Inhibitory effect of NRP-1 b1/b2 monoclonal antibody on invasion and migration of gastric cancer cell line BGC-823 and its mechanism

Objective To observe the effect of anti NRP-1 b1/b2 monoclonal antibody (NRP-1mAb)on migration and invasion of gastric cancer cell line BGC-823, and to explore the possible mechanism. Methods NRP-1mAb was prepared in the laboratory, and the purity of antibody was detected by flow cytometry. The different concentrations of NRP-1mAb were added into the culture medium of gastric cancer cell line BGC-823. The migration and invasion of cells after 12 hours was observed by using Transwell method. The phosphorylation of related signal proteins after NRP-1mAb was detected by Western blot analysis. Results When NRP-1mAb prepared by patented technology had the effects on BGC-823 cells after 12 hours, the number of migration and invasion of BGC-823 cells was reduced. The number of cells through the basement membrane in the control group (blank) and the administration group (NRP-1mAb 25, 100, 400 μg/ml) were 167 ± 9, 138 ± 5, 98 ± 5, 36 ± 4, respectively (F= 22.6, P < 0.01); the number of cells through the filtration membrane were 231 ± 40, 224 ± 19, 176 ± 26, 124 ± 34, respectively (F= 26.63, P < 0.01). There were statistically significant differences between the administered group and the control group at 100 and 400 μg/ml (all P < 0.001). High concentration of NRP-1mAb (100 μg/ml) decreased the phosphorylation level of Akt after 10 minutes' function on gastric cancer cells. However, it was difficult to detect phosphorylated Akt after 30 minutes. Conclusion NRP-1mAb may inhibit the migration and invasion of gastric cancer cell line BGC-823 by decreasing the phosphorylation of Akt, which is positively correlated with the concentration. Key words: Gastric neoplasms; Antibodies, monoclonal; Cell migration assays; Neoplasm invasiveness