上皮细胞黏附分子和紧密连接蛋白在甲状腺癌组织的表达及其临床意义

The expression and significance of epithelial cellular adhesion molecule and Claudin -7 in thyroid cancer

目的检测上皮细胞黏附分子（EpCAM）和紧密连接蛋白-7（Claudin-7）在甲状腺癌细胞和组织中的表达，探讨其临床意义。方法取乳头状甲状腺癌细胞株TPC-1、滤泡状甲状腺癌细胞株FTC-133、未分化的甲状腺癌细胞株FRO和ACT-1接种，并培养24 h。反转录-聚合酶链反应（RT-PCR）检测EpCAM和Claudin-7在甲状腺癌细胞株中的mRNA水平，Western blot检测EpCAM和Claudin-7在甲状腺癌细胞株中蛋白表达水平，荧光显微镜下观察EpCAM和Claudin-7在甲状腺癌细胞株中的表达。免疫组织化学法检测EpCAM和Claudin-7在甲状腺癌组织中的表达。结果EpCAM和Claudin-7在FRO和ACT-1细胞株中mRNA和蛋白水平均呈高表达（分别为18.7%、29.6%和81.5%、70.0%），而在TPC-1和FTC-133细胞中几乎不表达。荧光显微镜观察结果同RT-PCR和Western blot一致。免疫组织化学检测结果显示EpCAM和Claudin-7在其他类型的甲状腺癌中的阳性表达率分别为2.6%和5.2%，在未分化的甲状腺癌组织中的阳性表达率为64.9%和81.8%（P＝0.000）。 结论EpCAM在甲状腺未分化癌组织中高表达，而Claudin-7在甲状腺未分化癌组织中高表达，表明EpCAM和Claudin-7与甲状腺癌的恶性程度密切相关，对甲状腺癌的发生发展具有促进作用。

Objective To investigate the expression and significance of epithelial cellular adhesion molecule （EpCAM） and Claudin-7 in thyroid cancer cells and tissues. Methods Papillary thyroid carcinoma cell line TPC-1, follicular thyroid carcinoma cell line FTC-133, and undifferentiated thyroid cancer cell lines FRO and ACT-1 were inoculated and incubated for 24 h. The mRNA levels of EpCAM and Claudin-7 in thyroid cancer cell lines were detected by reverse transcriptase-polymerase chain reaction （RT-PCR）. Western blotting was used to investigate the protein levels of EpCAM and Claudin-7 in the thyroid cancer cells. The expressions of EpCAM and Claudin-7 in thyroid cancer cells were examined by fluorescence microscope. The expression levels of EpCAM and Claudin-7 in thyroid cancer tissues were tested by immunohistochemistry. Results The mRNA and protein expression levels of EpCAM and Claudin-7 were up-regulated in FRO and ACT-1 cells （Respectively, 18.7%, 29.6% and 81.5%, 70.0%）, but there were few expression in TPC-1 and FTC-133 cells. Immunohistochemstry showed the results from fluorescence microscope was in accordance with those from RT-PCR and Western blotting. The postive expression rates of EpCAM and Claudin-7 in the other thyroid cancer cells were 2.6% and 5.2% sperately, and were 64.9% and 81.8% in undifferential thyroid cancer tissue. Conclusion EpCAM and Claudin-7 are highly expressed in undifferentiated thyroid carcinoma, which promotes the occurrence and development of thyroid carcinoma.