Figure 5.

L61H46 inhibited STAT3 phosphorylation and p-STAT3 nuclear translocation induced by IL-6.

Notes: (A) L61H46 (2.5–5 μM) inhibited STAT3 phosphorylation induced by IL-6 in BXPC-3 human pancreatic cancer cells. After treating with L61H46 (2.5–5 μM) for 24 h, cells were stimulated by IL-6 (50 ng/mL) or (B) IFN-γ (50 ng/mL) for 30 min; napabucasin is 5 μM. The cells were harvested and analyzed for STAT3 and STAT1 phosphorylation by Western blotting as described in the “Western blot analysis” section. The density of p-STAT3 and p-STAT1 was analyzed by the ImageJ software. (C) After a serum-free overnight, BXPC-3 pancreatic cancer cells were pretreated with L61H46 (2.5 μM) for 24 h, followed by IL-6 (50 ng/mL) for 30 min, and then detected for STAT3 nuclear translocation by immunofluorescence staining. (D) The percentage of positive cells per field in each group was calculated. All images are representative of three independent experiments. The level of significance is indicated by *P<0.05, **P<0.01, and ***P<0.001.

Abbreviations: DAPI, 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride; DMSO, dimethyl sulfoxide; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; IFN, interferon; IL, interleukin; Napa, napabucasin.