Journal of Leukemia
Open Access

Abstract

Expression and Function of the Eph Receptor Family in Leukemia and Hematopoietic Malignancies: Prospects for Targeted Therapies

Sara Charmsaz and Andrew W Boyd

There has been considerable interest in recent years in the development of therapies, which target Eph receptors or their ephrin ligands. The Eph receptor tyrosine kinases and their membrane bound ephrin ligands are cell surface molecules involved in many biological functions and cell behaviors during embryogenesis and in adult life. However, they are also expressed in an aberrant fashion on many tumors and are re-expressed on normal cells in nonmalignant pathological states. Some of the eph/ephrins including EphA7 and EphA1 protein are thought to function as tumor suppressors in particular cancers. In tumors where Eph/ephrin proteins are expressed at high levels, being expressed on the cell surface these proteins are readily accessible to antibody-mediated therapies several of which are in advanced pre-clinical or early clinical evaluation, including antibodies specific for EphA2, EphA3, and EphB4 which are expressed on many different tumors. We will review the general features of the Eph/ephrin system and discuss the role of this system in normal hematopoiesis before focusing on the role of Eph proteins in leukemia and other hematological malignancies and possible avenues for therapy.