To synthesize long-acting and antiangiogenic
erythropoietin to be clinically applied for treatment of patients with solid
tumors, we synthesized a hybrid molecule of human
erythropoietin added onto the C-terminus with a
heparin-binding motif of human PLGF-2 to develop a novel derivative of long-acting and antiangiogenic
erythropoietin:
heparin-binding
erythropoietin (HEPO), and studied the characteristics of this novel
erythropoietin derivative. HEPO
cDNA was synthesized, expressed in insect cells, and the
protein was purified using a
heparin-sepharose affinity column. The erythropoietic and angiogenic effects of the partially purified
protein were analyzed in vitro and in vivo. The erythropoietic activity of the
protein was equivalent to natural EPO in vitro. In vivo administration of the
protein to mice revealed its long-acting erythropoietic activity as expected. Administration of the
protein inhibited angiogenesis in a mouse limb
ischemia model. In conclusion, the
heparin-binding motif of PLGF-2 may act as, so to speak, a superendostatin. This novel long-acting
erythropoietin derivative may have an advantage to inhibit
tumor growth while preserving hematopoietic and tissue-protective effects.