[Corrigendum] Saffron carotenoids inhibit STAT3 activation and promote apoptotic progression in IL‑6‑stimulated liver cancer cells

Figure 1.

Crocin inhibits both inducible and constitutive STAT3 activation in liver cancer cells. (A) Chemical structure of crocin. (B) IL-6 induced STAT3 activity in liver cancer cells. Hep3B and HepG2 cells (1×106/ml) were treated with IL-6 (10 ng/ml) for indicated time-points. Whole-cell extracts were prepared, and phosphorylated STAT3 was detected by western blotting as described in Materials and methods. (C) Crocin downregulated IL-6-induced phospho-STAT3 in a dose-dependent manner. Hep3B and HepG2 cells (1×106/ml) were treated with the indicated concentrations of crocin for 24 h and then stimulated with IL-6 (10 ng/ml) for 60 min. Whole-cell extracts were prepared, and phospho-STAT3 was detected by western blotting. The same blots were stripped and reprobed with the STAT3 antibody to verify equal protein loading. (D) Crocin downregulated IL-6-induced phospho-STAT3 in a time-dependent manner. Hep3B and HepG2 cells (1×106/ml) were treated with 20 µM crocin for the indicated time-points and then stimulated with IL-6 (10 ng/ml) for 60 min. Whole-cell extracts were prepared, and phospho-STAT3 was detected by western blotting. (E) Crocin suppresses phospho-STAT3 levels in breast and colon cancer cells. MDA-MB-231, HCT116, BxPC3, A549 and A2780 cells (1×106/ml) were not or were treated with 20 µM of crocin and stimulated with IL-6 (10 ng/ml) for 24 h, after which whole-cell extracts were prepared, and phospho-STAT3 was detected by western blotting. The same blots were stripped and reprobed with the STAT3 antibody.