Health / Medical Topics |
Thapsigargin Prodrug G-202
A soluble, thapsigargin prodrug containing the cytotoxic analog of thapsigargin, 8-O-(12Aminododecanoyl)-8-O debutanoylthapsigargin (12-ADT) linked, via a carboxyl group, to the targeting peptide containing aspartic acid with potential antineoplastic activity. Upon intravenous administration, the non-toxic prodrug targets prostate specific membrane antigen (PSMA), a type II membrane carboxypeptidase, which is overexpressed in prostate cancer cells and in the neovasculature of most solid tumors but not in normal blood vessels. G-202 is subsequently converted, through hydrolysis, into the active cytotoxic analog of thapsigargin 12-ADT-Asp. 12-ADT binds to and blocks the Sarcoplasmic/Endoplasmic Reticulum Calcium ATPase (SERCA) pump, thereby increasing the concentration of cytosolic calcium which leads to an induction of apoptosis. By preventing nutrient supply to tumor cells, G-202 may be able to inhibit tumor growth. Compared to thapsigargin alone, thapsigargin prodrug G-202 is able to achieve higher concentrations of the active agents at the tumor site while avoiding systemic toxicity. (NCI Thesaurus)