沉默Beclin1基因对β-榄香烯抑制人胃癌SGC-7901细胞增殖与诱导自噬的影响

Effect of Silencing Beclin 1 Gene on β-Elemene Inhibiting Proliferation and Inducing Autophagy of Human Gastric Cancer Sgc-7901 Cells

目的探讨Beclin1基因对β-榄香烯抗人胃癌SGC-7901细胞增殖及自噬诱导的影响。方法用前期实验构建成功的GV112-Beclin1-shRNA1(short hairpin RNA,短发夹RNA)慢病毒载体感染人胃癌SGC-7901细胞。采用四甲基偶氮唑盐微量酶反应比色法(MTT)检测β-榄香烯对SGC-7901细胞增殖的抑制作用,以及沉默Beclin1基因后对β-榄香烯抗增殖能力的影响。免疫蛋白印迹(Western blot)检测自噬相关蛋白LC3-II、P62的表达,评价β-榄香烯作用SGC-7901后的自噬水平和Beclin1基因沉默对β-榄香烯诱导自噬的影响。结果 MTT法显示,β-榄香烯能够抑制胃癌SGC-7901细胞增殖,抑制作用随浓度的增加而递增(浓度为20、50、100μg/mL比0μg/mL时,抑制率为21.5%、31.7%、37.4%比0,P<0.05);沉默Beclin1基因后β-榄香烯抑制胃癌SGC-7901细胞抑制率增加(42.3%比36.1%,P<0.05)。Western blot法显示,β-榄香烯能诱导SGC-7901细胞发生保护性自噬,自噬相关蛋白LC3-Ⅱ表达上调,P62蛋白表达下降,沉默Beclin1基因可抑制β-榄香烯对SGC-7901细胞保护性自噬的增强,LC3-Ⅱ蛋白表达水平下降,P62蛋白表达增加。结论β-榄香烯可诱导胃癌SGC-7901细胞发生保护性自噬,下调Beclin1基因有助于降低保护性自噬的发生,从而增强β-榄香烯的抗癌效果。

Objective To explore the effect of Beclin 1 gene expression on β-elemene inhibiting proliferation and inducing autophagy of human gastric cancer SGC-7901 cells by using RNA interference(RNAi) technique.Methods The GV112-Beclin 1-shRNA 1(short hairpin RNA) lentiviral vector successfully constructed in previous experiments was used to infect human gastric cancer SGC-7901 cells. The inhibitory effect of β-elemene on the proliferation of SGC-7901 cells and the effect of silencing Beclin 1 gene on anti-proliferative ability of β-elemene were detected by MTT assay. Western blot was performed to check the expression of autophagy-related proteins LC3-II and P62, and to evaluate the effect of β-elemene-induced autophagy level in SGC-7901 cells and Beclin1 gene silencing. Results MTT assay showed that β-elemene could inhibit the proliferation of SGC-7901 cells,and the inhibitory effect increased with the increase of concentration, i.e., when the concentration was 20, 50,100μg/mLvs 0μg/mL, the inhibitory rates were 21.5%, 31.7%, 37.4% vs 0, P<0.05, respectively. The inhibition rate of β-elemene on SGC-7901 cells increased after Beclin 1 gene was silenced, i.e., 42.3% vs 36.1%, P<0.05. Western blot indicated that β-elemene could induce SGC-7901 cells to produce protective autophagy, the expression of autophagy-related protein LC3-II up-regulated, and P62 protein expression down-regulated. Silencing Beclin 1 gene could inhibit β-elemene from enhancing the protective autophagy of SGC-7901 cells, the expression of LC3-II down-regulated, and P62 expression up-regulated. Conclusion β-elemene can induce protective autophagy in gastric cancer SGC-7901 cells. Down-regulation of Beclin 1 gene can reduce the occurrence of protective autophagy,thereby enhancing the anti-cancer effect of β-elemene. Silencing Beclin 1 gene combined with β-elemene may be a novel therapy for gastric cancer.