Nabeshima K, Shimao Y, Inoue T, Itoh H, Kataoka H, Koono M
Department of Pathology, Miyazaki Medical College, Kiyotake, Japan.
Int J Cancer. 1998 Dec 9;78(6):750-9. doi: 10.1002/(sici)1097-0215(19981209)78:6<750::aid-ijc13>3.0.co;2-#.
We presented earlier a 2-dimensional cell-motility assay using a highly metastatic variant (L-10) of human rectal-adenocarcinoma cell line RCM-1 as a motility model of tumor cells of epithelial origin. In this model, L-10 cells moved as coherent cell sheets when stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA), and we called this type of movement "cohort migration". Electron- and immunoelectron-microscope study of the migrating cell sheets demonstrated localized release from cell-cell adhesion only at the lower portion of the cells with loss of E-cadherin immunoreactivity, and this change was associated with increased tyrosine phosphorylation of the E-cadherin-catenin complex, including beta-catenin. In the present study, to obtain evidence to support the relevance of our model to carcinoma-cell movement in vivo, we sought a naturally occurring motogenic factor(s) able to induce this cohort migration. Among the factors examined, hepatocyte growth factor/scatter factor (HGF/SF) clearly induced cohort migration of L-10 cells. Additionally, not only L-10 but several other human colorectal-carcinoma cell lines showed this type of migration in response to HGF/SF, while yet others showed scattering-type motility. In this HGF/SF-induced migration, localized release from cell-cell adhesion was induced only at the lower portion of the cells, allowing them to extend leading lamellae, whereas close cell-cell contacts remained at the upper portion of the cells, as seen in TPA-induced cohort migration. Scattering-type cell lines tended to express more c-Met (receptor for HGF/SF) mRNA than the cell lines that showed cohort-type migration. LoVo, one of the scattering-type cell lines, expressed more c-Met protein and less E-cadherin than L-10, which showed cohort-type migration. HGF/SF treatment of LoVo reduced the amount of alpha-catenin complexed with E-cadherin more markedly than in L-10, but in both cell lines this reduction was not accompanied by increased tyrosine phosphorylation of beta-catenin, suggesting the presence of a mechanism other than phosphorylation for release from cell-cell adhesion during cell motility.
我们之前展示了一种二维细胞运动分析方法，该方法使用人直肠腺癌细胞系RCM - 1的高转移性变体（L - 10）作为上皮来源肿瘤细胞的运动模型。在这个模型中，当用12 - O - 十四酰佛波醇 - 13 - 乙酸酯（TPA）刺激时，L - 10细胞作为连贯的细胞片移动，我们将这种移动类型称为“群体迁移”。对迁移细胞片的电子显微镜和免疫电子显微镜研究表明，仅在细胞下部出现细胞间黏附的局部释放，同时E - 钙黏蛋白免疫反应性丧失，并且这种变化与包括β - 连环蛋白在内的E - 钙黏蛋白 - 连环蛋白复合物酪氨酸磷酸化增加有关。在本研究中，为了获得证据支持我们的模型与体内癌细胞运动的相关性，我们寻找一种能够诱导这种群体迁移的天然存在的促运动因子。在所检测的因子中，肝细胞生长因子/分散因子（HGF/SF）明显诱导了L - 10细胞的群体迁移。此外，不仅L - 10细胞，其他几种人结肠癌细胞系对HGF/SF也表现出这种迁移类型，而其他一些细胞系则表现出分散型运动。在这种HGF/SF诱导的迁移中，仅在细胞下部诱导细胞间黏附的局部释放，使它们能够伸出前缘片层，而在细胞上部仍保持紧密的细胞间接触，这与TPA诱导的群体迁移情况相同。分散型细胞系往往比表现出群体型迁移的细胞系表达更多的c - Met（HGF/SF的受体）mRNA。分散型细胞系之一的LoVo比表现出群体型迁移的L - 10细胞表达更多的c - Met蛋白和更少的E - 钙黏蛋白。用HGF/SF处理LoVo细胞比处理L - 10细胞更明显地减少了与E - 钙黏蛋白结合的α - 连环蛋白的量，但在这两种细胞系中，这种减少都没有伴随着β - 连环蛋白酪氨酸磷酸化的增加，这表明在细胞运动过程中，存在一种除磷酸化之外的从细胞间黏附中释放的机制。
