Role of MAPK pathways in MNK phosphorylation. A) ANBL-6 MM cells exposed to rapamycin (100 nM) for 30, 60 or 120 mins (C=control, no rap), followed by immunoblot assay for phospho-ERK, total-ERK, phospho-p38 or total p38 expression. B) MM cells pre-treated for 30 mins with U0126 at 1 or 10 uM (U1 and U2) or SB203580 at 12.5 or 25 uM (SB1 and SB2). Rapamycin then added at 100 nM for additional 3 hrs and immunoblot assay performed for expression of phospho-ERK, total ERK, phospho-HSP 27, total HSP-27, phospho-MNK, total MNK or GAPDH.