IL-13Rα2 Is a Biomarker of Diagnosis and Therapeutic Response in Human Pancreatic Cancer

IL-13Rα2 is a high-affinity binding protein for its ligand IL-13 and a cancer-testis antigen as it is expressed in the testis. IL-13Rα2 is highly expressed in various cancers, including pancreatic cancer, and consists of three domains: extracellular, transmembrane, and cytoplasmic. The extracellular domain binds to the ligand to form a biologically active complex, which initiates signaling through AP-1 and other pathways. IL-13Rα2 is also expressed in diseased cells such as fibroblasts that are involved in various inflammatory diseases, including cancer. We have reported that IL-13Rα2 is a prognostic biomarker for malignant glioma, adrenocortical cancer, and pancreatic cancer. In pancreatic cancer, a small sample of tissue could be examined for the expression of IL-13Rα2 by using the endoscopic ultrasound-fine needle aspiration technique (EUS-FNA). In addition, a peptide-based targeted approach using Pep-1L peptide could be used to study the biodistribution and whole-body cancer imaging for the screening of pancreatic cancer in suspected subjects.