title: Proteomic analysis identifies differentially expressed proteins after HDAC vorinostat and EGFR inhibitor gefitinib treatments in Hep-2 cancer cells.
abstract: Several solid tumors are characterized by poor prognosis and few effective treatment options, other than palliative chemotherapy in the recurrent/metastatic setting. Epidermal growth factor receptor (EGFR) has been considered an important anticancer target because it is involved in the development and progression of several solid tumors; however, only a subset of patients show a clinically meaningful response to EGFR inhibition, particularly to EGFR tyrosine kinase inhibitors such as gefitinib. We have recently demonstrated synergistic antitumor effect of the histone deacetylase inhibitor vorinostat combined with gefitinib. To further characterize the interaction between these two agents, cellular extracts from Hep-2 cancer cells that were untreated or treated for 24 h with either vorinostat or gefitinib alone or with a vorinostat/gefitinib combination were analyzed using 2-D DIGE. Software analysis using DeCyder was performed, and numerous differentially expressed protein spots were visualized between the four examined settings. Using MALDI-TOF MS and ESI-Ion trap MS/MS, several differentially expressed proteins were identified; some of these were validated by Western blotting. Finally, a pathway analysis of experimental data performed using MetaCore highlighted a relevant relationship between the identified proteins and additional potential effectors. In conclusion, we performed a comprehensive analysis of proteins regulated by vorinostat and gefitinib, alone and in combination, providing a useful insight into their mechanisms of action as well as their synergistic interaction.
authors.affiliation: Functional Proteomics Laboratory, Department of Molecular Biology, University of Siena, Siena, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Bianchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Bruzzese
authors.forename: Alessandra
authors.initials: A
authors.lastname: Leone
authors.forename: Assunta
authors.initials: A
authors.lastname: Gagliardi
authors.forename: Michele
authors.initials: M
authors.lastname: Puglia
authors.forename: Elena
authors.initials: E
authors.lastname: Di Gennaro
authors.forename: Monia
authors.initials: M
authors.lastname: Rocco
authors.forename: Anna
authors.initials: A
authors.lastname: Gimigliano
authors.forename: Biagio
authors.initials: B
authors.lastname: Pucci
authors.forename: Alessandro
authors.initials: A
authors.lastname: Armini
authors.forename: Luca
authors.initials: L
authors.lastname: Bini
authors.forename: Alfredo
authors.initials: A
authors.lastname: Budillon
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004357:Drug Synergism; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D000077156:Gefitinib; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D013058:Mass Spectrometry / Q000379:methods; D010449:Peptide Mapping; D020033:Protein Isoforms / Q000737:chemistry; D040901:Proteomics; D011799:Quinazolines / Q000494:pharmacology*; D012984:Software; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D057825:Two-Dimensional Difference Gel Electrophoresis; D000077337:Vorinostat
chemical_list: D000970:Antineoplastic Agents; D006877:Hydroxamic Acids; D020033:Protein Isoforms; D011799:Quinazolines; D000077337:Vorinostat; C512478:EGFR protein, human; D066246:ErbB Receptors; D000077156:Gefitinib