title: Identification of differentially expressed genes in SHSY5Y cells exposed to okadaic acid by suppression subtractive hybridization.
abstract: BACKGROUND
  Okadaic acid (OA), a toxin produced by several dinoflagellate species is responsible for frequent food poisonings associated to shellfish consumption. Although several studies have documented the OA effects on different processes such as cell transformation, apoptosis, DNA repair or embryogenesis, the molecular mechanistic basis for these and other effects is not completely understood and the number of controversial data on OA is increasing in the literature.
  
  
  RESULTS
  In this study, we used suppression subtractive hybridization in SHSY5Y cells to identify genes that are differentially expressed after OA exposure for different times (3, 24 and 48 h). A total of 247 subtracted clones which shared high homology with known genes were isolated. Among these, 5 specific genes associated with cytoskeleton and neurotransmission processes (NEFM, TUBB, SEPT7, SYT4 and NPY) were selected to confirm their expression levels by real-time PCR. Significant down-regulation of these genes was obtained at the short term (3 and 24 h OA exposure), excepting for NEFM, but their expression was similar to the controls at 48 h.
  
  
  CONCLUSIONS
  From all the obtained genes, 114 genes were up-regulated and 133 were down-regulated. Based on the NCBI GenBank and Gene Ontology databases, most of these genes are involved in relevant cell functions such as metabolism, transport, translation, signal transduction and cell cycle. After quantitative PCR analysis, the observed underexpression of the selected genes could underlie the previously reported OA-induced cytoskeleton disruption, neurotransmission alterations and in vivo neurotoxic effects. The basal expression levels obtained at 48 h suggested that surviving cells were able to recover from OA-caused gene expression alterations.
authors.affiliation: Toxicology Unit, Psychobiology Department, University of A Coruña, Edificio de Servicios Centrales de Investigación, Campus Elviña s/n, 15071 A Coruña, Spain.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Valdiglesias
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Tajes
authors.forename: Eduardo
authors.initials: E
authors.lastname: Pásaro
authors.forename: Josefina
authors.initials: J
authors.lastname: Méndez
authors.forename: Blanca
authors.initials: B
authors.lastname: Laffon
mesh_terms: D045744:Cell Line, Tumor; D003599:Cytoskeleton / Q000235:genetics; D030541:Databases, Genetic; D015536:Down-Regulation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D016900:Neurofilament Proteins / Q000235:genetics / Q000378:metabolism; D009478:Neuropeptide Y / Q000235:genetics / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D019319:Okadaic Acid / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000235:genetics; D050857:Synaptotagmins / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D016900:Neurofilament Proteins; D009478:Neuropeptide Y; C494292:SYT4 protein, human; C061195:neurofilament protein M; D050857:Synaptotagmins; D019319:Okadaic Acid