Fig. 5.

NP regulates eIF4E and 4E-BP1 functions in osteosarcoma cells. a, Protein synthesis was measured following vehicle and NP treatment in 143B and MG63 cells at 24 h through pulse labeling with ³H-leucine. b, Cytoplasmic extracts were prepared from 143B and MG63 osteosarcoma cells at 16 and 24 h following Veh and NP (3.0 μM) treatment. The extracts were subjected to immunoprecipitation (IP) with anti-4E-BP1 antibodies (b) or cap-binding (c) and analyzed by Western blot analysis using anti-eIF4E antibodies. d, Cytoplasmic extracts were analyzed by Western blot using anti–4E-BP1, anti–phosph-4EBP1Thr37/46, anti–non-phospho-4E-BP1, anti-eIF4E, and anti-GAPDH antibodies. Arrows represent phosphorylated proteins and dotted lines represent non-phosphorylated proteins