Figure 2. Fucoidan suppresses tumor growth and induces apoptosis-related proteins in vitro and in vivo.

(A) Continuous once daily feeding of C57BL/6 male mice with fucoidan (24 mg/kg) for 14 days prior to inoculation with LLC1 cells. After prior oral administration of fucoidan, LLC1 cells were subcutaneously inoculated into the abdomens of mice, and continuous once daily fucoidan feeding was performed (24 mg/kg) for 23 days. The tumor volumes were measured every 3 days for 23 days. (B) Tumor samples from the mice were collected at the end of the treatment. (C) The body weights of the mice were measured every 3 days for 23 days. (D) After fucoidan treatment, the tumors were collected. The tumor samples were homogenized, and Western blotting analyses of tumor samples were performed to detect ATF4 and CHOP expression. (E) Quantification of fucoidan-mediated up-regulation of the apoptotic protein levels in (D). (F) LLC1 cells were treated with fucoidan (100 μg/ml) for 3–9 h followed by Western blotting analyses of whole-cell lysates to detect the expressions of the following ER stress-related proteins: ATF4, CHOP, and GRP78. (G) Quantification of fucoidan-mediated up-regulation of ER stress-related protein levels in (F). (H) LLC1 cells were treated with various dosages of fucoidan (μg/ml) for 24 h followed by Western blotting analyses of whole-cell lysates to detect ATF4, CHOP and GRP78 expression. (I) Quantification of fucoidan-mediated up-regulation of the ER stress-related proteins levels in (H). (J) LLC1 cells were treated with fucoidan (0 to 400 μg/ml) for 24 h followed by Western blotting analyses of whole cell lysates to detect p-Akt (Ser 473) and p-ERK1/2 expression. Actin was used as an internal control.