Colorectal cancer cells induce lymphocyte apoptosis by an endothelial monocyte-activating polypeptide-II-dependent mechanism.

Endothelial monocyte-activating polypeptide-II (EMAP-II) was first isolated from cell growth medium conditioned by tumor cells, and is closely related or identical with the p43 component of the mammalian multisynthase complex. In its secreted form, EMAP-II has multiple cytokine-like activities in vitro, inducing procoagulant activity on the surface of endothelial cells, increasing expression of E- and P-selectins and TNF-R1, and directing migration of monocytes and neutrophils. EMAP-II has also been shown to induce apoptosis in endothelial cells, leading to the suggestion that it is a proinflammatory polypeptide with antiangiogenic activity.