Skubitz A P, Grossman M D, McCarthy J B, Wayner E A, Cameron J D
Department of Laboratory Medicine, University of Minnesota Medical School, Minneapolis 55455.
Invest Ophthalmol Vis Sci. 1994 May;35(6):2820-33.
This study was designed to determine whether the Y79 retinoblastoma cell line, a prototype for retinoblastoma cells, exhibits differential adhesive properties toward extracellular matrix (ECM)/basement membrane (BM) proteins compared to normal human retinal (NHR) cells. A second goal was to determine whether differences in adhesion are related to differences in the expression of integrin subunits.
Y79 cells and NHR cells were tested for their ability to adhere and spread in microtiter wells adsorbed with the ECM/BM proteins laminin, fibronectin, and type IV collagen, as well as fragments of these proteins. The presence of cell surface integrins was determined by flow cytometry, using monoclonal antibodies (mAbs) against integrin subunits. For inhibition assays, cells were preincubated with mAbs against integrin subunits before the adhesion assays.
NHR cells adhered to and spread on laminin, fibronectin, and type IV collagen, whereas Y79 cells only adhered moderately to fibronectin. NHR cells expressed high levels of beta 1, alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, alpha 6, and alpha v integrin subunits, and they used these integrin subunits to adhere to all three ECM proteins. In contrast, Y79 cells expressed high levels of only the alpha 4 and beta 1 integrin subunits, used to adhere to fibronectin.
Y79 cells have decreased adhesive capabilities toward ECM/BM proteins, compared to NHR cells. These differences can be attributed, in part, to their significantly lower levels of alpha 1, alpha 2, alpha 3, and alpha 5 integrin subunits, which serve as receptors for type IV collagen, laminin, and fibronectin.
本研究旨在确定视网膜母细胞瘤细胞系Y79（视网膜母细胞瘤细胞的原型）与正常人视网膜（NHR）细胞相比，对细胞外基质（ECM）/基底膜（BM）蛋白是否表现出不同的黏附特性。第二个目标是确定黏附差异是否与整合素亚基表达的差异有关。
检测Y79细胞和NHR细胞在吸附有ECM/BM蛋白层粘连蛋白、纤连蛋白和IV型胶原以及这些蛋白片段的微孔板中黏附与铺展的能力。使用针对整合素亚基的单克隆抗体（mAb），通过流式细胞术确定细胞表面整合素的存在。对于抑制试验，在黏附试验前，将细胞与针对整合素亚基的mAb进行预孵育。
NHR细胞可黏附并铺展于层粘连蛋白、纤连蛋白和IV型胶原上，而Y79细胞仅对纤连蛋白有中等程度的黏附。NHR细胞高水平表达β1、α1、α2、α3、α4、α5、α6和αv整合素亚基，它们利用这些整合素亚基黏附于所有三种ECM蛋白。相比之下，Y79细胞仅高水平表达用于黏附纤连蛋白的α4和β1整合素亚基。
与NHR细胞相比，Y79细胞对ECM/BM蛋白的黏附能力降低。这些差异部分可归因于其α1、α2、α3和α5整合素亚基水平显著较低，这些亚基作为IV型胶原、层粘连蛋白和纤连蛋白的受体。
