title: Differential expression of CDC25 phosphatases splice variants in human breast cancer cells.
abstract: BACKGROUND
  CDC25 phosphatases control cell cycle progression by activating cyclin dependent kinases. The three CDC25 isoforms encoding genes are submitted to alternative splicing events which generate at least two variants for CDC25A and five for both CDC25B and CDC25C. An over-expression of CDC25 was reported in several types of cancer, including breast cancer, and is often associated with a poor prognosis. Nevertheless, most of the previous studies did not address the expression of CDC25 splice variants. Here, we evaluated CDC25 spliced transcripts expression in anti-cancerous drug-sensitive and resistant breast cancer cell lines in order to identify potential breast cancer biomarkers.
  
  
  METHODS
  CDC25 splice variants mRNA levels were evaluated by semi-quantitative RT-PCR and by an original real-time RT-PCR assay.
  
  
  RESULTS
  CDC25 spliced transcripts are differentially expressed in the breast cancer cell lines studied. An up-regulation of CDC25A2 variant and an increase of the CDC25C5/C1 ratio are associated to the multidrug-resistance in VCREMS and DOXOR breast cancer cells, compared to their sensitive counterpart cell line MCF-7. Additionally, CDC25B2 transcript is exclusively over-expressed in VCREMS resistant cells and could therefore be involved in the development of certain type of drug resistance.
  
  
  CONCLUSIONS
  CDC25 splice variants could represent interesting potential breast cancer prognostic biomarkers.
authors.affiliation: Laboratoire d'Ingénierie Moléculaire et Biochimie Pharmacologique, EA 3940, FR CNRS 2843, Université Paul Verlaine-Metz, Metz, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Albert
authors.forename: Susana
authors.initials: S
authors.lastname: Santos
authors.forename: Eric
authors.initials: E
authors.lastname: Battaglia
authors.forename: Miguel
authors.initials: M
authors.lastname: Brito
authors.forename: Carolino
authors.initials: C
authors.lastname: Monteiro
authors.forename: Denyse
authors.initials: D
authors.lastname: Bagrel
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D020033:Protein Isoforms / Q000235:genetics; D012326:RNA Splicing; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020687:cdc25 Phosphatases / Q000097:blood / Q000235:genetics* / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D020687:cdc25 Phosphatases