Interferon-alpha and dexamethasone effect on AF10 myeloma cell line sialytransferase activity.

Interferon-alpha and the synthetic glucocorticoid dexamethasone are used in the treatment of multiple myeloma. The effect of 48 h exposure to recombinant interferon-alpha 2b (100 to 10,000 U/ml) and dexamethasone (1 microM to 1 mM) was studied in AF10, and IgE-secreting myeloma cell line. Interferon-alpha and dexamethasone at 10,000 U/ml and 1 mM respectively had a synergistic inhibitory effect on IgE concentration.

Sialyltransferase activity in AF10 myeloma cell line.

A STA was observed in a human-derived myeloma cell line, AF10, that produces IgE paraprotein. The STA in the culture medium of the AF10 myeloma cell line was associated in the 24 to 48 hr period of incubation with IgE biosynthesis, and increased thereafter up to 72 hr, while IgE remained stable. These data support our previous observations that human myeloma cells are associated with a relatively high production of sialyltransferase, which is released to the medium, presumably by a mechanism of shedding.