Inhibitory Role of Natural IgG Antibodies against VEGFR1 in the Proliferation of Pancreatic Cancer

Context Our recent study suggested that natural IgG antibodies against vascular endothelial growth factor receptor 1 (VEGFR1) had a role in inhibiting the proliferation of nasopharyngeal carcinoma (NPC) cells. Objective The present work was designed to test if plasma anti- VEGFR1 IgG could also inhibit the proliferation of pancreatic cancer cells. Design PANC-1 and SW1990 cell lines derived from pancreatic cancer were used for this in vitro study. They were cultured with 15% human plasma either positive or negative for anti-VEGFR1 IgG. Main outcome measures Cell viability was detected by cell counting kit-8. Flow cytometry was used to analyse cell apoptosis and quantitative real-time PCR was used to examine the expression of VEGFR1 mRNA. Setting Guangdong Medical University, Dongguan, China. Results Plasma anti-VEGFR1 IgG exhibited significant inhibitory effects on the proliferation of PANC-1 cell line but not SW1990 cell line; the proportion of apoptotic cells was higher in PANC-1 cells treated with anti-VEGFR1 IgG positive plasma than those cells treated with anti- VEGFR1 IgG negative plasma. Moreover, the expression of VEGFR1 mRNA was significantly higher in PANC-1 cells than SW1990 cells. Conclusions Plasma anti-VEGFR1 IgG antibody may be a promising agent for the treatment of pancreatic cancer that highly expresses VEGFR1.