EF24 Suppresses Cholangiocellular Carcinoma Progression, Inhibits STAT3 Phosphorylation, and Induces Apoptosis via ROS-Mediated Oxidative Stress

Figure 6

EF24 inhibits phosphorylation of STAT3. EF24 decreases Tyr⁷⁰⁵ phosphorylation of STAT3 in a dose- and time-dependent manner in SNU478 and HuCC-T1 cells without affecting total STAT3 expression levels as shown using Western blot analysis (a). Immunofluorescence staining of STAT3 in SNU478 cells confirmed that, in the presence of IL-6, EF24 inactivates STAT3 by inhibiting its phosphorylation and preventing its nuclear translocation (b). Inhibition of STAT3-Tyr⁷⁰⁵ phosphorylation caused by EF24 was reverted by pretreatment with GEE or NAC in Western blot analyses (c) (quantification of Western blot results is shown in the bar diagrams on the right, “” indicates p<0.05, “” indicates p<0.01, and “” indicates p<0.001).

(a)

(b)

(c)