Nangia-Makker Pratima, Balan Vitaly, Raz Avraham
Karmanos Cancer Institute, Wayne State University, Detroit, MI 48201, USA.
Cancer Microenviron. 2008 Dec;1(1):43-51. doi: 10.1007/s12307-008-0003-6. Epub 2008 Feb 20.
The relationship between a tumor cell and its microenvironment is bi-directional. The proteins expressed by the tumor cells alter the signatures on the seemingly normal stromal cells within the microenvironment, while the tumor cell signatures reflect the changes that occur as these cells interact with the host microenvironment. Galectin-3 is a carbohydrate-binding protein that is over-expressed in a variety of tumors and immune cells in response to various stimuli. Ever since its discovery, it has been associated with cell and extracellular matrix interactions. However, in the last decade, an extensive accumulation of data has changed the perspective of this multifunctional protein. The unique structure of this protein, consisting of a carbohydrate-binding domain and a matrix metalloproteinase cleavable domain, enables it to interact with a plethora of ligands in a carbohydrate-dependent or independent manner. It is now becoming evident that galectin-3 is involved with a variety of extracellular functions like cell adhesion, migration, invasion, angiogenesis, immune functions, apoptosis and endocytosis. Galectin-3 is a substrate for matrix metalloproteinases and its cleavage plays an important role in tumor progression and can be used as a surrogate diagnostic marker for in vivo MMP activity.
肿瘤细胞与其微环境之间的关系是双向的。肿瘤细胞表达的蛋白质会改变微环境中看似正常的基质细胞的特征，而肿瘤细胞的特征则反映了这些细胞与宿主微环境相互作用时发生的变化。半乳糖凝集素-3是一种碳水化合物结合蛋白，在各种肿瘤和免疫细胞中因各种刺激而过度表达。自发现以来，它一直与细胞和细胞外基质相互作用有关。然而，在过去十年中，大量数据的积累改变了对这种多功能蛋白质的看法。这种蛋白质的独特结构，由一个碳水化合物结合结构域和一个基质金属蛋白酶可切割结构域组成，使其能够以碳水化合物依赖或独立的方式与大量配体相互作用。现在越来越明显的是，半乳糖凝集素-3参与多种细胞外功能，如细胞粘附、迁移、侵袭、血管生成、免疫功能、凋亡和内吞作用。半乳糖凝集素-3是基质金属蛋白酶的底物，其切割在肿瘤进展中起重要作用，可作为体内基质金属蛋白酶活性的替代诊断标志物。
