HTR 8 SVneo cells were seeded in 6 well plates just prior to transfection. For optimum transfection efficacy, cells were seeded to a final cell confluency of 30 50%. Cells were transfected with either STAT3 siRNA inhibitor Rucaparib or scrambled siRNA comple ed with G Fectin for 24 h. After treatment with OSM for 48 h, cells were dislodged from the surface of 6 well culture plate for western blotting. Indirect immunofluorescence Cells were cultured on microscope cover slips. Thereafter, the cells were stimulated with 20 ng mL OSM or left untreated for 48 h, with or without stattic pretreatment, and then fi ed with 4% paraformalde hyde in 0. 01 M phosphate buffered saline for 5 min at room temperature. Ne t, these cells were incubated in 2% BSA containing 0. 1% Triton 100 for 30 min at room temperature.

Triton was used for permeabilization. We tested several blocking methods and solutions and found that 2% BSA was ideal as a blocking solution. Cells were then incubated with a mouse anti human monoclonal antibody against E cadherin in blocking solu tion for 1 day at 4 C, to allow good penetration of the pri mary antibodies. The cells were washed in PBS and incubated in the presence of appropriate secondary anti bodies conjugated with Cy3 for 2 h at room temperature. The fluorescent specimens were mounted using Vectashield mounting media. Digital images were acquired using a Zeiss LSM 510 Meta confocal microscope and were imported into Photoshop. We used Photoshop software to de crease the background on confocal images with DAPI staining, and adjusted contrast of the DIC images to im prove visualization of the cell morphology.

Ne t, the cells were treated with OSM for 48 h with or with out pretreatment with stattic for indirect immunofluorescence staining. The ne t steps were the same as those described above. Migration assay Cell wounding assays were also conducted as described by Jones et al, with minor modifications. Briefly, 5 105 HTR8 SVneo cells were plated in 6 well plates in 2 mL medium. The cells were then incubated in a humidified chamber with 5% CO2 at 37 C until they reached conflu ence, and were then wounded using a sterile pipette tip, leaving a denuded area and a sharp demarcation line. Total STAT3 protein e pression did not change sig nificantly at any time point. Stattic, a STAT3 inhibitor, suppressed OSM induced STAT3 phos phorylation in HTR8 SVneo cells.

Monolayers were then rinsed 4 times with s PBS to remove the scraped cells. The cells were incubated for 12 h at 37 C in 5% CO2 with or without OSM or function blocking anti gp130 antibodies, and then photographed. Wound closure was assessed using a LEICA DM IRB DC 300 microscope Cilengitide at 100�� magnification. Cell migration distance was measured using Olympus 6. 51 software and compared with baseline mea surements. To evaluate the effects of stattic on OSM induced cell migrations, cells were incubated for 12 h at 37 C in 5% CO2 with or without OSM or stattic and then photographed.