title: RedOx status, proteasome and APEH: insights into anticancer mechanisms of t10,c12-conjugated linoleic acid isomer on A375 melanoma cells.
abstract: This study describes the investigation of the efficiency of conjugated linoleic acid (CLA) isomers in reducing cancer cells viability exploring the role of the oxidative stress and acylpeptide hydrolase (APEH)/proteasome mediated pathways on pro-apoptotic activity of the isomer trans10,cis12 (t10,c12)-CLA. The basal activity/expression levels of APEH and proteasome (β-5 subunit) were preliminarily measured in eight cancer cell lines and the functional relationship between these enzymes was clearly demonstrated through their strong positive correlation. t10,c12-CLA efficiently inhibited the activity of APEH and proteasome isoforms in cell-free assays and the negative correlation between cell viability and caspase 3 activity confirmed the pro-apoptotic role of this isomer. Finally, modulatory effects of t10,c12-CLA on cellular redox status (intracellular glutathione, mRNA levels of antioxidant/detoxifying enzymes activated through NF-E2-related factor 2, Nrf2, pathway) and on APEH/β-5 activity/expression levels, were investigated in A375 melanoma cells. Dose- and time-dependent variations of the considered parameters were established and the resulting pro-apoptotic effects were shown to be associated with an alteration of the redox status and a down-regulation of APEH/proteasome pathway. Therefore, our results support the idea that these events are involved in ROS-dependent apoptosis of t10,c12-CLA-treated A375 cells. The combined inhibition, triggered by t10,c12-CLA, via the modulation of APEH/proteasome and Nrf2 pathway for treating melanoma, is suggested as a subject for further in vivo studies.
authors.affiliation: Institute of Food Sciences, National Research Council (CNR-ISA), Avellino, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bergamo
authors.forename: Ennio
authors.initials: E
authors.lastname: Cocca
authors.forename: Rosanna
authors.initials: R
authors.lastname: Palumbo
authors.forename: Marta
authors.initials: M
authors.lastname: Gogliettino
authors.forename: Mose
authors.initials: M
authors.lastname: Rossi
authors.forename: Gianna
authors.initials: G
authors.lastname: Palmieri
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007700:Kinetics; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D050984:NF-E2 Transcription Factor, p45 Subunit / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D000970:Antineoplastic Agents; D044243:Linoleic Acids, Conjugated; D050984:NF-E2 Transcription Factor, p45 Subunit; C494692:NFE2 protein, human; D017382:Reactive Oxygen Species; C496197:trans-10,cis-12-conjugated linoleic acid; D010447:Peptide Hydrolases; C038220:acylaminoacyl-peptidase; D053148:Caspase 3; C088874:PSMB5 protein, human; D046988:Proteasome Endopeptidase Complex