title: Modulation of tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis by chemotherapy in thyroid cancer cell lines.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many human cancer cells but not in normal cells. Thyroid cancer cells, however, appear to be relatively resistant to TRAIL-induced apoptosis. We therefore investigated the effect of chemotherapy on TRAIL-induced apoptosis in thyroid cancer cells. We used six thyroid cancer cell lines: TPC-1, FTC-133, FTC-236, FTC-238, XTC-1, and ARO82-1. We used flow cytometry to measure apoptosis, dimethyl-thiazol-diphenyltetrazolium bromide (MTT) assay to measure antiproliferation effects and Western blot to determine the expression of Bcl family proteins. Troglitazone, paclitaxel, geldanamycin, and cycloheximide were used for pretreatment. We used the Student's t test and analysis of variance (ANOVA) for statistical analysis. All thyroid cancer cell lines, except the TPC-1 cell line, were resistant to TRAIL, and growth inhibition was less than 20% at concentration of 800 ng/mL of TRAIL. In both TPC-1 (TRAIL-sensitive) and FTC-133 (TRAIL-resistant) thyroid cancer cell lines, pretreatment with troglitazone, cycloheximide, and paclitaxel enhanced TRAIL-induced cell death significantly but pretreatment with geldanamycin did not. There were no significant changes in Bcl-2, Bcl-xl, and Bax protein expression after troglitazone treatment. In conclusion, TRAIL in combination with troglitazone, paclitaxel, and cycloheximide induces apoptosis in thyroid cancer cells at suboptimal concentrations that cannot be achieved using TRAIL alone.
authors.affiliation: Department of Surgery, University of California, San Francisco, UCSF/Mount Zion Medical Center, San Francisco, California 94143-1674, USA. clarko@surgery.ucsf.edu
authors.forename: Jin-Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Mariwil G
authors.initials: MG
authors.lastname: Wong
authors.forename: Margaret
authors.initials: M
authors.lastname: Lobo
authors.forename: William C
authors.initials: WC
authors.lastname: Hyun
authors.forename: Quan-Yang
authors.initials: QY
authors.lastname: Duh
authors.forename: Orlo H
authors.initials: OH
authors.lastname: Clark
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002839:Chromans / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D008562:Membrane Glycoproteins / Q000494:pharmacology*; D017239:Paclitaxel / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D045162:Thiazolidinediones / Q000494:pharmacology; D013964:Thyroid Neoplasms / Q000378:metabolism / Q000503:physiopathology*; D000077288:Troglitazone; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D002839:Chromans; D008562:Membrane Glycoproteins; D011500:Protein Synthesis Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D045162:Thiazolidinediones; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; D000077288:Troglitazone; D017239:Paclitaxel