The characteristic gene expressions of MAPK phosphatases 1 and 2 in hepatocarcinogenesis, rat ascites hepatoma cells, and regenerating rat liver.
mRNA levels of mitogen-activated protein kinase phosphatases, MKP-1 and MKP-2, were determined during chemical hepatocarcinogenesis and during regeneration of rat liver. In chemical hepatocarcinogenesis, the mRNA levels of MKP-1 were increased in primary hepatomas but decreased in rat ascites hepatomas as compared with normal liver. MKP-2 was undetectable in normal liver but strongly expressed in hepatomas. The MKP-2 mRNA level was increased with expression of malignant phenotypes in hepatomas. In regenerating liver, the mRNA level of MKP-1 increased immediately but transiently after partial hepatectomy, and peaked again on day 10, the time when hepatocytes cease proliferation. The elevated expression of MKP-1 on day 10 suggests some roles of MKP-1 as a negative regulator in hepatocyte proliferation.
Yokoyama
A
A
Section of Biochemistry, Hokkaido University, Sapporo, Japan.
Karasaki
H
H
Urushibara
N
N
Nomoto
K
K
Imai
Y
Y
Nakamura
K
K
Mizuno
Y
Y
Ogawa
K
K
Kikuchi
K
K
D000818:Animals; D001201:Ascites / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000235:genetics; D054638:Dual Specificity Phosphatase 1; D054637:Dual-Specificity Phosphatases; D015972:Gene Expression Regulation, Neoplastic; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D008115:Liver Regeneration / Q000235:genetics*; D008297:Male; D054639:Mitogen-Activated Protein Kinase Phosphatases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar
D018797:Cell Cycle Proteins; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D054639:Mitogen-Activated Protein Kinase Phosphatases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D054638:Dual Specificity Phosphatase 1; D054637:Dual-Specificity Phosphatases; C517021:Dusp1 protein, rat; C094132:Dusp4 protein, rat; D017027:Protein Tyrosine Phosphatases