STAT3 DNA binding Assay

STAT3 DNA binding activity was determined using commercially available TransAM ^TM STAT3 assay kit (Active motif Inc, Carlsbad, CA). Briefly, after overnight incubation in CO₂ incubator, the cells were incubated with BLN-A (0, 20 and 30 µM) for 4 h. After 4 h drug treatment, the cells were stimulated with IL-6 for 30 min. Finally, nuclear extracts were prepared and subjected for STAT3 DNA binding activity according to the kit instructions.