Llorens A, Rodrigo I, López-Barcons L, Gonzalez-Garrigues M, Lozano E, Vinyals A, Quintanilla M, Cano A, Fabra A
Department of Cancer and Metastasis, Institut de Recerca Oncològica, Barcelona, Spain.
Lab Invest. 1998 Sep;78(9):1131-42.
To assess the role of gelatinases in mouse skin tumor progression and their link to the expression of E-cadherin (E-CD), the cell-cell adhesion protein, we used the highly metastatic squamous HaCa4 cell line and several HaCa4-derived clones obtained by transfection of the mouse E-CD cDNA. Expression of matrix metalloproteinase-9 (MMP-9) mRNA and protein activity were present in E-CD (-) HaCa4 and control clones in culture, but they were strongly diminished in E-CD (+) clones (E24 and E62) at subconfluence. To explore the suppressive effect of the cell-cell contacts mediated by E-CD on MMP-9 expression, we introduced a plasmid encoding mouse E-CD antisense cDNA into the E24 cell clone. The transfectant P1-clones obtained with reduced or absent E-CD expression showed increased levels of MMP-9 gelatinase, motility in vitro, and metastatic potential in vivo. Expression of MMP-9 in the various cell clones was also negatively modulated by cell density, but this effect was much stronger in E-CD (+) cells, despite the fact that all of the cell clones analyzed maintained the expression of P-cadherin and made cell-cell contacts at high cell density. Our results indicate that in this cell system, the E-CD-mediated cell-cell contacts are involved in the down-regulation of MMP-9 expression. Thus, the loss of E-CD triggers a migratory and invasive phenotype in mouse squamous carcinoma cells.
为了评估明胶酶在小鼠皮肤肿瘤进展中的作用及其与细胞间粘附蛋白E-钙粘蛋白（E-CD）表达的联系，我们使用了高转移性的鳞状HaCa4细胞系以及通过转染小鼠E-CD cDNA获得的几个HaCa4衍生克隆。基质金属蛋白酶-9（MMP-9）mRNA的表达和蛋白活性在培养的E-CD（-）HaCa4和对照克隆中均有存在，但在亚汇合状态下，它们在E-CD（+）克隆（E24和E62）中显著降低。为了探究由E-CD介导的细胞间接触对MMP-9表达的抑制作用，我们将编码小鼠E-CD反义cDNA的质粒导入E24细胞克隆。获得的E-CD表达降低或缺失的转染子P1克隆显示出MMP-9明胶酶水平升高、体外运动能力增强以及体内转移潜能增加。MMP-9在各种细胞克隆中的表达也受到细胞密度的负调控，但尽管所有分析的细胞克隆均维持P-钙粘蛋白的表达并在高细胞密度下形成细胞间接触，这种效应在E-CD（+）细胞中要强得多。我们的结果表明，在这个细胞系统中，E-CD介导的细胞间接触参与了MMP-9表达的下调。因此，E-CD的缺失触发了小鼠鳞状癌细胞的迁移和侵袭表型。
