Effect of calmodulin and voltage-dependent Ca²⁺ channel on the proliferation of heptoma cells induced by epidermal growth factor

Abstract

The effect of thyrosine kinase, calmodulin and voltage-dependent Ca²⁺ channel on the proliferation of hepatoma cells induced by EGF was studied. Hepatoma cell line SMMC7721 was cultured in RPMI1640 serum-free medium. DNA synthesis rate of hepatoma cells was measured by H-TdR incorporation. 10⁻⁹ mol/L EGF could significantly stimulate the proliferation of hepatoma cells (P<0.05), and this effect might be significantly inhibited by tyrosine kinase inhibitor (P<0.001). Calmodulin inhibitor W-7 had no effect on the basic phase of cultured hepatoma cells (P>0.05), but it had very significantly inhibitory effect on the proliferation of hepatoma cells induced by EGF (P<0.001). Voltage-dependent Ca²⁺ channel inhibitor Varapamil had no inhibition on the proliferation of hepatoma cells induced by EGF (P>0.05). It had no effect on the basic phase of cultured hepatoma cells, (P>0.05). It is suggested that tyrosine kinase and Ca²⁺-calmodulin-dependent pathway may play a critical role on the proliferation of heptoma cells induced by EGF and voltage-dependent Ca²⁺ channel is independent of the effect of EGF.

Keywords

epidermal growth factor / human hepatoma cell line / Ca²⁺-calmodulin-dependent pathway / tyrosine kinase / voltage-dependent Ca²⁺ channel

References

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