title: PS-341 and histone deacetylase inhibitor synergistically induce apoptosis in head and neck squamous cell carcinoma cells.
abstract: Proteasome inhibitor PS-341 (also known as bortezomib) and histone deacetylase (HDAC) inhibitors have emerged as novel therapeutic agents for a variety of malignancies. In this study, we examined whether PS-341 and the HDAC inhibitor trichostatin A (TSA) induced apoptosis in head and neck squamous cell carcinoma (HNSCC), a common and lethal malignancy. We found that, although TSA treatment alone did not induce apoptosis in HNSCC cells, it significantly enhanced PS-341-induced apoptosis in HNSCC cells in vitro. Consistently, TSA significantly improved PS-341-mediated inhibition of HNSCC tumor growth in nude mice. Mechanistically, we found that TSA increased PS-341-induced Noxa expression and caspase activation in HNSCC cells. The knockdown of Noxa significantly reduced apoptosis induced by cotreatment of PS-341 and TSA. Taken together, our results provide new insight into the mechanisms of synergistic antitumor activity of the PS-341 and HDAC inhibitor regimen, offering a new therapeutic strategy for HNSCC patients.
authors.affiliation: Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, California 90095, USA.
authors.forename: Jinkoo
authors.initials: J
authors.lastname: Kim
authors.forename: Jean
authors.initials: J
authors.lastname: Guan
authors.forename: Insoon
authors.initials: I
authors.lastname: Chang
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.forename: Demin
authors.initials: D
authors.lastname: Han
authors.forename: Cun-Yu
authors.initials: CY
authors.lastname: Wang
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D015152:Blotting, Northern; D015153:Blotting, Western; D001897:Boronic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D000069286:Bortezomib; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D056572:Histone Deacetylase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D006657:Histones / Q000378:metabolism; D006801:Humans; D006877:Hydroxamic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D008819:Mice, Nude; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D011719:Pyrazines / Q000008:administration & dosage / Q000494:pharmacology*; D034622:RNA Interference; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; C498702:PMAIP1 protein, human; D019253:Proto-Oncogene Proteins c-bcl-2; D011719:Pyrazines; C012589:trichostatin A; D000069286:Bortezomib; D020169:Caspases