title: Perilipin 1 is a highly specific marker for adipocytic differentiation in sarcomas with intermediate sensitivity.
abstract: OBJECTIVE
  Liposarcomas are the most common soft tissue sarcomas of adults. The identification of lipoblastic cells in soft tissue sarcomas is mandatory for the diagnosis of most subtypes of liposarcomas but may be difficult in conventional histology. The present study focuses on the expression and possible diagnostic impact of two PAT family proteins, perilipin 1/perilipin and perilipin 2/adipophilin in human liposarcomas.
  
  
  METHODS
  Eighty-seven cases of liposarcomas and 30 cases of non-lipomatous sarcomas were investigated immunohistochemically for perilipin 1 and 2 using entire tissue sections. Statistical analyses were performed using appropriate tests.
  
  
  RESULTS
  Most liposarcomas and non-lipomatous sarcomas displayed positivity for perilipin 2. In contrast, while more than two-thirds of liposarcomas presented perilipin 1 positivity, all non-lipomatous sarcomas studied were negative for this marker, with statistical significance (p < 0.001). Perilipin 1 expression increased with adipocytic differentiation of liposarcoma subtypes showing statistical significance (p < 0.001). Non-lipomatous sarcomas demonstrated variable expression levels of perilipin 2. The expression level of perilipin 2 appeared to be correlated with tumor cell degeneration, e.g., through hypoxia.
  
  
  CONCLUSIONS
  Perilipin 2 is not well suitable for distinction between liposarcomas and non-lipomatous sarcomas. However, perilipin 1 appeared to be a highly specific marker for liposarcoma and adipocytic differentiation in sarcomas with intermediate sensitivity.
authors.affiliation: Institute of Pathology, Philipps University of Marburg and University Hospital Giessen and Marburg, Baldingerstrasse, 35043, Marburg, Germany. westhoff@med.uni-marburg.de.
authors.forename: Christina C
authors.initials: CC
authors.lastname: Westhoff
authors.affiliation: Institute of Pathology, Philipps University of Marburg and University Hospital Giessen and Marburg, Baldingerstrasse, 35043, Marburg, Germany.|MVZ Bad Salzungen, Ruhla, Germany.
authors.forename: Janice
authors.initials: J
authors.lastname: Mrozinski
authors.affiliation: Institute of Pathology, Philipps University of Marburg and University Hospital Giessen and Marburg, Baldingerstrasse, 35043, Marburg, Germany.|Institute of Pathology, Municipal Hospital Dresden-Friedrichstadt, Dresden, Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Riedel
authors.affiliation: Helmholtz Group for Cell Biology, German Cancer Research Center, Heidelberg, Germany.
authors.forename: Hans W
authors.initials: HW
authors.lastname: Heid
authors.affiliation: Institute of Pathology, Philipps University of Marburg and University Hospital Giessen and Marburg, Baldingerstrasse, 35043, Marburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Moll
mesh_terms: D017667:Adipocytes; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002454:Cell Differentiation; D006801:Humans; D008080:Liposarcoma / Q000378:metabolism*; D000070778:Perilipin-1 / Q000378:metabolism*; D000070780:Perilipin-2 / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; C000602978:PLIN1 protein, human; C000602982:PLIN2 protein, human; D000070778:Perilipin-1; D000070780:Perilipin-2
keywords: Adipophilin; Degeneration; Differential expression; Hypoxia; Liposarcoma; PAT family protein; Perilipin 1; Perilipin 2; Soft tissue sarcoma