(A) WT and IL16 KO SL-1 cells were pretreated with DMSO, 40 μM, or 80 μM STAT5 inhibitor (STAT5-I) for 1 hr, followed by stimulation with anti-mouse Ig(G+M) (5 μg/mL) for 48 hr. Immunoblot analyses were performed with specific antibodies as indicated. (B) SL-1 cells were transfected with vector, STAT3-expressing plasmid, or STAT3C-expressing plasmid with Flag tag, followed by anti-mouse Ig(G+M) (5 μg/mL) treatment for 48 hr. Immunoblot analyses were performed with the indicated antibodies. (C) WT and IL16 KO SL-1 cells were treated with (+) or without (-) anti-mouse Ig(G+M) (5 μg/mL) for 48 hr. Immunoblot analyses were performed with the specific antibodies as indicated. (D) Quantitation of phosphorylated STAT3(Y705) relative to total STAT3 and p21 relative to GAPDH based on immunoblot detection in C using the ImageJ image analysis software. (E) WT and IL16 KO SL-1 cells were treated with DMSO or Orthovanadate (50 μM) in the presence or absence of anti-mouse Ig(G+M) (5 μg/mL) for 48 hr. Immunoblot analyses were performed with the specific antibodies as indicated.