Endoglin (CD105): A Strong Candidate for Immunologic Targeting of Tumor Neovasculature in Human Malignancies

Tumor-associated angiogenesis is a well-acknowledged therapeutic target for human malignancies, and different markers of tumor neovasculature are actively investigated as potential candidates for antiangiogenetic therapy in cancer. Among these is endoglin (CD105), a homodimeric transmembrane glycoprotein overexpressed on proliferating endothelial cells, which has been identified as a functional component of the transforming growth factor-β (TGF-β) receptor system about a decade ago. The large body of experimental data accumulated so far indicates that CD105 plays a crucial role in angiogenesis and vascular integrity; furthermore, intratumoral microvessel density as evaluated by staining for CD105 represents a strong prognostic factor in solid malignancies of different histology. In this work, we review the biologic features of CD105 and the complex of evidences highlighting its great potentialities as novel target for diagnostic and therapeutic approaches in human malignancies.