Fucoxanthin induces GADD45A expression and G1 arrest with SAPK/JNK activation in LNCap human prostate cancer cells.

BACKGROUND/AIM The antitumor effect of fucoxanthin, a marine carotenoid found in brown algae, was investigated on prostate cancer cells. MATERIALS AND METHODS LNCap prostate cancer cells were treated with fucoxanthin and the effects were evaluated in relation to cell proliferation, cell cycle, expression of growth arrest, DNA damage-inducible protein (GADD45) genes, and phosphorylation status of mitogen-activated protein kinases. RESULTS Fucoxanthin inhibited the growth of LNCap prostate cancer cells in a dose-dependent manner. Growth-inhibitory effects were accompanied by the induction of GADD45A expression and G(1) cell cycle arrest, but not apoptosis. Furthermore, fucoxanthin activated c-Jun N-terminal kinase (SAPK/JNK), while the inhibition of SAPK/JNK attenuated the induction of G(1) arrest and GADD45A expression by fucoxanthin. CONCLUSION These results show that fucoxanthin induces G(1) cell cycle arrest in prostate cancer cells, and suggest that ADD45A and SAPK/JNK might be involved in these effects.