Regulation of expression of vascular endothelial growth factor A and C by cytokines and hypoxia in pancreatic cancer cells

Objective:To explore the regulation of production and secretion of vascular endothelial growth factor (VEGF) A and C in cultured human pancreatic cancer cell lines by cytokines such as interleukin(IL)-1α, IL-6, and tumor necrosis factor (TNF)α and S-nitroso-nacetyl-penicillamine (SNAP, NO donor, induce hypoxia in the culture medium). Methods:The mRNA expression of VEGF A and C were detected by Northern blot and protein expression was measured by Western blot in 6 cell lines (ASPC-1, CAPAN-1, MIA-PaCa2, PANC-1, COLO-357, and T3M4). VEGF A and C expressions in cultured CAPAN-1 and COLO-357 cells were analyzed by reverse-transcription polymerase chain reaction (RT-PCR) after stimulation with IL-1α(10 μg/L), IL-6 (100 μg/L), TNFα(50 μg/L), or SNAP (25 mg/L). Results:Northern blot analysis revealed the expressions of the 4.1 kb VEGF-A mRNA transcript and 2.4 kb VEGF-C mRNA transcript in all 6 tested cell lines. Western blot showed the expression of 43×103 VEGF-A protein and 55×103 VEGF-C protein in the 6 cell lines. RT-PCR analysis showed that the levels of VEGF-A mRNA had 1-2 fold increase and VEGF-C mRNA had 1 fold increase in COLO-357 cells after IL-1α stimulation. The levels of VEGF-A mRNA had 2-5 fold increase and VEGF-C mRNA had 1 fold increase in CAPAN-1 cells after IL-6 stimulation. TNFa stimulation caused 1-2.5 fold decrease of VEGF-A mRNA and 1-2 fold decrease of VEGF-C mRNA in COLO-357 cells and caused 1 fold decrease of VEGF-A mRNA and 1.6-2.5 fold decrease of VEGF-C mRNA in CAPAN-1 cells. SNAP stimulated 5 fold increase of VEGF-A mRNA in COLO-357 cells and 4 fold increase of VEGF-A mRNA in CAPAN-1 cells. Conclusion:IL-1α, IL-6, TNFα, and SNAP influence the biological properties of pancreatic cancer cells by regulating expression of VEGF-A and VEGF-C.