Figure 6.

S1P₁ regulates expression of pro-survival protein Mcl-1. (a) Control and S1P₁-expressing CCL39 cells were switched to serum-free medium (SF) for the indicated times before preparation of detergent-soluble cell extracts. Samples were equalised for protein content before fractionation via SDS-PAGE and subsequent immunoblotting with the indicated antibodies. Quantitation of Mcl-1 expression normalised to GAPDH in control and S1P₁-expressing CCL39 cells is presented as mean values±S.E. for n=3 separate experiments. *P<0.05 versus CCL39 control cells at the indicated time point. (b) Control and S1P₁-expressing CCL39 cells were switched to either SF medium or fresh growth medium (C) for 16 h in the presence of LY294002 (LY, 20 μM) or GF109203X (5 μM) either alone or in combination, or a vehicle control for 16 h before preparation of cell extracts, fractionation via SDS-PAGE and subsequent immunoblotting with the indicated antibodies. Quantitation of Mcl-1 expression normalised to GAPDH in control and S1P₁-expressing CCL39 cells is presented as mean values±S.E. for n=3 separate experiments. *P<0.05 versus CCL39 control cells, ^ΨP<0.05 versus vehicle-treated CCL39/mycS1P₁ cells