高表达鞘氨醇激酶对胃癌细胞生物学特性的影响

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

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-SPKWT)及突变体(rAd-SPKDN)SPK基因导入人胃癌细胞BGC-823。以Westernblot检测外源SPK基因的表达,以[γ-32P]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5-FU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。

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 Westem 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 iraportant roles in the regulation of migration and apoptosis of gastric carcinoma cells, therefore it may be of a new target for tumor treatment.