title: Pleiotropic effects of fenretinide in neuroblastoma cell lines and multicellular tumor spheroids.
abstract: The efficacy and mechanism of action of fenretinide (4-HPR), a vitamin A analogue, was investigated in a panel of six neuroblastoma cell lines and multicellular tumor spheroids. The latter are three dimensional cell aggregates and as such, a model for micrometastases. In all cell lines, the production of reactive oxygen species (ROS) increased with 163-680% after 1 h of treatment with 4-HPR. In addition, a decrease of the mitochondrial membrane potential of 30-75% was observed after 4 h of incubation with 4-HPR. A 6-12-fold difference was observed between the IC50 values for cell proliferation and viability between the most sensitive (IMR32) and most resistant (NASS) cell line towards 4-HPR. Flow cytometric analysis showed an increased amount of apoptotic bodies and no cell-cycle arrest. The antioxidant Trolox completely inhibited the accumulation of 4HPR-induced ROS and prevented the 4HPR-associated cytotoxicity. In all neuroblastoma spheroids, 4-HPR induced a complete cytostasis at clinical relevant concentrations (3-10 microM). Immunohistochemical analysis of 4-HPR-treated spheroids showed a decreased staining for proliferation marker Ki-67 and an increased staining for cleaved-PARP, a marker of apoptosis. Our results suggest that 4-HPR might be a promising agent for the treatment of micrometastases and high-risk neuroblastoma.
authors.affiliation: Laboratory Genetic Metabolic Diseases and Department of Pediatrics/Emma Children's Hospital, Academic Medical Centre, University of Amsterdam, 1100 DE Amsterdam, The Netherlands.
authors.forename: Roos
authors.initials: R
authors.lastname: Cuperus
authors.forename: Godelieve A M
authors.initials: GA
authors.lastname: Tytgat
authors.forename: René
authors.initials: R
authors.lastname: Leen
authors.forename: Pedro
authors.initials: P
authors.lastname: Brites
authors.forename: Johannes
authors.initials: J
authors.lastname: Bras
authors.forename: Huib N
authors.initials: HN
authors.lastname: Caron
authors.forename: André B P
authors.initials: AB
authors.lastname: Van Kuilenburg
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002449:Cell Aggregation / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002839:Chromans / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D017313:Fenretinide / Q000494:pharmacology*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc; D006801:Humans; D007150:Immunohistochemistry; D020128:Inhibitory Concentration 50; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D009447:Neuroblastoma / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018874:Spheroids, Cellular; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D002839:Chromans; D017382:Reactive Oxygen Species; D017313:Fenretinide; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid