Lauri D, Martin-Padura I, Biondelli T, Rossi G, Bernasconi S, Giavazzi R, Passerini F, Van Hinsbergh V, Dejana E
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Lab Invest. 1991 Nov;65(5):525-31.
We investigated the effects of beta 1 integrins on tumor cell (TC) adhesion to unstimulated and interleukin-1 (IL-1) activated endothelial cells (EC). IL-1 treatment (20 units/ml for 6 hours) of cultured human umbilical vein EC significantly increased adhesion of seven human TC lines of different origin. A goat antiserum raised to purified alpha 5 beta 1 integrin abolished the IL-1 induced increment in adhesion of two osteosarcomas, one melanoma, one lung, and one kidney carcinoma, whereas it did not affect adhesion of two colon carcinoma cell lines. Further studies were performed on MG63 osteosarcoma cells. Adhesion of MG63 osteosarcoma cells to EC was dependent on time of EC treatment with IL-1: it was maximal at 12 hours and declined at 24 hours. alpha 5 beta 1 antiserum blocked IL-1 induced increase in MG63 adhesion at any time of EC treatment. This effect appears to be mainly directed to MG63 integrins since selective incubation of the antiserum with EC, but not with MG63, did not modify TC adhesion. Using a series of antibodies to different alpha and beta chains, we found that only monoclonal antibodies (mAb) to alpha 4, alpha 5, and beta 1 could inhibit MG63 adhesion to IL-1 activated EC, whereas alpha 2, alpha 6, and beta 3 antibodies were ineffective. Antibodies to fibronectin had very little activity on MG63 adhesion to EC matrix and did not significantly affect MG63 adhesion to control or IL-1 treated EC. Antibodies to alpha 4, alpha 5, and beta 1 were only partially effective in inhibiting MG63 adhesion to EC matrix. These data indicate that the capacity of alpha 4 beta 1 and alpha 5 beta 1 integrins to bind fibronectin contributed very little to MG63 adhesion to EC. The importance of beta 1 integrins in promoting a direct interaction between EC and MG63 was further shown by inhibition of rosette formation among these cells in suspension by the alpha 5 beta 1 antiserum. Only a VCAM-1/INCAM110 mAb, but not ELAM-1 or ICAM-1 mAbs, could inhibit MG63 adhesion to IL-1 activated EC. Overall these data indicate that at least two members of the beta 1 integrin subfamily (alpha 4 beta 1 and alpha 5 beta 1) are involved in MG63 adhesion to cytokine treated EC. This integrin function might be important at early stages of TC interaction with the vessel wall.
我们研究了β1整合素对肿瘤细胞（TC）黏附于未刺激的和白细胞介素-1（IL-1）激活的内皮细胞（EC）的影响。用IL-1（20单位/毫升，处理6小时）处理培养的人脐静脉EC，可显著增加7种不同来源的人TC系的黏附。一种针对纯化的α5β1整合素产生的山羊抗血清消除了IL-1诱导的两种骨肉瘤、一种黑色素瘤、一种肺癌和一种肾癌黏附的增加，而对两种结肠癌细胞系的黏附没有影响。对MG63骨肉瘤细胞进行了进一步研究。MG63骨肉瘤细胞对EC的黏附取决于EC用IL-1处理的时间：在12小时时最大，在24小时时下降。α5β1抗血清在EC处理的任何时间都能阻断IL-1诱导的MG63黏附增加。这种作用似乎主要针对MG63整合素，因为抗血清与EC而非MG63的选择性孵育并未改变TC黏附。使用一系列针对不同α和β链的抗体，我们发现只有针对α4、α5和β1的单克隆抗体（mAb）能抑制MG63对IL-1激活的EC的黏附，而α2、α6和β3抗体则无效。针对纤连蛋白的抗体对MG63黏附于EC基质的活性很小，且对MG63黏附于对照或IL-1处理的EC没有显著影响。针对α4、α5和β1的抗体在抑制MG63黏附于EC基质方面仅部分有效。这些数据表明，α4β1和α5β1整合素结合纤连蛋白的能力对MG63黏附于EC的贡献很小。α5β1抗血清抑制这些细胞在悬浮液中形成玫瑰花结，进一步表明β1整合素在促进EC与MG63之间直接相互作用中的重要性。只有VCAM-1/INCAM110 mAb，而不是ELAM-1或ICAM-1 mAb，能抑制MG63对IL-1激活的EC的黏附。总体而言，这些数据表明β1整合素亚家族的至少两个成员（α4β1和α5β1）参与了MG63对细胞因子处理的EC的黏附。这种整合素功能在TC与血管壁相互作用的早期阶段可能很重要。
