Activated STAT3 in U266 cells is decreased by treatment with BMP-2.

U266 cells were cultured with 50 ng/mL BMP-2 for the indicated times and examined for levels of tyrosine-phosphorylated (P-tyr) STAT3 by means of immunoblotting with antiphosphotyrosine antibody (upper panel). The same blot was reprobed with anti-STAT3 antibody and confirmed to contain an equal amount of protein extract on each lane (lower panel).