title: Eph-A2 and Eph-A4 expression in human benign and malignant thyroid lesions: an immunohistochemical study.
abstract: BACKGROUND
  Ephrin receptors (Ephs) are frequently overexpressed in a wide variety of human malignant tumors, being associated with tumor growth, invasion, metastasis and angiogenesis. The aim of the present study was to evaluate the clinical significance of Eph-A2 and Eph-A4 expression in human benign and malignant thyroid lesions.
  
  
  METHODS
  Eph-A2 and Eph-A4 protein expression was assessed immunohistochemically on paraffin-embedded thyroid tissues from 131 patients with benign and malignant lesions.
  
  
  RESULTS
  Eph-A2 was significantly overexpressed in malignant compared to benign thyroid lesions (p<0.001). Papillary carcinoma cases presented significantly increased Eph-A2 expression compared to those with hyperplasia nodules (p<0.001). Eph-A4 expression was not differentiated between cases with malignant or benign thyroid lesions. Papillary carcinoma cases presented significantly increased Eph-A4 expression compared to those with hyperplasia nodules (p=0.006). In the subgroup of malignant thyroid lesions, Eph-A2 and Eph-A4 expression was not associated with TNM stage, capsular, lymphatic or vascular invasion.
  
  
  CONCLUSIONS
  The present data suggest that Eph-A2, but not Eph-A4, overexpression may be associated with the malignant transformation of thyroid neoplasia. Further studies conducted on cohorts including a higher proportion of patients with advanced nodal and metastatic disease are recommended to draw definite conclusions on the clinical significance of Eph proteins in thyroid neoplasia.
authors.affiliation: Department of Forensic Medicine and Toxicology, Medical School, University of Athens, Athens, Greece.
authors.forename: Nikolaos P
authors.initials: NP
authors.lastname: Karidis
authors.forename: Constantinos
authors.initials: C
authors.lastname: Giaginis
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Tsourouflis
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Alexandrou
authors.forename: Ioanna
authors.initials: I
authors.lastname: Delladetsima
authors.forename: Stamatios
authors.initials: S
authors.lastname: Theocharis
mesh_terms: D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D036104:Receptor, EphA2 / Q000378:metabolism*; D036122:Receptor, EphA4 / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology*
chemical_list: D036104:Receptor, EphA2; D036122:Receptor, EphA4