Forskolin and rolipram suppress the growth of several malignant lymphoid lines.

(A) MTT assays demonstrate that 20 μM forskolin and 20 μM rolipram (F+R, cross-hatched bars) suppress proliferation of 2 pediatric ALL lines: T-cell ALL line CEM and the B-precursor ALL line Reh. There is minimal effect from 1 μM dexamethasone (DEX, open bars) alone, and no additive effect seen in combination with forskolin and rolipram (F+R+D, filled bars). Lymphoblastoid cells and PBMCs freshly obtained from a healthy volunteer are virtually unaffected by the same treatments. (B) MTT assays of cell lines derived from adult lymphoid malignancies show variable degrees of growth suppression by combinations of dexamethasone, forskolin, and rolipram. The cell lines that were assayed include Jurkat, RPMI-8402, Molt-16, Karpas-422, Ramos, ST-486, and DW-6. Error bars represent SD.