title: The role of CD147 in the invasiveness of follicular thyroid carcinoma cells.
abstract: BACKGROUND
  In patients without metastases, capsular and vascular invasion must be noted to make the diagnosis of follicular thyroid carcinoma (FTC). Some patients are initially diagnosed as follicular adenoma (FA) but develop metastases, indicating the original lesion was FTC. A diagnostic marker for FTCs that appear to be FAs by conventional histopathology is urgently needed. CD147 is a transmembrane glycoprotein that induces matrix metalloproteinases (MMPs) and participates in carcinoma invasion. The objective of this study was to determine whether CD147 is upregulated in FTC and if measures directed against it could reduce the invasive activity of FTC cells.
  
  
  METHODS
  The expression levels of CD147, MMP-1, MMP-2, MMP-3, MMP-7, and MMP-9 in surgical specimens of normal thyroid (n=8), FA (n=20), and FTC (n=9) was determined using immunoblot and immunohistochemical techniques. CD147 protein expression levels of epithelial growth factor stimulated FTC-133 cell lines was measured by immunoblotting with and without cell signaling inhibitors such as wortmannin, PD98059, SP600125, and SB203580. This was also done after exposure to short-hairpin interference RNA directed against CD147.
  
  
  RESULTS
  Immunoblot analysis of thyroid tissues revealed significant increases in signals for CD147, MMP-3, MMP-7, and MMP-9 in FTC compared with FA or normal tissue, or both. Immunohistochemical analysis revealed colocalization of determinants of CD147 with those of all of MMPs studied, mainly in follicular cells in normal and neoplastic cells in FA and FTC; their immunoreactivities were to some extent more intense in the FTC than FA or normals. In FTC-133 cells, immunoreactive signals for CD147 were upregulated by epidermal growth factor (EGF), and the EGF-driven increases in CD147 were prevented by inhibitors against phosphoinositol-3 kinase (PI3K), extracellular signal-regulated protein kinase (ERK), or c-Jun N-terminal kinase (JNK) but not p38. RNA interference targeted against CD147 reduced the invasive activity of FTC-133 cells and was associated with downregulation of MMP-2, MMP-3, MMP-7, and MMP-9.
  
  
  CONCLUSIONS
  These results provide in vivo evidence for CD147 upregulation in FTC and in vitro evidence for EGF-stimulated CD147 induction via the PI3K, ERK, and JNK pathways. They suggest the involvement of CD147 in the invasiveness of FTC cells via regulation of MMPs.
authors.affiliation: Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan. yomi@research.twmu.ac.jp
authors.forename: Yoko
authors.initials: Y
authors.lastname: Omi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Shibata
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okamoto
authors.forename: Takao
authors.initials: T
authors.lastname: Obara
authors.forename: Makio
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D018263:Adenocarcinoma, Follicular; D000236:Adenoma / Q000235:genetics / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D051926:Basigin / Q000235:genetics / Q000502:physiology*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005260:Female; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008875:Middle Aged; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D015398:Signal Transduction / Q000187:drug effects; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult
chemical_list: D051926:Basigin; D004815:Epidermal Growth Factor; D020782:Matrix Metalloproteinases; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors