title: Serotonin receptors, novel targets of sulforaphane identified by proteomic analysis in Caco-2 cells.
abstract: Cancer chemopreventive activity of sulforaphane has been predominantly associated with its ability to induce phase II detoxification enzymes. In the present study, novel targets of sulforaphane were identified and characterized using a proteomics approach. Two-dimensional gel electrophoresis and mass spectrometry were used to produce protein profiles of human colon adenocarcinoma Caco-2 cells treated with 5 mumol/L sulforaphane for 48 h and control cells (0.05% DMSO). Gel comparisons showed the down-regulation to undetectable level of the serotonin receptor 5-HT(3) after sulforaphane treatment. In addition, Aldo-keto reductase and d-dopachrome decarboxylase were also differentially expressed in control and treated cell extracts. To elucidate two-dimensional gel findings, the neurotransmitter receptors 5-HT(3A), 5-HT(1A), 5-HT(2C), and the serotonin reuptake transporter were analyzed using Western blotting. Results showed a decrease of neurotransmitter receptors in a dose-dependent manner after sulforaphane treatment. Moreover, after exposure of Caco-2 cells to sulforaphane, nicotinic acetylcholine receptor protein level was increased. These findings suggested a potential effect of sulforaphane on serotonin release. Activation of neurotransmitter receptors followed by initiation of cyclic AMP signaling might be crucial events in colon carcinoma progression. Thus, the effect of sulforaphane may help to elucidate signaling pathways serotonin-mediated in colon cancer and lead to development of potential novel therapeutic agents.
authors.affiliation: School of Medicine, Health Policy and Practice, University of East Anglia, Norwich Research Park, Norwich, United Kingdom.
authors.forename: Lina
authors.initials: L
authors.lastname: Mastrangelo
authors.forename: Aedin
authors.initials: A
authors.lastname: Cassidy
authors.forename: Francis
authors.initials: F
authors.lastname: Mulholland
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Yongping
authors.initials: Y
authors.lastname: Bao
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000378:metabolism; D054316:Biomarkers, Pharmacological / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism; D018938:Caco-2 Cells; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000378:metabolism; D016503:Drug Delivery Systems; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D017879:Isothiocyanates; D020543:Proteome / Q000032:analysis; D040901:Proteomics; D011985:Receptors, Serotonin / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D012702:Serotonin Antagonists / Q000302:isolation & purification* / Q000494:pharmacology; D013454:Sulfoxides; D013861:Thiocyanates / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D054316:Biomarkers, Pharmacological; D014408:Biomarkers, Tumor; D017879:Isothiocyanates; D020543:Proteome; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D013454:Sulfoxides; D013861:Thiocyanates; C016766:sulforaphane