title: Cell heterogeneity and subpopulations in solid tumors characterized by simultaneous immunophenotyping and DNA content analysis.
abstract: BACKGROUND
  Heterogeneity in human malignant tumors is a well-described phenomenon and of interest with regard to subpopulations with differences in clonality, metastatic potential, and response to therapy under different treatment regimes. The aim of this study was the simultaneous characterization of surface markers and DNA content of solid tumors to identify tumor cell subpopulations and to study the association between the expression of antigens and DNA content.
  
  
  METHODS
  In the present study, six different malignant tumors grown as xenografts in nude mice were characterized by five-parameter flow cytometry. Immunophenotyping was performed using a variety of direct fluorescence-conjugated antibodies. In all cases, simultaneous detection of DNA content was done after staining with 7-aminoactinomycin D.
  
  
  RESULTS
  Tumor cells were characterized by light scatter properties, antigen expression, and DNA content. Tumor cell heterogeneity, subpopulations, and DNA content-dependent antigen expression were identified.
  
  
  CONCLUSIONS
  This method offers the possibility of characterizing solid tumors according to their immunophenotype and DNA content. The results obtained can be used to identify changes in immunophenotypic and DNA profiles of tumor cell populations before and after therapy and might be useful to define parameters predictive for response to therapy.
authors.affiliation: Department of Radiation Oncology, University of Münster, Münster, Germany. stkoene@uni-muenster.de
authors.forename: S
authors.initials: S
authors.lastname: Könemann
authors.forename: A
authors.initials: A
authors.lastname: Schuck
authors.forename: J
authors.initials: J
authors.lastname: Malath
authors.forename: T
authors.initials: T
authors.lastname: Rupek
authors.forename: K
authors.initials: K
authors.lastname: Horn
authors.forename: M
authors.initials: M
authors.lastname: Baumann
authors.forename: J
authors.initials: J
authors.lastname: Vormoor
authors.forename: C
authors.initials: C
authors.lastname: Rübe
authors.forename: N
authors.initials: N
authors.lastname: Willich
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D004273:DNA, Neoplasm / Q000032:analysis* / Q000187:drug effects; D003609:Dactinomycin / Q000031:analogs & derivatives / Q000494:pharmacology; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000494:pharmacology; D006801:Humans; D016130:Immunophenotyping; D051379:Mice; D008819:Mice, Nude; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000235:genetics* / Q000276:immunology* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D005456:Fluorescent Dyes; D003609:Dactinomycin; C025942:7-aminoactinomycin D