title: Targeting GSTP1-1 induces JNK activation and leads to apoptosis in cisplatin-sensitive and -resistant human osteosarcoma cell lines.
abstract: The effect of the glutathione transferase P1-1 (GSTP1-1) targeting has been investigated in both sensitive (U-2OS) and cisplatin-resistant (U-2OS/CDDP4 μg) human osteosarcoma cell lines. Despite the different enzyme's content, inhibition of GSTP1-1 by 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) causes the activation of c-Jun N-terminal kinase (JNK) and apoptosis in both cell lines. However, different time courses of JNK activation and cell responses are observed. Whereas in the U-2OS/CDDP4 μg cell line drug treatment results in an early increase of caspase activity and secondary necrosis, in the U-2OS cells it mainly causes an early cell cycle arrest followed by apoptosis. In order to elucidate the action mechanism of NBDHEX we performed a proteomic investigation by label-free nLC-MS(E). The high-throughput analysis associated with a bioinformatic tool suggested the involvement of the TNF receptor associated factor (TRAF) family in the cellular response to the drug treatment. We report experimental evidence of the interaction between GSTP1-1 and TRAF2 and we demonstrate that NBDHEX is able to dissociate the GSTP1-1 : TRAF2 complex. This restores the TRAF2 : ASK1 signaling, thereby leading to the simultaneous and prolonged activation of JNK and p38. These mitogen-activated protein kinases (MAPKs) mediate different effects: JNK is crucial for apoptosis, whereas p38 causes an increase in the p21 level and a concomitant cell cycle arrest. Our study shows that GSTP1-1 plays an important regulatory role in TRAF signaling of osteosarcoma and discloses new features of the action mechanism of NBDHEX that suggest potentially practical consequences of these findings.
authors: Department of Chemical Sciences and Technologies, University of Tor Vergata, Rome, Italy.
authors: Andrea
authors: A
authors: Sau
authors: Giuseppe
authors: G
authors: Filomeni
authors: Silvia
authors: S
authors: Pezzola
authors: Simona
authors: S
authors: D'Aguanno
authors: Francesca Pellizzari
authors: FP
authors: Tregno
authors: Andrea
authors: A
authors: Urbani
authors: Massimo
authors: M
authors: Serra
authors: Michela
authors: M
authors: Pasello
authors: Piero
authors: P
authors: Picci
authors: Giorgio
authors: G
authors: Federici
authors: Anna Maria
authors: AM
authors: Caccuri
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D005786:Gene Expression Regulation; D051549:Glutathione S-Transferase pi / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism; D012516:Osteosarcoma / Q000378:metabolism* / Q000473:pathology; D010069:Oxadiazoles / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D015398:Signal Transduction; D047992:TNF Receptor-Associated Factor 2 / Q000235:genetics / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: C528479:6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol; D000970:Antineoplastic Agents; D010069:Oxadiazoles; D047992:TNF Receptor-Associated Factor 2; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D048031:JNK Mitogen-Activated Protein Kinases; D048055:Mitogen-Activated Protein Kinase 8; D048051:p38 Mitogen-Activated Protein Kinases; D002945:Cisplatin