Epidermal growth factor inhibits growth while increasing the expression of an ecto-Ca2+-ATPase of a human hepatoma cell line.
We have obtained a cloned cell line (Li-7A) from primary cultures of a human hepatoma xenograft (Li-7). Li-7A was able to grow in the absence of serum. Growth was stimulated 0-3 fold by addition of newborn calf serum, but was inhibited in DME/F12 media containing nine growth factors. The ectoMg2+-ATPase was 1.5-2 fold higher than the ectoCa2+-ATPase activity in cells grown in media with or without serum. In cells grown in media supplemented with the nine factors, the ectoCa2+-ATPase activity exceeded the ectoMg2+-ATPase, and there was also a 5-10 fold increase in its specific activity. Inhibition of growth was due to epidermal growth factor alone. The increased expression of the ectoCa2+-ATPase was absolutely dependent on EGF, but also required hydrocortisone and cholera toxin. The characteristics of Li-7A cells make it a suitable system for studying both the mechanism of action of EGF and plasma membrane ATPases.
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Salas-Prato
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Villela
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D000251:Adenosine Triphosphatases / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D002999:Clone Cells / Q000201:enzymology; D003470:Culture Media; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D008113:Liver Neoplasms / Q000201:enzymology*; D014168:Transferrin / Q000494:pharmacology
D003470:Culture Media; D007328:Insulin; D014168:Transferrin; D004815:Epidermal Growth Factor; D002772:Cholera Toxin; D000251:Adenosine Triphosphatases; C027201:ectoATPase; D006854:Hydrocortisone