Up-regulation of Na(+),K(+)-ATPase alpha 3-isoform and down-regulation of the alpha1-isoform in human colorectal cancer.
We investigated expression levels of Na(+),K(+)-ATPase alpha-isoforms and their ATPase activities in human colorectal cancer tissue and the accompanying normal mucosa. A decrease in expression of the alpha1-isoform protein was observed in all sampled cancer tissues compared with the normal mucosae. The level of ouabain (5 microM)-sensitive Na(+),K(+)-ATPase activity in carcinomas was 81+/-5% that of in the normal mucosae. The mRNA expression of alpha2- and alpha 4-isoforms was decreased in almost all the carcinoma samples. Interestingly, the expression level of the alpha 3-isoform protein in the cancer tissue was higher than that of the normal mucosa. These results indicate that a decrease in the alpha1-isoform expression and an increase in the alpha 3-isoform expression may be associated with colorectal cancer.
Sakai
Hideki
H
Department of Pharmaceutical Physiology, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan. sakaih@ms.toyama-mpu.ac.jp
Suzuki
Tomoyuki
T
Maeda
Mizuki
M
Takahashi
Yuji
Y
Horikawa
Naoki
N
Minamimura
Tetsuji
T
Tsukada
Kazuhiro
K
Takeguchi
Noriaki
N
D044466:Asian People; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D015870:Gene Expression; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008297:Male; D010042:Ouabain / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation
D007527:Isoenzymes; D012333:RNA, Messenger; D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase