title: Expression of tenascin-c and CD44 receptors in cardiac myxomas.
abstract: BACKGROUND
  Myxomas are the most frequent primary cardiac neoplasms. They have an abundant extracellular matrix rich in proteoglycans. Interactions between cells and matrix are very important in the development of tumors, but data about myxomas in this setting are scarce because of the rarity of such neoplasms. The expression of tenascin-c and hyaluran receptors in cardiac myxoma has never been investigated. Moreover, it is now well recognized that cells of cardiac myxoma differentiate along endothelial lines.
  
  
  METHODS
  We have analyzed left atrial myxomas from 13 consecutive patients (six male and seven female, surgically treated), via immunohistochemical methods for the expression of molecules also implicated in angiogenesis in normal and pathological conditions, like tenascin-c and hyaluran receptors CD44s, CD44v5 and CD44v6.
  
  
  RESULTS
  Our data suggest that tenascin-c and CD44s play a synergic and perhaps complementary role in development of cardiac myxomas. In particular, tenascin-c seems to promote aggregation of cells and differentiation in vascular structures, whereas CD44s receptors might be important for cellular motility. Cell proliferation rate in such tumors was very low (MIB-1 labeling index <1%) and uniform in all the areas of the neoplasms regardless of the presence of characteristic structures such as cords and rings of multinucleated cells or the expression of tenascin-c and CD44 receptors.
  
  
  CONCLUSIONS
  This study shows that cardiac myxomas express in the extracellular matrix tenascin-c and on the cellular membranes of neoplastic cells the hyaluran receptor CD44s. Such molecules take part in the mechanism of development of the myxomas and might be in the future the target of nonsurgical treatments.
authors.affiliation: Department of Pathology, School of Medicine, University Magna Graecia, Catanzaro, Italy. gdonato@unicz.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Donato
authors.forename: Francesco
authors.initials: F
authors.lastname: Conforti
authors.forename: Valeria
authors.initials: V
authors.lastname: Zuccalà
authors.forename: Emilio
authors.initials: E
authors.lastname: Russo
authors.forename: Lorenza
authors.initials: L
authors.lastname: Maltese
authors.forename: Ida
authors.initials: I
authors.lastname: Perrotta
authors.forename: Andrea
authors.initials: A
authors.lastname: Amorosi
mesh_terms: D005260:Female; D006338:Heart Neoplasms / Q000098:blood supply / Q000737:chemistry* / Q000276:immunology / Q000601:surgery; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis*; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009232:Myxoma / Q000098:blood supply / Q000737:chemistry* / Q000276:immunology / Q000601:surgery; D009389:Neovascularization, Pathologic / Q000276:immunology / Q000378:metabolism; D019063:Tenascin / Q000032:analysis*
chemical_list: C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D019063:Tenascin