title: Evaluation of tissue factor expression in canine tumor cells.
abstract: OBJECTIVE
  To determine whether canine tumor cell lines express functional tissue factor and shed tissue factor-containing microparticles.
  
  
  METHODS
  Cell lines derived from tumors of the canine mammary gland (CMT12 and CMT25), pancreas (P404), lung (BACA), prostate gland (Ace-1), bone (HMPOS, D-17, and OS2.4), and soft tissue (A72); from normal canine renal epithelium (MDCK); and from a malignant human mammary tumor (MDA-MB-231).
  
  
  METHODS
  Tissue factor mRNA and antigen expression were evaluated in cells by use of canine-specific primers in a reverse transcriptase PCR assay and a rabbit polyclonal anti-human tissue factor antibody in flow cytometric and immunofluorescent microscopic assays, respectively. Tissue factor procoagulant activity on cell surfaces, in whole cell lysates, and in microparticle pellets was measured by use of an activated factor X-dependent chromogenic assay.
  
  
  RESULTS
  Canine tissue factor mRNA was identified in all canine tumor cells. All canine tumor cells expressed intracellular tissue factor; however, the HMPOS and D-17 osteosarcoma cells lacked surface tissue factor expression and activity. The highest tissue factor expression and activity were observed in canine mammary tumor cells and pulmonary carcinoma cells (BACA). These 3 tumors also shed tissue factor-bearing microparticles into tissue culture supernatants.
  
  
  CONCLUSIONS
  Tissue factor was constitutively highly expressed in canine tumor cell lines, particularly those derived from epithelial tumors. Because tumor-associated tissue factor can promote tumor growth and metastasis in human patients, high tissue factor expression could affect the in vivo biological behavior of these tumors in dogs.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. ts23@cornell.edu
authors.forename: Tracy
authors.initials: T
authors.lastname: Stokol
authors.forename: Janelle L
authors.initials: JL
authors.lastname: Daddona
authors.forename: Lamya S
authors.initials: LS
authors.lastname: Mubayed
authors.forename: Jakob
authors.initials: J
authors.lastname: Trimpert
authors.forename: Sungkwon
authors.initials: S
authors.lastname: Kang
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D004283:Dog Diseases / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D005434:Flow Cytometry / Q000662:veterinary; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008856:Microscopy, Fluorescence / Q000662:veterinary; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012441:Saccharomyces cerevisiae; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D012333:RNA, Messenger; D013925:Thromboplastin