Endothelial monocyte activating polypeptide-II induced gene expression changes in endothelial cells

In the current study we used microarray (MA) analysis to examine gene expression changes in human umbilical vein endothelial cells (HUVEC) exposed to the tumor-derived cytokine, endothelial monocyte-activating polypeptide-II (EMAP-II). HUVEC treated with EMAP-II for 0.5, 1, 2, 4 and 8 h, were analyzed using 10K cDNA arrays. Our results demonstrated that changes in gene expression of <0.5 and >2 fold were seen for 69 genes and the majority of gene changes occurred early. Validation of MA analysis for 10 genes by real time RT-PCR, demonstrated the gene changes to be consistent and specific to HUVEC when compared to human fibroblasts treated with EMAP-II. Among these genes, downregulated in ovarian cancer 1 (DOC1) gene was studied further because of its possible role in EMAP-II induced cytoskeletal remodeling. DOC1 expression was silenced using small interfering RNA. SiRNA to DOC1 completely abolished EMAP-II stimulated gene expression of DOC1. Silencing of DOC1 gene expression reversed the modulatory effect of EMAP-II on 4 other genes, suggesting that DOC1 might play a role in mediating some of the effects of EMAP-II on endothelial cells.