Synergistic inhibitory effect of gamma-interferon and EGF on A431 cells.
Addition of high concentrations (100ng/ml) of epidermal growth factor (EGF) to cultures of the epidermoid-carcinoma cell-line A431, which expresses high levels of the EGF receptor, resulted in 50 percent reduction in growth rate. At a lower level (10 ng/ml) of EGF no such inhibitory effect was observed. Addition of gamma-interferon at a concentration of 100 u/ml, but not alpha-interferon at the same concentration. inhibited the growth rate of A431 cells by 50 percent. Incubation of the cells in medium containing both 10 ng/ml of EGF and 1000 u/ml of gamma-interferon led to a complete growth arrest. After 48 hours this inhibition was not reversible and resulted in excessive cell-death after approximately seven days. The human lung cancer cell-line U-1752, which expresses low levels of the EGF receptor, was not inhibited by EGF even at high concentrations. Gamma-interferon did not increase the sensitivity of these cells to EGF. The results show that the modulating effect of gamma-interferon on EGF activity is variable and probably depends on cell line, receptor concentration as well as the primary effect of EGF on different cells.
Lombardero
J
J
Department of Biochemistry, INOR, Havana, Cuba.
Perez
R
R
Skoog
L
L
D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D004357:Drug Synergism; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014846:Vulvar Neoplasms / Q000473:pathology
D004815:Epidermal Growth Factor; D007371:Interferon-gamma; D066246:ErbB Receptors