Sivertsen Stine, Hadar Rivka, Elloul Sivan, Vintman Lina, Bedrossian Carlos, Reich Reuven, Davidson Ben
Department of Pathology, Radiumhospitalet-Rikshospitalet Medical Center, University of Oslo, Montebello, N-0310 Oslo, Norway.
Lung Cancer. 2006 Dec;54(3):309-17. doi: 10.1016/j.lungcan.2006.08.010. Epub 2006 Sep 25.
Snail, Slug and Sip1 regulate cadherin and protease expression and mediate epithelial-mesenchymal transition in cancer. We analyzed the expression of cadherins and matrix metalloproteinases (MMP) and their transcriptional regulators in malignant mesothelioma (MM). One hundred and ten MM specimens (86 solid, 24 effusions) and 10 non-malignant effusions with reactive mesothelial cells (RMC) were analyzed for E-cadherin, N-cadherin and P-cadherin protein expression using immunhistochemistry. MM effusions were further analyzed for expression of Snail, Slug, Sip1, E-cadherin, MMP-2, MMP-9, MT1-MMP (MMP-14) and the MMP inhibitor TIMP-2, and for MMP-2 and MMP-9 activity using RT-PCR, Western blotting, immunhistochemistry and zymography. Results were analyzed for relationship with specimen type (biopsy versus effusion) and anatomic site (pleural versus peritoneal). E-cadherin, N-cadherin and P-cadherin expression was found in 69/110 (63%), 87/110 (79%) and 84/110 (76%) MM cases, respectively. Pleural and peritoneal MM showed comparable expression, but all three cadherins were upregulated in effusions compared to solid tumors (p<0.001). RMC were uniformly negative for E-cadherin and N-cadherin, and showed P-cadherin expression in 7/10 specimens. Immunohistochemistry localized MMP-2, MMP-9 and TIMP-2 to MM cells in 11/15, 14/15 and 8/15 effusions, respectively. RT-PCR showed direct association between MMP-2 mRNA expression level and the levels of MT1-MMP (p=0.027) and TIMP-2 (p=0.011). Snail protein expression showed positive association with MT1-MMP (p=0.016) and TIMP-2 (p=0.02) mRNA expression, but its expression was unrelated to MMP-2 and MMP-9 expression or activity. Snail, Slug and Sip1 levels did not show inverse association with E-cadherin levels. Our data show that E-cadherin and N-cadherin are selectively expressed in malignant mesothelial cells, and that P-cadherin and N-cadherin are expressed with similar frequency in MM. In agreement with our earlier data for ovarian carcinoma, cadherin expression is upregulated in effusions compared to solid lesions. The increased E-cadherin expression in effusions may be related to lack of negative regulation at the epigenetic level. The relationship between Snail and MMP in MM is uncertain at present.
蜗牛蛋白（Snail）、蛞蝓蛋白（Slug）和Sip1调节钙黏蛋白和蛋白酶的表达，并介导癌症中的上皮-间质转化。我们分析了恶性间皮瘤（MM）中钙黏蛋白和基质金属蛋白酶（MMP）及其转录调节因子的表达。使用免疫组织化学方法分析了110例MM标本（86例实体瘤、24例积液）和10例伴有反应性间皮细胞（RMC）的非恶性积液中E-钙黏蛋白、N-钙黏蛋白和P-钙黏蛋白的蛋白表达。对MM积液进一步分析Snail、Slug、Sip1、E-钙黏蛋白、MMP-2、MMP-9、MT1-MMP（MMP-14）和MMP抑制剂TIMP-2的表达，并使用逆转录聚合酶链反应（RT-PCR）、蛋白质印迹法、免疫组织化学和酶谱法分析MMP-2和MMP-9的活性。分析结果与标本类型（活检与积液）和解剖部位（胸膜与腹膜）的关系。在110例MM病例中，分别有69/110（63%）、87/110（79%）和84/110（76%）检测到E-钙黏蛋白、N-钙黏蛋白和P-钙黏蛋白表达。胸膜和腹膜MM显示出相似的表达，但与实体瘤相比，所有三种钙黏蛋白在积液中均上调（p<0.001）。RMC中E-钙黏蛋白和N-钙黏蛋白均呈阴性，10例标本中有7例显示P-钙黏蛋白表达。免疫组织化学显示，在15例积液中的11例、14例和8例中，MMP-2、MMP-9和TIMP-2分别定位于MM细胞。RT-PCR显示MMP-2 mRNA表达水平与MT1-MMP（p=0.027）和TIMP-2（p=0.011）水平直接相关。蜗牛蛋白表达与MT1-MMP（p=0.016）和TIMP-2（p=0.02）mRNA表达呈正相关，但其表达与MMP-2和MMP-9的表达或活性无关。Snail、Slug和Sip1水平与E-钙黏蛋白水平未显示出负相关。我们的数据表明，E-钙黏蛋白和N-钙黏蛋白在恶性间皮细胞中选择性表达，且P-钙黏蛋白和N-钙黏蛋白在MM中的表达频率相似。与我们早期关于卵巢癌的数据一致，与实体病变相比，积液中钙黏蛋白表达上调。积液中E-钙黏蛋白表达增加可能与表观遗传水平缺乏负调控有关。目前MM中蜗牛蛋白与MMP之间的关系尚不确定。
