Fanelli Mariel A, Montt-Guevara Magdalena, Diblasi Angela M, Gago Francisco E, Tello Olga, Cuello-Carrión F Darío, Callegari Eduardo, Bausero Maria A, Ciocca Daniel R
Oncology Laboratory, Institute of Experimental Medicine and Biology of Cuyo, Regional Center for Scientific and Technological Research, National Research Council (CONICET), Mendoza, Argentina.
Cell Stress Chaperones. 2008 Summer;13(2):207-20. doi: 10.1007/s12192-007-0007-z. Epub 2008 Mar 5.
The cadherin-catenin proteins have in common with heat shock proteins (HSP) the capacity to bind/interact proteins of other classes. Moreover, there are common molecular pathways that connect the HSP response and the cadherin-catenin protein system. In the present study, we have explored whether in breast cancer the HSP might interact functionally with the cadherin-catenin cell adhesion system. Beta-catenin was immunoprecipitated from breast cancer biopsy samples, and the protein complexes isolated in this way were probed with antibodies against HSP family members. We are thus the first to demonstrate a specific interaction between beta-catenin and Hsp27. However, beta-catenin did not bind Hsp60, Hsp70, Hsp90, gp96, or the endoplasmic reticulum stress response protein CHOP. To confirm the finding of Hsp27-beta-catenin interaction, the 27-kDa immunoprecipitated band was excised from one-dimensional polyacrylamide gel electrophoresis gels and submitted to liquid chromatography-tandem mass spectrometry with electrospray ionization, confirming a role for Hsp27. In addition, beta-catenin interacted with other proteins including heat shock transcription factor 1, P-cadherin, and caveolin-1. In human breast cancer biopsy samples, beta-catenin was coexpressed in the same tumor areas and in the same tumor cells that expressed Hsp27. However, this coexpression was strong when beta-catenin was present in the cytoplasm of the tumor cells and not when beta-catenin was expressed at the cell surface only. Furthermore, murine breast cancer cells transfected with hsp25 showed a redistribution of beta-catenin from the cell membrane to the cytoplasm. When the prognostic significance of cadherin-catenin expression was examined by immunohistochemistry in breast cancer patients (n = 215, follow-up = >10 years), we found that the disease-free survival and overall survival were significantly shorter for patients expressing P-cadherin and for patients showing expression of beta-catenin in the cytoplasm only (not at the cell surface). The interactions of beta-catenin with Hsp27 and with HSF1 may explain some of the molecular pathways that influence tumor cell survival and the clinical significance in the prognosis of the breast cancer patients.
钙黏蛋白 - 连环蛋白与热休克蛋白（HSP）具有共同特点，即都能够结合/与其他类别的蛋白质相互作用。此外，存在连接热休克蛋白反应和钙黏蛋白 - 连环蛋白系统的共同分子途径。在本研究中，我们探究了在乳腺癌中热休克蛋白是否可能与钙黏蛋白 - 连环蛋白细胞黏附系统发生功能相互作用。从乳腺癌活检样本中免疫沉淀β-连环蛋白，并用针对热休克蛋白家族成员的抗体探测以这种方式分离出的蛋白质复合物。因此，我们首次证明了β-连环蛋白与Hsp27之间存在特异性相互作用。然而，β-连环蛋白不与Hsp60、Hsp70、Hsp90、gp96或内质网应激反应蛋白CHOP结合。为了证实Hsp27与β-连环蛋白相互作用的发现，从一维聚丙烯酰胺凝胶电泳凝胶中切下27 kDa的免疫沉淀条带，并将其提交给带电喷雾电离的液相色谱 - 串联质谱分析，证实了Hsp27的作用。此外，β-连环蛋白与其他蛋白质相互作用，包括热休克转录因子1、P-钙黏蛋白和小窝蛋白 - 1。在人乳腺癌活检样本中，β-连环蛋白在表达Hsp27的相同肿瘤区域和相同肿瘤细胞中共表达。然而，当β-连环蛋白存在于肿瘤细胞的细胞质中时这种共表达强烈，而当β-连环蛋白仅在细胞表面表达时则不然。此外，用hsp25转染的小鼠乳腺癌细胞显示β-连环蛋白从细胞膜重新分布到细胞质中。当通过免疫组织化学检查乳腺癌患者（n = 215，随访时间>10年）中钙黏蛋白 - 连环蛋白表达的预后意义时，我们发现表达P-钙黏蛋白的患者以及仅在细胞质中（而非细胞表面）显示β-连环蛋白表达的患者的无病生存期和总生存期明显缩短。β-连环蛋白与Hsp27以及与HSF1的相互作用可能解释了一些影响肿瘤细胞存活的分子途径以及在乳腺癌患者预后中的临床意义。
