Figure 6

OSM stimulation enhances MMP2 and VEGF activity and OSA cell invasion. A) Canine (OSA8) or human (SJSA) OSA cells were treated with 0, 50, or 100 ng/mL rhOSM or 100 ng/mL OSM in combination with the small molecule STAT3 inhibitor LLL3 (40 μM) for 72 hours. Media was collected, processed, and gel zymography performed as described previously [6]. B) Canine (OSA8) and human (SJSA) OSA cells were plated in serum free media with 50 ng/mL rhOSM in the upper wells of plates for invasion assays. Cells were incubated overnight to allow for invasion through a layer of Matrigel. The lower chamber of each treatment group contained either 10% fetal bovine serum alone (C10), C10 media with rhOSM (50 ng/mL), C10 media with rhHGF (50 ng/mL), or C10 media with both cytokines at 50 ng/mL. Cells were counted in ten random fields in quadruplicate replicates. The bars refer to the standard error of the mean. **p < 0.01; ***p < 0.001 C) Canine (OSA8) or human (SJSA) OSA cells were treated with 0, 50 ng/mL rhOSM, 50 ng/mL rhHGF, or the two cytokines together at 50 ng/mL for 72 hours. Media was collected, processed, and gel zymography performed as described previously. D) Canine (OSA8) and human (SJSA) OSA cells were left untreated or incubated with 50 or 100 ng/mL rhOSM, or 100 ng/mL rhOSM + LLL3 40 μM for 24 hours. Media was collected and VEGF concentrations determined by ELISA. E) Human (SJSA) OSA cells left untreated or incubated with 50 or 100 ng/mL rhOSM, or 100 ng/mL rhOSM + 40 μM LLL3 for 72 hours. Protein lysates were generated and separated by SDS-PAGE and Western blotting for VEGF and β-actin was performed.