Fig. 4
From: The paradox role of caspase cascade in ionizing radiation therapy
A schematic representation of caspase activation resulting in cell death and tumor cell repopulation. Caspase 3 upregulation followed by apoptosis stimuli lead to iPLA2 (Ca(2+)-independent cytosolic phospholipase A2) activation and cell death. Hydrolysis of fatty acids by iPLA2 results in arachidonic acid release and production of PGE2 (Prostaglandin E2) a well-known product of cyclooxygenase enzymes which induce tumor cell repopulation