Röwer Claudia, George Christian, Reimer Toralf, Stengel Bernd, Radtke Anngret, Gerber Bernd, Glocker Michael O
Proteome Center Rostock, University of Rostock, Schillingallee 69, 18057 Rostock, Germany.
Proteome Center Rostock, University of Rostock, Schillingallee 69, 18057 Rostock, Germany; Department of Obstetrics and Gynecology, University of Rostock, Südring 81, 18059 Rostock, Germany.
Transl Oncol. 2018 Feb;11(1):1-10. doi: 10.1016/j.tranon.2017.10.004. Epub 2017 Nov 10.
Lymph node metastasis status is a prognostic factor for further lymph node involvement and for patient survival in breast cancer patients. Frozen section analysis of lymph nodes is a reliable method for detection of macro-metastases. However, this method is far less effective in detecting micro-metastases, requesting improved diagnostic procedures.
We investigated expression and truncation of ezrin in (i) sentinel lymph node metastases, (ii) unaffected axillary lymph nodes, (iii) primary breast tumors, and (iv) healthy glandular breast tissues using 2D gel electrophoresis, SDS-PAGE, and mass spectrometry in addition to Western blotting.
Full-length ezrin (E1; amino acids 1-586) is present in all four investigated tissues. Two truncated ezrin forms, one missing about the first hundred amino acids (E2a) and the other lacking about 150 C-terminal amino acids (E2b) were detectable in primary tumor tissues and in sentinel lymph node metastases but not in glandular tissues. Strikingly, an ezrin truncation (E3) which consists approximately of amino acids 238-586 was found strongly expressed in all sentinel lymph node metastases. Moreover, an N-terminal ezrin fragment (E4) that consists approximately of amino acids 1-273 was identified in sentinel lymph node metastases as well.
We show for the first time the existence of tissue-dependent specific ezrin truncations. The distinguished strong Western blot staining of ezrin E3 in sentinel lymph node metastases underlines its capability to substantiate the occurrence of lymph node (micro)metastases in breast cancer patients.
淋巴结转移状态是乳腺癌患者进一步发生淋巴结受累及患者生存的一个预后因素。淋巴结的冰冻切片分析是检测宏观转移的可靠方法。然而，该方法在检测微转移方面效果要差得多，需要改进诊断程序。
除蛋白质免疫印迹法外，我们还使用二维凝胶电泳、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和质谱分析法，研究了埃兹蛋白在（i）前哨淋巴结转移灶、（ii）未受影响的腋窝淋巴结、（iii）原发性乳腺肿瘤和（iv）健康乳腺腺组织中的表达及截短情况。
全长埃兹蛋白（E1；氨基酸1-586）在所有四种研究组织中均有存在。在原发性肿瘤组织和前哨淋巴结转移灶中可检测到两种截短的埃兹蛋白形式，一种缺失约前一百个氨基酸（E2a），另一种缺少约150个C端氨基酸（E2b），但在腺组织中未检测到。引人注目的是，在所有前哨淋巴结转移灶中均发现一种约由氨基酸238-586组成的埃兹蛋白截短体（E3）强烈表达。此外，在前哨淋巴结转移灶中还鉴定出一种约由氨基酸1-273组成的N端埃兹蛋白片段（E4）。
我们首次证明了组织依赖性特异性埃兹蛋白截短体的存在。前哨淋巴结转移灶中埃兹蛋白E3在蛋白质免疫印迹法中显著的强染色突出了其证实乳腺癌患者淋巴结（微）转移发生的能力。
