title: Expression of proliferation markers and cell cycle regulators in T cell lymphoproliferative skin disorders.
abstract: BACKGROUND
  Abnormal cell proliferation, which results from deregulation of the cell cycle, is fundamental in tumorigenesis.
  
  
  OBJECTIVE
  To investigate the expression of proliferation markers and cell cycle regulators in a range of T cell lymphoproliferative skin diseases.
  
  
  METHODS
  We studied skin specimens of 51 patients with parapsoriasis (PP), mycosis fungiodes (MF), or lymphomatoid papulosis (LyP). Immunohistochemistry was performed for Ki-67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance protein 7 (MCM7), and p21.
  
  
  RESULTS
  MF with stage IIB-IV and LyP showed a significantly greater number of Ki-67-positive cells than PP (P=0.02 and 0.001) and MF I-IIA (P=0.019 and 0.003), respectively. MCM7 staining revealed significantly higher labeling indices for MF IIB-IV and LyP when compared to PP (P=0.002 and 0.04) and MF I-IIA (P=0.0005 and 0.01), respectively. Compared to PP and MF I-IIA, MF IIB-IV was associated with significantly higher labeling indices for PCNA (P=0.006 and 0.0004). p21 staining was significantly increased in MF IIB-IV and LyP when compared to PP (P=0.006 and 0.003) and MF I-IIA (P=0.003). However, p21 staining was all in all very weak.
  
  
  CONCLUSIONS
  Ki-67 and PCNA seem to be useful immunohistological parameters for the correlation with the clinical stage of MF. In the differentiation and prognostication of T cell lymphoproliferative skin disorders, MCM7 may serve as a novel biomarker which is, in contrast to Ki-67 and PCNA, stable throughout the cell cycle.
authors.affiliation: Department of Dermatology, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany. t.gambichler@klinikum-bochum.de
authors.forename: Thilo
authors.initials: T
authors.lastname: Gambichler
authors.forename: Stefan
authors.initials: S
authors.lastname: Bischoff
authors.forename: Falk G
authors.initials: FG
authors.lastname: Bechara
authors.forename: Peter
authors.initials: P
authors.lastname: Altmeyer
authors.forename: Alexander
authors.initials: A
authors.lastname: Kreuter
mesh_terms: D018797:Cell Cycle Proteins / Q000032:analysis*; D002454:Cell Differentiation; D049109:Cell Proliferation; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis; D004268:DNA-Binding Proteins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D017731:Lymphomatoid Papulosis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D064168:Minichromosome Maintenance Complex Component 7; D009182:Mycosis Fungoides / Q000737:chemistry* / Q000276:immunology / Q000473:pathology; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000032:analysis; D010267:Parapsoriasis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D012867:Skin / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D012878:Skin Neoplasms / Q000737:chemistry* / Q000276:immunology / Q000473:pathology; D016176:T-Lymphocyte Subsets / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism