靶向沉默SPHK1基因诱导人胃癌SGC-7901细胞凋亡

Silencing expression of SPHK1 gene induces the apoptosis of human gastric cancer SGC-7901 cells in vitro

目的探讨用小干扰核酸(Small interfering RNA,siRNA)靶向沉默神经鞘氨酸激酶1(sphingosine kinase1,SPHK1)基因敲除后对胃癌SGC-7901细胞凋亡的影响。方法人工化学合成SPHK1 siRNA和对照siRNA,分别转染胃癌SGC-7901细胞。Western blot法检测SPHK1、Bcl-2和Bax蛋白的表达;流式细胞术(Flow Cytometry,FCM)检测细胞凋亡的变化。结果 SPHK1 siRNA转染胃癌SGC-7901细胞后,SPHK1蛋白表达明显下调;与对照组相比,SPHK1 siRNA转染组Bcl-2蛋白表达下调了55%(P<0.01),Bax蛋白表达差异无统计学意义,Bcl-2/Bax比值下调54%(P<0.05);SPHK1 siRNA转染组早期凋亡细胞明显增多(P<0.01),晚期凋亡细胞无明显变化。结论 SPHK1特异性siRNA可阻断SGC-7901细胞SPHK1蛋白的表达,并通过影响Bcl-2通路诱导细胞凋亡。

Objective To investigate the effect of the siRNA targeting SPHK1 gene on the apoptosis of SGC-7901 cells of human gastric cancer in vitro. Methods Specific small interfering RNA （siRNA）targeting SPHK1 gene and control siRNA were chemically synthesized and transfected into SGC-7901 cells respectively. The expressions of SPHK1 ,Bcl-2 and Bax proteins were tested by Western blotting. And the apoptosis of SGC-7901 cells was tested by Flow Cytometry. Results In SPHK1 siRNA treated SGC-7901 cells, the protein expression of SPHK1 was significantly decreased （P 〈 0.01）. Compared with the control group, Bcl-2 protein level was reduced by 55% in the SPHK1 siRNA transfected group by 55% （P 〈 0.01 ）, with no significant difference for the expression of Bax protein while the ratio of Bcl-2/Bax protein expression was reduced by 54%（P 〈 0.05）. The number of the early apoptosis ceils for the SPHK1 siRNA transfected group was significantly more than that for the control siRNA transfected group （P 〈 0.01 ） but with no significant difference for the number of late apoptosis cells. Conclusions SPHK1 siRNA was able to specifically knock down the expression of SPHK1 and induce cell apoptosis by regulation the Bcl-2 pathway.