title: Chromosomal rearrangements in PLAG1 of myoepithelial salivary gland tumours.
abstract: PLAG1 mutations are related to the development of pleomorphic adenomas. A specific aspect of PA is the histological diversity of this entity, containing cells with mesenchymal, epithelial and myoepithelial differentiation. Evidence for myoepithelial cells in PA raises the question whether the very rare entity of pure myoepithelial salivary gland tumours shows chromosomal translocations and rearrangements and whether activation of PLAG1 can be detected.
  
  
  METHODS
  Fluorescence in-situ hybridisation (FISH) was established using the DNA-probes PLAG 233, PLAG 234, PLAG 235. The probes were generated from plasmids. Standardization of FISH was achieved in human lymphocytes. Routinely formalin-fixed, paraffin-embedded slices of myoepithelial salivary gland tumours were available for study. In some cases isolated nuclei were investigated. Isolation of the nuclei was performed according to Hedley. Scoring of the FISH was done with a Laser-scanning microscope (spot-counting: fluorescence signals/100 cells/slice). The number of signal variants was determined. All evaluated regions were registered on microphotographs.
  
  
  RESULTS
  PLAG1 was only rarely detected. PLAG1 is evidently not involved in the development of myoepithelial tumours. The proportion of 8q12-alterations in myoepithelial tumours was very low.
  
  
  CONCLUSIONS
  PLAG1 is an insufficient marker to differentiate between benign and malignant myoepithelial tumours.
authors.affiliation: Oral and Cranio-Maxillofacial Surgery, Eppendorf University Hospital, University of Hamburg, Martinistr. 52, D-20246 Hamburg, Germany. rfriedrich@uke.de
authors.forename: Reinhard E
authors.initials: RE
authors.lastname: Friedrich
authors.forename: Julia
authors.initials: J
authors.lastname: Dilcher
authors.forename: Michael
authors.initials: M
authors.lastname: Jaehne
authors.forename: Thomas
authors.initials: T
authors.lastname: Löning
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002898:Chromosomes, Human, Pair 8; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009208:Myoepithelioma / Q000235:genetics*; D012468:Salivary Gland Neoplasms / Q000235:genetics*; D014178:Translocation, Genetic
chemical_list: D004268:DNA-Binding Proteins; C104382:PLAG1 protein, human