Article Abstract

Antibody-drug conjugate targeting protein tyrosine kinase 7, a receptor tyrosine kinase-like molecule involved in WNT and vascular endothelial growth factor signaling: effects on cancer stem cells, tumor microenvironment and whole-body homeostasis

Authors: Masaru Katoh


Cancer stem cells (CSCs) and tumor-initiating cells (TICs) are subpopulations of tumor cells that are defined by selfrenewal and multi-differentiation potentials and in vivo tumorigenicity potential, respectively (1,2). Because TICs de-differentiate into CSCs owing to their plasticity, and then, CSCs give rise to proliferating or differentiated bulk tumor cells for tumor initiation, CSCs and TICs are almost similar concepts in the field of cancer biology. CSCs/TICs have been identified in a variety of human cancers, such as breast cancer (3), colorectal cancer (4), gastric cancer (5) and lung cancer (6), and are characterized by cancer typeor subtype-specific CSC markers, such as BMI1 (7), CD133 (PROM1) (8), LGR5 (GPR49) (9) and PTK7 (2,10).