SIGNIFICANCE OF PLATELET-DERIVED ENDOTHELIAL-CELL GROWTH-FACTOR IN THE ANGIOGENESIS OF HUMAN GASTRIC-CANCER

We have previously shown that platelet-derived endothelial cell growth factor (PD-ECGF) is associated with angiogenesis of human colon cance r; this factor is expressed at high levels in vascular tumors that exp ress low levels of vascular endothelial growth factor (VEGF), In these colon cancers, the major source of PD-ECGF is the infiltrating cells, In this study, we examined the role of PD-ECGF in the angiogenesis of human gastric cancer, Immunostaining for PD-ECGF was done on 93 gastr ic cancers previously stained for VEGF, basic fibroblast growth factor , and factor VIII-related antigen (specific for endothelial cells), To determine the cell type expressing PD-ECGF, double staining was done using antibodies to both PD-ECGF and CD68 (specific for macrophages), PD-ECGF was expressed more frequently in infiltrating cells (positive CD68 staining; 53.8%) than in tumor epithelium (9.7%; P < 0.0001), Inf iltrating cells simultaneously stained positive for both PD-ECGF and C D68, An association between PD-ECGF expression in infiltrating cells, VEGF expression in tumor epithelium, and vessel count was observed in intestinal-type gastric cancer but not in diffuse-type gastric cancer. Vessel count was greater in tumors with high expression of both PD-EC GF and VEGF than in those with high expression of either factor alone (P = 0.002), Multiple angiogenic factors expressed by both tumor cells and infiltrating cells may play a role in the regulation of angiogene sis in intestinal-type gastric cancer.