细胞微缺氧模型的建立及其对胃癌细胞生物学行为的影响

背景与目的:缺氧是实体瘤微环境的基本特征之一,体外制造微缺氧的细胞培养环境,对研究缺氧对肿瘤细胞的影响有重要意义。目前建立体外缺氧细胞培养模型的方法较为烦琐,尚缺少微缺氧对胃癌细胞影响较为完整的研究。本实验运用GasPaK产气袋法体外创建胃癌细胞微缺氧培养模型,并观察该状态下细胞生物学行为的变化。方法:运用产气袋法(GasPaK)制造微缺氧条件,血气分析监测RPMI-1640培养液中PO2、PCO2和pH值变化。流式细胞仪分析微缺氧对SGC-7901细胞周期分布的影响,光镜及透射电镜观察微缺氧条件下SGC-7901细胞形态的改变,台盼蓝染色计数微缺氧对活细胞数的影响,MTT法检测微缺氧对SGC-7901细胞粘附能力的影响,游走实验检测微缺氧对SGC-7901细胞游走运动能力的影响。结果:GasPaK产气袋法在0.5～48h内PO2、PCO2和pH稳定,并能达到微缺氧细胞培养的条件。微缺氧处理SGC-7901细胞16h后未见细胞周期的变化。微缺氧导致部分SGC-7901细胞形态发生改变。微缺氧处理16h后活细胞计数无明显下降,微缺氧组SGC-7901细胞粘附能力增强,游走穿膜细胞数(196±9)是对照组(114±7)的1.71倍(P<0.05)。结论:通过GasPaK产气袋法制造的微缺氧肿瘤细胞培养环境,达到了条件稳定、重复性好的特点。微缺氧对SGC-7901细胞有影响,但这种影响相对较小,SGC-7901细胞对微缺氧有一定的耐受性。     

RNA干扰缺氧诱导因子1α对食管鳞癌和胃腺癌细胞生物学行为的影响

目的 探讨缺氧诱导因子1α(HIF-1α)对人食管痛及胃癌细胞体外增殖、迁移及血管生成拟态的影响.方法 将HIF-1α shRNA重组质粒pGCsi-shHIF-1 α稳定转染人食管鳞癌细胞Eca-109和胃腺癌细胞SGC-7901,采用Western blot方法检测常氧及缺氧情况下各组转染细胞HIF-1α的抑制效果,采用平板克隆形成实验和四甲基偶氮唑蓝(MTT)法检测转染细胞的增殖活性,采用Transwell小室检测转染细胞的迁移能力,采用三维培养方法观察Eca-109和SGC-7901细胞能否形成血管网状结构及转染细胞株的管腔形成能力.结果 常氧及缺氧情况下,各转染组细胞HIF-1α蛋白表达量均为0,与未转染组(Eca-109组分别为0.74±0.05和1.11±0.06,SGC-7901组分别为0.60±0.05和0.96±0.07)比较,表达均被显著抑制(均P＜0.01).与空载体组和未转染组相比,转染组细胞的增殖活性显著降低(均P＜0.05),体外迁移能力显著降低(均P＜0.01).Eca-109细胞株各组中,常氧情况下,Eca-109组和Eca-109/shRNA组形成管状结构数目分别为(30.8±3.9)个和(3.7±2.8)个,差异有统计学意义(P＜0.01);缺氧情况下,分别为(34.3±3.4)个和(3.9±2.7)个,差异有统计学意义(P＜0.01).缺氧情况下,Eca-109组形成管状结构数日较常氧时明显增加(P＜0.05).SGC-7901细胞株各组中,常氧情况下,SGC-7901组和SGC-7901/shRNA组形成管状结构数目分别为(26.2±3.4)个和(4.9±3.5)个,差异有统计学意义(P＜0.01);缺氧情况下,分别为(30.1±4.1)个和(5.3±3.6)个,差异有统计学意义(P＜0.01).缺氧情况下,SGC-7901组形成管状结构数日较常氧时明显增加(P＜0.05).结论 Eca-109细胞和SGC-7901细胞均能形成血管生成拟态管状结构.RNA于扰沉默HIF-1α能有效抑制Eca-109细胞和SGC-7901细胞增殖、迁移及体外血管生成拟态管状结构形成.

Abstract：

Objective To investigate the effect of hypoxia inducible factor-1α (HIF-1α) on the proliferation, migration and vasculogenic mimicry(VM ) in human esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 in vitro.Methods The recombinant plasmid pGCsi-shHIF-1α was transfected into Eca-109 and SGC-7901 cells by LipofectamineTM 2000.The inhibitory effect of HIF-1α was measured at protein level by Western blot under normoxia and hypoxia.The cell proliferation was detected by colony formation and MTT assays.The migration of transfected cells was assayed using Transwell chambers.Whether Eca-109 and SGC-7901 cells could form the capillary tube-like structures (TLSs) was observed by 3-dimensional culture, and the tube formation of transfected cells was detected by tube-like structure formation assay.Results The expression of HIF-1α protein in each group of transfected cells was significantly suppressed under normoxia and hypoxia ( Eca-109: 0.00, 0.74 ± 0.05;0.00, 1.11±0.06; SGC-7901: 0.00, 0.60 ±0.05; 0.00, 0.96 ±0.07, P＜0.01).Colony formation and MTT assays showed that the cell proliferation of the pGCsi-shHIF-1α transfected cells was slower than that of the control groups (104.7±9.6, 151.7±4.5; 88.3±5.1, 128.3±6.7, P＜0.05).The migration of the recombinant plasmid-transfected cells was significantly suppressed compared with that of cells transfected with empty vector (55.5 ± 11.2, 121.9 ± 17.3; 64.7 ± 10.8, 132.3 ± 16.0, P ＜ 0.01 ).Both the Eca-109 and SGC-7901 cells could form TLSs when cultured on matrigel, and the number of tubules was significantly increased under hypoxia (30.8 ± 3.9, 34.3 ± 3.4;26.2±3.4,30.1±4.1,P＜0.05),the tubule-forming ability of transfected groups was significantly inhibited under normoxia and hypoxia ( Eca109: 3.7±2.8, 30.8±3.9; 3.9 ±2.7, 34.3 ±3.4; SGC-7901: 4.9 ±3.5, 26.2 ±3.4; 5.3 ±3.6,30.1 ±4.1, P＜0.01 ).Conclusions Both the esophageal squamous cell carcinoma cell line Eca-109 and gastric adenocarcinoma cell line SGC-7901 are capable of forming vasculogenic mimicry structures in vitro.The recombinant plasmid pGCsi-shHIF-1α can efficiently suppress their proliferation, migration and vasculogenic mimicry formation.     

S100A4协同HIF-1通过WNT/β-catenin通路调控胃癌细胞SGC-7901的迁移和侵袭

目的:探讨S100A4在低氧条件下对胃癌细胞SGC-7901迁移及侵袭的作用及其可能的机制.方法:将化学合成的si-S100A4质粒和阴性对照(si-Ctr1)质粒分别转染胃癌细胞株SGC-7901,根据培养条件的不同分为常氧条件(normal,Nor)+si-S 100A4组、Nor+ si-Ctrl组、低氧条件(hypoxia,Hyp)+si-Ctr1)组、Hyp+si-S 100A4组.应用Western blotting检测低氧条件下胃癌SGC-7901细胞中HIF-1及S100A4蛋白的表达变化,检测低氧条件下胃癌细胞中抑制S100A4的表达对细胞中S100A4、p-catenin及TCF-4表达的影响,Transwell小室法分别检测低氧及S100A4对胃癌SGC-7901细胞迁移及侵袭能力的影响.结果:低氧条件下:(1)胃癌SGC-7901细胞中HIF-1和S100A4表达水平均明显升高(3.12±0.23 vs 1.02±0.05,P＜0.01;2.75±0.32 vs 1.05±0.07,P＜0.01),且两者变化明显相关(r=0.67,P＜0.01);(2)胃癌SGC-7901细胞的侵袭及迁移能力增加[(223.31±35.12) vs (131.29±26.40)、(142.27±26.37)个,P＜0.05].干扰低氧条件中S100A4的表达:(1)明显减少低氧对细胞中Lcatenin及TCF-4的促进作用(均P＜0.01);(2)明显减少低氧对SGC-7901细胞的侵袭及迁移能力的促进作用[(161.37±31.02) vs (88.21±22.42)、(95.36±21.29)个,P＜0.05].结论:S100A4能够促进胃癌细胞SGC-7901的迁移和侵袭,该作用可能是通过S100A4协同HIF-1通过Wnt/β-catenin通路的调控实现的.     

莪术醇生物修饰构建的瘤苗治疗胃癌的实验研究

目的探讨中药莪术的提取物——莪术醇修饰构建的肿瘤细胞疫苗对SGC-7901胃癌的抗瘤效应及联合新城鸡疫病毒(NDV)疫苗的综合效应。方法对SGC-7901胃肿瘤细胞进行系列处理,用莪术醇及NDV对其进行系列生物构建,修饰构建的瘤苗经免疫小鼠(1次/周×3)21天后,接种SGC-7901胃肿瘤细胞,根据设计观察各组抑制肿瘤肺转移、皮下结节形成、生存时间状况及LAK细胞的杀伤效应。结果经莪术醇修饰构建的SGC-7901肿瘤疫苗与对照组相比能明显阻止胃癌细胞的肺转移,显著抑制皮下肿瘤结节形成,明显延长荷瘤鼠的生存时间(P<0.05);用各组免疫接种后长期存活的脾细胞制备的LAK细胞,较同龄未免疫小鼠的脾细胞制备的LAK细胞具有更强的抗瘤效应(P<0.05);由NDV构建的疫苗的抗瘤作用低于莪术醇瘤苗组,莪术醇与NDV联合构建的瘤苗其抗瘤作用未呈现生物放大及相加效应。结论莪术醇修饰构建的SGC-7901新型肿瘤疫苗可以增强胃肿瘤细胞的免疫原性,对胃癌有较好的实验治疗作用。     

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。     

人胃癌细胞株ＳＧＣ-７９０１体外乏氧环境ＨＩＦ-１α、ＶＥＧＦ-Ａ和ＶＥＧＦ-Ｄ基因表达变化

目的：观察乏氧干预对人胃癌细胞ＳＧＣ-７９０１乏氧诱导因子-１α（ＨＩＦ-１α）、血管内皮生长因子-Ａ（ＶＥＧＦ-Ａ）和血管内皮生长因子 Ｄ（ＶＥＧＦ-Ｄ）表达的影响,以及乏氧诱导因子-１α和血管内皮生长因子表达的相关性。方法：将人胃癌细胞ＳＧＣ-７９０１体外培养并乏氧干预０、４、１６、２４ｈ,以反转录 聚合酶链式反应（ＲＴ-ＰＣＲ）方法检测４组ＨＩＦ-１α、ＶＥＧＦ-Ａ、ＶＥＧＦ-ＤｍＲＮＡ的表达情况;免疫印迹（Ｗｅｓｔｅｒｎｂｌｏｔ）检测４组ＨＩＦ-１α、ＶＥＧＦ-Ａ、ＶＥＧＦ-Ｄ蛋白表达情况。结果：与０ｈ相比,４ｈＨＩＦ-１αｍＲＮＡ转录处于下降水平（Ｐ＜０.０５）,１６ｈＨＩＦ-１αｍＲＮＡ转录上升（Ｐ＜０.０５）,２４ｈ转录达到最高水平（Ｐ＜０.０５）。ＶＥＧＦ-ＡｍＲＮＡ和ＶＥＧＦ-ＤｍＲＮＡ表达量均随时间的延长逐渐增加（Ｐ＜０.５）。ＨＩＦ-１α、ＶＥＧＦ-Ａ、ＶＥＧＦ-Ｄ蛋白表达量随乏氧时间的延长逐渐增加（Ｐ＜０.０５）。结论：胃癌细胞株ＳＧＣ-７９０１乏氧环境中,ＨＩＦ-１α、ＶＥＧＦ-Ａ和ＶＥＧＦ-Ｄ的ｍＲＮＡ与蛋白表达均明显增加。     

胃癌细胞外泌体调控M2型巨噬细胞极化及对胃癌细胞增殖和迁移的影响

目的:探究胃癌细胞外泌体调控M2型巨噬细胞极化及对胃癌细胞增殖和迁移能力的影响。方法:差速离心法提取胃黏膜上皮细胞GES-1和胃癌细胞株MGC-803、SGC-7901外泌体,透射电镜和Western blot鉴定外泌体,将U937细胞与PMA共孵育诱导U937细胞分化为巨噬细胞的同时分别与PBS、GES-1 exo、MGC-803 exo、SGC-7901 exo、IL-4孵育48 h,流式细胞术检测孵育后各组细胞CD206和HLA-DR表达,qRT-PCR检测CCL17、CXCL8、IL-10、TGF-β、TNF-α、IL-6、IL-1β表达,Western blot检测p-NF-κB、NF-κB、IκBα表达水平,将各组诱导后的U937细胞与MGC-803、SGC-7901共培养后,收集MGC-803、SGC-7901细胞,MTT检测各组细胞的增殖能力,Transwell小室法检测各组细胞的迁移能力。结果:差速离心法提取的外泌体符合外泌体的形态特征,并且在激光共聚焦显微镜下观察到外泌体可被U937细胞摄取,与MGC-803 exo、SGC-7901 exo共孵育后的U937细胞CD206显著高表达,HLA-DR低表达（P＜0.05）,CCL17、CXCL8、IL-10、TGF-β表达显著上调（P＜0.05）,TNF-α、IL-6、IL-1β表达显著下调（P＜0.05）,NF-κB磷酸化水平显著增加（P＜0.05）,IκBα表达显著增加（P＜0.05）,并且与MGC-803 exo、SGC-7901 exo诱导极化后的巨噬细胞共培养组MGC-803、SGC-7901细胞增殖和迁移能力显著增强（P＜0.05）。结论:胃癌细胞能够通过激活NF-κB信号通路促进M2型巨噬细胞极化进而诱导MGC-803、SGC-7901细胞增殖和迁移能力的增强。     

Hypoxia-inducible factor-1α enhances the malignant phenotype of multicellular spheroid HeLa cells in vitro

The purpose of this study was to clarify the direct effect of hypoxia-inducible factor-1α (HIF-1α) on tumor growth, apoptosis and migration in vitro. To achieve this aim, a comparison was made of the differences in growth rates, apoptotic indices and cell invasive ability in the human cervical cancer cell line HeLa and the HIF-1α-blocked counterpart in a three-dimensional spheroid culture. A significant decrease in cell proliferation and invasion, and an increase in cell apoptosis were observed in HIF-1α-blocked cells in the three-dimensional culture. The data indicated that a multicellular spheroid culture is an ideal model of hypoxia in vitro and that HIF-1α is a significant regulator of adaptive processes that promote tumor cell malignant phenotypes, such as proliferation, anti-apoptosis and invasive ability.     

α-Mangostin inhibits hypoxia-driven ROS-induced PSC activation and pancreatic cancer cell invasion

Recent advances indicating a key role of microenvironment for tumor progression, we investigated the role of PSCs and hypoxia in pancreatic cancer aggressiveness, and examined the potential protective effect of α-mangostin on hypoxia-driven pancreatic cancer progression. Our data indicate that hypoxic PSCs exploit their oxidative stress due to hypoxia to secrete soluble factors favouring pancreatic cancer invasion. α-Mangostin suppresses hypoxia-induced PSC activation and pancreatic cancer cell invasion through the inhibition of HIF-1α stabilization and GLI1 expression. Increased generation of hypoxic ROS is responsible for HIF-1α stabilization and GLI1 upregulation. Therefore, α-mangostin may be beneficial in preventing hypoxia-induced pancreatic cancer progression.     

TNF-α expression in the UCB-MSCs as stable source inhibits gastric cancers growth in nude mice

Mesenchymal stem cells (MSCs) are potentially vehicles for therapy of malignant diseases. In our study, we investigated whether UCB-MSCs are capable to carry TNF-α to target tumor cells in vivo. The human gastric cancer cells SGC-7901 were subcutaneously injected into the abdomen near groins of 15 nude mice to establish experiment tumor models. MSC-TNF-α demonstrated a strong suppressive effect on the tumor growth compared with MSC and NaCl. Thus, MSC-TNF-α can obviously inhibit Gastric cancers growth in nude mice, indicating that UCB-MSCs may have the potential to become a prevention approach against gastric cancer.     

单细胞克隆形态结合SEMA3B检测分离胃癌中致瘤成分的研究

目的 探讨单克隆形态结合SEMA3B检测分离胃癌中的致瘤成分。方法 采用克隆的形态并分类,计算克隆形成率;采用Western blot法检测不同克隆细胞中SEMA3B的表达,并观察各组克隆细胞的体内成瘤能力。结果 SGC-7901细胞可形成3种克隆形态,分为Holoclone型、Paraclone型和Meroclone型,总克隆形成率为(10.20±1.07)%;Western blot法检测发现SEMA3B在Holoclone型中表达最强,并且Holoclone型克隆细胞具有很强的体内成瘤能力。结论 本研究为探寻SEMA3B在胃癌中成瘤和增殖的作用提供了理论依据。     

HIF-1α反义寡核苷酸增强胃癌细胞对顺铂的敏感性

目的研究缺氧诱导因子-1α(hypoxia inducible factor1α,HIF-1α)反义寡核苷酸(antisense ol-igodexynucleotide,ASODN)对人胃癌细胞凋亡及化疗药物敏感性的影响。方法人工合成HIF-1αASODN经阳离子脂质体包裹后瞬时转染人胃癌SGC-7901细胞系。采用RT-PCR和免疫细胞化学检测转染后HIF-1α基因表达情况,MTT法观察化疗药物敏感性的变化,AO/EB染色及TUNEL检测SGC-7901细胞转染后顺铂诱导的凋亡。结果经HIF-1αASODN处理的SGC-7901细胞HIF-1α基因表达明显下调,HIF-1αASODN处理的SGC-7901细胞加顺铂作用后与对照组比较,细胞凋亡率明显增加,化疗药物敏感性增强。结论阳离子脂质体转染HIF-1αASODN具有促进化疗药物诱导胃癌SGC-7901细胞凋亡及增强化疗药物敏感性作用。     

巴佛洛霉素A1抑制胃癌SGC-7901细胞中VEGF-C的表达

目的:研究巴佛洛霉素A1(Bafilomycin A1)对胃癌细胞株SGC-7901的增殖、迁移和血管生成的影响,并探讨可能的机制.方法:巴佛洛霉素A1(10 nmol/mL)处理SGC-7901细胞后,检测液泡-ATP酶(vacular-ATPases,V-ATPases)活性及培养液pH值,并分别用CCK-8法检测...     

4-1BB基因在不同分化胃癌细胞株中的表达

目的：研究共刺激因子4-1BB在人胃高分化腺癌细胞株MKN-28、人胃中分化腺癌细胞株SGC-7901、人胃低分化腺癌细胞株BGC-823、人胃粘液腺癌细胞株MGC-803中的表达及其生物学意义。方法：用RT-PCR法测定胃癌细胞株中4-1BB mRNA表达;免疫细胞化学法测定胃癌细胞株中4-1BB蛋白表达;MTT法测定人淋巴细胞对胃癌细胞的体外杀伤活性;ELISA法检测人淋巴细胞与胃癌细胞共培养上清液中IL-2、IL-10、TNF-α的含量。结果：RT-PCR结果示4-1BB mRNA表达率从高到低依次为：MGC-803（77.30%）、BGC-823（71.68%）、SGC-7901（40.06%）、MKN-28（37.65%）。免疫细胞化学结果显示4-1BB着色程度由深到浅依次为：MGC-803、BGC-823、SGC-7901、MKN-28。MTT结果显示各时间段（24、48、72h）不同效靶比（10∶1,20∶1,40,∶1）下,人淋巴细胞对胃癌细胞的体外杀伤活性由高到低的顺序为：MKN-28、SGC-7901、BGC-823、MGC-803。ELISA结果显示在各效靶细胞比下,人淋巴细胞与胃癌细胞共培养上清液中IL-2、TNF-α的含量由高到低的顺序均为：MKN-28、SGC-7901、BGC-823、MGC-803。而IL-10的含量由高到低的顺序为：MGC-803、BGC-823、SGC-7901、MKN-28。结论：人胃癌细胞株MKN-28、SGC-7901、BGC-823、MGC-803中4-1BB基因的mRNA和蛋白均有表达,且胃癌细胞株的恶性程度越高其4-1BB表达水平越高;淋巴细胞对低表达4-1BB胃癌细胞的杀伤力较高;提示4-1BB可能通过抑制细胞因子TNF-α、IL-2和促进细胞因子IL-10的产生调节肿瘤免疫。     

Regulation of HIF-1α signaling and chemoresistance in acute lymphocytic leukemia under hypoxic conditions of the bone marrow microenvironment

Overcoming resistance to chemotherapy is the main therapeutic challenge in the treatment of acute lymphocytic leukemia (ALL). Interactions between leukemia cells and the microenvironment promote leukemia cell survival and confer resistance to chemotherapy. Hypoxia is an integral component of bone marrow (BM) microenvironment. Hypoxia-inducible factor-1α (HIF-1), a key regulator of the cellular response to hypoxia, regulates cell growth and metabolic adaptation to hypoxia. HIF-1α expression, analyzed by Reverse Phase Protein Arrays in 92 specimens from newly diagnosed patients with pre-B-ALL, had a negative prognostic impact on survival (p = 0.0025). Inhibition of HIF-1α expression by locked mRNA antagonist (LNA) promoted chemosensitivity under hypoxic conditions, while pharmacological or genetic stabilization of HIF-1α under normoxia inhibited cell growth and reduced apoptosis induction by chemotherapeutic agents. Co-culture of pre-B ALL or REH cells with BM-derived mesenchymal stem cells (MSC) under hypoxia resulted in further induction of HIF-1α protein and acquisition of the glycolytic phenotype, in part via stroma-induced AKT/mTOR signaling. mTOR blockade with everolimus reduced HIF-1α expression, diminished glucose uptake and glycolytic rate and partially restored the chemosensitivity of ALL cells under hypoxia/stroma co-cultures. Hence, mTOR inhibition or blockade of HIF-1α-mediated signaling may play an important role in chemosensitization of ALL cells under hypoxic conditions of the BM microenvironment.     

缺氧对于人胃腺癌SGC-7901细胞MTA1表达及侵袭力的影响

目的：研究缺氧对胃腺癌细胞生物学行为的影响及可能机制。方法：对人胃腺癌SGC-7901细胞进行缺氧培养,对照组有氧培养,用Transwell实验检测两组细胞的侵袭能力,用Western blot法和RT-PCR检测两组细胞MTA1表达情况。结果：实验组细胞侵袭能力增加,穿过膜细胞数明显高于对照组[（28±5.6）/HPF vs（13±4.1）/HPF,P〈0.05];MTA1 mRNA表达水平明显高于对照组（P〈0.05）,实验组中MTA1蛋白相对含量也明显高于对照组（P〈0.05）。结论：缺氧导致SGC-7901细胞侵袭能力增加,这与其使细胞中MTA1表达增加有关。     

缺氧诱导因子-1α与结直肠癌

缺氧诱导因子(HIF)-1α是细胞及组织缺氧情况下产生的一种调节缺氧反应的转录激活因子,能诱导多种缺氧反应性表达,使细胞及组织产生一系列反应以适应缺氧环境.肿瘤缺氧微环境及HIF-1α的表达与结直肠癌的发生发展、侵袭转移及治疗预后密切相关,已成为结直肠肿瘤研究的热点.     

ＣＩＫ细胞及上清液抗胃癌细胞株ＳＧＣ-７９０１活性的研究*

目的：探讨由多种细胞因子诱导的杀伤细胞（ＣＩＫ）在体外的增殖情况,分析体外ＣＩＫ细胞对胃癌细胞株ＳＧＣ-７９０１的杀伤作用。方法：健康人外周血单核细胞（ＰＢＭＣ）在体外诱导成ＣＩＫ细胞,计数培养不同时间的ＣＩＫ细胞,并用流式细胞术动态分析其表型特征。倒置显微镜下观察ＣＩＫ细胞作用于ＳＧＣ-７９０１胃癌细胞的形态学变化;流式细胞仪检测ＣＩＫ细胞培养上清液对胃癌细胞的诱导凋亡作用;采用ＭＴＴ法检测ＣＩＫ细胞对ＳＧＣ-７９０１胃癌细胞株的杀伤活性。结果：ＣＩＫ细胞随体外培养时间的延长,数量及杀伤活性均增加。体外培养２１ｄ,细胞总数增殖倍数１１１.６３±１０.９７,ＣＤ３＋ＣＤ５６＋双阳性细胞数量亦增加,比例达（３５.８±９.７）％,其后两者数量逐渐降低。ＣＩＫ细胞上清液能够诱导胃癌细胞株凋亡;ＣＩＫ细胞对胃癌ＳＧＣ-７９０１细胞株有明显的杀伤作用,最高杀伤率为（７４.９１±２.７１）％。结论：ＣＩＫ细胞具有较强的抗胃癌细胞活性,体外培养１４～２１ｄ时具有较强的抗瘤活性,其主要通过直接杀伤及释放细胞因子诱导凋亡的作用杀伤肿瘤细胞。