Epigenetic regulation of Delta-Like1 controls Notch1 activation in gastric cancer

The Notch signaling pathway drives proliferation, differentiation, apoptosis, cell fate, and maintenance of stem cells in several tissues. Aberrant activation of Notch signaling has been described in several tumours and in gastric cancer (GC), activated Notch1 has been associated with de-differentiation of lineage-committed stomach cells into stem progenitors and GC progression. However, the specific role of the Notch1 ligand DLL1 in GC has not yet been elucidated. To assess the role of DLL1 in GC cancer, the expression of Notch1 and its ligands DLL1 and Jagged1, was analyzed in 8 gastric cancer cell lines (KATOIII, SNU601, SNU719, AGS, SNU16, MKN1, MKN45, TMK1). DLL1 expression was absent in KATOIII, SNU601, SNU719 and AGS. The lack of DLL1 expression in these cells was associated with promoter hypermethylation and 5-aza-2'dC caused up-regulation of DLL1. The increase in DLL1 expression was associated with activation of Notch1 signalling, with an increase in cleaved Notch1 intracellular domain (NICD) and Hes1, and down-regulation in Hath1. Concordantly, Notch1 signalling was activated with the overexpression of DLL1. Moreover, Notch1 signalling together with DLL1 methylation were evaluated in samples from 52 GC patients and 21 healthy control as well as in INS-GAS mice infected with H. pylori and randomly treated with eradication therapy. In GC patients, we found a correlation between DLL1 and Hes1 expression, while DLL1 methylation and Hath1 expression were associated with the diffuse and mixed type of gastric cancer. Finally, none of the samples from INS-GAS mice infected with H. pylori, a model of intestinal-type gastric tumorigenesis, showed promoter methylation of DLL1. This study shows that Notch1 activity in gastric cancer is controlled by the epigenetic silencing of the ligand DLL1, and that Notch1 inhibition is associated with the diffuse type of gastric cancer.     

DON 对胃癌细胞HGC-27 细胞周期和凋亡的影响

 目的 探讨脱氧雪腐镰刀菌烯醇（DON）对体外培养胃癌细胞HGC-27细胞周期和凋亡的影响。方法 体外培养的胃癌细胞HGC-27经50、100、1000、2000μg／L DON处理12h、24h、48h，应用流式细胞术（FCM）进行细胞周期分析，检测凋亡情况及其量效关系，Western blot检测凋亡相关蛋白Bax、Bcl-2和Caspase-3的表达情况。结果 FCM检测结果表明，较高浓度（1000和2000μg／L）DON处理对细胞周期分布的影响随处理时间不同有明显差异。DON处理12h，可明显降低G0／G1细胞百分率、增加S期细胞百分率。处理时间延长至24h和48h，则表现为G0／G1细胞百分率增加，S期细胞百分率降低（P〈0．05）。DON处理24h和48h，各DON实验组HGC-27细胞凋亡率均高于对照组，在50～2000ug／L浓度范围内，凋亡率随着DON处理浓度的升高而升高。Western blot检测凋亡相关蛋白结果显示，DoN处理12、24和48h，Bax和Caspase-3蛋白表达均明显升高，而Bcl-2蛋白表达降低。结论 DON处理可影响体外培养的胃癌细胞象HGC-27细胞的细胞周期分布，其作用依DON浓度和作用时间的不同而有差异。同时DON可诱导HGC-27细胞凋亡，上调Bax和Caspase-3蛋白表达和下调Bcl-2蛋白表达可能是其诱导细胞凋亡的机制之一。     

生姜提取物对胃癌HGC-27细胞增殖和凋亡影响机制探讨

目的生姜提取物活性成分如生姜醇提物与6-姜酚参与调控多种肿瘤细胞增殖、凋亡及侵袭过程。HGC-27细胞株为常见的人未分化胃腺癌细胞。本研究旨在探讨生姜醇提物与6-姜酚单体对胃腺癌HGC-27细胞增殖、周期和凋亡影响及其可能的信号通路。方法利用有机溶剂提取法和中压制备色谱技术,得到生姜醇提物以及6-姜酚单体,经HPLC分析6-姜酚纯度不低于98.0%。以不同浓度(2、3和4 mg/mL)的生姜醇提物与6-姜酚(100、200、300和400μmol/L)处理HGC-27细胞24h,CCK-8法检测其对细胞增殖的影响;流式细胞术检测细胞周期及凋亡;实时荧光定量PCR检测细胞周期调控蛋白及凋亡相关蛋白mRNA表达的变化。结果CCK-8实验结果显示,生姜醇提物及6-姜酚均可浓度依赖性地抑制HGC-27细胞增殖,F值分别为2110和40.23,均P<0.01。流式细胞术检测结果显示,当2、3和4mg/mL生姜醇提物处理细胞24h后,G1期细胞比例增加至(50.86±1.64)%、(56.78±0.60)%和(55.74±0.43)%,高于空白对照组(46.14±2.60)%,差异有统计学意义,均P<0.01;而3和4mg/mL生姜醇提物处理组凋亡率则分别增至(20.96±0.39)%和(27.36±4.48)%,与空白对照组(14.92±1.38)%相比,差异均有统计学意义,均P<0.05。当300和400μmol/L 6-姜酚处理细胞24h后,G1期细胞比例增加至(53.85±0.62)%和(51.70±1.78)%,高于空白对照组(42.57±0.19)%,差异有统计学意义,P<0.01;而其凋亡率分别增至(9.47±1.56)%和(17.04±0.60)%,与空白对照组(4.81±1.56)%相比,差异有统计学意义,P<0.01。实时荧光定量PCR检测结果显示,生姜醇提物上调促凋亡蛋白Bax mRNA表达,同时下调凋亡抑制蛋白Bcl-2 mRNA表达,而6-姜酚则增加Bax/Bcl-2比例,并下调细胞周期调控蛋白Cyclin E1 mRNA表达,上调细胞周期蛋白激酶抑制因子p21 mRNA表达。结论生姜醇提物及6-姜酚对胃癌HGC-27细胞增殖均有抑制作用,并使细胞周期发生G1期阻滞及诱导细胞凋亡,为成为治疗胃癌的天然药物提供新依据。     

CTBP1 strengthens the cisplatin resistance of gastric cancer cells by upregulating RAD51 expression

Drug resistance is a key factor affecting the treatment of gastric cancer. The resistance of gastric cancer cells to anticancer drugs, such as cisplatin (DDP), remains a major challenge to patient recovery. The present study aimed to investigate the roles of C-terminal-binding protein 1 (CTBP1) in the DDP resistance of gastric cancer cells and to determine its regulatory effect on DNA repair protein RAD51 homolog 1 (RAD51). The DDP-resistant human gastric cancer AGS and HGC cell lines, AGS/DDP and HGC-27/DDP, respectively, were established and CTBP1 expression was detected by western blotting. In addition, Cell Counting Kit-8, colony formation and flow cytometry assays were performed to detect the proliferation and apoptosis of these two cell lines following CTBP1 knockdown. The expression levels of apoptosis-related proteins were detected by western blotting. In addition, RAD51 was overexpressed in CTBP1 knockdown cells, and proliferation and apoptosis were subsequently determined using the aforementioned methods. The results demonstrated that CTBP1 expression was notably increased in DDP-resistant gastric cancer cells. Furthermore, CTBP1 knockdown suppressed the proliferation and induced the apoptosis of AGS/DDP and HGC-27/DDP cells. Notably, CTBP1 promoted RAD51 expression in DDP-resistant gastric cancer cells. Overexpression of RAD51 in CTBP1 knockdown AGS/DDP and HGC-27/DDP cells rescued the proliferation and alleviated the apoptosis of these cells. Taken together, the results of the present study suggested that CTBP1 may enhance the DDP resistance of gastric cancer cells by activating RAD51 expression, thus providing a potential novel therapy (CTBP1 knockdown) for the clinical treatment of patients with gastric cancer.     

姜黄素对肝癌细胞凋亡及TNF-ɑ、IL-1β、IL-6炎性因子影响的机制研究

目的 探讨姜黄素对肝癌细胞凋亡及肿瘤坏死因子α(TNF-ɑ)、白介素1β(IL-1β)、白介素-6(IL-6)炎性因子的影响及机制.方法 采用5、10、20、40、80、160μmol/L的姜黄素处理人肝癌HepG2细胞24、48 h后,CCK8实验检测细胞的增殖情况,计算IC50值;50μmol/L的姜黄素处理HepG2细胞48 h后,流式细胞仪检测细胞凋亡情况;Western blot检测TNF-ɑ、IL-1β、IL-6、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved Caspase-3)、Notch1、Hes1蛋白表达情况.结果 细胞抑制率随着姜黄素作用时间及浓度的增加显著升高.根据IC50值选择50μmol/L的姜黄素作为研究对象;以50μmol/L的姜黄素处理肝癌细胞的凋亡率及Cleaved Caspase-3蛋白表达明显高于对照组,TNF-ɑ、IL-1β、IL-6、Notch1、Hes1蛋白表达均明显低于对照组(P﹤0.01).结论 姜黄素可呈时间及剂量依赖式抑制人肝癌HepG2细胞增殖,可诱导细胞的凋亡,可通过降低TNF-ɑ、IL-1β、IL-6的表达达到抗炎作用,其机制与抑制Notch1信号通路有关.     

盐酸罗哌卡因对胃癌MGC-803细胞增殖和凋亡的作用

目的:探讨盐酸罗哌卡因对人胃癌MGC-803细胞增殖和凋亡的影响。方法:细胞计数试剂盒（CCK-8）检测盐酸罗哌卡因对MGC-803细胞增殖能力的影响，并确定盐酸罗哌卡因的用药浓度，流式细胞术检测盐酸罗哌卡因对MGC-803细胞周期的影响，Annexin V-FITC/PI法检测盐酸罗哌卡因对MGC-803细胞凋亡的影响，蛋白免疫印迹法（Western blot）检测盐酸罗哌卡因对MGC-803细胞中B细胞淋巴瘤/白血病-2（Bcl-2）、Bcl-2相关X蛋白（Bax）和剪切的含半胱氨酸的天冬氨酸蛋白水解酶3（Cleaved Caspase-3）蛋白表达水平。结果:随着盐酸罗哌卡因用药浓度的升高，MGC-803细胞增殖能力逐渐降低，根据CCK-8实验结果分别筛选出浓度为10、50 μg/ml和100 μg/ml的盐酸罗哌卡因用于后续实验。盐酸罗哌卡因能够明显阻滞细胞周期于G2期，诱导细胞凋亡，抑制Bcl-2蛋白表达，促进Bax和Cleaved Caspase-3蛋白表达。结论:盐酸罗哌卡因能够抑制胃癌MGC-803细胞增殖，阻碍MGC-803细胞周期进程，诱导细胞凋亡，该过程可能与下调Bcl-2蛋白表达，上调Bax和Cleaved Caspase-3蛋白表达有关。     

LINC00519 通过 miR-876-3p/HMGA1 轴调控胃癌细胞的增殖、凋亡、 迁移和侵袭

目的：探讨长基因间非编码RNA 00519（long intergene non-coding RNA 00519,LINC00519）调控miR-876-3p/高迁移 率家族蛋白A1（high mobility group protein A1,HMGA1）轴在胃癌HGC-27细胞的增殖、凋亡、迁移和侵袭中的作用。方法：采用 qPCR检测胃癌细胞 HGC-27 和胃黏膜上皮细胞 GES-1 中 LINC00519 的表达水平。将HGC-27细胞按转染处理分为si-NC、 si-LINC00519、si-LINC00519+anti-miR-NC和si-LINC00519+anti-miR-876-3p组,采用集落形成实验检测细胞克隆形成能力,流式 细胞术检测细胞凋亡和周期分布 ,Transwell 实验检测细胞迁移和侵袭。双荧光素酶报告实验和qPCR验证LINC00519与 miR-876-3p、miR-876-3p与HMGA1之间的相互作用。结果：HGC-27细胞中LINC00519表达较GES-1细胞显著升高（ P<0.05）,转染siRNA后si-LINC00519 组 HGC-27细胞中LINC00519的表达水平较si-NC组显著降低（t=47.294 ,P<0.01）。与 si-NC组 比较,si-LINC00519组HGC-27细胞克隆数、迁移侵袭数、S期细胞比例均显著降低（均P<0.01）,凋亡率、G0/G1期细胞比例均显著 升高（均 P<0.01）。与si-LINC00519+anti-miR-NC 组比较,si-LINC00519+anti-miR-876-3p组HGC-27 细胞克隆数、迁移侵袭数、 S期细胞比例升高（均P<0.01）,凋亡率、G0/G1期细胞比例显著降低（均P<0.01）。LINC00519能够靶向负调控miR-876-3p的表 达,miR-876-3p靶向负调控HMGA1的表达。结论：敲降LINC00519能够通过调控miR-876-3p/HMGA1轴抑制胃癌HGC-27细 胞的增殖、迁移和侵袭,诱导细胞凋亡。     

Induction of apoptosis and cell cycle arrest by a specific c-Jun NH2-terminal kinase (JNK) inhibitor, SP-600125, in gastrointestinal cancers

The c-Jun NH(2)-terminal kinase (JNK) is activated in several tumor cell lines. The aim of this study was to determine the effects of SP-600125, a specific JNK inhibitor, on the viability, apoptosis, cell cycle distribution of gastrointestinal cancer cells, and the potential anti-tumor mechanisms. Three gastric cancer cell lines, AGS, BCG-823 and MKN-45, and three colorectal cancer cell lines, SW1116, COLO205 and HT-29, were used. Cells were treated with SP-600125, and cell viability, apoptosis and cell cycle distribution, caspase-3 activity, expression of JNK and apoptosis related proteins were detected. SP-600125 inhibited cell proliferation by 10-80% for the different cell lines, and increased apoptosis by 1.5-4.5 folds for COLO205, BCG-823, MKN-45, AGS cells. Caspase-8 and caspase-3 were involved in the induction of apoptosis. SP-600125 caused G2/M cell cycle arrest and elevation of cyclin B1 and p27(kip). The differential response in cells to SP-600125 was associated with the basal level of phosphorylated JNK2. It is concluded that SP-600125 inhibits proliferation, induces apoptosis and causes cell cycle arrest in gastrointestinal cancer cells, indicating that JNK inhibitors have an anti-tumor effect and are potential therapeutic agents for cancers.     

c-Myc在人胃癌组织中的表达及其对胃癌细胞增殖、迁移和侵袭的影响

目的:探讨c-Myc在人胃癌组织中的表达及其对胃癌细胞增殖、迁移和侵袭的影响。方法:免疫组化和qRT-PCR检测胃癌组织及其癌旁组织中c-Myc的表达;qRT-PCR和Western blot检测人胃黏膜细胞GES-1和人胃癌细胞HGC-27、AGS、SGC-7901中c-Myc的表达;HGC-27细胞转染siRNA-NC和siRNA-c-Myc。48 h后,CCK-8检测细胞增殖能力;流式细胞术检测细胞周期;Transwell实验检测细胞迁移和侵袭;Western blot检测细胞低氧诱导因子-1α（hypoxia inducible factor-1α,HIF-1α）、CXC亚家族受体4（cysteine X cysteine receptor 4,CXCR4）和基质细胞衍生因子（stromal cell derived factor-1,SDF-1）蛋白表达。结果:与癌旁组织相比,胃癌组织中c-Myc mRNA表达和免疫组化评分升高（P＜0.05）。与GES-1组相比,HGC-27组、SGC-7901组和AGS组中c-Myc mRNA和蛋白表达均升高（P＜0.05）。与siRNA-NC组相比,siRNA-c-Myc组细胞在24 h、48 h和72 h增殖能力减弱（P＜0.05）,G0/G1期细胞比例升高（P＜0.05）,G2/M和S期细胞比例降低（P＜0.05）,迁移细胞数和侵袭细胞数减少（P＜0.05）,HIF-1α、CXCR4和SDF-1蛋白表达降低（P＜0.05）。结论:敲低c-Myc可抑制胃癌细胞增殖、迁移和侵袭,诱导细胞周期阻滞,该作用可能是通过抑制HIF-1α/CXCR4通路实现的。     

miR-875-5p通过靶向USF2抑制胃癌细胞的增殖、迁移和侵袭

目的:探讨miR-875-5p对胃癌细胞增殖、迁移和侵袭的影响及其机制。方法:采用qPCR法检测胃癌细胞BGC-823、HGC-27、MGC-803、SGC-7901、AGS、MKN-45和胃黏膜上皮细胞GES-1中miR-875-5p的表达水平。利用脂质体转染技术,分别将miR-875-5p模拟物/抑制剂(mimic/inhibitor)及其阴性对照质粒(miR-NC/Anti-miR-NC)转染至AGS细胞/MKN-45细胞,构建过表达/抑制miR-875-5p的细胞模型,空白对照组(Control组)不转染。通过CCK-8、克隆形成、Transwell等实验分别检测miR-875-5p表达变化对细胞增殖、克隆形成、迁移和侵袭的影响。采用双荧光素酶报告基因实验验证miR-875-5p与上游刺激因子2(USF2)的靶向关系,WB实验验证miR-875-5p对USF2的调控作用并检测USF2蛋白的表达。构建MKN-45细胞裸鼠移植瘤模型,验证miR-875-5p过表达对MKN-45细胞成瘤能力的影响。结果:miR-875-5p在6种胃癌细胞中表达水平显著低于胃黏膜上皮细胞GES-1(均P<0.01)。与Control组和miR-NC组相比,miR-875-5p mimic组AGS细胞的增殖、克隆形成率、迁移和侵袭细胞数,以及USF2蛋白的表达均显著降低(P<0.05或P<0.01);miR-875-5p inhibitor组MKN-45细胞的增殖、克隆形成率、迁移和侵袭细胞数,以及USF2蛋白的表达均显著提高(P<0.05或P<0.01)。双荧光素酶报告基因实验证明,miR-875-5p能够直接靶向USF2基因。体内成瘤实验结果表明,过表达miR-875-5p显著抑制MKN-45细胞移植瘤的生长(均P<0.01)。结论:miR-875-5p通过靶向USF2抑制胃癌细胞的增殖、迁移和侵袭。     

姜黄素调控Notch信号通路对肺癌干细胞增殖及凋亡的影响

目的:研究姜黄素对肺癌干细胞增殖及凋亡的影响。方法:利用免疫磁珠标记肺癌表面标记物乙醛脱氢酶1(ALDH1)，从肺癌A549细胞系中分离肺癌干细胞；MTT实验检测姜黄素对肺癌干细胞增殖的影响；流式细胞仪检测姜黄素对肺癌干细胞凋亡的影响；Western blot检测Notch1和Hes1蛋白的表达情况；抑制剂γ-分泌酶抑制Notch信号通路研究对肺癌干细胞增殖及凋亡的影响。结果:利用免疫磁珠分选法分选出肺癌细胞系A549中ALDH1+肺癌干细胞。MTT检测结果显示，姜黄素能够呈浓度依赖性的抑制肺癌干细胞的增殖；经姜黄素处理后的肺癌干细胞，与对照组相比，凋亡率明显升高，Notch1和Hes1蛋白的表达明显下降。经γ-分泌酶抑制剂处理肺癌干细胞后，实验结果显示，γ-分泌酶抑制剂通过下调Notch1和Hes1蛋白的表达调控Notch信号通路抑制肺癌干细胞的增殖，诱导其凋亡。结论:姜黄素抑制肺癌干细胞的增殖，诱导其凋亡与Notch信号通路有关。     

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.     

Expression of p27 is associated with Bax expression and spontaneous apoptosis in oral and oropharyngeal carcinoma.

p27Kip1, a cyclin-dependent kinase inhibitor, is a negative regulator of the cell cycle, and apoptosis is a genetically encoded program of cell death. To clarify the relationship between the cell cycle and apoptosis, we investigated expression of p27, cyclin D1 and apoptosis-related proteins (p53, Bax, Bcl-2 and c-Myc) in 60 cases of oral and oropharyngeal squamous-cell carcinoma (SCC) using an immuno-histochemical approach, and evaluated spontaneous apoptosis in vivo. Our most notable finding was that spontaneous apoptosis in the p27-positive group was significantly higher than that in the p27-negative group (p = 0.028). In addition, the percentage of p27-positive cells was clearly correlated with that of Bax-positive cells (gamma = 0.288, p = 0.028) and with that of cyclin D1-positive cells (gamma = 0.416, p = 0.002). Expression of p27 was inversely associated with the clinical stage of total tumor progression (p = 0.027). However, no correlation was found between p27 expression and the following parameters: gender, tumor size, lymph node metastasis, overall survival and disease-free survival. Our results give evidence that the action of the cell-cycle regulator p27 is closely linked with apoptosis in clinical samples from patients and indicate that over-expression of p27 might induce apoptosis in cancer cells through elevation of Bax expression, thereby acting on tumor progression.     

Helicobacter pylori strain-specific genotypes and modulation of the gastric epithelial cell cycle

Helicobacter pylori cag+ strains enhance gastric epithelial cell proliferation and attenuate apoptosis in vivo, which may partially explain the increased risk of gastric cancer associated with these strains. The goals of this study were to identify specific H. pylori genes that regulate epithelial cell cycle events and determine whether these effects were dependent upon p53-mediated pathways. AGS gastric epithelial cells were cultured alone or in the presence of 21 clinical H. pylori isolates, H. pylori reference strain 60190, or its isogenic cagA-, picB-, vacA-, or picB-/vacA- derivatives. Coculture of H. pylori with AGS cells significantly decreased cell viability, an effect most prominent with cag+ strains (P < 0.001 versus cag-strains). cag+ strains significantly increased progression of AGS cells from G1 into G2-M at 6 h and enhanced apoptosis by 72 h. Compared with the parental 60190 strain, the picB- mutant attenuated cell cycle progression at 6 h (P < or = 0.05), and decreased apoptosis with enhanced AGS cell viability at 24 h (P < or = 0.04). The vacA- mutant decreased apoptosis and enhanced viability at later (48-72 h) time points (P < or = 0.05). Compared with the wild-type strain, the picB-/vacA- double mutant markedly attenuated apoptosis and increased cell viability at all time points (P < or = 0.05). Furthermore, cocolonization with H. pylori had no significant effect on expression of p53, p21, and MDM2. The diminished AGS cell viability, progression to G2-M, and apoptosis associated with cag+ H. pylori strains were dependent upon expression of vacA and genes within the cag pathogenicity island. These results may explain heterogeneity in levels of gastric epithelial cell proliferation and apoptosis found within H. pyloricolonized mucosa.     

阿帕替尼对胃癌HGC-27细胞放射敏感性的影响及其作用机制

目的 探讨阿帕替尼对胃癌HGC-27细胞放射敏感性的影响及可能的作用机制。方法 以不同浓度阿帕替尼（5 μmol/L、10 μmol/L、15 μmol/L、20 μmol/L）以及不同照射剂量（2 Gy、4 Gy、6 Gy、10 Gy、20 Gy）分别处理HGC-27细胞,再选取2 Gy和6 Gy单独照射或联合10 μmol/L阿帕替尼处理HGC-27细胞;采用ELISA法检测细胞中血管内皮生长因子（vascular endothelial growth factor,VEGF）的表达情况,CCK-8法检测细胞增殖能力,流式细胞术检测细胞凋亡和细胞周期,免疫荧光染色技术检测γ-H2AX的表达情况。结果 阿帕替尼呈浓度及时间依赖性抑制胃癌HGC-27细胞增殖（均P<0.05）;不同剂量照射可促进细胞VEGF表达释放,且呈时间及剂量依赖性（均P<0.01）。10 μmol/L阿帕替尼分别联合2 Gy和6 Gy照射后,HGC-27细胞增殖抑制作用、细胞凋亡率及G2/M期的细胞比例均较单照组升高（均P<0.01）,且6 Gy联合组的作用强度大于2 Gy联合组（均P<0.01）。6 Gy联合组细胞核内γ-H2AX焦点淬灭较6 Gy单照组延迟。结论 阿帕替尼通过抑制细胞增殖,促进细胞凋亡并诱导细胞周期再分布增强胃癌HGC-27细胞放射敏感性,其作用机制可能与延迟γ-H2AX表达而干扰DNA双链断裂修复有关。     

抑制NEK7促进肝癌细胞凋亡的实验

目的 采用体外实验验证抑制NEK7表达后肝癌细胞增殖、衰老及凋亡的变化,并探索其机制。方法 Western blot及RT-PCR检测不同肝癌细胞系及人肝永生化THLE-2细胞系中的NEK7表达,针对NEK7基因序列设计抑制其表达的shRNA,转染肝癌细胞后,观察细胞体外增殖活性、衰老、凋亡及细胞周期的变化,Western blot检测抑制NEK7表达后细胞周期相关因子的变化。结果 肝癌细胞中NEK7呈高表达,shRNA慢病毒转染肝癌细胞抑制NEK7表达后,肝癌细胞增殖能力受到抑制,细胞衰老及凋亡比例显著升高,S及G2/M期细胞数明显减少,细胞周期受到阻滞,C-myc、c-Fos、cyclin D1、cyclin E等细胞周期因子表达水平受到抑制,P16及P27表达水平升高,CDK2、CDK4及CDK6的表达无明显变化。结论 靶向抑制NEK7表达,降低了肝癌细胞的增殖能力,并促进细胞衰老、诱导其凋亡,同时肝癌细胞周期进程受阻。     

miR-126-5p靶向Notch2 对结肠癌SW480 细胞增殖、迁移、侵袭和凋亡的影响

目的:探讨miR-126-5p 对结肠癌SW480 细胞增殖、迁移、侵袭和凋亡的影响及其作用机制。方法：用miR-126 mimic和pcDNA Notch2（pc-Notch2）等分别或同时转染结肠癌SW480 细胞,用qPCR法检测miR-126-5p 和Notch2 的表达;荧光素酶报告实验观察miR-126-5p 和Notch2 的靶向关系;CCK-8 法、划痕愈合实验、Transwell 小室法和Annexin V/PI 染色流式细胞术分别检测转染细胞的增殖、迁移、侵袭和凋亡,Western blotting 检测Notch2、增殖细胞核抗原（proliferating cell nuclear antigen, PCNA）、cleaved Caspase-3、MMP-2 和MMP-9 的表达。结果：转染miR-126 mimic 能显著升高SW480 细胞miR-126-5p 的表达水平（P<0.01）和显著抑制SW480 细胞Notch2 的表达（P<0.01）,同时证实Notch2 上存在miR-126-5p 的结合位点。上调miR-126-5p 显著抑制SW480 细胞增殖并降低PCNA的表达水平（P<0.01）、升高细胞凋亡率和cleaved Caspase-9 的表达水平（均P<0.01）,pc-Notch2显著减弱miR-126 mimic 对SW480 细胞增殖和凋亡的调控作用;miR-126 mimic 显著降低SW480 细胞划痕愈合率和穿膜细胞数（均P<0.01）、抑制MMP-2 和MMP-9 的表达（P<0.01）;pc-Notch2 显著减弱miR-126 mimic 对SW480 细胞迁移、侵袭及MMP-2、MMP-9表达的抑制作用（均P<0.01）。结论：miR-126-5p 通过抑制Notch2 表达,降低结肠癌SW480 细胞增殖、迁移和侵袭能力。     

绿原酸对人胶质瘤细胞U251的抗肿瘤活性及其促凋亡机制

 目的 研究绿原酸对人胶质瘤细胞U251细胞株增殖、凋亡的作用及其机制。方法 培养人胶质瘤U251细胞，不同浓度绿原酸处理细胞48 h后，CCK-8法检测细胞生长抑制率，观察细胞形态学变化；Annexin V-FITC/PI染色法检测细胞凋亡，RT-PCR及Western blot检测p53、Livin、Bcl-2、Bax mRNA和蛋白的表达，Western blot检测Caspase-3蛋白的表达。结果 不同浓度绿原酸干预U251细胞48 h后显著抑制细胞的增殖活性，促进细胞凋亡，并且能够上调p53和Bax基因，下调Livin、Bcl-2 mRNA和蛋白的表达，促进Caspase-3蛋白的表达。结论 绿原酸可能是通过上调p53和Bax的表达，下调Livin和Bcl-2的表达，激活Caspase-3蛋白，最终诱导U251细胞凋亡。     

亚砷酸诱导肺腺癌A549细胞凋亡及对MAPK／ERK信号通路的影响

目的探讨亚砷酸对肺腺癌A549细胞凋亡、MAPK／ERK信号通路的影响及其作用机制。方法体外培养肺腺癌A549细胞,实验组采用不同浓度(1、3、6 μmol／L)亚砷酸处理,对照组加入等体积的二甲基亚砜(DMSO),MTT法检测细胞增殖率,FMC法检测细胞周期分布与细胞凋亡率,Hoechst 33342观察凋亡小体,Western blotting检测Bcl 2、Bax、p53、Caspase 3及MAPK／ERK信号通路相关蛋白表达水平,RT PCR检测PCNA、CDK2、CyclinA1表达量。结果实验组肺腺癌A549细胞增殖率、凋亡率、凋亡小体数量随着亚砷酸处理时间延长而降低,且存在剂量反应效应(P<005);Western blotting结果显示，实验组肺腺癌A549细胞中Bax、p53、Caspase 3、p JNK／JNK及p38蛋白水平高于对照组,而Bcl 2、p ERK／ERK蛋白含量低于对照组,均呈剂量依赖性,差异均有统计学意义(P<005);RT PCR结果显示实验组肺腺癌A549细胞PCNA、CDK2、CyclinA1表达量低于对照组,均呈剂量依赖性,差异均有统计学意义(P<005)。结论亚砷酸可以通过下调细胞周期基因水平、上调细胞凋亡相关因子含量、降低MAPK／ERK信号传导,来诱导肺腺癌A549细胞凋亡。