INTERFERON-ALPHA AND DEXAMETHASONE EFFECT ON AF10 MYELOMA CELL-LINE SIALYLTRANSFERASE ACTIVITY

Interferon-α and the synthetic glucocorticoid dexamethasone are used in the treatment of multiple myeloma. The effect of 48 h exposure to recombinant interferon-α 2b (100 to 10,000 U/ml) and dexamethasone (1 μM to 1 mM) was studied in AF10, an IgE-secreting myeloma cell line. Interferon-α and dexamethasone at 10,000 U/ml and 1 mM respectiviely had a synergistic inhibitory effect on IgB concentration. Interferon-a and dexamethasone had an additive inhibitory effect on myeloma cell concentration. Interferon-α at 10,000 U/ml caused a twofold increase in sialyltransferase activity. Dexamethasone decreased sialyltransferase activity and attenuated the stimulatory effect of interferon-α. These data suggest that combined interferon-α and dexamethasone therapy might have a synergistic effect on monoclonal protein production and a diverse effect on sialyltransferase activity. © 1993 Academic Press. All rights reserved.