Screening for beneficial effects of oral intake of sweet corn by DNA microarray analysis.
To identify novel functions of the oral intake of sweet corn, we performed DNA microarray analysis of the livers of sweet corn-fed mice. Functional annotation clustering 1600 genes with expression levels that were affected (more than 1.5-fold change) by dietary sweet corn indicated that both cell proliferation and programmed cell death were modulated by sweet corn intake. In the Wnt signaling pathway, which is involved in cell proliferation, the levels of Jun and beta-catenin expression were downregulated by dietary sweet corn. The mRNA levels of Rb and p53, negative regulators of the cell cycle, were increased in mice fed with sweet corn. Dietary corn upregulated expression levels of genes that regulate apoptosis positively (for example, BOK, BID, CASP4). These results suggested that sweet corn is a valuable food for suppressing cancer. Oral administration of sweet corn inhibited tumor growth (36.6% reduce in tumor weight, P < 0.05) in mice inoculated with Ehrlich tumor cells.
Tokuji
Yoshihiko
Y
Dept of Agriculture and Life Science, Obihiro Univ of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan. tokuji@obihiro.ac.jp
Akiyama
Kyoko
K
Yunoki
Keita
K
Kinoshita
Mikio
M
Sasaki
Keiko
K
Kobayashi
Hitoshi
H
Wada
Masahiro
M
Ohnishi
Masao
M
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D002286:Carcinoma, Ehrlich Tumor / Q000178:diet therapy*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D005260:Female; D005786:Gene Expression Regulation; D008099:Liver / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008813:Mice, Inbred ICR; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D012639:Seeds; D047368:Tumor Burden; D003313:Zea mays
D016588:Anticarcinogenic Agents; D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; D012333:RNA, Messenger