Possible Role of Epidermal Growth Factor Receptors in the Therapy of Pancreatic Cancer

Pancreatic cancer is considered an 'orphan' cancer because of its relative low incidence. Unfortunately, even with early diagnosis, mortality rates are high and it ranks eighth in the worldwide ranking of deaths due to cancer. The administration of chemotherapeutic agents for the treatment of advanced disease has failed, and current research focuses on the understanding of molecular pathways in order to investigate the role of targeted therapy. It has been known that the development and the progression of pancreatic cancer are caused by the activation of oncogenes, the inactivation of tumor suppressor genes, and the deregulation of many signaling pathways of various growth factors, among which the epidermal growth factor receptor (EGFR) plays an important role. Growth factor receptors and their ligands not only regulate normal cell processes, but have also been identified as key regulators of human cancer formation. EGFR has been found to be expressed and altered in pancreatic cancer and clearly plays a significant role in tumor development and progression, including cell proliferation, regulation of apoptotic cell death, angiogenesis, and metastatic spread. The amplitude and kinetics of growth factor signaling are determined mainly by a highly regulated endocytic process that sorts and directs activated receptors to degradation in lysosomes. Therefore, EGFR is a legitimate therapeutic target. The aim of this review is to outline the endocytic escape of EGFRs in cancer with special attention towards recent advances in various approaches adopted for EGFR targeting.