High expression of heparin-binding EGF-like growth factor in rat hepatocarcinogenesis.
Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a member of the EGF family and is highly expressed in hepatoma tissues but not in normal liver. However, it is unknown when HB-EGF is induced during hepatocarcinogenesis and what are the mechanisms underlying its high expression in hepatoma. To address this issue, the expression of HB-EGF was investigated during hepatocarcinogenesis in LEC (Long-Evans with a cinnamon-like coat color) rats, which spontaneously develop hepatitis and hepatoma. LEA (Long-Evans with an agouti coat color) rats were used as controls. Furthermore, the induction of HB-EGF mRNA by various agents was investigated in a rat hepatoma cell line and hepatocytes in primary culture. Expression of HB-EGF mRNA in the liver was very low at the stage of acute and chronic hepatitis and markedly increased at the stage of hepatoma in LEC rats. Non-involved tissues adjacent to hepatoma showed low expression of HB-EGF mRNA. Immunochemical studies revealed positive staining in hepatoma tissues. Induction of HB-EGF mRNA by several growth factors was observed in a hepatoma cell line but not in normal hepatocytes. Our results suggest that HB-EGF is associated with the early progression steps of hepatoma.
Miyoshi
E
E
Department of Biochemistry, Osaka University Medical School, Japan.
Higashiyama
S
S
Nakagawa
T
T
Suzuki
K
K
Horimoto
M
M
Hayashi
N
N
Fusamoto
H
H
Kamada
T
T
Taniguchi
N
N
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066257:Heparin-binding EGF-like Growth Factor; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008113:Liver Neoplasms / Q000378:metabolism*; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000378:metabolism; D051381:Rats; D011922:Rats, Mutant Strains; D017207:Rats, Sprague-Dawley
C587885:Hbegf protein, rat; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D004815:Epidermal Growth Factor