Figure 4. Fucoidan suppresses p-IRE-1\XBP-1 splicing in MDA-MB-231 cells (A) and HCT116 cells (B).

Cells were treated with fucoidan as described in the “Materials and Methods” and in Figure 2. The phosphorylation of IRE-1 (p-IRE-1) and XBP-1 splicing were remarkably reduced by fucoidan as assessed by immunoblot. Its downstream target, p58^IPK, was not subsequently decreased. Data are expressed as mean ± SD in triplicate experiments. Note that TG-treated cells (2.0 µM, 24 h) showed an increased p-IRE-1 and XBP-1s in both cells. *p<0.05; **p<0.01.