Hepatopoietin acts as an autocrine growth factor in hepatoma cells.
Hepatopoietin (HPO) is a novel human hepatotrophic factor. Its known function is mainly limited to supporting liver regeneration. Recently, it was shown by our laboratory that HPO acts as a mitogen for hepatoma cell lines and that there are HPO-specific receptors on the surface of these cells (Wang, G., et al., J Biol Chem 1999;274:11469-11472), indicating that HPO might be involved in oncogenesis in the liver. To study this hypothesis, we first conducted experiments in vitro to identify the existence of an autocrine loop of HPO/HPO receptor in hepatoma cell lines. It was demonstrated that HPO was actually expressed by hepatoma cells, such as HepG2, Bel 7402, and SMMC-7721, and secreted into the culture medium. Furthermore, it was shown that HPO-neutralizing antibody has an inhibitory effect on the uptake of tritiated thymidine by hepatoma cells. The results strongly suggest that HPO acts as an autocrine factor for hepatoma cells in vitro.
Li
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Y
Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese National Human Genome Center in Beijing, Beijing, P. R. China.
Xing
G
G
Wang
Q
Q
Li
M
M
Wei
H
H
Fan
G
G
Chen
J
J
Yang
X
X
Wu
C
C
Chen
H
H
He
F
F
D000368:Aged; D019898:Autocrine Communication / Q000502:physiology*; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D004797:Enzyme-Linked Immunosorbent Assay; D006133:Growth Substances / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000502:physiology*; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013936:Thymidine / Q000378:metabolism; D014407:Tumor Cells, Cultured
D006133:Growth Substances; C052675:autocrine growth factor, hepatoma cells; D017228:Hepatocyte Growth Factor; D013936:Thymidine