title: Sensitization of mesothelioma to TRAIL apoptosis by inhibition of histone deacetylase: role of Bcl-xL down-regulation.
abstract: The TNF-related apoptosis-inducing ligand (TRAIL) is an immunological inducer of apoptosis selectively killing many, but not all, cancer cells. Malignant mesothelioma (MM) is fatal neoplasia with no current treatment, most likely due to high resistance of MM cells towards inducers of apoptosis, including TRAIL. We studied whether inhibition of histone deacetylase (HDAC), recently shown to sensitize malignant cells to a variety of apoptogenic substances, renders MM cells susceptible to TRAIL. Indeed, sub-apoptotic doses of the HDAC inhibitor suberohydroxamic acid (SBHA) sensitized MM cells to TRAIL apoptosis. Of the apoptotic mediators tested, the anti-apoptotic protein Bcl-x(L) was strongly down-regulated by combined treatment of the cells with SBHA and TRAIL but not by the HDAC inhibitor alone, while little or no change in the expression of other Bcl-2 family members highly expressed in MM cells, including Mcl-1 and Bax, was observed. Our data suggest a cross-talk between HDAC inhibition and TRAIL that results in modulation of expression of specific apoptotic mediators, and point to the potential of their combinatorial use in treatment of TRAIL-resistant neoplastic disease.
authors.affiliation: School of Health Sciences, Griffith University, Southport, Qld, Australia. j.neuzil@griffith.edu.au
authors.forename: Jiri
authors.initials: J
authors.lastname: Neuzil
authors.forename: Emma
authors.initials: E
authors.lastname: Swettenham
authors.forename: Nina
authors.initials: N
authors.lastname: Gellert
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D045744:Cell Line, Tumor; D015536:Down-Regulation; D004351:Drug Resistance; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D008654:Mesothelioma / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D051020:bcl-X Protein
chemical_list: D051017:Apoptosis Regulatory Proteins; C494811:BCL2L1 protein, human; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; D051020:bcl-X Protein; D006655:Histone Deacetylases