Differential expression of claudin-2 in normal human tissues and gastrointestinal carcinomas

• DOI: 10.1007/s00428-005-0120-2
• Publication Date: 2005-11-17T18:43:29Z
• Authors: Phyu Phyu Aung; Yoshitsugu Mitani; Yuichi Sanada; Hirofumi Nakayama; Keisuke Matsusaki; Wataru Yasui
• Keywords: 0301 basic medicine; Reverse Transcriptase Polymerase Chain Reaction; Gene Expression Profiling; Gene Expression; Membrane Proteins; Adenocarcinoma; 3. Good health; Immunoenzyme Techniques; 03 medical and health sciences; Stomach Neoplasms; Cell Line, Tumor; Claudins; Biomarkers, Tumor; Humans; RNA, Messenger; Colorectal Neoplasms; Neoplasm Staging

Claudins are involved in the formation of tight junctions in epithelial and endothelial cells. Claudins form a family of 24 members displaying organ- and tissue-specific patterns of expression. In the present study, we evaluated the specificity of the claudin-2 expression in various normal human tissues and gastrointestinal cancers by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry. In 14 various normal tissues, claudin-2 mRNA was expressed in the kidney, liver, pancreas, stomach, and small intestine; the highest level of which was detected in the kidney. Colorectal cancers (CRCs) expressed claudin-2 mRNA at high levels. Immunohistochemical analysis of claudin-2 in 146 gastric cancers (GCs) and 99 CRCs demonstrated claudin-2 expression in 2.1% of GCs and 25.3% of CRCs, respectively. There was no obvious correlation between claudin-2 expression and clinicopathological parameters of CRCs. These results suggest that the expression of claudin-2 may involve organ specificity, and increased expression of claudin-2 may participate in colorectal carcinogenesis.