Isolation of highly metastatic clone from human oral cancer cell line transfected active form rho gene and Identification of metastasis relation molecule.

已知fos基因的ras活化可引导转移性表达。Rho是一种类似ras的低分子量G蛋白，可以通过降低细胞粘附能力来增强细胞运动，这对癌症的侵袭或转移至关重要。rho的作用和作用机制近年来越来越受到关注。Akedo等人在体外实验中报道，激活人rho可提高大鼠腹水肝癌细胞向间皮细胞单层的侵袭能力。另一方面，利用口腔癌细胞系进行肿瘤转移的研究较少。我们曾将人口腔癌细胞系移植到裸鼠背部，研究其致瘤性，但未发现淋巴结转移。高转移性口腔癌实验模型是研究口腔癌转移的必要条件。因此，我们将rho基因活性形式的质粒pcDSR αrhoval^<14>转染下龈原发鳞状细胞癌建立的口腔癌细胞系NOS-1，以获得稳定的转染物。此外，我们研究了这些细胞是否可以建立高度转移到淋巴结的肿瘤细胞系。因此，通过共转染pcDSR αrhoVal^<14>和耐药基因pSV2neo，获得了表达活性人rhoA基因的稳定的转染物。通过吞噬动力学跟踪试验，这些克隆对细胞运动的促进作用是对照的2倍。可在裸鼠舌上原位移植，未见淋巴结转移。在本研究中，表达活性形式rhoA基因的克隆的细胞运动性增强，但它们没有淋巴转移潜力。

An activated ras of fos gene has been known to guide metastatic potential expression. Rho, which is one of the ras-like low molecular weight G proteins, may cause an enhancement of cell motility that is essentiality for invasion or metastasis of cancer by decreasing cellular adhesion abilities. The function and action mechanism of rho has been noted recently. Akedo et al. reported that an activated human rho increased invasion ability of rat ascites hepatoma cells into mesothelial cell monolayer in an in vitro experiment.In the other hand, there were few studies of cancer metastasis using oral cancer cell lines. We have searched tumorigenicity by transplanting humans oral cancer cell line in the back of nude mouse, but lymphnode metastasis was not recognized. Highly metastasizing experimental model of oral cancer is necessary for studies of metastasis of oral cancer. So, we transfected plasmid pcDSR αrhoval^<14> that was active form of rho gene into NOS-1, the oral cancer cell line established form the primary squamous cell carcinoma of the lower gingiva, in order to obtain stable transfectants. Further, we examined whether highly metastasizing tumor cell line to the lymph node could be established from these cells.Consequently, stable transfectants which expressed active human rhoA gene were obtained by cotransfecting pcDSR αrhoVal^<14> and drug resistance gene pSV2neo. These clones promoted cell motility 2 times larger than that of the control by a phagokinetic track assay. They were transplantable orthotopically in the tongue of nude mouse, but lymph node metastasis was not observed.In this study, the cell motility of the clones that expressed active form rhoA gene showed an enhancement, but they did not give the lymphogenous metastatic potential.