Fucoxanthin, a natural carotenoid, induces G1 arrest and GADD45 gene expression in human cancer cells.
BACKGROUND
Although the antitumor effects of fucoxanthin are known, the precise mechanism of action has yet to be elucidated.


METHODS
HepG2 and DU145 cells were used for these investigations. The effect of fucoxanthin on gene expression was assayed using a DNA microarray system. Northern blot and/or quantitative RT-PCR were carried out to confirm any changes in gene expression. The effect of fucoxanthin on cell cycle progression was analyzed using flow cytometry. RNA interference experiments were employed for the GADD45 gene.


RESULTS
Fucoxanthin markedly induced GADD45A, a cell cycle-related gene, in HepG2 and DU145 cells. Concomitant G1 arrest, but not apoptosis, was observed in both cell types following treatment with fucoxanthin. The introduction of siRNA against GADD45A partially perturbed the induction of Gi arrest by fucoxanthin in both cell types.


CONCLUSIONS
Fucoxanthin induced G1 arrest in HepG2 and DU145 cells. GADD45A may be involved in fucoxanthin-induced G1 arrest.
Yoshiko
Satomi
S
Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. ysatomi@koto.kpu-m.ac.jp
Hoyoku
Nishino
N
D006528:Carcinoma, Hepatocellular; D002338:Carotenoids / Q000494:pharmacology*; D018797:Cell Cycle Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D016193:G1 Phase / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D008113:Liver Neoplasms; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D011471:Prostatic Neoplasms; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D024341:Xanthophylls / Q000494:pharmacology*; D000097642:GADD45 Proteins
D002338:Carotenoids; D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D024341:Xanthophylls; C439070:GADD45A protein, human; D000097642:GADD45 Proteins; C025164:fucoxanthin