The regulatory mechanism mechanism of cellular activities by extracllular matrix

细胞与细胞外基质的附着对于大多数动物细胞发挥细胞的生长、运动以及纤维连接蛋白和纤溶蛋白等活性是非常重要的。在本研究中，我们研究了细胞对这些蛋白的附着与细胞活性之间的关系。1. 在人妊娠早期胎盘中，发现细胞滋养细胞在基侧表达VLA5纤维连接蛋白受体；在成熟胎盘中，合胞滋养细胞在基侧表达VLA6层粘连蛋白受体。这些结果表明，细胞利用特定的受体与它们所附着的细胞外基质成分相对应。2. 在接下来的研究中。我们检测了层粘连蛋白和67K层粘连蛋白受体在两种不同转移潜能的小鼠肺癌细胞系中的表达。结果表明，高转移细胞株的层粘连蛋白mRNA水平较低，但水平相近。这些发现提示未被占用的层粘连蛋白受体可能导致转移性的差异。3. 我们还发现3LL细胞对纤维连接蛋白的附着被(-)-表儿茶素和(-)-表没食子儿茶素抑制。这一结果可以解释(-)-表没食子儿茶素在体内抑制这些细胞的肺转移。因此，目前的工作证明了细胞附着对各种细胞活动的重要性。

The cell attachment to the extracellular matrixt is very important for most animal cells to exert cell's activities such as growth, locomotion and as fibronectin and alminin are now known. In the present study, we examined the relationship between the cell attachment to these proteins and cellular activities. 1. In the human placenta at early gestation, cytorophoblasts were found to express VLA5 fibronectin receptor on the basal sideIn the mature placenta, syncytiotrophoblasts expressed VLA6 laminin receptor on the basal side. These results indicate that cells make use of specific receptor for their attachment in correspondence to the extracellular matrix component to which they attach. 2. In the next study. we examined the expression of laminin and 67K laminin receptor in two cell lines with different metastatic potentials of murine lung carcinoma. It was demonstrated that the laminin mRNA level was lower in the high metastatic cell lines were at the similar level. These findings suggest that unoccupied laminin receptor may contribute to the difference in metastativ property. 3. We also found that the 3LL cell attachment to fibronectin was inhibited by (-) -epicatechin and (-)-epigallocatechin. The results can explain the previous finding that (-)-epigallocatechin inhibited the lung metastasis of these cells in vivo. Thus, the present work demonstrated the importance of the cell attachment for various cellular activities.