title: Stem cell marker CD271 is expressed by vasculogenic mimicry-forming uveal melanoma cells in three-dimensional cultures.
abstract: OBJECTIVE
  Cancer stem cells have increased resistance against a variety of anti-tumor treatment modalities. Vasculogenic mimicry (VM) patterns are present in numerous malignant tumor types, represent the formation of perfusion pathways by tumor cells, and their presence in tumors is associated with adverse outcome. Earlier we have shown that VM-forming tumor cells in three-dimensional (3D) uveal melanoma cultures have increased resistance against cytotoxic agents and oncolytic herpes simplex virus-mediated destruction. The purpose of the current study was to explore the possibility that this increased resistance of VM-forming tumor cells is due to a cancer stem cell phenotype.
  
  
  METHODS
  The expression of cancer stem cell marker cluster of differentiation 271 (CD271) was determined in traditional two-dimensional (2D) and 3D cultures of C918 uveal melanoma cells by fluorescent immunocytochemistry.
  
  
  RESULTS
  We found that the VM-forming tumor cell subpopulation in 3D cultures expressed CD271. In contrast, cells grown in 2D cultures and tumor cell subpopulations not participating in VM formation in 3D cultures were negative for CD271.
  
  
  CONCLUSIONS
  These findings suggest that VM-forming uveal melanoma cells acquire a cancer stem cell-like phenotype that may play a role in the increased therapy resistance of these cells.
authors.affiliation: Department of Pathology, University of Illinois at Chicago, College of Medicine, Chicago, IL 60612, USA.
authors.forename: Klara
authors.initials: K
authors.lastname: Valyi-Nagy
authors.forename: Bernadett
authors.initials: B
authors.lastname: Kormos
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ali
authors.forename: Deepak
authors.initials: D
authors.lastname: Shukla
authors.forename: Tibor
authors.initials: T
authors.lastname: Valyi-Nagy
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D018929:Cell Culture Techniques; D019008:Drug Resistance, Neoplasm; D005123:Eye / Q000098:blood supply* / Q000473:pathology; D005134:Eye Neoplasms / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000378:metabolism* / Q000473:pathology; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D009389:Neovascularization, Pathologic; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D017475:Receptors, Nerve Growth Factor / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014604:Uveal Neoplasms / Q000378:metabolism* / Q000473:pathology; D000098943:Uveal Melanoma
chemical_list: D014408:Biomarkers, Tumor; C484065:NGFR protein, human; D009419:Nerve Tissue Proteins; D017475:Receptors, Nerve Growth Factor