Magnolol, a natural compound, induces apoptosis of SGC-7901 human gastric adenocarcinoma cells via the mitochondrial and PI3K/Akt signaling pathways

Gastric cancer is the fourth most commonly diagnosed cancer with the second highest mortality rate worldwide. Surgery, chemotherapy and radiation therapy are generally used for the treatment of stomach cancer but only limited clinical response is shown by these therapies and still no effectual therapy for advanced gastric adenocarcinoma patients is available. Therefore, there is a need to identify other therapeutic agents against this life-threatening disease. Plants are considered as one of the most important sources for the development of anticancer drugs. Magnolol, a natural compound possesses anticancer properties. However, effects of Magnolol on human gastric cancer remain unexplored. The effects of Magnolol on the viability of SGC-7901 cells were determined by the MTT assay. Apoptosis, mitochondrial membrane potential and cell cycle were evaluated by flow cytometry. Protein expression of Bcl-2, Bax, caspase-3 and PI3K/Akt was analysed by Western blotting. Magnolol induced morphological changes in SGC-7901 cells and its cytotoxic effects were linked with DNA damage, apoptosis and S-phase arrest in a dose-dependent manner. Magnolol triggered the mitochondrial-mediated apoptosis pathway as shown by an increased ratio of Bax/Bcl-2, dissipation of mitochondrial membrane potential (ΔΨm), and sequential activation of caspase-3 and inhibition of PI3K/Akt. Additionally, Magnolol induced autophagy in SGC-7901 cells at high concentration but was not involved in cell death. Magnolol-induced apoptosis of SGC-7901 cells involves mitochondria and PI3K/Akt-dependent pathways. These findings provide evidence that Magnolol is a promising natural compound for the treatment of gastric cancer and may represent a candidate for in vivo studies of monotherapies or combination antitumor therapies.     

Ginsenoside-Rh2 Inhibits Proliferation and Induces Apoptosis of Human Gastric Cancer SGC-7901 Side Population Cells

Objectives: To observed the effects of ginsenoside -Rh2 (GS-Rh2) on proliferation and apoptosis of side population (SP) human gastric cancer SGC-7901 cells. Materials and Methods: SGC-7901 SP and Non-SP cells were sorted by flow cytometry and assessed using the cck-8 method. Expression of apoptosis-related proteins Bax and Bcl-2 of SP before and after the intervention was determined by Western-blotting. Results: It was found that the proliferation of SP was significantly faster than that of NSP (<0.05). In addition, GS-Rh2 inhibited proliferation of gastric cancer SP cells, induced cell cycle arrest and cell apoptosis, and changed the expression of BAX/Bcl-2 proteins in a time-dependent and concentration-dependent manner (<0.05). Conclusions: With increase of GS-Rh2 dose, GS-Rh2 gradually inhibit the proliferation of SGC-7901 SP cells, which have high proliferation rate, through G1/G0 phase arrest, followed by apoptosis which involves the up-regulation of Bax and the down-regulation of Bcl-2.     

S-benzyl-cysteine-mediated Cell Cycle Arrest and Apoptosis Involving Activation of Mitochondrial-dependent Caspase Cascade through the p53 Pathway in Human Gastric Cancer SGC-7901 Cells

S-benzyl-cysteine (SBC) is a structural analog of S-allylcysteine (SAC), which is one of the major watersolublecompounds in aged garlic extract. In this study, anticancer activities and the underlying mechanismsof SBC action were investigated and compared these with those of SAC using human gastric cancer SGC-7901cells. SBC significantly suppressed the survival rate of SGC-7901 cells in a concentration- and time-dependentmanner, and the inhibitory activities of SBC were stronger than those of SAC. Flow cytometry revealed that SBCinduced G2-phase arrest and apoptosis in SGC-7901 cells. Typical apoptotic morphological changes were observedby Hoechst 33258 dye assay. SBC-treatment dramatically induced the dissipation of mitochondrial membranepotential (ΔΨm), and enhanced the enzymatic activities of caspase-9 and caspase-3 whilst hardly affectingcaspase-8 activity. Furthermore, Western blotting indicated that SBC-induced apoptosis was accompanied byup-regulation of the expression of p53, Bax and the down-regulation of Bcl-2. Taken together, this study suggestedthat SBC exerts cytotoxic activity involving activation of mitochondrial-dependent apoptosis through p53 andBax/Bcl-2 pathways in human gastric cancer SGC-7901 cells.     

丹参酮Ⅰ对人胃腺癌细胞SGC-7901增殖、凋亡的影响

目的：研究丹参酮I（Tan I）对SGC-7901人胃腺癌细胞增殖、凋亡的影响。方法：体外培养SGC-7901细胞,实验分为对照组,5-FU250μg/ml,Tan I 0.5μg/ml,Tan I 1μg/ml,Tan I 2μg/ml,Tan I 4μg/ml。MTT法检测SCG-7901细胞增殖情况;Hoechst33258/PI双荧光活染法观察凋亡细胞核形态学改变;流式细胞仪检测细胞周期分布,免疫细胞化学SABC法检测SGC-7901人胃腺癌细胞中Bcl-2的表达。结果：Tan I对胃腺癌细胞的生长有明显的抑制作用;Tan I作用后胃腺癌细胞表现为凋亡特征性的形态改变;Tan I可浓度依赖性引起G1期细胞数量增多,S期细胞减少;Tan I作用组胃腺癌细胞Bcl-2表达明显减少。结论：TanI对体外培养的SGC-7901人胃腺癌细胞的生长有明显的抑制作用,可通过促进其凋亡、影响细胞周期分布及抑制SGC-7901人胃腺癌细胞Bcl-2的表达发挥其抗肿瘤作用。     

多烯磷脂酰胆碱与奥沙利铂协同抗胃癌细胞增殖的研究

目的 探讨多烯磷脂酰胆碱联合奥沙利铂对胃癌细胞增殖的影响。方法 采用四甲基偶氮唑盐（MTT）比色法检测多烯磷脂酰胆碱、奥沙利铂及两药联合对胃癌SGC-7901细胞增殖的影响;流式细胞术检测各组细胞周期分布及凋亡情况;Western blotting检测各组凋亡相关蛋白细胞色素c、Bcl-2、Bax、caspase-9、caspase-3和细胞周期调控蛋白细胞因子D1、细胞因子E的表达水平。结果 奥沙利铂显著抑制胃癌SGC-7901细胞增殖,且呈剂量和时间依赖性（P＜0.05）;多烯磷脂酰胆碱促进胃癌SGC-7901细胞增殖,其作用呈剂量依赖性（P＜0.05）;两药联合表现为协同作用,与奥沙利铂单药组比较,差异有统计学意义（P＜0.05）。奥沙利铂使胃癌细胞增殖停滞在G0／G1期,并具有诱导胃癌细胞凋亡的作用;多烯磷脂酰胆碱可增强奥沙利铂诱导细胞凋亡及细胞周期停滞的作用,但这两种增强作用均与多烯磷脂酰胆碱的浓度无关（P＞0.05）。Western blotting检测结果显示,多烯磷脂酰胆碱联合奥沙利铂上调细胞色素c的水平并激活其下游蛋白Bcl-2、Bax、caspase-9、caspase-3,下调细胞因子D1、细胞因子E的表达水平。结论 多烯磷脂酰胆碱与奥沙利铂可抑制胃癌SGC-7901细胞的增殖和诱导细胞凋亡,将细胞阻滞于G0／G1期,两药联合可能会产生协同抗肿瘤的作用。     

Ad-PTEN体外对SGC-7901胃癌细胞生长的抑制作用

目的：探讨腺病毒介导的PTEN基因表达体外对SGC-7901胃癌细胞生长抑制作用及其分子机制。方法：将携有PTEN基因的复制缺陷型腺病毒载体（Ad-PTEN）感染SGC-7901胃癌细胞,用RT-PCR法检测Ad-PTEN在细胞中的表达,光学显微镜及荧光显微镜下观察Ad-PTEN感染细胞前后形态的变化,MTT法检测Ad-PTEN对SGC-7901胃癌细胞生长的抑制作用,用流式细胞术（FCM）检测SGC-7901胃癌细胞凋亡率。RT-PCR分析Bax、Bcl-2、p53、Survivin细胞凋亡相关基因的表达。结果：Ad-PTEN基因组感染SGC-7901胃癌细胞后,RT-PCR结果显示PTEN目的基因能在SGC-7901胃癌细胞中转录,其表达可明显抑制该胃癌细胞的生长,并诱导细胞凋亡。其凋亡机制可能与Bax/Bcl-2比值、p53基因表达上调、Survivin下调有关。结论：重组腺病毒Ad-PTEN具有抑制SGC-7901胃癌细胞生长和诱导细胞凋亡的作用。     

丹参酮Ⅰ对人胃腺癌细胞SGC-7901增殖、凋亡的影响

目的:研究丹参酮I(Tan I)对SGC-7901人胃腺癌细胞增殖、凋亡的影响。方法:体外培养SGC-7901细胞,实验分为对照组,5-FU250μg/ml,Tan I 0.5μg/ml,Tan I 1μg/ml,Tan I 2μg/ml,Tan I 4μg/ml。MTT法检测SCG-7901细胞增殖情况;Hoechst33258/PI双荧光活染法观察凋亡细胞核形态学改变;流式细胞仪检测细胞周期分布,免疫细胞化学SABC法检测SGC-7901人胃腺癌细胞中Bcl-2的表达。结果:Tan I对胃腺癌细胞的生长有明显的抑制作用;Tan I作用后胃腺癌细胞表现为凋亡特征性的形态改变;Tan I可浓度依赖性引起G1期细胞数量增多,S期细胞减少;Tan I作用组胃腺癌细胞Bcl-2表达明显减少。结论:TanI对体外培养的SGC-7901人胃腺癌细胞的生长有明显的抑制作用,可通过促进其凋亡、影响细胞周期分布及抑制SGC-7901人胃腺癌细胞Bcl-2的表达发挥其抗肿瘤作用。     

Evodiamine,a constituent of Evodiae Fructus,induces anti-proliferating effects in tumor cells

We found that evodiamine, a major alkaloidal component of Evodiae Fructus (Goshuyu in Japan), inhibited proliferation of several tumor cell lines, but had less effect on human peripheral blood mononuclear cells (PBMC). We used human cervical cancer cells, HeLa, as a model to elucidate the molecular mechanisms of evodiamine-induced tumor cell death. The results showed that evodiamine induced oligonucleosomal fragmentation of DNA in HeLa cells and increased the activity of caspase-3, but not that of caspase-1, in vitro . Both evodiamine-induced DNA fragmentation and caspase-3 activity were effectively inhibited by a caspase-3 inhibitor, z-DEVD-fmk (z-Asp-Glu-Val-Asp-fmk). In addition, evodiamine increased the expression of the apoptosis inducer Bax, but decreased the expression of the apoptosis suppressor Bcl-2 in mitochondria. Taken together, our data indicated that evodiamine alters the balance of Bcl-2 and Bax gene expression and induces apoptosis through the caspase pathway in HeLa cells. (Cancer Sci 2003; 94: 92–98)     

Induction of mitochondria-mediated apoptosis in human gastric adenocarcinoma SGC-7901 cells by kuraridin and Nor-kurarinone isolated from Sophora flavescens

The study was designed as one of a series to find novel anticancer compounds from Chinese herbs. For this purpose, we screened an ethanol extract of 300 herbs against SGC-7901 cells. Sophora flavescen was included in those showing potential cytotoxic activity. Target compounds were therefore isolated and analyzed on analytical HPLC. Chromatography showed only one peak with a purity of 97%. The ESI-MS spectrum showed two molecular ions: m/z 424(M+) and 438(M+). Furthermore, combining the data of 1HNMR and 13CNMR, it was deduced that this product was a mixture of two compounds; kuraridin (1) and nor-kurarinone (2). The concentration was [1]:[2]=9:10, the chemical structural formulae are C25H28O6 and C26H30O6. In this study, mechanisms involved by the mixture of compounds 1 and 2-induced growth inhibition including apoptosis and G2/M phase arrest in human gastric adenocarcinoma SGC-7901 cells were examined for the first time. Triggering of the mitochondrial apoptotic pathway was demonstrated by loss of mitochondrial membrane potential, reduction in the Bcl-2/Bax ratio, and significant activation and cleavage of caspase-3. Additionally, the production of reactive oxygen species (ROS) was also increased. Taken together, our results indicated that the cytotoxic efficacy of the mixture of compounds 1 and 2 is mainly due to induction of cell cycle arrest and apoptosis.     

西黄浸提液抑制胃癌SGC-7901 细胞增殖的可能机制

[摘要] 目的：探讨西黄浸提液对胃癌SGC-7901 细胞增殖的影响及其可能机制。方法：常规培养胃癌细胞株SGC-7901,用CCK-8 法和细胞流式细胞术检测不同质量浓度（3.2、6.4、12.8 和25.6 mg/ml）的西黄浸提液在不同时间点（24、48 和72 h）对SGC-7901 细胞增殖和凋亡的影响,用qPCR法检测不同质量浓度西黄浸提液对SGC-7901 细胞凋亡相关基因Bax 和Bcl-2 mRNA表达的影响,用Western blotting 检测西黄浸提液对凋亡相关蛋白caspase 3、caspase 9、Bax和Bcl-2 表达的影响。结果：3.2~25.6 mg/ml的西黄浸提液均能有效地抑制胃癌SGC-7901 细胞的增殖（P<0.05 或P<0.01）,并且随浓度增加SGC-7901 细胞凋亡率增加（P<0.01）。西黄浸提液能够显著上调SGC-7901 细胞Bax mRNA和下调Bcl-2 mRNA表达水平（P<0.05 或P<0.01）,并可增加caspase3、caspase 9 和Bax 蛋白表达、降低Bcl-2 蛋白表达（P<0.05 或P<0.01）。结论：西黄浸提液通过触发细胞凋亡抑制胃癌SGC-7901细胞的增殖,此可成为一个潜在的胃癌辅助治疗的方法。     

Induction of Cytotoxicity and Apoptosis in Human Gastric Cancer Cell SGC-7901 by Isovaltrate Acetoxyhydrin Isolated from Patrinia heterophylla Bunge Involves a Mitochondrial Pathway and G2/M Phase Cell Cycle Arrest

Background: Our previous study demonstrated cytotoxicity of a crude extract from Patrinia heterophylla Bunge(PHEB). In the present study, we aimed to investigate the effects of isovaltrate acetoxyhydrin (IA) isolated fromPHEB on the gastric cancer cell SGC-7901, in order to explore a potential treatment for gastric cancer. Methods:MTT assays were employed to determine the effects of IA on cell vitality and proliferation, with monitoring ofcell morphology changes and examination of apoptosis with Annexin V-PI staining. Flow cytometry was used toassess cell cycle progression and mitochondrial membrane potential. The activity of caspase 3, 9 was evaluatedby spectrophotometry, and the protein levels of Bax, Bcl2 and Cyclin B1 were analyzed with Western blottingof total proteins extracted from cultured cells. Results: The results demonstrated direct toxicity of IA towardsSGC-7901 cells. Evidence of apoptosis included blebbing and chromatin condensation. Annexin V-PI assaysrevealed early apoptosis, involving rapid depolarization of mitochondrial membranes and activity of caspase3, 9 signaling pathways. Western blotting showed that Bcl2 and Bax proteins was down- and up-regulated,respectively, and cyclin B1 was up-regulated. Cell cycle analysis further indicated that IA could induce G2/Mphase arrest in SGC-7901 cells. Conclusions: In conclusion, we believe that IA induces apoptosis of SGC-7901cells, therefore providing a potential therapeutic agent for treatment of gastric cancer.     

小檗胺对胃癌细胞增殖、凋亡的影响及其分子机制

目的:探讨小檗胺对胃癌细胞（AGS和SGC-7901）增殖、凋亡的影响并探讨其分子机制。方法:利用MTT 实验检测胃癌细胞的增殖,利用集落形成实验检测胃癌细胞的生长, 流式细胞技术检测胃癌细胞的凋亡率以及细胞周期, Western blot检测凋亡相关蛋白的表达水平。结果:小檗胺（0~64 μg/ml）能够剂量依赖性以及时间依赖性的抑制 AGS和SGC-7901细胞的增殖 （P＜0.05）。集落形成实验结果显示小檗胺(32 μg/ml)能够抑制AGS和SGC-7901细胞的生长 （P＜0.05）。流式细胞实验显示,小檗胺(32 μg/ml)同时能够促进AGS和SGC-7901细胞的凋亡 （P＜0.05）,增殖G0/G1期细胞比例,降低S期细胞比例 （P＜0.05）。Western blot实验结果显示小檗胺(32 μg/ml)能够增加AGS和SGC-7901细胞的cleaved caspase-3,cleaved caspase-9以及Bax的蛋白水平,同时降低Bcl-2的蛋白水平 （P＜0.05）。结论:小檗胺能够抑制胃癌细胞的增殖,其机制可能与改变细胞周期以及促进细胞凋亡有关。     

Curcumin Induces Apoptosis in SGC-7901 Gastric Adenocarcinoma Cells via Regulation of Mitochondrial Signaling Pathways

Curcumin, a polyphenol compound derived from the rhizome of the plant Curcuma longa L. has been verifiedas an anticancer compound against several types of cancer. However, understanding of the molecular mechanismsby which it induces apoptosis is limited. In this study, the anticancer efficacy of curcumin was investigated inhuman gastric adenocarcinoma SGC-7901 cells. The results demonstrated that curcumin induced morphologicalchanges and decreased cell viability. Apoptosis triggered by curcumin was visualized using Annexin V-FITC/7-AAD staining. Curcumin-induced apoptosis of SGC-7901 cells was associated with the dissipation of mitochondrialmembrane potential (MMP) and the release of cytochrome c into the cytosol. Furthermore, the down-regulationof Bcl-2 and up-regulation of Bax that led to the cleavage of caspase-3 and increased cleaved PARP was observedin SGC-7901 cells treated with curcumin. Therefore, curcumin-induced apoptosis of SGC-7901 cells might bemediated through the mitochondria pathway, which gives the rationale for in vivo studies on the utilization ofcurcumin as a potential cancer therapeutic compound.     

pseudo-G-Rh2 induces mitochondrial-mediated apoptosis in SGC-7901 human gastric cancer cells

This study was designed to investigate the effect of pseudo-G-Rh2, a novel metabolite of ginsenoside Rh2, on the apoptosis of SGC-7901 human gastric cancer cells. Pseudo-G-Rh2 demonstrated antitumor activity and significantly inhibited the proliferation of SGC-7901 cells in a concentration-dependent manner. After treatment with pseudo-G-Rh2, SGC-7901 cells showed typical apoptotic morphological features, such as chromatin condensation and DNA fragmentation. Pseudo-G-Rh2 could induce mitochondrial membrane potential loss, which led to the release of cytochrome c (Cyt?c), Smac/Diablo and apoptosis-inducing factor (AIF) to the cell cytoplasm. Furthermore, pseudo-G-Rh2 exposure not only decreased the expression of the Bcl-2 protein but also increased the expression of the Bax protein and the activities of caspase-9 and caspase-3 in SGC-7901 cells. These results demonstrated that pseudo-G-Rh2 inhibited the proliferation of SGC-7901 cells by initiating apoptosis. Pseudo-G-Rh2-induced apoptosis was associated with a drop in the mitochondrial transmembrane potential, down-regulation of Bcl-2, up-regulation of Bax and activation of caspase-9 and caspase-3.     

奥沙利铂通过调控miRNA-7-5p/RAF-1促进胃癌SGC-7901细胞凋亡的研究

目的探讨奥沙利铂如何调控MAPK通路,抑制胃癌细胞的增殖。方法NCBI检索文献,利用TargetScan、StarBase和miRBase数据库,进行GO分析与KEGG通路富集,找到相关miRNAs,预测靶基因。应用Real-time PCR、MTT、Hoechst33258、流式细胞术、细胞划痕实验、Western blot等方法分析人胃癌SGC-7901细胞的增殖、细胞周期、侵袭及蛋白表达情况。结果胃癌细胞中miR-7-5p显著低表达,RAF1与miR-7-5p存在互靶关系。miR-7-5p mimics与奥沙利铂均可促进SGC-7901细胞的凋亡,提高G1期细胞百分率(P<0.05),降低侵袭、迁移速度。caspase3、caspase9蛋白表达升高,Bcl-2/Bax比值降低(P<0.05)。结论过表达miR-7-5p与奥沙利铂均可促进胃癌SGC-7901细胞的凋亡,提示奥沙利铂可能通过上调miRNA-7-5p促进SGC-7901细胞的凋亡,降低侵袭、迁移速度。     

The apoptotic effect of apigenin on human gastric carcinoma cells through mitochondrial signal pathway

This study aims to explore the apoptotic function of apigenin on the gastric cancer cells and the related mechanism. The gastric cancer cell lines HGC-27 and SGC-7901, and normal gastric epithelial cell line GES1 were treated with different concentrations of apigenin. Cell proliferation was tested. Morphological changes of the apoptotic cells were observed after Hoechst33342 staining. The apoptosis rate of the gastric cancer cells were measured with flow cytometry. Changes of the cell cycle were explored. The mitochondrial membrane potential changes were analyzed after JC-1 staining. Bcl-2 family proteins and caspases-3 expression with apigenin treatment was analyzed by real-time PCR. Cell proliferation of HGC-27 and SGC-7901 was inhibited by apigenin, and the inhibition was dose-time-dependent. Gastric carcinoma cells treated by apigenin had no obvious cell cycle arrest, but were observed with the higher apoptosis rate and the typical apoptotic morphological changes of the cell nucleus. JC-1 staining showed that apigenin could reduce mitochondrial membrane potential of gastric carcinoma cells. Real-time PCR results showed that apigenin significantly increased caspase-3 and Bax expression level, and down-regulated Bcl-2 expression in a dose-dependent manner in gastric carcinoma cells. However, the GES1 was almost not affected by apigenin treatment. Apigenin can inhibit cell lines HGC-27 and SGC-7901 proliferation in a time and dose-dependent manner, reduce anti-apoptotic protein Bcl-2 levels, enhance apoptosis-promoting protein Bax level, result in mitochondrial membrane potential decreasing and caspase-3 enzyme activating, then lead to cell apoptosis.     

miR-361-5p通过靶向CCND1逆转胃癌SGC-7901细胞奥沙利铂耐药性

目的:探讨miR-361-5p对胃癌SGC-7901细胞奥沙利铂(oxaliplatin,OXA)耐药性的影响及其作用机制.方法:采用qPCR法检测miR-361-5p在胃癌细胞MKN-45、MGC80-3、SGC-7901和OXA耐药细胞SGC-7901/OXA中的表达水平.利用脂质体转染技术分别将miR-361-5...     

白杨素对人胃癌SGC-7901细胞增殖与凋亡的影响

 目的 探讨白杨素（Chrysin,ChR）诱导人胃癌SGC-7901细胞株凋亡的作用及机制。方法 分别用10、20、40、80μM的ChR处理人胃癌细胞株SGC-790148h,采用MTT比色法检测ChR对SGC-7901细胞的增殖抑制效应;采用丫啶橙（AO）染色、流式细胞术检测ChR诱导SGC-7901细胞凋亡的发生;应用Western-blot法检测凋亡相关基因NF-κB、Bcl-2、Bax的蛋白表达,并用计算机图像分析软件进行半定量分析。结果 MTT比色法显示的10～80μM的ChR在体外对人胃癌SGC-7901细胞有增殖抑制率为：9.71%～53.64%,该作用呈浓度依赖性;AO染色荧光显微镜观察ChR在体外能诱导人胃癌SGC-7901细胞发生凋亡,出现早期凋亡细胞及凋亡小体;流式细胞术检测结果显示：ChR呈浓度依赖性地诱导SGC-7901细胞凋亡,凋亡率为2.35%-20.8%;Western-blot检测结果显示：凋亡相关基因Bcl-2、NF-κB蛋白表达下调,Bax蛋白表达上调。结论 ChR对体外培养人胃癌细胞具有增殖抑制和诱导凋亡作用,呈浓度依赖性。ChR对人胃癌细胞增殖抑制和诱导凋亡作用机制可能与其抑制NF-κB活化、下调Bcl-2蛋白表达和上调Bax蛋白表达相关。     

microRNA-21通过Bcl-2通路调节胃癌紫杉醇化疗耐药性

目的:研究miR-21在胃癌组织中的表达水平及对胃癌生物学行为的影响,探讨miR-21与紫杉醇化疗耐药性的关系及机制。方法:实时荧光定量（real-time quantitative polymerase chain reaction,RT-qPCR）比较25例胃癌组织和癌旁组织中miR-21的表达差异;细胞实验探讨miR-21对胃癌细胞增殖、凋亡能力的影响;MTT法测定紫杉醇对SGC-7901细胞的生长抑制率;Western blot验证Bcl-2、Bax、PTEN蛋白表达和miR-21的关系。结果:miR-21在胃癌组织中表达水平高于癌旁正常组织（P=0.015）;与NC组比较,转染miR-21模拟物的胃癌SGC-7901细胞增殖能力（P＜0.05）增强,下调miR-21表达水平可促进胃癌细胞凋亡(P＜0.05);转染miR-21 mimic组的紫杉醇对胃癌细胞的抑制率明显低于miR-21 inhibitor组;miR-21 inhibitor组较NC组中Bcl-2的蛋白水平下降（P=0.000）,而PTEN（P=0.039）、Bax（P=0.037）表达升高。结论:miR-21在胃癌组织中过表达,且过表达的miR-21可能通过升高Bcl-2表达并降低Bax、PTEN蛋白表达从而促进胃癌细胞增殖,抑制胃癌细胞凋亡,并增加紫杉醇化疗耐药性。