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目的:观察胃癌MKN-45细胞中Notch信号通路抑制剂3，5-二氟苯乙酰基-L-丙氨酰基-L-2-苯基甘氨酸叔丁酯(DAPT)对自噬的影响及自噬抑制剂氯喹(CQ)对Notch信号通道的影响，探讨DAPT联合CQ对MKN-45细胞增殖、凋亡的影响。方法:将MKN-45细胞分成4个组，对照组(Control组，RPMI 1640完全培养基培养)；氯喹组(CQ组，含40 μmol/L氯喹的RPMI 1640完全培养基培养)；γ-分泌酶抑制剂组(DAPT组，含80 μmol/L DAPT的RPMI 1640完全培养基培养)；联合用药组(Comb组，含40 μmol/L CQ和80 μmol/L DAPT的RPMI 1640完全培养基培养)。应用噻唑蓝(MTT)法、流式细胞仪检测细胞增殖、凋亡；应用透射电镜、蛋白质印迹法(Western blot)、反转录-聚合酶链反应(RT-PCR)检测细胞自噬水平；应用Western blot检测Notch信号通路表达。两组间比较采用独立样本n t检验。n 结果:MTT结果显示，Comb组[(55.09±1.38)%]细胞增殖能力明显低于DAPT组[(78.83±1.74)%]和CQ组[(64.82±1.89)%]，差异均有统计学意义(n t＝18.514、7.185，n P<0.01)。流式细胞结果显示，Comb组[(43.43±2.30)%]凋亡率明显高于DAPT组[(27.26±3.02)%]和CQ组[(22.16±2.24)%]，差异均有统计学意义(n t＝7.339、11.415，n P<0.01)。Western blot、RT-PCR结果显示，DAPT组自噬相关的微管相关蛋白1轻链3Ⅱ(LC3Ⅱ)、苄氯素1(Beclin1)、自噬相关基因7(ATG7)信使核糖核酸(mRNA)、自噬相关基因12(ATG12) mRNA的相对表达量(0.587±0.030、1.503±0.066、1.797±0.110、2.433±0.111)明显高于Control组(0.333±0.002、1.137±0.068、1.000±0.000、1.000±0.000)，差异均有统计学意义(n t＝14.893、6.695、12.527、22.446，n P<0.01)。CQ组Notch1蛋白的相对表达量(0.932±0.061)明显高于Control组(0.477±0.031)，差异有统计学意义(n t＝11.590，n P<0.01)。n 结论:胃癌MKN-45细胞中自噬与Notch信号通路存在交叉对话，两者相互调节，DAPT联合CQ可以使胃癌MKN-45细胞增殖能力下降、凋亡率提高。“,”Objective:To explore the effects of Notch signaling pathway inhibitor N-[N-(3, 5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) on autophagic signaling pathway and the effects of autophagy inhibitor chloroquine (CQ) on Notch signaling pathway in MKN-45, and preliminarily investigate the effects of DAPT combined with CQ on the proliferation and apoptosis of MKN-45.Methods:The cells were divided into 4 groups: the control group (cultured in complete medium of RPMI 1640 without intervention drugs); CQ group (cultured on RPMI 1640 complete medium containing 40 μmol/L CQ); DAPT group roswell park memorial institute(RPMI) 1640 complete medium containing 80 μmol/L DAPT); combined treatment group (RPMI 1640 complete medium containing 40 μmol/L CQ and 80 μmol/L DAPT). Methyl thiazolyl tetrazolium (MTT) assay and flow cytometry were used to detect cell proliferation and apoptosis. Transmission electron microscopy, Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed to detect the level of autophagy. Western blotting was used to detect the expression of Notch signaling pathway.comparison between two groups was done with independent sample n T-test.n Results:MTT and flow cytometry results showed that cell proliferation in combined treatment group [(55.09±1.38)%] was significantly lower than that in DAPT group [(78.83±1.74)%] and CQ group [(64.82±1.89)%,n t=18.514, 7.185, n P<0.01], and apoptosis rate in combined treatment group [(43.43±2.30)%] was significantly higher than that in DAPT group [(27.26±3.02)%] and CQ group [(22.16±2.24)%,n t=7.339, 11.415, n P<0.01]. Western blotting and RT-PCR indicated that the relative expression of microtubuler-associated protein 1 light chain 3Ⅱ(LC3Ⅱ), Beclin1, autophagy-related gene 7(ATG7) mRNA and ATG12 mRNA in DAPT group (0.587±0.030, 1.503±0.066, 1.797±0.110, 2.433±0.111) was significantly higher than that in control group (0.333±0.002, 1.137±0.068, 1.000±0.000, 1.000±0.000,n t=14.893, 6.695, 12.527, 22.446, n P<0.01). The relative expression of Notch 1 protein in CQ group (0.932±0.061) was significantly higher than that in control group (0.477±0.031,n t=11.590, n P<0.01).n Conclusion:Our results suggested that autophagy and Notch signaling pathway in gastric cancer MKN-45 cells have a cross-talk. The two regulate each other. DAPT combined with CQ can reduce the proliferation ability and increase the apoptosis rate of gastric cancer MKN-45 cells and enhance the therapeutic effect on gastric cancer cells.