CONTEXT: The bacterium Pseudomonas syringae pv. syringae (Pss) is a pathogen of many plant species and causes, for example, brown spot disease in bean plants (Phaseolus vulgaris). Pss excretes the syringolins, natural product molecules that act as a virulence factors and inhibit the proteasome of the host plants. OBJECTIVE: Proteasome inhibitors belong to an important class of anticancer agents and bortezomib (Velcade(®)) has been Food and Drug Administration-approved for the treatment of multiple myeloma (MM) and mantle cell lymphoma. Syringolins represent a new class of proteasome inhibitors and the present work was undertaken to design a potent syringolin-inspired analogue (TIR-203) for anticancer drug development. MATERIALS AND METHODS: TIR-203 was tested against human MM and neuroblastoma (NB) cells. Cancer cells were treated with TIR-203 at various concentrations (0-10 µM) and the cell viability was measured using the MTS assay. To determine the effects on proteasomal activities, the cell culture-based proteasome inhibition assay was used. Syringolin A (SylA) and bortezomib were included as controls. RESULTS: TIR-203 inhibited the cell proliferation of MM and NB cells in a dose-dependent manner at significantly lower concentrations than SylA. In MM cells, TIR-203 effectively inhibited the chymotrypsin-like (CT-L), caspase-like (C-L), and trypsin-like (T-L) activities of the proteasome. In NB cells, TIR-203 inhibited the CT-L and C-L activities, but not the T-L activity. DISCUSSION AND CONCLUSIONS: The newly designed proteasome inhibitor TIR-203 is more potent than the natural product SylA and strongly inhibits the cell viability and proteasomal activity of MM and NB cells.
CONTEXT: The bacterium Pseudomonas syringae pv. syringae (Pss) is a pathogen of many plant species and causes, for example, brown spot disease in bean plants (Phaseolus vulgaris). Pss excretes the syringolins, natural product molecules that act as a virulence factors and inhibit the proteasome of the host plants. OBJECTIVE: Proteasome inhibitors belong to an important class of anticancer agents and bortezomib (Velcade(®)) has been Food and Drug Administration-approved for the treatment of multiple myeloma (MM) and mantle cell lymphoma. Syringolins represent a new class of proteasome inhibitors and the present work was undertaken to design a potent syringolin-inspired analogue (TIR-203) for anticancer drug development. MATERIALS AND METHODS: TIR-203 was tested against human MM and neuroblastoma (NB) cells. Cancer cells were treated with TIR-203 at various concentrations (0-10 µM) and the cell viability was measured using the MTS assay. To determine the effects on proteasomal activities, the cell culture-based proteasome inhibition assay was used. Syringolin A (SylA) and bortezomib were included as controls. RESULTS: TIR-203 inhibited the cell proliferation of MM and NB cells in a dose-dependent manner at significantly lower concentrations than SylA. In MM cells, TIR-203 effectively inhibited the chymotrypsin-like (CT-L), caspase-like (C-L), and trypsin-like (T-L) activities of the proteasome. In NB cells, TIR-203 inhibited the CT-L and C-L activities, but not the T-L activity. DISCUSSION AND CONCLUSIONS: The newly designed proteasome inhibitor TIR-203 is more potent than the natural product SylA and strongly inhibits the cell viability and proteasomal activity of MM and NB cells.
Authors: André S Bachmann; John Opoku-Ansah; Tannya R Ibarra-Rivera; Lisette P Yco; Sudhakar Ambadi; Christopher C Roberts; Chia-En A Chang; Michael C Pirrung Journal: J Biol Chem Date: 2016-02-23 Impact factor: 5.157
Authors: Kyle A Totaro; Dominik Barthelme; Peter T Simpson; Xiuju Jiang; Gang Lin; Carl F Nathan; Robert T Sauer; Jason K Sello Journal: ACS Infect Dis Date: 2016-12-05 Impact factor: 5.084
Authors: Kyle A Totaro; Dominik Barthelme; Peter T Simpson; Robert T Sauer; Jason K Sello Journal: Bioorg Med Chem Date: 2015-07-26 Impact factor: 3.641
Authors: Marquicia R Pierce; Reeder M Robinson; Tannya R Ibarra-Rivera; Michael C Pirrung; Nathan G Dolloff; André S Bachmann Journal: Leuk Res Date: 2019-11-12 Impact factor: 3.156