Wenzel C T, Scher R L, Richtsmeier W J
Department of Surgery-Otolaryngology-Head and Neck Surgery, Duke Comprehensive Cancer Center, Duke University, Durham, NC, USA.
Arch Otolaryngol Head Neck Surg. 1995 Nov;121(11):1279-86. doi: 10.1001/archotol.1995.01890110053010.
To examine the direct adhesion of head and neck squamous cell carcinoma (HNSCC) cells to basal and cytokine-activated human endothelial cells and to determine the cell adhesion molecules (CAMs) that mediate binding under these two conditions.
Using an established model of tumor metastasis, the adhesion of four HNSCC cell lines to human umbilical vein endothelial cell (HUVEC) monolayers was examined, with and without pretreatment of HUVEC with tumor necrosis factor alpha (TNF-alpha). Surface CAM expression of HNSCC and HUVEC was determined by flow cytometry, and the results were used to direct studies of adhesion blocking using monoclonal antibodies. The contribution of various CAM to HNSCC binding of basal and cytokine-activated human endothelial cells in vitro was established.
Adhesion of HNSCC to HUVEC monolayers was determined by a sodium chromate Cr 51-labeling assay in the presence or absence of monoclonal antibodies directed against specific CAMs.
Four HNSCC cell lines were shown by flow cytometry to constitutively express the following CAMs: intercellular CAM-1, CD44, lymphocyte function-associated antigen-3, integrin chains alpha 6 and beta 1, and sialyl Lewis(x). No cell lines expressed lymphocyte function-associated antigen-1 or the integrin subunit alpha 4. Adhesion of JHU-011-SCC to TNF-alpha-activated HUVEC was enhanced above the untreated level in a time-dependent manner, with maximal adhesion at 12 hours. This increase correlated with endothelial-selectin expression by HUVEC and HNSCC expression of its ligand sialyl Lewis(x). Monoclonal antibody to sialyl Lewis(x) blocked the increased adhesion to TNF-alpha-activated HUVEC in two of four HNSCC cell lines. Monoclonal antibody to the alpha 6 integrin reduced binding to TNF-alpha-activated and non-activated HUVEC and to subendothelial matrix, but not to fibronectin.
Studies of four HNSCC cell lines disclosed a consistent and distinctive pattern of adhesion molecule expression. The alpha 6 integrin subunit may be involved in direct adhesion to nonactivate and cytokine-activated endothelial cells or to laminin present on the endothelial surface. Sialyl Lewis(x) was more specifically involved in the increased adhesion to cytokine-activated HUVEC. This suggests that the sialyl Lewis(x)-endothelial-selectin ligand interaction may be important in facilitating HNSCC adhesion during metastasis to sites of active or chronic inflammation in vivo.
研究头颈部鳞状细胞癌（HNSCC）细胞与基底及细胞因子激活的人内皮细胞的直接黏附，并确定在这两种条件下介导结合的细胞黏附分子（CAMs）。
利用已建立的肿瘤转移模型，检测四种HNSCC细胞系与人脐静脉内皮细胞（HUVEC）单层的黏附情况，HUVEC分别进行或不进行肿瘤坏死因子α（TNF-α）预处理。通过流式细胞术测定HNSCC和HUVEC的表面CAM表达，并将结果用于指导使用单克隆抗体进行黏附阻断研究。确定了各种CAM对体外基底及细胞因子激活的人内皮细胞与HNSCC结合的贡献。
在存在或不存在针对特定CAMs的单克隆抗体的情况下，通过铬酸钠Cr 51标记试验测定HNSCC与HUVEC单层的黏附情况。
流式细胞术显示四种HNSCC细胞系组成性表达以下CAMs：细胞间黏附分子-1、CD44、淋巴细胞功能相关抗原-3、整合素链α6和β1以及唾液酸化路易斯（x）。没有细胞系表达淋巴细胞功能相关抗原-1或整合素亚基α4。JHU-011-SCC与TNF-α激活的HUVEC的黏附以时间依赖性方式增强，高于未处理水平，在12小时时达到最大黏附。这种增加与HUVEC的内皮选择素表达及其配体唾液酸化路易斯（x）的HNSCC表达相关。针对唾液酸化路易斯（x）的单克隆抗体在四种HNSCC细胞系中的两种中阻断了对TNF-α激活的HUVEC的黏附增加。针对α6整合素的单克隆抗体减少了与TNF-α激活和未激活的HUVEC以及内皮下基质的结合，但不减少与纤连蛋白的结合。
对四种HNSCC细胞系的研究揭示了黏附分子表达的一致且独特模式。α6整合素亚基可能参与与未激活和细胞因子激活的内皮细胞或内皮表面存在的层粘连蛋白的直接黏附。唾液酸化路易斯（x）更具体地参与了与细胞因子激活的HUVEC的黏附增加。这表明唾液酸化路易斯（x）-内皮选择素配体相互作用在促进HNSCC在体内转移至活跃或慢性炎症部位期间的黏附中可能很重要。
