高表达鞘氨醇激酶对胃癌细胞生物学特性的影响

目的研究高表达鞘氨醇激酶（SPK）对人胃癌细胞增殖、迁移和凋亡等细胞生物学行为的影响。方法以重组腺病毒为载体，将人野生型（rAd—SPK^WT）及突变体（rAd—SPK^DV）SPK基因导入人胃癌细胞BCC-823。以Western blot检测外源SPK基因的表达，以γ^82P]ATP掺入法测定SPK酶活性，用迁移扩散盒技术测定细胞的迁移能力。结果重组腺病毒可有效介导SPK在人胃癌细胞BGC-823中的表达。酶活性分析表明野生型SPK基因可增强SPK活性，而突变体SPK基因抑制SPK活性；高表达野生型SPK可以促进胃癌细胞的迁移，抑制5-FU对胃癌细胞的细胞毒作用，而高表达突变体SPK可以抑制胃癌细胞的迁移，增强5FU对胃癌细胞的细胞毒作用。结论SPK可以抑制5-FU诱导的胃癌细胞凋亡，促进胃癌细胞迁移，有可能成为胃癌新的治疗靶点。

The effect of overexpression of sphingosine kinase on biological characters of gastric carcinoma cells

Objective To investigate the roles of sphingosine kinase (SPK) on the regulation of proliferation, migration and apoptosis of gastric carcinoma cells. Methods BGC-823 cells were infected with adenoviral carriers bringing the wild type SPK gene and SPK mutant (SPK DN ), and their effect on the migration and 5-FU-induced apoptosis of BGC-823 cells was evaluated. The adenovirus-mediated expression of SPK was detected by Western blot, and cellular SPK enzyme activity was assayed. The cell migration was investigated by Transwell Migration Technology. Results The adenovirus-mediated wild type SPK gene increased the cellular SPK activity, thus leading to enhanced migration and resistance to 5-FU-induced apoptosis of BGC-823 cells. Whereas overexpression of SPK mutant (SPK DN ) decreased the cellular SPK activity, thus inhibited the migration and sensitized BGC-823 to 5-FU-induced apoptosis. Conclusion SPK plays important roles in the regulation of migration and apoptosis of gastric carcinoma cells, therefore it may be of a new target for tumor treatment.