鞘氨醇激酶1抑制剂联合化疗药物对胃癌细胞SGC7901生长的影响

Antitumor effect of sphingosine kinase 1 inhibitor in combination with chemotherapy on SGC7901 gastric cancer cells in vitro

目的观察鞘氨醇激酶1（SphKl）抑制剂二甲基鞘氨醇（DMS）与化疗药物联用对胃癌细胞SGC7901生长的影响，以评价SphKl抑制剂能否成为新的化疗增敏剂。方法1μmol／LDMS与不同浓度的5-氟尿嘧啶（5-Fu）、顺铂（DDP）、丝裂霉素（MMC）单独和（或）联合作用胃癌SGC7901细胞24h，采用四甲基偶氮唑蓝（MTT）法检测各组细胞抑制率，运用SAS软件对抑制率进行反应曲面分析，根据反应曲面方程系数判断联用时的相互作用关系。结果单用1μmol／LDMS对SGC7901细胞增殖抑制率为（10．23±0．74）％，1、5、25μg/ml5-Fu对SGC7901细胞增殖抑制率分别为（9．95±3．24）％、（21．04±2．19）％和（45．49±3．60）％，0．5、2．5、12．5μg/mlDDP对SGC7901细胞增殖抑制率分别为（9．38±0．79）％、（19．61±0．90）％和（29．83±O．54）％，0．1、0．5、2．5μg／mlMMC对SGC7901细胞增殖抑制率分别为（15．35±0．77）％、（24．72±O．83）％和（30．68±0．28）％，不同浓度药物之间的差异均有统计学意义（P〈0．05）。1μmol／LDMS与1、5、25μg／rnl5-Fu联用24h，对SGC7901细胞增殖抑制率分别为（16．76±0．41）％、（27．28±0．29）％和（52．56±3．60）％；1μmol／LDMS与0．5、2．5、12．5μg/／mlDDP联用24h，对SGC7901细胞增殖抑制率分别为（15．35±0．86）％、（25．57±0．27）％、（36．37±0．51）％；1μmol／LDMS与0．1、0．5、2．5μg/／mlMMC联用24h，对SGC7901细胞增殖抑制率分别为（21．02±0．28）％、（32．10±0．27）％、（36．36±0．28）％。不同浓度的化疗药物单用组与联用DMS组的增殖抑制率差异均有统计学意义（P〈0．05），且联用DMS组的增殖抑制率均高于单用组（P〈0．05），DMS与5-Fu、DDP、MMC具有协同作用。结论DMS与化疗药物联用可抑制胃癌细胞的生长，并具有协同作用，SphKa有望成为提高化疗药物疗效的新靶点。

Objective To study the effect of the sphingosine kinase 1 （SphK1） inhibitor N, N- dimethylsphingosine （DMS） in combination with chemotherapeutic drugs （DDP, 5-Fu, MMC ） on the proliferation of gastric cancer cells （ SGC7901 ） in vitro, and to evaluate whether SphK1 inhibitors could be used as synergetic agents in chemotherapy. Methods SGC7901 cells were incubated in vitro with DMS （1μmol/L） and 5-Fu, DDP, MMC at different concentrations in combination or separately for 24 h. The effects on the growth and survival of SGC7901 cells were determined by MrlT assay. The inhibition rates were assessed by response surface analysis and the interactive relationships between the combined drugs were evaluated on the basis of positive/negative values of the cross product coeflqcients in the response surface equation. Results The growth inhibition rate of the gastric cancer cells by treatment with DMS （ 1 μmnol/L） was （ 10. 23±0.74） %. The growth inhibition rates of the gastric cancer cells treated with 5-Fu （ 1,5 and 25μg/ml） for 24 h were （9.95±3.24）%, （21.04±2. 19）%, and （45.49±3.60）%, respectively. The growth inhibition rates of the gastric cancer cells treated with DDP （0.5, 2.5 and 12.5 μg/ml） for 24 h were （9.38±0.79 ） %, （ 19.61±0.90 ） %, and （ 29.83±0.54 ） %, respectively. The growth inhibition rates of the gastric cancer cells treated with MMC （0.1,0.5 and 2.5 μg/ml） for 24 h were （ 15.35±0.77） %, （24.72±0.83 ） %, and （ 30.68±0.28） %, respectively. There were significant differences among theinhibition rates caused by different concentrations of the drugs （ P 〈 0.05 ）. When 1 μmol/L DMS was used in combination with 5-Fu （ 1.5, and 25 μg/ml） for 24 h, the growth inhibition rates of the cancer ceils were （ 16.76±0.41 ） %, （27.28±0.29） % and （52.56±3.60） %, respectively. When 1 tLmol/L DMS was used in combination with DDP （0.5, 2.5, and 12.5 μg/ml） for 24 h, the growth inhibition rates of the cancer cells were （ 15.35±0. 86）%, （25.57±0.27）%, （36.37±0. 51 ）%, respectively. When 1 μmol/L DMS was used in combination with MMC （0. 1, 0.5, and 2.5μg/ml） for 24 h, the growth inhibition rates of the cancer cells were （ 21.02±0.28 ） %, （ 32. 10±0.27 ） %, （ 36.36±O. 28 ） %, respectively. There were also significant differences among the growth inhibition rates caused by different concentrations of the drugs alone and in combination groups （P 〈 0.05）. Conehtsions DMS can suppress the proliferation of SGC7901 cells in vitro, and there are evident synergetic effects when it is used in combination with chemotherapeutic drugs. The results of this study indicate that SphK1 inhibitors may become novel and promisiny chemotherapeutic sensitizers.