High expression of claudin-1 protein in papillary thyroid tumor and its regional lymph node metastasis.
Claudins, known as major contributors in the formation of the tight junction, are differentially expressed in malignant tumors as compared to the corresponding healthy tissues. Therefore, they are thought to play a role in carcinogenesis and tumor progression. Altered expression of claudin-1 has been reported in several tumor types including endometrial, papillary renal cell and colonic carcinoma, and increased claudin-1 mRNA levels have been observed in papillary thyroid carcinoma (PTC). In this study, we aimed at determining the pattern of claudin-1 expression in various types of thyroid lesions at the protein level and investigating the immunolocalization of beta-catenin reported to regulate claudin-1 expression. Samples included 19 PTCs, ten cases of corresponding regional lymph node metastasis, eight papillary microcarcinomas (PMC), 17 follicular thyroid carcinomas (FTC) and 19 follicular adenomas (FA). All cases were evaluated by quantitative immunohistochemistry. Conspicuous claudin-1 immunostaining was detected in the majority of PTC/PMC primary tumors and lymph node metastases (19/27 and 9/10, respectively). On the other hand, we found weak or no claudin-1 expression in any of the FA and FTC cases or peritumoral non-malignant thyroid tissues. Our data prove that high claudin-1 protein expression is specific for PTC and its regional lymph node metastases, while we failed to verify that claudin-1 is regulated by beta-catenin in thyroid tumors. Based on these results, claudin-1 may be a useful tumor marker for PTC.
Németh
Júlia
J
2nd Department of Pathology, Semmelweis University, Ulloi út 93, 1091, Budapest, Hungary.
Németh
Zsuzsanna
Z
Tátrai
Péter
P
Péter
Ilona
I
Somorácz
Aron
A
Szász
Attila Marcell
AM
Kiss
András
A
Schaff
Zsuzsa
Z
D000231:Adenocarcinoma, Papillary / Q000378:metabolism* / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002648:Child; D062445:Claudin-1; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis*; D008875:Middle Aged; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology*; D055815:Young Adult
D014408:Biomarkers, Tumor; C568108:CLDN1 protein, human; D062445:Claudin-1; D008565:Membrane Proteins