Fig. 5. SOCS1 elevate OPN mRNA in RCS cells. (A) RCS WT and HEK-293T cells were stimulated with 50 ng/ml FGF and 5 µg/ml heparin for different periods of time (as indicated) after 8 hours of starvation with serum-free medium. Northern analysis of 2 µg mRNA hybridized with the OPN probe. (B) RCS WT cells and RCS cells stably transfected with Myc-tagged SOCS1 (RCS S1) were starved for 8 hours in serum-free medium and then treated as indicated with different concentration of FGF and heparin for 24 hours. Northern analysis of 10 µg total RNA hybridized with the OPN probe. The amount of RNA on the membrane was visualized by Methylene-Blue staining of the 18S ribosomal RNA.