h. In separate experiments, conditioned media collected either from clone 2 or Sema 3A siRNA transfected B16F1 or B16F1 were used in ” the lower chamber as chemoattractant for B16F10 migration. In another experiments, A375 and SK-Mel-28 cells, treated with 100 ng/ml of Sema 3A were used in the upper portion of invasion chambers. FBS was used as chemoattractant. The cells invaded to the reverse side of the filter were stained, photographed, counted in 3 high-power fields under an inverted microscope, analyzed statistically and represented in the form of bar graph. The endothelial-melanoma cell PF-562271 supplier interaction was shown by direct co-migration or co-invasion assays as described. Briefly, HUVEC were added in upper chamber and control B16F10 or clones 2 cells were used in lower chamber. Anti-NRP1 blocking antibody was used in upper chamber. In separate experiments, conditioned media collected either from clone 2 or Sema 3A siRNA transfected B16F1 or B16F1 were used in the lower chamber. FBS serve as chemoattractant for HUVEC migration and invasion. After 18 h, the migrated or invaded HUVEC in the reverse side of the filter were stained, photographed, analyzed statistically and represented graphically. DNA ladder assay Both control B16F10 and clone 2 cells either untreated or treated with two different concentrations of curcumin were incubated at 37uC for 12 h, lysed in ladder assay buffer and genomic DNA was isolated by isopropanol precipitation method. Equal amount of DNA was analyzed by 2% agarose gel electrophoresis. In vivo tumorigenicity, in vivo invasion, histopathology and immunohistochemistry Control B16F10 and clone 2 cells were injected ” subcutaneously into the dorsal flank region of C57BL/6 male mice. In separate experiments, serum free conditioned 
media collected from clone 2 cells was injected twice a week into the tumor site of mice generated by control cells. Tumor length and width were measured every week. After 4 weeks, mice were sacrificed, photographed, tumors were dissected out, weighted and used for histopathological and immunohistochemical studies. The mice were also dissected ventrally, photographed and the metastasized organs such as liver, intestine and kidney were used for histopathological studies. In vivo metastasis study by intra-cardiac injection Control B16F10 and clone 2 cells were injected intracardiacly into anesthetized C57BL/6 male mice. After 3 weeks, mice were sacrificed; photographed, metastasized organs were dissected out and used for histopathological studies. BrdU incorporation assay SK-Mel-28 cells were seeded on coverslip and treated with 100 ng/ml Sema 3A for 24 h followed by incubation with complete media supplemented with BrdU for another 24 h. Cells were fixed with 100% cold methanol and stained with BrdU labeling and detection kit, visualized under fluorescence microscope, photographed and analyzed. Statistical analysis The cell migration, invasion, MTT assays, tumor-endothelial interaction assays, tumor weights and volumes were analyzed statistically. Statistical differences were determined by paired Student’s t test. Differences were considered significant when P,0.05. Wound assay and time laps microscopy To further confirm the motility of control B16F10 and clone 2 cells, wound assay was performed as described. Briefly, clone 2 cells either alone or treated with anti-Sema 3A or antiNRP1 blocking antibody were used for wound assay. In separate experiments, control B16F10 cells either alone or treat