siRNA介导NF-κB p65沉默联合5-Fu诱导胃癌细胞SGC7901凋亡

目的运用siRNA抑制胃癌细胞株SGC7901中NF-κB p65基因的表达,探讨其对细胞增殖和凋亡的影响,并分析该基因对化疗药物5-氟尿嘧啶(5-Fu)耐药性的作用。方法将SGC7901细胞分为空白对照组、脂质体组、5-Fu组、siRNA组和联合组,除空白对照组外,各组分别给予相应的药物。Western blot法检测各组细胞NF-κBp65蛋白的表达;Annexin V-PI法检测细胞凋亡;MTT法检测各组细胞的增殖水平。结果NF-κBp65蛋白在空白对照组和脂质体组中高表达,在5-Fu组、siRNA组和联合组中低表达,其中以联合组表达量最低;各组细胞早期凋亡率分别为1.40%±0.20%、2.36%±0.58%、6.68%±0.34%、6.60%±0.64%和21.62%±1.12%,其中以联合组最高;细胞的增殖活性随着siRNA浓度的增加和作用时间的延长而下降。结论siRNA能有效抑制NF-κBp65基因的表达,从而抑制SGC7901细胞增殖,促进其凋亡,并增强肿瘤细胞对化疗药物的敏感性。

Apoptosis of Gastric Carcinoma SGC7901 Cells Induced by siRNA-mediated Nuclear Factor-kappa B p65 Gene Silencing Combined with 5-Fu

Objective To inhibit the expression of nuclear factor-kappa B(NF-κB)p65 gene in gastric carcinoma SGC7901 cells by siRNA, investigate the effect on cell proliferation and apoptosis and analyze the effect of NF-κB p65 gene on resistance to 5fluorouracil(5-Fu)as a chemotherapeutics. Methods SGC7901 cells were divided into one blank control and four test groups. The cells in four test groups were treated with liposome, 5-Fu, siRNA and 5-Fu + siRNA, while those in blank control group were untreated. The expressions of NF-κB p65 protein in cells of various groups were determined by Western blot, the cell apoptosis by Annexin Ⅴ-PI method, and the cell proliferation level by MTT method. Results The expression levels of NF-κB p65 protein were high in the SGC7901 cells in blank control and liposome groups, while low in 5-Fu, siRNA and 5-Fu + siRNA groups, of which that in 5-Fu + siRNA group was the lowest. The early apoptosis rates of cells in blank control, liposome, 5-Fu, siRNA and 5-Fu + siRNA groups were 1. 40% ± 0. 20%, 2. 36% ± 0. 58%, 6. 68% ± 0. 34%, 6. 60% ± 0. 64% and 21. 62% ± 1. 12% respectively, of which that in 5-Fu + siRNA group was the highest. The proliferation activity of cells decreased with the increasing siRNA concentration and the increasing time for treatment. Conclusion The siRNA inhibited the expression of NF-κB p65 gene effectively, thus inhibited the proliferation and promoted the apoptosis of SGC7901 cells and enhanced the sensitivity of tumor cells to chemotherapeutics.