title: Proteomic analysis of mouse thymoma EL4 cells treated with bis(tri-n-butyltin)oxide (TBTO).
abstract: Here, we report the results of proteomic analysis of the mouse thymoma EL4 cell line exposed to bis(tri-n-butylin)oxide (TBTO), an immunotoxic organotin compound. The objective of the work was to examine whether TBTO affects the expression of proteins in this cell line and to compare the differentially expressed proteins with the corresponding mRNA expression data. The identified proteins were quantified using a label-free quantitative method based on counting the observed peptides as an index of protein abundance. The calculation of the ratio of peptides obtained from exposed and control samples allowed us to evaluate the effect of TBTO on protein expression and to compare these results to those obtained in gene expression profiling studies. Correlation of some of the differentially expressed proteins and their corresponding mRNAs was observed. The analysis of the protein ratios revealed that 12 proteins were significantly affected. These proteins included cytoskeleton proteins myosin-9, spectrin beta 2 and plectin 8. The first two proteins were down-regulated 3-fold, whereas the third was up-regulated 2-fold. Ras-related Rab1, a GTP binding protein and T-complex protein-1 subunit alpha, a chaperonin, were decreased 2- and 3.6-fold, respectively. The ribosomal S10 and eukaryotic translation factor (eIf4G1), which are involved in protein synthesis, were down-regulated 2.6- and 3.7-fold, respectively. Also, proteins involved in splicing of pre-mRNA and in transcription, splicing factor arginine/serine-rich 2 and chromodomain-helicase-DNA binding protein 4 (Chd4), were decreased 2.6- and 4.5 times, respectively. Nuclear RNA helicase II was reduced 2.8-fold. Finally, prothymosin-alpha (ProTalpha), an essential protein for cell proliferation, and a protein similar to ProTalpha, (with a molecular weight and a pI (3.54) comparable to that of ProTalpha) were also down-regulated 6-and 8-fold, respectively. We propose that the observed down-regulation of the expression level of ProTalpha in the TBTO-exposed cells could account for the previously reported anti-proliferative effect of TBTO.
authors: National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands. Ahmed.Osman@rivm.nl
authors: Ahmed M
authors: AM
authors: Osman
authors: Sandra
authors: S
authors: van Kol
authors: Ad
authors: A
authors: Peijnenburg
authors: Marco
authors: M
authors: Blokland
authors: Jeroen L A
authors: JL
authors: Pennings
authors: Jos C S
authors: JC
authors: Kleinjans
authors: Henk
authors: H
authors: van Loveren
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D056404:Chaperonin Containing TCP-1 / Q000235:genetics / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D054697:Cytostatic Agents / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D039603:Eukaryotic Initiation Factor-4G; D020869:Gene Expression Profiling; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D013945:Thymoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D013947:Thymosin / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism; D043922:Toxicogenetics; D014220:Trialkyltin Compounds / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020761:rab1 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D003598:Cytoskeletal Proteins; D054697:Cytostatic Agents; C491908:Eif4g1 protein, mouse; D039603:Eukaryotic Initiation Factor-4G; D009687:Nuclear Proteins; D010446:Peptide Fragments; D010448:Peptide Initiation Factors; D011498:Protein Precursors; C484540:Rab33a protein, mouse; D012261:Ribonucleoproteins; C499372:SRSF2 protein, mouse; D014220:Trialkyltin Compounds; C040782:prothymosin alpha; D000068103:Serine-Arginine Splicing Factors; C005961:bis(tri-n-butyltin)oxide; D013947:Thymosin; D056404:Chaperonin Containing TCP-1; C509277:Mi-2beta protein, mouse; D004265:DNA Helicases; D020365:RNA Helicases; D020691:rab GTP-Binding Proteins; D020761:rab1 GTP-Binding Proteins