Stattic treatment decreases STAT3 activation and induces proinflammatory mediator expression. (a) STAT3 activation in tumor cells, as detected by EMSA. Stat-3/3, Stat3 homodimer; Stat-3/1, Stat3/Stat1 heterodimer, Stat-1/1, Stat1 homodimer. The STAT3 homodimer band in both Cal27 and HN11 cell lines was decreased after treatment with 10μM Stattic for 48h, compared to untreated and to 1-0.1 μM Stattic treatments. U937 stimulated with IL-6 is the positive control (lane 5). Pre-incubation with an anti-STAT3 antibody shifted the STAT3 homodimer band (supershift band; lane 6). (b) qRT-PCR analysis showed up-regulation of proinflammatory cytokine and chemokines mRNA by 10mM Stattic for 48h, compared to untreated, DMSO only (drug diluent), and to 1 μM Stattic treatment. Histograms represent the means of at least three experiments normalized to GAPDH mRNA expression (internal control). Data are presented as fold difference relative to untreated cell lines. * p <0.05.