title: Altered expression of the gap junction protein connexin43 is associated with papillary thyroid carcinomas when compared with other noncancer pathologies of the thyroid.
abstract: BACKGROUND
  Gap junctions are membrane structures composed of connexins (Cx) that allow diffusion of small molecules between cells. They are involved in tissue homeostasis, and various organ dysfunctions have been associated with gap junction defects. To verify their possible involvement in thyroid pathologies, the expression of connexin43 (Cx43), the major Cx in the human thyroid, was evaluated in a variety of diseases including cancer.
  
  
  METHODS
  There were 122 samples from various thyroid pathologies that were collected to analyze the presence of Cx43 by immunofluorescence. Through confocal microscopy, different patterns of Cx43 localization were identified as normal (membrane) or abnormal (cytoplasmic or lack of detection). The analysis of Cx43 expression was further performed by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry in a subset of 25 papillary carcinomas and compared with nontumoral thyroid tissues.
  
  
  RESULTS
  The presence of Cx43 was commonly altered in thyroid cancer, as abnormal Cx43 staining was detected in 94.1% of cancer, 47.4% of adenomas, 45.7% of multinodular goiter, 16.7% of Graves' disease, and 25% of thyroiditis. In papillary carcinoma samples, the deregulation of Cx43 expression was mostly the consequence of a decrease of Cx43 mRNA (68% of cases) when compared with normal tissue. When Cx43 mRNA was not downregulated (32% of cases), both loss of membrane staining and aberrant cytoplasmic distribution of the protein were observed.
  
  
  CONCLUSIONS
  These results show that aberrations of Cx43 expression are associated with thyroid papillary carcinoma.
authors.affiliation: Department of Visceral Surgery, Jean Bernard Hospital, University Hospital Center (CHU) of Poitiers, Poitiers, France.
authors.forename: Claudia
authors.initials: C
authors.lastname: Dominguez
authors.forename: Lucie
authors.initials: L
authors.lastname: Karayan-Tapon
authors.forename: Thibault
authors.initials: T
authors.lastname: Desurmont
authors.forename: Hélène
authors.initials: H
authors.lastname: Gibelin
authors.forename: Sophie
authors.initials: S
authors.lastname: Crespin
authors.forename: Gaëlle
authors.initials: G
authors.lastname: Fromont
authors.forename: Pierre
authors.initials: P
authors.lastname: Levillain
authors.forename: Gauthier
authors.initials: G
authors.lastname: Bouche
authors.forename: Anne
authors.initials: A
authors.lastname: Cantereau
authors.forename: Marc
authors.initials: M
authors.lastname: Mesnil
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Kraimps
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D002277:Carcinoma; D002291:Carcinoma, Papillary; D018031:Connexin 43 / Q000378:metabolism*; D015536:Down-Regulation; D017629:Gap Junctions / Q000378:metabolism; D006044:Goiter, Nodular / Q000378:metabolism* / Q000473:pathology; D006111:Graves Disease / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000378:metabolism; D012189:Retrospective Studies; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology; D013966:Thyroiditis / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D018031:Connexin 43; D012333:RNA, Messenger