Krajewska Maryla, Olson Allen H, Mercola Dan, Reed John C, Krajewski Stan
Burnham Institute for Medical Research, La Jolla, CA 92037, USA.
Prostate. 2007 Jun 15;67(9):907-10. doi: 10.1002/pros.20578.
Claudins are a family of approximately 23 integral membrane tight junction (TJ) proteins that maintain cell polarity and paracellular barrier functions in epithelial and endothelial cells. Although Claudin-1 was demonstrated to be typically downregulated in various cancers, the precise expression patterns of this protein in normal and neoplastic tissues remain poorly characterized.
Using immunohistochemistry, the expression of Claudin-1 was investigated in prostate tissue samples arranged in a tissue microarray (TMA) format and comprising elements of normal prostatic epithelium (n = 6), benign prostatic hyperplasia (BPH; n = 38), prostatic intraepithelial neoplasia (PIN; n = 11), and prostate adenocarcinoma (n = 48). The Claudin-1 expression pattern was compared with that of the basal cell-specific markers, p63, and HMW cytokeratin (34betaE12), by employing double-labeling techniques in conjunction with image analysis methods utilizing color deconvolution algorithms.
In benign prostatic epithelium, pronounced Claudin-1 expression was observed in the basal cell layer with no staining in luminal cells. Prostate adenocarcinoma specimens from 98% (47/48) patients lacked Claudin-1 immunostaining, and no cases contained >5% immunopositive tumor cells.
Claudin-1 immunohistochemistry should be considered for use as a new diagnostic tool for distinguishing malignant from benign lesions of the prostate.
紧密连接蛋白是一族约23种整合膜紧密连接（TJ）蛋白，可维持上皮细胞和内皮细胞的细胞极性及细胞旁屏障功能。尽管已证实在多种癌症中紧密连接蛋白-1通常下调，但该蛋白在正常组织和肿瘤组织中的精确表达模式仍未得到充分表征。
采用免疫组织化学方法，对以组织微阵列（TMA）形式排列的前列腺组织样本中紧密连接蛋白-1的表达进行研究，这些样本包括正常前列腺上皮成分（n = 6）、良性前列腺增生（BPH；n = 38）、前列腺上皮内瘤变（PIN；n = 11）和前列腺腺癌（n = 48）。通过采用双重标记技术并结合利用颜色反卷积算法的图像分析方法，将紧密连接蛋白-1的表达模式与基底细胞特异性标志物p63和高分子量细胞角蛋白（34βE12）的表达模式进行比较。
在良性前列腺上皮中，在基底细胞层观察到明显的紧密连接蛋白-1表达，而管腔细胞无染色。98%（47/48）患者的前列腺腺癌标本缺乏紧密连接蛋白-1免疫染色，且无病例含有>5%的免疫阳性肿瘤细胞。
紧密连接蛋白-1免疫组织化学应被视为一种区分前列腺良恶性病变的新诊断工具。
