FIG 4.

Both YAP and MRTF-A are required for S1P to increase CCN1 expression. (A) Glioblastoma cells were transfected with siRNA specific to YAP for 48 h. Total cell lysates were subject to immunoblotting for YAP and GAPDH (loading control) (blots shown are representative of three experiments). MRTF-A protein levels were not affected by YAP knockdown (not shown). (B) Glioblastoma cells were transfected with siRNA specific to MRTF-A for 48 h. Total cell lysates were subject to immunoblotting for MRTF-A protein and GAPDH (loading control) (blots shown are representative of three experiments). YAP protein levels were not affected by MRTF-A knockdown (not shown). (C) Glioblastoma cells were transfected with siYAP, siMRTF-A, or both (double KD) for 48 h. Cells were serum starved for 24 h and then treated with 0.3 μM S1P for 1 h. Total cell lysates were subject to immunoblotting for CCN1 protein and GAPDH (loading control). **, P < 0.01 versus siCon (n = 5).