SOX1过表达抑制食管癌细胞的增殖并促进凋亡的发生

目的 探索SOX1过表达对食管癌细胞增殖及凋亡的作用及其机制。方法 构建SOX1过表达细胞株，检测SOX1 mRNA和蛋白表达，CCK-8检测细胞增殖，细胞划痕及结晶紫染色检测细胞的迁移及克隆形成能力，Hochest染色实验检测细胞凋亡情况，Western blotting检测GSK-3β及Wnt/β-catenin通路相关蛋白表达水平。结果 SOX1过表达组mRNA显著高于对照组(P<0.01)。CCK-8 OD值及增殖曲线绘制表明SOX1过表达组增殖速率显著降低(P<0.05);SOX1过表达组细胞的迁移速率和克隆形成能力明显下降(P<0.05);显微镜下观察到SOX1过表达组细胞的皱缩明显，提示凋亡的发生；Western blotting检测结果表明，SOX1过表达组GSK-3β上调，Wnt信号通路相关基因β-catenin、Cyclin D1、c-Myc蛋白表达明显下降(P<0.05)。结论 SOX1通过抑制Wnt/β-catenin信号传导抑制食管癌细胞的增殖和促进凋亡。     

靶向抑制胃癌细胞中TROP2基因的表达对胃癌细胞增殖及凋亡的影响研究

目的探讨RNA干扰肿瘤相关钙信号传导因子2(TROP2)基因的表达对胃癌细胞增殖及凋亡的影响及机制。方法以人胃黏膜正常细胞GES-1作为对照,RT-PCR检测人胃癌SGC-7901、MNK-28、BGC-823细胞中TROP2 mRNA表达;TROP2 siRNA、Control siRNA转染SGC-7901细胞,不作任何处理的细胞作为空白对照组,48 h后Western blotting检测TROP2、Ki67、Cleaved caspase3、β-catenin、Cyclin D1蛋白表达;CCK8实验和流式细胞仪分别检测细胞的增殖及凋亡情况。结果 TROP2 mRNA在人胃癌SGC-7901、MNK-28、BGC-823细胞表达均显著高于GES-1细胞(P0.01),TROP2基因在SGC-7901细胞中的表达最高,选择作为后续的研究对象;转染TROP2 siRNA后TROP2蛋白表达显著降低(P0.01);与对照组及Control-siRNA组比较,TROP2-siRNA组细胞存活率及Ki67、β-catenin、Cyclin D1蛋白表达显著降低,细胞凋亡率及Cleaved caspase3蛋白表达显著升高(P0.01)。结论RNA干扰抑制TROP2基因的表达可降低胃癌细胞的增殖及诱导细胞凋亡,其机制是下调Wnt/β-catenin信号通路。     

survivin基因表达对肺鳞状细胞癌细胞侵袭的影响

目的探讨survivin基因对肺鳞状细胞癌细胞侵袭能力的影响及作用机制。方法应用survivin基因小干扰RNA（siRNA）转染处理人肺鳞状细胞癌细胞后,用荧光实时定量PCR和Western blot检测survivin mRNA和survivin蛋白表达,用软琼脂集落培养试验和Boyden小室模型试验检测癌细胞的锚着不依赖性增殖和侵袭能力,用琼脂糖凝胶电泳和细胞凋亡原位检测试剂盒检测癌细胞失巢凋亡情况。结果转染组癌细胞survivin mRNA和survivin蛋白表达明显受抑制,且与时间和浓度相关。与对照组比较,转染组细胞形成的软琼脂集落数和穿膜细胞数明显减少,细胞出现明显凋亡现象,并出现明显DNA条带。结论survivin基因siRNA转染可明显抑制肺鳞状细胞癌细胞的锚着不依赖性增殖和恶性侵袭,其机制可能与诱导失巢凋亡有关。     

PAK6基因对人乳腺癌放疗敏感性及细胞凋亡影响及机制

目的探讨P21激活的蛋白激酶(PAK)6基因对乳腺癌细胞放疗敏感性及细胞凋亡的影响。方法以乳腺癌细胞MDA-MB-468为研究对象,细胞转染PAK6小干扰RNA(PAK6 siRNA组)和阴性对照序列(siRNA对照组),qRT-PCR和Western印迹检测转染效果。流式细胞术检测细胞凋亡,细胞克隆实验检测放疗敏感性,Western印迹检测细胞中β-连环蛋白(catenin)、Wnt信号通路下游靶基因c-myc、活化的含半胱氨酸的天冬氨酸蛋白水解酶(酶切Caspase)-3表达水平。结果 siRNA对照组PAK6mRNA和蛋白水平、细胞凋亡率及细胞中β-catenin、c-myc、酶切Caspase-3蛋白水平与未转染组相比差异无统计学意义(P0.05)。PAK6 siRNA组PAK6 mRNA和蛋白水平均明显低于未转染组,细胞凋亡率及细胞中酶切Caspase-3蛋白水平明显高于未转染组,细胞中β-catenin、c-myc蛋白水平明显低于未转染组(P0.01)。PAK6 siRNA组放疗敏感性较未转染组显著增加,增敏比为:1.896。结论干扰PAK6表达能够促进乳腺癌细胞凋亡,增加乳腺癌细胞放疗敏感性,作用机制可能与Wnt信号通路及酶切Caspase-3水平有关。     

根皮素对结肠癌细胞增殖、凋亡及Wnt/β-catenin信号通路的影响

目的 探究根皮素对结肠癌SW480细胞增殖、凋亡及Wnt/β-catenin信号通路的影响。方法 设置对照组、低浓度组(25μmol/L根皮素)、中浓度组(50μmol/L根皮素)、高浓度组(100μmol/L根皮素)、高浓度+LiCl组(100μmol/L根皮素+20 mmol/L Wnt激活剂),MTT法检测SW480细胞活力；克隆形成实验检测SW480细胞增殖情况；流式细胞术检测SW480细胞凋亡情况；Western blotting检测SW480细胞中增殖、凋亡及通路相关蛋白表达情况。结果 相较于对照组，低浓度组、中浓度组、高浓度组SW480细胞存活率、c-Myc、Cyclin D1、β-catenin、p-GSK-3β/GSK-3β水平显著降低，克隆细胞数减少而细胞凋亡率、Caspase-3、Bax表达水平显著提高(P<0.05),呈剂量依赖性；与高浓度组相比，高浓度+LiCl组细胞存活率、c-Myc、CyclinD1、β-catenin、p-GSK-3β/GSK-3β水平显著提高，克隆细胞数增加而细胞凋亡率、Caspase-3、Bax表达水平显著降低(P<0.0...     

沉默RORα通过活化Wnt/β-catenin通路靶基因促进人胃癌细胞增殖

目的 探讨人胃癌细胞中维甲酸相关孤核受体(ROR)α与Wnt/β-连环素(catenin)通路的相互作用。方法 噻唑蓝(MTT)实验验证沉默RORα对胃癌细胞系MGC803的增殖作用；实时定量聚合酶链反应(RT-PCR)、Western印迹与免疫共沉淀检测敲低RORα对Wnt/β-catenin通路相关分子与靶基因表达；荧光素酶报告检测c-Myc基因启动子活性。结果 敲低RORα可显著促进胃癌细胞增殖(P<0.05)。当RORα被敲低时可显著上调Wnt1 mRNA和蛋白表达(P<0.05);但对β-catenin无明显影响(P>0.05)。免疫共沉淀提示敲低RORα可显著降低RORα与β-catenin的结合效率(P<0.05)。RORα敲低后，核内β-catenin与转录因子(TCF)-4表达水平明显升高(P<0.05)。Wnt通路下游基因Axin、c-Myc、c-Jun和基质金属蛋白酶(MMP)-9的mRNA和蛋白水平显著上调(P<0.05)。荧光素酶报告提示，敲低RORα可显著增强c-Myc启动子活性(P<0.05)。结论 敲低RORα可...     

过表达Krüppel样因子9对脂多糖诱导的肺泡上皮细胞损伤的影响及机制

目的:探讨Krüppel样因子9(KLF9)对脂多糖(LPS)诱导的人肺泡上皮细胞A549增殖、凋亡和炎症的影响及机制。方法:A549细胞随机分为四组:NC组、LPS组、LPS+pcDNA-con组和LPS+pcDNA-KLF9组。qRT-PCR检测KLF9、IL-6、IL-1β和TNF-αmRNA的表达,MTT法检测细胞活力,流式细胞术检测细胞凋亡情况,Western blot检测KLF9、CyclinD1、Bax、Bcl-2、β-catenin和GSK-3β蛋白的表达。结果:与NC组相比,LPS组的细胞存活率显著降低,细胞凋亡率显著增加,KLF9、CyclinD1和Bcl-2蛋白的表达显著降低,Bax蛋白和炎症因子IL-6、IL-1β和TNF-α的表达显著升高;与LPS+pcDNA-con组相比,LPS+pcDNA-KLF9组细胞存活率显著升高,细胞凋亡率显著降低,KLF9、CyclinD1和Bcl-2蛋白的表达显著升高,Bax蛋白和炎症因子IL-6、IL-1β和TNF-α的表达显著降低(P<0.05)。过表达KLF9可抑制LPS诱导的A549细胞中Wnt/β-catenin信号通路的激活。结论:过表达KLF9可减轻脂多糖诱导的肺泡上皮细胞损伤,这可能与抑制Wnt/β-catenin信号通路有关。     

Wnt信号通路对脑胶质瘤凋亡的影响及其机制

目的初探Wnt信号通路对脑胶质瘤U87细胞凋亡的影响及其机制。方法采用Annexin V-FITC/PI流式细胞仪和Western Blot法检测加入抑制剂LXAV939和不加抑制剂的两组实验的细胞凋亡率及其参与Wnt信号通路的Wnt1和β-catenin蛋白的表达情况。结果经抑制剂LXAV939处理的U87细胞的凋亡率明显大于对照组(P0.05);Wnt1和β-catenin蛋白的表达明显低于对照组(P0.05)。结论 Wnt信号抑制剂LXAV939能诱导脑胶质瘤U87细胞凋亡,其机制可能与下调Wnt1和β-catenin蛋白有关。     

ABCE1基因的siRNA转染对肺癌NCI-H446细胞E-cadherin、β-catenin表达的影响

目的探讨ABCE1基因的siRNA转染对肺癌NCI-H446细胞E-cadherin、β-catenin表达的影响。方法将ABCE1基因的SiRNA表达质粒Si-1、Si-N转染入肺癌NCI-H446细胞,分别为Si-1组、Si-N组。另设正常对照组。用蛋白质印迹和半定量RT-PCR法检测转染后不同时点三组细胞的ABCE1蛋白、mRNA。用免疫组化ABC法检测E-cadherin、β-catenin。结果Si-1组转染96 h后ABCE1 mRNA仅为正常对照组的24.35%,ABCE1蛋白仅为正常对照组的40.82%。Si-1组细胞E-cadherin、β-catenin表达明显高于正常对照组和Si-N组。结论ABCE1基因的siRNA转染能上调肺癌NCI-H446细胞黏附因子E-cadherin、β-catenin的表达。     

miR-183调控Wnt/β-catenin信号通路影响胃癌SGC-7901细胞生物学特性的研究

背景 miR-183在胃癌、乳腺癌、膀胱癌等多种肿瘤组织中低表达,发挥抑癌基因的作用,但其在胃癌中作用机制目前尚不十分清楚.研究表明, miR-183可以通过调节Wnt/β-catenin信号通路抑制骨肉瘤细胞的生长、迁移和侵袭,而Wnt/β-catenin信号通路在胃癌中高度激活与胃癌的发生和转移密切相关.但miR-183是否调节Wnt/β-catenin信号通路影响胃癌细胞生物学特性尚不清楚.目的探讨miR-183调控Wnt/β-catenin信号通路对胃癌细胞生物学特性的影响.方法采用q RT-PCR检测miR-183在不同胃癌细胞株中的表达情况,在胃癌细胞SGC-7901中转染miR-183mimics或mimics对照,分别设为miR-183组和miR-NC组, qRT-PCR检测转染效率,噻唑蓝增殖实验检测SGC-7901细胞增殖变化,流式细胞仪检测SGC-7901细胞凋亡情况, Transwell实验检测SGC-7901细胞侵袭和迁移能力, Western blot法检测凋亡相关及Wnt/β-catenin信号通路相关蛋白表达水平.使用Wnt/β-catenin信号通路激动剂氯化锂处理过表达miR-183的SGC-7901细胞,观察SGC-7901细胞生物学特性的变化.结果与正常胃黏膜上皮GES-1细胞相比, 4株胃癌细胞中miR-183的表达水平明显降低(P 0.05).转染miR-183mimics后SGC-7901细胞中miR-183的表达水平显著升高(P0.05).过表达miR-183后SGC-7901细胞OD值降低(P0.05),凋亡率、Bax和Cleaved Caspase-3蛋白表达水平升高(P 0.05),侵袭和迁移细胞数减少(P0.05),β-catenin、p-GSK-3β和Cyclin D1蛋白表达水平下调(P0.05), GSK-3β蛋白表达水平上调(P 0.05).激活Wnt/β-catenin信号通路部分逆转了过表达miR-183对SGC-7901细胞增殖、侵袭和迁移的抑制作用及凋亡促进作用(P0.05).结论miR-183可能通过抑制Wnt/β-catenin信号通路阻碍人胃癌SGC-7901细胞增殖、侵袭和迁移能力,促进细胞凋亡.     

Cytochrome 1A1 and 1B1 gene diversity in the Zanzibar islands

Amodiaquine (AQ) is a 4‐aminoquinoline widely used in the treatment of malaria as part of the artemisinin combination therapy (ACT). AQ is metabolised towards its main metabolite desethylamodiaquine mainly by cytochrome P450 2C8 (CYP2C8). CYP1A1 and CYP1B1 play a minor role in the metabolism but they seem to be significantly involved in the formation of the short‐lived quinine‐imine. To complete the genetic variation picture of the main genes involved in AQ metabolism in the Zanzibar population, previously characterised for CYP2C8, we analysed in this study CYP1A1 and CYP1B1 main genetic polymorphisms. The results obtained show a low frequency of the CYP1A1*2B/C allele (2.4%) and a high frequency of CYP1B1*6 (approximately 42%) followed by CYP1B1*2 (approximately 27%) in Zanzibar islands. Genotype data for CYP1A1 and CYP1B1 show a low incidence of fast metabolisers, revealing a relatively safe genetic background in Zanzibar’s population regarding the appearance of adverse effects.     

CYP1A1 , GSTM1 , GSTT1 and NQO1 polymorphisms and colorectal adenomas in Japanese men

AIM: To investigate the role of functional genetic poly-morphisms of metabolic enzymes of tobacco carcinogens in the development of colorectal adenomas. METHODS: The study subjects were 455 patients with colorectal adenomas and 1052 controls with no polyps who underwent total colonoscopy in a preretirement health examination at two Self Defense Forces hospitals. The genetic polymorphisms studied wereCYP1A1*2A (rs 4646903), CYP1A1*2C (rs 1048943), GSTM1 (null or non-null genotype), GSTT1 (null or non-null genotype) and NQO1 C609T (rs 1800566). Genotypes were determined by the polymerase chain reaction (PCR)-restriction fragment length polymorphism or PCR method using genomic DNA extracted from the buffy coat. Cigarette smoking and other life-style factors were ascertained by a self-administered questionnaire. The associations of the polymorphisms with colorectal adenomas were examined by means of OR and 95%CI, which were derived from logistic regression analysis. Statistical adjustment was made for smoking, alcohol use, body mass index and other factors. The gene-gene interaction and effect modification of smoking were evaluated by the likelihood ratio test. RESULTS: None of the five polymorphisms showed a significant association with colorectal adenomas, nor was the combination of GSTM1 and GSTT1 . A borderline significant interaction was observed for the combination of CYP1A1*2C and NQO1 (P = 0.051). The OR associated with CYP1A1*2C was significantly lower than unity among individuals with the NQO1 609CC genotype. The adjusted OR for the combination of the CYP1A1*2C allele and NQO1 609CC genotype was 0.61 (95%CI: 0.42-0.91). Although the interaction was not statistically significant (P = 0.24), the OR for individuals carrying the CYP1A1*2C allele and GSTT1 null genotype decreased significantly compared with those who had neither CYP1A1*2C allele nor GSTT1 null genotype (adjusted OR: 0.69, 95%CI: 0.49-0.97). Smoking did not modify the associations of the individual polymorphisms with colorectal adenomas. There w     

Inhibition of procarcinogen-bioactivating human CYP1A1, CYP1A2 and CYP1B1 enzymes by melatonin

Abstract:  Administration of melatonin to rodents decreases the incidence of tumorigenesis initiated by benzo[ a ]pyrene or 7,12-dimethylbenz[ a ]anthracene, which requires bioactivation by cytochrome P450 enzymes, such as CYP1A1, CYP1A2 and CYP1B1, to produce carcinogenic metabolites. The present study tested the hypothesis that melatonin is a modulator of human CYP1 catalytic activity and gene expression. As a comparison, we also investigated the effect of melatonin on the catalytic activity of CYP2A6, which is also a procarcinogen-bioactivating enzyme. Melatonin (3–300 μ m ) decreased 7-ethoxyresorufin O -dealkylation catalyzed by human hepatic microsomes and recombinant CYP1A1, CYP1A2 and CYP1B1, whereas it did not affect coumarin 7-hydroxylation catalyzed by hepatic microsomes or recombinant CYP2A6. Melatonin inhibited CYP1 enzymes by mixed inhibition, with apparent K _i values (mean ± S.E.M.) of 59 ± 1 (CYP1A1), 12 ± 1 (CYP1A2), 14 ± 2 (CYP1B1) and 46 ± 8 μ m (hepatic microsomes). Additional experiments indicated that melatonin decreased benzo[ a ]pyrene hydroxylation catalyzed by hepatic microsomes and CYP1A2 but not by CYP1A1 or CYP1B1. Treatment of MCF-10A human mammary epithelial cells with melatonin (up to 300 μ m ) did not affect basal or benzo[ a ]pyrene-inducible CYP1A1 or CYP1B1 gene expression. Consistent with this finding, melatonin did not influence reporter activity in aryl hydrocarbon receptor-dependent pGudluc6.1-transfected MCF-10A cells treated with or without benzo[ a ]pyrene, as assessed in an in vitro cell-based luciferase reporter gene assay. Overall, melatonin is an in vitro inhibitor of human CYP1 catalytic activity, and it may be useful to develop potent analogues of melatonin as potential cancer chemopreventive agents that block CYP1-mediated chemical carcinogenesis.     

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1)

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.     

Interleukin 1 (IL 1)

Interleukin 1 is an essential factor of macrophage dependent T cell activation and has a large quantity of other biological activities. This paper gives a review of present knowledge of Interleukin 1. In addition to biochemical properties, the IL 1 production and IL 1 activities, methods for determining of IL 1 and inhibitory factors of IL 1 induced T cell proliferation are described.     

Pandemic H1N1 influenza

The 2009 H1N1 influenza A virus that has targeted not only those with chronic medical illness, the very young and old, but also a large segment of the patient population that has previously been afforded relative protection - those who are young, generally healthy, and immune naive. The illness is mild in most, but results in hospitalization and severe ARDS in an important minority. Among those who become critically ill, 20-40% will die, predominantly of severe hypoxic respiratory failure. However, and potentially in part due to the young age of those affected, intensive care with aggressive oxygenation support will allow most people to recover. The volume of patients infected and with critical illness placed substantial strain on the capacity of the health care system and critical care most specifically. Despite this, the 2009 pandemic has engaged our specialty and highlighted its importance like no other. Thus far, the national and global critical care response has been brisk, collaborative and helpful - not only for this pandemic, but for subsequent challenges in years ahead.