Figure 6. Epothilone B significantly restrained STAT3 signal pathway both in direct and indirect manner. (A) RAW264.7 cells were stimulated with RANKL (100ng/mL) with or without Epothilone B (10μM) for the 0-60 minutes. The expression of p-Akt, Akt, p-PI3K, PI3K, p-STAT3 and STAT3. (B) RAW264.7 cells were divided into 3 groups. One group was pretreated with RANKL (100ng/mL), M-CSF (100ng/mL) and LPS (100ng/mL) in presence of Epothilone B (10μM) for 24 h. The other two groups were pretreated with RANKL (100ng/mL), M-CSF (100ng/mL) and LPS (100ng/mL) but in absence of Epothilone B (10μM) for 24 h. After that, one group was treated with vehicle, and the others were incubated with Epothilone B (10μM) for 2 h. Next, all groups were treated with RANKL (100ng/mL) for 30 min. The cell lysates were analyzed by Western blot for CD9, IL-6, gp130, STAT3, p-STAT3. β-actin was used as an internal control. Quantification of IL-6, gp130 and CD9 relative to β-actin, and p-STAT3 relative to STAT3. Data in the figures represent mean ± SD. N.S. represented no significant difference. *p < 0.05, **p < 0.01, ***p < 0.001 based on one way ANOVA.