Figure 4. SOX9 does not alter Sp1 expression, but physically interacts with Sp1 in melanoma cells.

A. 526mel and 624mel cells were transfected with an anti-SOX9 siRNA or a scrambled control. 72 hours post-transfection, proteins were extracted from cells and Sp1 expression was evaluated via Western blot. B.-D. 526mel and 624mel cell lysates were immunoprecipitated with an anti-SOX9 antibody B. Anti-vinculin antibody C. or no antibody D. served as negative controls. Cell lysates and immunoprecipitates were analyzed by immunoblotting for Sp1. All blots show one representative experiment out of 3 performed.