Altered Expression of the Gap Junction Protein Connexin43 Is Associated with Papillary Thyroid Carcinomas When Compared with Other Noncancer Pathologies of the Thyroid

Background: Gap junctionsare membrane structurescomposed of connexins(Cx) that allow diffusion of small molecules between cells. They are involved in tissue homeostasis, and various organ dysfunctionshave been associated with gap junctiondefects. 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 th...