The mechanism of L-canavanine cytotoxicity: arginyl tRNA synthetase as a novel target for anticancer drug discovery.
There is a clear need for agents with novel mechanisms of action to provide new therapeutic approaches for the treatment of pancreatic cancer. Owing to its structural similarity to L-arginine, L-canavanine, the beta-oxa-analog of L-arginine, is a substrate for arginyl tRNA synthetase and is incorporated into nascent proteins in place of L-arginine. Although L-arginine and L-canavanine are structurally similar, the oxyguanidino group of L-canavanine is significantly less basic than the guanidino group of L-arginine. Consequently, L-canavanyl proteins lack the capacity to form crucial ionic interactions, resulting in altered protein structure and function, which leads to cellular death. Since L-canavanine is selectively sequestered by the pancreas, it may be especially useful as an adjuvant therapy in the treatment of pancreatic cancer. This novel mechanism of cytotoxicity forms the basis for the anticancer activity of L-canavanine and thus, arginyl tRNA synthetase may represent a novel target for the development of such therapeutic agents.
Bence
Aimee K
AK
Division of Pharmaceutical Sciences, 800 Rose Street, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0082, USA.
Crooks
Peter A
PA
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism; D001126:Arginine-tRNA Ligase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002172:Canavanine / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use / Q000633:toxicity*; D006801:Humans; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D011487:Protein Conformation / Q000187:drug effects
D000970:Antineoplastic Agents; D002172:Canavanine; D001120:Arginine; D001126:Arginine-tRNA Ligase