Time course of OSM-induced IL-6 mRNA expression in U343 cells treated with compound HAK-2. Compound HAK-2 completely suppresses exclusively the second IL-6 mRNA expression peak. U343 cells were stimulated with 100 ng/ml OSM and treated with 0.1% DMSO as solvent control (solid line, black triangle) or 20 μM HAK-2 (dashed line, white triangle). Samples were harvested at time points indicated to extract total RNA. IL-6 mRNA expression was analyzed by qRT-PCR. All data points are presented as mean ± SD, and were obtained from experiments carried out in quadruplicate. Statistical analysis were performed between control and HAK-2 samples from same time point. ns, not significant; ***p < 0.001.