E-cadherin loss rather than β-catenin alterations is a common feature of poorly differentiated thyroid carcinomas

• Published in: Histopathology Vol. 42; no. 6; pp. 580 - 587
• Main Authors: Rocha, A S, Soares, P, Fonseca, E, Cameselle-Teijeiro, J, Oliveira, M C, Sobrinho-Simões, M
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-06-2003; Blackwell
• Subjects: Adult; Aged; Aged, 80 and over; beta Catenin; Biological and medical sciences; Biomarkers, Tumor - metabolism; Cadherins - genetics; Cadherins - metabolism; Carcinoma - genetics; Carcinoma - metabolism; Carcinoma - pathology; Cytoskeletal Proteins - genetics; Cytoskeletal Proteins - metabolism; DNA Mutational Analysis; DNA, Neoplasm - analysis; E-cadherin; Endocrinopathies; Female; Humans; Immunoenzyme Techniques; Male; Malignant tumors; Medical sciences; Microdissection; Middle Aged; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; poorly differentiated carcinomas; thyroid; Thyroid Neoplasms - genetics; Thyroid Neoplasms - metabolism; Thyroid Neoplasms - pathology; Thyroid. Thyroid axis (diseases); Trans-Activators - genetics; Trans-Activators - metabolism; α-catenin; β-catenin; γ-catenin; Endocrinopathy; Human; Immunohistochemistry; Carcinoma; Microdissection; poorly differentiated carcinomas; Thyroid diseases; Cell adhesion molecule; Thyroid gland; Malignant tumor; Cell differentiation; Carcinogenesis; E-cadherin; Pathology; β-catenin; thyroid; γ-catenin; α-catenin; Molecular biology; E Cadherin; Catenin
• ISSN: 0309-0167; 1365-2559
• DOI: 10.1046/j.1365-2559.2003.01642.x

Aims: To investigate the immunohistochemical and molecular genetic features of the cadherins/catenins complex in thyroid carcinoma based on the hypothesis that poorly differentiated carcinoma of the thyroid represents an intermediate step between well‐differentiated and undifferentiated carcinomas.
Methods and results: Immunohistochemistry for E‐, P‐ and N‐cadherins and α‐, β‐ and γ‐catenins was performed in a series of 17 cases of poorly differentiated carcinoma of the thyroid. All cases showed absence of membranous expression of E‐cadherin with no aberrant expression of P‐ or N‐cadherins; regarding catenins there was heterogeneous loss of expression with membranous immunolocalization of the three catenins in most cases. Molecular analysis of the E‐cadherin gene and exon 3 of the β‐catenin gene was also performed by polymerase chain reaction/single‐strand conformation polymorphism and sequencing. No mutations in either gene were detected in any case.
Conclusions:  In contrast to previous reports, our results suggest that loss of E‐cadherin rather than β‐catenin mutation is the crucial event in determining the differentiation ‘level’ of thyroid carcinomas.