Different effects of cyclic AMP and butyrate on eosinophilic differentiation, apoptosis and bcl-2 expression of a human eosinophilic leukemia cell line, EoL-1.

A human eosinophilic leukemia cell line, EoL-1, stopped proliferating at the G1 phase, differentiated into eosinophilic granule-containing cells, and died by apoptosis when stimulated with dibutyryl cyclic AMP (dbcAMP). To clarify the effects of dbcAMP, the effects of butyrate and cAMP-increasing reagents, prostaglandin E2 (PGE2) and forskolin, on EoL-1 cellular differentiation and apoptosis were examined and compared. PGE2 and forskolin but not butyrate induced differentiation to eosinophilic granule-containing cells, suggesting that cAMP played a primary role in eosinophilic differentiation of EoL-1 cells.