = 4, F = 1.02), and there were no significant differences compared to normal rats. This indicated that intrathecal injection of TLR4 siRNA439 (SITLR4) could prevent the initial development of bone cancer pain. (C, D) In the siRNA-treated WBCP group, the PWTs were significantly elevated compared with the mismatch siRNA- and vehicle-treated rats(n = 10, ANOVA2w, P < 0.01, pos-hoc Bonferroni, df = 4, F = 0.96), but still lower than in normal rats (P < 0.05) Meanwhile, spontaneous pain was attenuated compared with mismatch siRNA- and vehicle-treated rats(n = 10, ANOVA2w, P < 0.01, pos-hoc Bonferroni, df = 4, F = 1.05). However, the ambulatory score was still higher than in normal rats (P < 0.05), which indicated that intrathecal injection of TLR4 siRNA439 (SITLR4) could alleviate, but not reverse, well-established bone cancer pain. Values are presented as mean ± SEM. *P < 0.05, **P < 0.01 vs. normal group; ▲ P < 0.05, ▲ ▲ P < 0.01 vs. vehicle-treated group; #P < 0.05, ##P < 0.01 vs. bone cancer pain group; ◆P < 0.05, ◆◆P < 0.01 vs. mismatch siRNA-treated group. Arrows indicate the siRNA injection times.