Folded and unfolded conformations of proteins involved in pancreatic cancer: a layman's guide

Pancreatic cancer (PC) is one of the most difficult illnesses to treat, since the 5-year survival rate is lower than 5% in patients and no substantial advances in its treatment have been achieved in the last 20 years. Since cancer deregulation and progression are associated with changes in at least one biochemical pathway, the knowledge of the structure of the proteins involved in such routes seems to be crucial in order to understand how this cancer progresses and, more importantly, to design more efficient and rationally designed drugs. In this review, we describe the fold and structures of proteins involved in different signaling pathways that intervene during PC development and progression. In particular, we will focus on the most frequently mutated, or alternatively differently expressed, proteins in PC. The current knowledge suggests that most of the proteins carry out their function by interacting with others via specific domains and through key residues at the recognition interfaces; these amino acids are mutated in patients developing PC. Furthermore, phosphorylation seems to be a crucial regulation step along several signaling pathways. Finally, we show not only that well-folded proteins in several signaling pathways are critical in the development of PC, but also that natively unfolded "hub" proteins, able to interact with DNA or proteins, are also important in such cancer progression.