Actin and Vimentin proteins with N-terminal deletion detected in tumor-bearing rat livers induced by intraportal-vein injection of Ha-ras-transfected rat liver cells.
The introduction of the tumorigenic v-Ha-ras oncogene-transformed rat liver epithelial cells (WBras), which is deficient in gap junctional intercellular communication (GJIC), into F344 rats, induces significant formation of hepatocellular tumors. GJIC plays a major role in maintaining tissue homeostasis. Using this in vivo tumor model system, we used 2-dimensional electrophoresis with isoelectric focusing in the first dimension and SDS-PAGE in the second dimension to globally identify proteins that are uniquely expressed in the livers of WBras-treated rats as compared to the sham control. Immunoblotting was used to identify Ras and Connexin43, which were the positive and negative marker proteins, respectively, of the introduced WBras cells. As predicted, immunoblotting indicated that the whole liver of tumor-bearing animals exhibited a decreased level of Connexin43 and an increased level of Ras. Connexin43 and GJIC were expressed and functional in normal liver, but not in the tumor. In addition to these 2 markers, an additional 4 proteins exhibited decreased levels and 2 proteins exhibited increased levels in the livers of tumor-bearing animals. N-Terminal sequencing analysis was used to identify these proteins, which were glucose-regulated protein 78, 2 isoforms of heat shock protein 60, and the beta-chain of ATP synthase for the down regulated proteins, and beta-Actin with a 46 amino acid deletion from its N-terminus and Vimentin with a 71 amino acid deletion from its N-terminus for the up regulated proteins. These data offer potentially new markers of liver tumorigenicity, particularly, Vimentin. (
Nakamura
Yasushi
Y
Department of Food Sciences and Nutritional Health, Kyoto Prefectural University, Shimogamo-Hangi, Sakyo, Kyoto, Japan. yas@kpu.ac.jp
Kominami
Akari
A
Tsujimoto
Yoshiyuki
Y
Nakayama
Yuko
Y
Kitahashi
Tsukasa
T
Yoshimoto
Sonoko
S
Kubo
Asuka
A
Watanabe
Shinpei
S
Kageyama
Minami
M
Yokoyama
Meiko
M
Kido
Yasuhiro
Y
Kobayashi
Yukiko
Y
Kuwahata
Masashi
M
Chang
Chia-Cheng
CC
Upham
Brad L
BL
Trosko
James E
JE
Park
Eun Young
EY
Sato
Kenji
K
D000199:Actins / Q000737:chemistry*; D000818:Animals; D002450:Cell Communication; D002460:Cell Line; D018031:Connexin 43 / Q000032:analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D017629:Gap Junctions / Q000502:physiology; D011905:Genes, ras; D006651:Histocytochemistry; D008099:Liver / Q000737:chemistry* / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000737:chemistry* / Q000209:etiology; D008297:Male; D011169:Portal Vein; D051381:Rats; D011916:Rats, Inbred F344; D014162:Transfection; D014463:Ultrasonography; D014746:Vimentin / Q000737:chemistry*
D000199:Actins; D018031:Connexin 43; D014746:Vimentin