title: A combination of eicosapentaenoic acid-free fatty acid, epigallocatechin-3-gallate and proanthocyanidins has a strong effect on mTOR signaling in colorectal cancer cells.
abstract: Colorectal cancer (CRC) is one of the major causes of cancer death worldwide. The development of novel anti-CRC agents able to overcome drug resistance and/or off-target toxicity is of pivotal importance. The mammalian target of rapamycin (mTOR) plays a critical role in CRC, regulating protein translation and controlling cell growth, proliferation, metabolism and survival. The aim of this study was to explore the effect of a combination of three natural compounds, eicosapentaenoic acid-free fatty acid (EPA-FFA), epigallocatechin-3-gallate (EGCG) and proanthocyanidins (grape seed [GS] extract) at low cytotoxic concentrations on CRC cells and test their activity on mTOR and translational regulation. The CRC cell lines HCT116 and SW480 were treated for 24h with combinations of EPA-FFA (0-150 µM), EGCG (0-175 µM) and GS extract (0-15 µM) to evaluate the effect on cell viability. The low cytotoxic combination of EPA-FFA 150 µM, EGCG 175 µM and GS extract 15 µM completely inhibited the mTOR signaling in HCT116 and SW480 cells, reaching an effect stronger than or comparable to that of the mTOR inhibitor Rapamycin in HCT116 or SW480 cells, respectively. Moreover, the treatment led to changes of protein translation of ribosomal proteins, c-Myc and cyclin D1. In addition, we found a reduction of clonal capability in both cell lines, with block of cell cycle in G0G1 and induction of apoptosis. Our data suggest that the low cytotoxic combination of EPA-FFA, EGCG and GS extract, tested for the first time here, inhibits mTOR signaling and thus could be considered for CRC treatment.
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy.
authors.forename: Leonarda
authors.initials: L
authors.lastname: D'Angelo
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Piazzi
authors.affiliation: Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Pacilli
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Prossomariti
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Fazio
authors.affiliation: Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, 40138 Bologna, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Montanaro
authors.affiliation: Department of Food Science, University of Naples "Federico II", 80055 Portici (NA), Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Graziani
authors.affiliation: Food Quality & Design group, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Fogliano
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy, Endocrinology Unit, Department of Medical and Surgical Sciences, S.Orsola-Malpighi Hospital, 40138 Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Munarini
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy and.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bianchi
authors.affiliation: Gastroenterology Unit, Department of Medical and Surgical Sciences, S.Orsola-Malpighi Hospital, 40138 Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Belluzzi
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Bazzoli
authors.affiliation: Department of Surgical and Medical Sciences, University of Bologna, 40138 Bologna, Italy, Center for Applied Biomedical Research (CRBA), S.Orsola-Malpighi Hospital, University of Bologna, 40138 Bologna, Italy, luigi.ricciardiello@unibo.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ricciardiello
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D056604:Grape Seed Extract / Q000494:pharmacology; D006801:Humans; D044945:Proanthocyanidins / Q000008:administration & dosage / Q000494:pharmacology*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; C530104:CCND1 protein, human; D056604:Grape Seed Extract; D044945:Proanthocyanidins; D016271:Proto-Oncogene Proteins c-myc; D019938:Cyclin D1; D002392:Catechin; D015118:Eicosapentaenoic Acid; C045651:epigallocatechin gallate; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases