title: Proteome profiling of cancer-associated fibroblasts identifies novel proinflammatory signatures and prognostic markers for colorectal cancer.
abstract: OBJECTIVE
  Cancer-associated fibroblasts (CAF) are essential components of the stroma that play a critical role in cancer progression. This study aimed to identify novel CAFs markers that might contribute to the invasion and the prognosis of colorectal cancer.
  
  
  METHODS
  The azoxymethane/dextran sodium sulfate mouse model of sporadic colon cancer represents an adequate source for the isolation of CAFs and normal fibroblasts. By using the explants technique, we purified CAFs and normal fibroblasts from colon tissues. Whole-cell extracts and supernatants were subjected to in-depth quantitative proteomic analysis by tandem mass spectrometry. Further validations of upregulated proteins in CAFs were carried out by chemokine microarray and immunohistochemical analyses of mouse and human tissues.
  
  
  RESULTS
  Using a fold-change of 1.4 or more, we found 132 and 125 differentially expressed proteins in whole-cell extracts and supernatants, respectively. We found CAFs-associated proinflammatory and desmoplastic signatures. The proinflammatory signature was composed of several cytokines. Among them, CCL2 and CCL8 caused an increase in migration and invasion of colorectal cancer KM12 cells. The desmoplastic signature was composed of 30 secreted proteins. In mouse and human samples, expression of LTBP2, CDH11, OLFML3, and, particularly, FSTL1 was significantly increased in the tumoral stroma, without significant expression in the cancer epithelial cells. The combination of CALU and CDH11 stromal expression showed a significant association with disease-free survival and poor prognosis.
  
  
  CONCLUSIONS
  We have identified LTBP2, CDH11, OLFML3, and FSTL1 as selective biomarkers of cancer stroma, and CALU and CDH11 as candidate stromal biomarkers of prognostic significance in colon cancer.
authors.affiliation: Authors' Affiliations: Department of Cellular and Molecular Medicine; Proteomics Core Facility, Centro de Investigaciones Biológicas (CIB-CSIC); Department of Pathology, Fundación Jiménez Díaz; Department of Oncology, Hospital Puerta de Hierro Majadahonda, Madrid; and IMIM-Hospital del Mar, Barcelona, Spain.
authors.forename: Sofia
authors.initials: S
authors.lastname: Torres
authors.forename: Rubén A
authors.initials: RA
authors.lastname: Bartolomé
authors.forename: Marta
authors.initials: M
authors.lastname: Mendes
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Barderas
authors.forename: M Jesús
authors.initials: MJ
authors.lastname: Fernandez-Aceñero
authors.forename: Alberto
authors.initials: A
authors.lastname: Peláez-García
authors.forename: Cristina
authors.initials: C
authors.lastname: Peña
authors.forename: María
authors.initials: M
authors.lastname: Lopez-Lucendo
authors.forename: Roi
authors.initials: R
authors.lastname: Villar-Vázquez
authors.forename: Antonio García
authors.initials: AG
authors.lastname: de Herreros
authors.forename: Felix
authors.initials: F
authors.lastname: Bonilla
authors.forename: J Ignacio
authors.initials: JI
authors.lastname: Casal
mesh_terms: D000818:Animals; D015415:Biomarkers; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D051379:Mice; D058628:Myofibroblasts / Q000378:metabolism; D011379:Prognosis; D060066:Protein Interaction Maps; D020543:Proteome; D015203:Reproducibility of Results; D017154:Stromal Cells / Q000378:metabolism
chemical_list: D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D020543:Proteome