title: Differential expression of claudin-2 in normal human tissues and gastrointestinal carcinomas.
abstract: 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.
authors.affiliation: Department of Molecular Pathology, Graduate School of Biomedical Sciences Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, Japan.
authors.forename: Phyu Phyu
authors.initials: PP
authors.lastname: Aung
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Mitani
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sanada
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nakayama
authors.forename: Keisuke
authors.initials: K
authors.lastname: Matsusaki
authors.forename: Wataru
authors.initials: W
authors.lastname: Yasui
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D057167:Claudins; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007124:Immunoenzyme Techniques; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009367:Neoplasm Staging; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; C491875:CLDN2 protein, human; D057167:Claudins; D008565:Membrane Proteins; D012333:RNA, Messenger