title: Lung mesenchymal cells function as an inductive microenvironment for human lung cancer propagating cells†.
abstract: OBJECTIVE
  The aim of the present study was to characterize the biological properties and in vivo tumourigenic potential of mesenchymal cells (MCs) obtained from non-small-cell lung cancer (NSCLC) samples.
  
  
  METHODS
  NSCLC samples (53 adenocarcinomas and 24 squamous-cell carcinomas) surgically removed from 46 males and 31 females were processed to identify mesenchymal cells from human lung cancer (hLc-MCs). hLc-MCs were separated from neoplastic epithelial cells, expanded and extensively characterized in vitro. Subsequently, female BALB/c nude mice were subcutaneously injected with either 10(6) or 2.5 × 10(6) Calu-3 (human adenocarcinoma cell line able to reproducibly induce xenografted tumours) alone or in combination with equal doses of hLc-MCs. Control animals were injected with the two doses of hLc-MCs only.
  
  
  RESULTS
  Primary cultures of hLc-MCs were obtained from >80% of NSCLC specimens. The typical MCs immunophenotype was documented by the expression of CD90, CD105, CD73, CD13 and CD44 at fluorescence-activated cell sorting analysis. CD45, CD14, CD34 and epithelial antigens were negative while CD117 (c-kit) and CD133 (prominin) were partially expressed. Interestingly, nuclear transcription factors octamer-binding transcription factor 3/4 and sex determining region Y-box 2 involved in stemness, thyroid transcription factor 1 in bronchoalveolar commitment, and ETS1 in carcinogenesis, were expressed in hLc-MCs isolated from NSCLC. Specific conditioned media and cocultures confirmed the supportive role of hLc-MCs for cancer cells. In vivo experiments showed that at both doses Calu-3 xenografts doubled in size when hLc-MCs were coinjected. Cell tracking in xenografted tumours, by immunofluorescence combined with fluorescence in situ hybridization analysis, documented hX-chromosome-labelled, Calu-3-derived cytokeratin-positive adenocarcinoma structures surrounded by hLc-MCs.
  
  
  CONCLUSIONS
  Tumour-propagating cells require the inductive interaction of resident mesenchymal cells to foster lung cancer development.
authors.affiliation: Thoracic Surgery, Department of Surgical Science, University Hospital of Parma, Parma, Italy luca.ampollini@unipr.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Ampollini
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Denise
authors.initials: D
authors.lastname: Madeddu
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Falco
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Frati
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Lorusso
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Gallia
authors.initials: G
authors.lastname: Graiani
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Saccani
authors.affiliation: Department of Biomedical, Biotechnological and Translational Sciences, University Hospital of Parma, Parma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Gervasi
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Rossetti
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Bonomini
authors.affiliation: Department of Biomedical, Biotechnological and Translational Sciences, University Hospital of Parma, Parma, Italy.
authors.forename: Letizia
authors.initials: L
authors.lastname: Gnetti
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Costanza Annamaria
authors.initials: CA
authors.lastname: Lagrasta
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Enrico Maria
authors.initials: EM
authors.lastname: Silini
authors.affiliation: Cardiothoracic Department, Humanitas Institute, Milan, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Quaini
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Petronini
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Alfieri
authors.affiliation: Thoracic Surgery, Department of Surgical Science, University Hospital of Parma, Parma, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Rusca
authors.affiliation: Thoracic Surgery, Department of Surgical Science, University Hospital of Parma, Parma, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Carbognani
authors.affiliation: Clinical and Experimental Medicine, University Hospital of Parma, Parma, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Quaini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D063646:Carcinogenesis / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D045744:Cell Line, Tumor; D005260:Female; D064593:Heterografts; D006801:Humans; D008168:Lung / Q000473:pathology*; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D009368:Neoplasm Transplantation; D014411:Neoplastic Stem Cells / Q000473:pathology*; D059016:Tumor Microenvironment
keywords: Cancer stem cell niche; Lung cancer; Mesenchymal cells; Tumour microenvironment; Tumour xenografts