Fig. 1

Genipin suppresses STAT-3 activity in HCC. (a) HCC cells were treated with genipin or geniposide for 24 h before transfection with plasmid containing the luciferase reporter gene. Relative luciferase activity was detected using dual-luciferase reporter systems. (b) Liver cancer cells were treated with genipin or geniposide for 24 h, and western blot was performed to detect the protein expressions of STAT-3, p-STAT-3 (Y705), and p-STAT-3 (S727). (c) MHCC97L cells were seeded in coverslips coated with gelatin, and then genipin (0–20 μM) was added into each sample for 12 h and co-cultured with or without 10-ng/μl IL-6 for 20 min. STAT-3 expression and location was examined by immunofluorescent staining. Cell nuclei were detected by DAPI stanning (left). MHCC97L cells were seeded in coverslips coated with gelatin, and then cells were treated with genipin for 12 h and co-cultured with or without 10-ng/μl IL-6 for 20 min. Cytoplasmic and nuclear STAT-3 levels were detected by western blotting assay (right). (d) MHCC97L cells were exposed to genipin for 24 h. STAT-3 DNA-binding activity was analyzed by EMSA assay. (e) MHCC97L cells were exposed to genipin for 24 h. The protein expression of STAT-3 target genes were examined by western blot assay. (f) MHCC97L cells were exposed to genipin for 24 h. Binding ability of STAT-3 with its target genes was analyzed by ChIP assay. Data presented as mean ± SD. *P < 0.05 and **P < 0.01