Specific Expression of Human Intelectin-1 in Malignant Pleural Mesothelioma and Gastrointestinal Goblet Cells

Malignant pleural mesothelioma (MPM) is a fatal tumor. It is often hard to discriminate MPM from metastatic tumors of other types because currently, there are no reliable immunopathological markers for MPM. MPM is differentially diagnosed by some immunohistochemical tests on pathology specimens. In the present study, we investigated the expression of intelectin-1, a new mesothelioma marker, in normal tissues in the whole body and in many cancers, including MPM, by immunohistochemical analysis. We found that in normal tissues, human intelectin-1 was mainly secreted from gastrointestinal goblet cells along with mucus into the intestinal lumen, and it was also expressed, to a lesser extent, in mesothelial cells and urinary epithelial cells. Eighty-eight percent of epithelioid-type MPMs expressed intelectin-1, whereas sarcomatoid-type MPMs, biphasic MPMs, and poorly differentiated MPMs were rarely positive for intelectin-1. Intelectin-1 was not expressed in other cancers, except in mucus-producing adenocarcinoma. These results suggest that intelectin-1 is a better marker for epithelioid-type MPM than other mesothelioma markers because of its specificity and the simplicity of pathological assessment. Pleural intelectin-1 could be a useful diagnostic marker for MPM with applications in histopathological identification of MPM.

恶性胸膜间皮瘤（Malignant pleural mesothelioma, MPM）是一种致死性肿瘤。由于目前尚无可靠的MPM免疫病理标志物，该疾病常难以与其他类型的转移性肿瘤相鉴别。当前，临床需通过病理标本的多项免疫组化检测对MPM进行鉴别诊断。本研究采用免疫组化分析方法，检测了新型间皮瘤标志物intelectin-1在全身正常组织以及包括MPM在内的多种癌症中的表达情况。研究发现，在正常组织中，人intelectin-1主要由胃肠道杯状细胞分泌，与黏液一同进入肠腔；此外在间皮细胞与尿道上皮细胞中也有少量表达。在上皮样型MPM中，88%的病例可检测到intelectin-1表达，而肉瘤样型MPM、双相型MPM及低分化MPM几乎均为intelectin-1阴性。除产黏液性腺癌外，其他类型癌症均未检测到intelectin-1的表达。上述结果表明，相较于其他间皮瘤标志物，intelectin-1凭借其高特异性与病理评估的简便性，可作为上皮样型MPM更优异的标志物。胸膜组织中的intelectin-1有望成为MPM的有效诊断标志物，应用于MPM的组织病理学鉴定。