MTDH在肿瘤发生、发展中的作用

异黏蛋白(metadherin, MTDH)是近来发现的一个新的癌基因,在多种肿瘤中过表达,包括乳腺癌、前列腺癌、食管癌、肝癌、神经母细胞瘤和恶性黑色素瘤,对乳腺癌细胞在肺中的定植有增强作用.MTDH增强肿瘤细胞的侵袭性,通过NF-κB途径增加黏附分子的表达.MTDH是Ha-ras下游基因,Ha-ras通过PI3K/AKT/GSK3β/c-Myc途径诱导MTDH大量表达.MTDH对多种肿瘤的发生和发展起着重要的作用,有望成为肿瘤靶向治疗的靶点.     

党参多糖抑制PI3K / AKT 通路对人肝癌HepG2 细胞生长和运动能力的 影响

目的:采用体外培养人肝癌HepG2细胞为研究对象,探讨党参多糖(CPP)对HepG2细胞生长和运动能力的影响及其机制。方法:用不同浓度(0、0.1、0.25、0.5、1、2.5、5、10、20、50、100、200、300和400μmol/L)党参多糖作用于体外培养的人肝癌HepG2细胞,采用CCK-8法检测细胞存活率,选择5,10和20μmol/L进行后续实验。流式细胞术检测细胞凋亡率;划痕实验检测细胞迁移;Transwell检测细胞侵袭;Western blot检测上皮标志蛋白E-钙黏蛋白(E-cadherin)和间质标志蛋白N-钙黏蛋白(N-cadherin)N-cadherin、波形蛋白(Vimentin)的表达水平以及信号通路磷脂酰肌醇3-激酶(PI3K)、AKT的磷酸化情况;最后,20μmol/L党参多糖或PI3K激活剂740Y-P单独使用或联用处理HepG2细胞,检测细胞增殖、凋亡、迁移、侵袭和PI3K/AKT信号通路磷酸化。结果:党参多糖能促进体外培养HepG2细胞凋亡,抑制细胞增殖、迁移和侵袭能力;同时调节E-cadherin、N-cadherin、Vimentin和PI3K/AKT相关蛋白表达;最后,20μmol/L党参多糖和740Y-P联用能有效逆转740Y-P对细胞增殖、凋亡、侵袭和迁移能力的调节作用。结论:党参多糖能有效抑制人肝癌HepG2细胞的生长和运动能力,其机制与调节PI3K/AKT信号通路有关。     

HIF-1α对食管癌Eca109细胞体内外侵袭转移的影响及其分子机制

目的:采用RNA干扰技术(RNAi)观察低氧诱导因子-1α(HIF-1α)对食管癌Eca109细胞及其裸鼠移植瘤侵袭转移的影响及其作用机制。方法:CoCl2模拟肿瘤低氧微环境,分别用RT-PCR和免疫细胞化学法检测体外低氧条件下Eca109细胞中HIF-1α、E-钙黏蛋白及基质金属蛋白酶-2(MMP-2)mRNA及蛋白的表达。RT-PCR检测RNAi沉默HIF-1α对E-钙黏蛋白及MMP-2 mRNA表达的影响。通过细胞划痕试验和Transwell试验检测RNAi对Eca109细胞侵袭和转移能力的影响。建立Eca109细胞裸鼠移植瘤模型,观察HIF-1α对肿瘤生长及淋巴结转移的影响;采用Western blot检测各组移植瘤中HIF-1α、E-钙黏蛋白及MMP-2的表达,分析HIF-1α在离体和在体对肿瘤生长、侵袭及转移的影响。结果:低氧诱导Eca109细胞的HIF-1α蛋白表达升高,E-钙黏蛋白的mRNA及蛋白表达降低和MMP-2 mRNA及蛋白表达升高,但对HIF-1αmRNA无明显影响。用RNAi能有效沉默HIF-1α,并可逆转低氧导致的E-钙黏蛋白及MMP-2的降低及升高,使Eca109细胞迁移速度减慢,侵袭穿膜细胞数减少(P<0.05);在体内使移植瘤生长减缓,淋巴结转移率降低(P<0.05)。结论:HIF-1α在体内外通过影响E-钙黏蛋白和MMP-2表达,来影响食管癌Eca109细胞的生长、侵袭和转移。     

木犀草素对人肝癌HepG2细胞株侵袭、迁移和黏附能力的影响

目的:探讨木犀草素对人肝癌HepG2细胞株侵袭、迁移和黏附能力的影响及其作用机制。方法:采用不同浓度木犀草素处理体外培养的人肝癌HepG2细胞株,Transwell实验检测细胞的侵袭能力,划痕实验检测细胞的迁移能力,黏附实验评价细胞的黏附能力,Western blot检测E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)、波形蛋白(vimentin)和Snai1蛋白的表达。结果:木犀草素可明显降低肝癌HepG2细胞的体外侵袭、迁移及黏附能力(P0.01),且在一定浓度范围内呈明显量效关系。木犀草素处理肝癌细胞后,上皮细胞标志蛋白E-cadherin表达明显上调,间质细胞标志蛋白N-cadherin和vimentin以及转录因子Snai1表达均明显下调,木犀草素对以上蛋白的调节呈明显浓度依赖性。结论:木犀草素体外具有抑制肝癌HepG2细胞株侵袭、迁移和黏附的作用,其作用机制可能与调控上皮-间质转化有关。     

桔梗皂苷D介导PI3K/AKT/mTOR信号通路调控子宫内膜癌细胞株ECC-1增殖、侵袭和迁移

目的 探讨桔梗皂苷D介导磷酸肌醇-3-激酶（PI3K）/蛋白激酶B(AKT)/哺乳动物雷帕霉素靶蛋白（mTOR信号通路调控子宫内膜癌细胞株ECC-1增殖、侵袭和迁移作用。方法 将人子宫内膜癌细胞株ECC-1分为对照组,桔梗皂苷D低、中、高剂量组（9μmol/L、18μmol/L、36μmol/L）,PI3K抑制剂（PQR309）组（1μmol/L）,PI3K激动剂（IGF-1）组（100 mg/L）。培养48 h后,四甲基偶氮唑蓝、侵袭小室和划痕实验分别检测细胞增殖、侵袭和迁移活性;实时定量聚合酶链反应和蛋白免疫印迹法检测细胞PI3K、AKT、mTOR、c-Myc、细胞周期蛋白激酶6(CDK6)、E-钙黏蛋白（E-cadherin）、波形蛋白（Vimentin）、锌指转录因子（Snail）信使核糖核酸（mRNA）和蛋白表达及p-PI3K、p-AKT、p-mTOR水平。结果 与对照组比,IGF-1组细胞侵袭细胞数和细胞划痕愈合率上升,PI3K、AKT、mTOR mRNA和蛋白表达及p-PI3K、p-PI3K/PI3K、p-AKT、p-AKT/AKT、p-mTOR、p-mTOR/mTOR水...     

连环蛋白家族成员P120ctn的作用及相关机制

连环蛋白P120可在细胞连接处与E-钙黏蛋白结合形成连环蛋白-钙黏蛋白复合体,调控钙黏蛋白介导的细胞黏附作用;在胞质内可与Rho家族GTP酶相互作用调节细胞骨架的运动;在细胞核内可与核转录因子NF-κB和转录抑制因子Kaiso结合,影响炎性反应和细胞增殖.P120对细胞黏附、细胞动力、炎性反应和细胞增殖的影响使其与损伤...     

Effects of hypoxia on migration and invasion of esophageal carcinoma Eca109 cells

目的 探讨低氧对食管癌迁移及侵袭能力的影响及其作用机制.方法 采用CoCl2化学低氧法模拟肿瘤低氧微环境,半定量RT-PCR和免疫细胞化学分别检测不同低氧时相时食管癌Eca109细胞中低氧诱导因子-1α(HIF-1α)、E-钙黏蛋白及基质金属蛋白酶-2(MMP-2)mRNA及蛋白的表达.Western印迹法检测雷帕霉素联合低氧处理Eca109细胞后,HIF-1α、E-钙黏蛋白及MMP-2的变化.细胞划痕试验和Transwell实验检测雷帕霉素联合低氧对Eca109细胞迁移及侵袭能力的影响.结果 Eca109细胞在低氧状态下,HIF-1α mRNA无明显变化,仅蛋白表达增多;E-钙黏蛋白的mRNA表达明显降低(P＜0.05),蛋白表达减少;MMP-2 mRNA表达明显升高(P＜0.05),蛋白表达增多.雷帕霉素在低氧状态下可显著抑制HIF-1α及MMP-2表达,促进E-钙黏蛋白高表达.经雷帕霉素处理后,Eca109细胞在低氧状态下,迁移速度减慢,侵袭穿膜细胞数减少(P＜0.05).结论 低氧使Eca109细胞中HIF-1α蛋白表达增多,后者可能通过下调E-钙黏蛋白、上调MMP-2表达促进食管癌在低氧状态下的迁移及侵袭.     

IL-8通过激活PI3K/AKT通路促进结肠癌细胞增殖、迁移和侵袭

为研究IL-8对结肠癌细胞增殖、迁移和侵袭的影响并探讨其作用机制,应用免疫组织化学法检测结肠癌组织和正常癌旁组织中IL-8的表达;MTT法检测不同浓度IL-8处理或抑制PI3K/AKT信号通路后结肠癌细胞SW480的增殖情况;Western blotting检测IL-8处理后SW480细胞中p-AKT、t-AKT蛋白的表达;Transwell法检测抑制PI3K/AKT通路或IL-8处理后SW480细胞的迁移和侵袭能力。结果显示,与癌旁组织相比,结肠癌组织中IL-8的表达水平明显提高;IL-8处理后SW480细胞的增殖、迁移和侵袭能力明显增加,且PI3K/AKT通路异常激活;抑制PI3K/AKT通路可逆转IL-8对SW480细胞增殖、迁移和侵袭的促进作用。由此IL-8可促进结肠癌细胞增殖、迁移和侵袭,其机制可能与激活PI3K/AKT通路有关,可为IL-8在结肠癌中的治疗提供参考。     

黄精皂苷对TGF-β1诱导的HK-2细胞EMT、补体系统和PI3K/AKT/NF-κB信号通路的影响

目的分析黄精皂苷通过PI3K/AKT/NF-κB信号通路调控补体系统对转化生长因子-β1(transforming growth factor-β1,TGF-β1)诱导的HK-2细胞上皮-间质转化(epithelial-to-mesenchymal transition,EMT)的影响及机制。方法 HK-2细胞分为4组:对照组、黄精皂苷组、TGF-β1组、TGF-β1+黄精皂苷组。在培养基中加入终质量浓度为10 ng/ml的TGF-β1处理48 h诱导。黄精皂苷终质量浓度为20 ng/ml,培养48 h。检测各组细胞迁移和侵袭的能力,并检测E-钙黏蛋白(E-cad)、N-钙黏蛋白(N-cad)、波形蛋白(Vimentin,Vim)mRNA和蛋白水平评估EMT。通过RT-qPCR和Western blot检测C3aR、C5aR、PI3K、AKT、NF-κB m RNA和蛋白表达量。结果 4组细胞的上述指标比较差异显著(P<0.05)。黄精皂苷组细胞的迁移能力(22.75%±1.98%)、C3aR、C5aR、PI3K、AKT、NF-κB、N-cad、Vim的mRNA和蛋白表达量显著低...     

E-钙黏蛋白siRNA促进胃癌细胞SGC7901耐药与增殖

目的研究E-钙黏蛋白siRNA对胃癌细胞SGC7901化疗敏感性和增殖能力的影响,并对其相关机制进行初步探讨。方法用Lipofectamine 2000将E-钙黏蛋白siRNA及阴性对照序列转入细胞SGC7901,用MTT法检测细胞对药物的敏感性并观察细胞增殖能力。Western印迹法检测细胞E-钙黏蛋白、PTEN、AKT、p-AKT、BAX和BCL-2蛋白表达。结果 SGC7901细胞转染E-钙黏蛋白siRNA后显著抑制细胞E-钙黏蛋白蛋白表达(P<0.05)。转染E-钙黏蛋白siRNA后细胞对CDDP、5-FU、紫杉醇和ADR的IC50分别为(mg/L):4.375±0.199、6.855±0.780、2.530±0.259和0.368±0.042;阴性对照组分别为(mg/L):2.882±0.166、4.058±0.946、1.483±0.225和0.228±0.012,转染E-钙黏蛋白siRNA细胞对CDDP、5-FU、紫杉醇和ADR的IC50显著高于阴性对照组(P<0.05)。转染E-钙黏蛋白siRNA细胞增殖能力显著高于阴性对照组(P<0.05)。转染E-钙黏蛋白siRNA72 h后PTEN和BA...     

雷公藤甲素抗肿瘤血管新生的研究进展（英文）

雷公藤甲素(triptolide,TPL)是从中草药雷公藤中提取的一种有效活性物质,已被用来治疗多种疾病,包括系统性红斑狼疮,类风湿性关节炎,肾病综合征等,TPL甚至有很强的抑制肿瘤的活性。近些年的研究显示,TPL具有抗血管新生的能力,TPL不仅可以抑制肿瘤的增殖,诱导细胞的凋亡,还可以抑制肿瘤的转移,可以增加其它化疗药物的抗肿瘤活性。本综述将讨论TPL在抗肿瘤血管新生方面的研究进展,以及初步探讨其潜在的作用机制。     

Changes in activity of neutral proteases in tissues of ground squirrels in the dynamics of hibernation

Total activities of neutral proteases in the cerebral, hepatic, and myocardial tissues of ground squirrel vary during hibernation: in autumn (before hibernation) activities of the enzymes in the brain and myocardium start increasing, while in the liver they do not change. A common feature for all tissues is minimum activity of active neutral proteases in the middle of hibernation month 1 bout, while the maximum activity is recorded before awakening. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 9, pp. 278–280, September, 2008     

Kinetics of decline of maternal measles virus-neutralizing antibodies in sera of infants in France in 2006

The optimal age for measles vaccination is an important health issue, since maternal antibodies may neutralize the vaccine antigen before a specific immune response develops, while delaying vaccination may increase the risk of complicated diseases in infants. However, measles vaccination impacts the duration of protection afforded by transplacental transfer of maternal antibodies: vaccination-induced maternal antibodies disappear faster than disease-induced antibodies. In order to maintain protection against measles in infants, it is important to monitor the dynamics of this phenomenon in vaccinated populations. To assess the current situation in France, a multicenter, prospective seroepidemiological study was conducted in seven French hospitals between October 2005 and January 2007. Maternal measles antibody concentrations from 348 infants 0 to 15 months old were measured using the plaque reduction neutralization assay. Geometric mean concentrations and the percentage of infants with maternal measles antibody concentrations above the protection threshold (≥120 mIU/ml) were assessed according to age. Results show that after more than 20 years of routine measles vaccination in France, maternal measles-neutralizing antibodies decrease dramatically in French infants by 6 months of age, from 1,740 mIU/ml for infants 0 to 1 month old to 223 mIU/ml for infants 5 to 6 months old, and that 90% of infants are not protected against measles after 6 months of age. Infant protection against measles could be optimized both by increasing herd immunity through an increased vaccine coverage and by lowering the age of routine vaccination from 12 to 9 months.     

Effect of vitamin C in reducing the toxicity of endosulfan in liver in rabbits

In this study, the effect of endosulfan, an organochlorine pesticide, and the ameliorating effect of vitamin C on the livers of New Zealand white rabbits were studied. Livers of the rabbits were examined grossly and histopathologically, and caspase-3 activity was detected by immunohistochemical methods. A total of twenty-four rabbits were divided into four groups (n=6). Rabbits in Group I (END) were daily given a sublethal dose of endosulfan (1 mg/kg bw) in corn oil by oral gavage for 6 weeks. Group II (END+C) received the same dose of endosulfan and additionally Vit C (20 mg/kg bw) every other day during this period. Group III (OIL+C) received corn oil daily by oral gavage and vitamin C every other day for 6 weeks. Group IV (OIL), the control group, received only corn oil daily, by oral gavage throughout the experiment. The concentration of α-endosulfan in the END group was higher in livers (0.102±0.012 ppb) than the β-endosulfan (0.072±0.001 ppb). Decreased accumulation of α and β endosulfan was observed in the END+C group (0.025±0.003 and 0.016±0.002 ppb, respectively) (p<0.0001). The most prominent gross findings at the necropsy were seen in the END group, in which swollen and pale livers were commonly observed. Hemorrhages, degenerations, necrosis, and in some rabbits bile duct hyperplasia were the marked histopathological findings of the END group. Caspase-3 positive reaction was more severe in this group than in the others. An ameliorating effect of Vit C on gross, histopathological and immunohistochemical findings was observed in the END+C group. The results revealed that endosulfan is highly toxic for rabbit livers. However, toxicity was decreased by Vit C treatment, which reduced the accumulation of endosulfan in livers four-fold.