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201.
为了探索CCCTC结合因子(CCCTC-binding factor, CTCF)对人胆管癌细胞的生长、迁移和侵袭能力的影响及其潜在的分子作用机制,利用慢病毒感染法获得稳定过表达或敲低CTCF的胆管癌细胞系,采用蛋白质免疫印迹法(Western blotting, Wb)检测CTCF蛋白表达水平,采用Cell Counting Kit-8(CCK-8)法和克隆形成实验检测细胞生长情况,采用Transwell小室实验检测细胞迁移和侵袭能力,采用GraphPad软件(v6)的Mann-Whitney U检验分析CTCF基因在癌和癌旁组织间的mRNA差异表达.结果显示:过表达CTCF可显著促进HCCC-9810和RBE胆管癌细胞的生长、迁移和侵袭能力;敲低CTCF呈现相反的表型.通过通路富集分析发现:CTCF的表达水平在胆管癌中与p53信号通路活性显著负相关,过表达CTCF可显著下调p53及其靶基因p21的mRNA和蛋白表达水平,而敲低CTCF则显著促进p53和p21的mRNA和蛋白表达水平.综上,本研究揭示CTCF可能通过抑制p53信号通路而促进胆管癌细胞生长、迁移和侵袭而发挥促癌基因的功能. 相似文献
202.
本文用MNDO方法全参数优化了反应物、产物和反应过渡态的几何构型,对反应途径进行了计算,从理论上论证了反应物和产物间异构化反应的机理,得到了最终产物为顺式产物的依据. 相似文献
203.
本文用量子化学从头计算方法研究了乙二醛在碱性条件下的Cannizzaro重排反应,得到了该反应可行的微观机理,与同位素跟踪实结果一致。 相似文献
204.
The territorial features of the amospheric environment in Beijing were described in described in detail,and the transportation pathways of the atmosphere pollutants found by the dot aggregation in the form of the meshwork.The concept on convergence belt of the atmosphere pollutants was given.The vertical distribution of the atmospheric pollutants in Beijing was detected by the neighboring areas of Beijing.The sand-dust storm in China were studie by both satellite inspection technology and analysis of atmospheric flow fields,According tp tje dostrobitopms of sand-dust storm sources to impact on the air environment in China,the sand-dust sources insia were situatad in the desert and Gobi in the Inner Mongolia and Xinjiang autonomous regions .The sand-dust surces outside China were situated in the desert and Gohi in Russina,Hazakhsten and Mongolia.A very strong sand-dust storm taken place on the 20th Mar,2002 is given as exa-mple. 相似文献
205.
泛素—蛋白酶体途径通过降解许多诸如细胞周期因子、调节蛋白等蛋白,从而参与调节许多重要的生命活动。此途径的失调与许多人类疾病有关。针对此途径的研究为人类疾病预防和治疗提供了一个新思路。 相似文献
206.
Hongmei Wang Changcheng Song Chongwen Duan Weixian Shi Cunxi Li Dayuan Chen Yongchao Wang 《科学通报(英文版)》2002,47(2):127-132
Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation
with reagents that would block the UPP. They were the monoclonal antibody against ubiquitinated proteins—UCP1; the polyclonal
antibody against ubiquitin—anti-Ub, and a special inhibitor against proteasome—ALLN. Furthermore, we treated the capacitated
sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation
and acrosome reaction, but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role
in mouse in vitro fertilization. 相似文献
207.
Kejie Zhang Lifang Huang Hanying Sun Yan Zhu Yi Xiao Mei Huang Wenli Liu 《自然科学进展(英文版)》2009,19(5):557-562
The aim of the present study was to investigate the role of the Notch signaling pathway in premature senescence of murine bone marrow stromal cells in vitro. The intracellular domain of Notch 1 (ICN) was transfected into cultured murine bone marrow stromal cells by lipofectamine transfection. After three days, the proliferation of transfected cells was measured by MTT assay. Cell cycle distribution
was analyzed by flow cytometry. Senescence-associated beta-galactosidase (SA-beta-gal) was measured, and the percentage of positive cells was evaluated by assessing 1000 cells in random fields of view. The expressions of p53 and p21Cip1/Waf1 were analyzed by both RT-PCR and Western blot analysis. The results showed that activation of Notch signaling inhibited proliferation of murine bone marrow
stromal cells with induction of G1 arrest, increased the percentage of SA-beta-gal positive cells, and upregulated p53 and p21Cip1/Waf1 mRNA and protein expression levels. Thus, the activated Notch signaling could induce premature senescence of bone marrow stromal cells through the p53-p21Cip1/Waf1 pathway. 相似文献
208.
LU Yujie WANG Xia LOU Yonggen CHENG Jiaan 《科学通报(英文版)》2006,51(20):2457-2465
In response to herbivory, plants release volatiles to attract the natural enemies of herbivores[1,2]. This phe- nomenon has been reported in more than 23 plant spe- cies[3―6], and several field studies have shown that these herbivore-induced volatiles en… 相似文献
209.
高校图书馆文化建设的途径探析 总被引:1,自引:0,他引:1
阐述了图书馆文化的内涵,分析了图书馆文化的构成要素,探讨了高校图书馆文化建设的基本途径。 相似文献
210.
With atomic force microscopy (AFM) we systematically studied the DNA condensations on mica surfaces induced by multivalent cation spermidine. The pattern of the DNA condensates is a flat single layer, with a core in the centre and DNA wrapping around it at high density. We assume this to be a two-dimensional condensation of free coiled DNA onto negatively charged mica surfaces by the multivalent cation. The DNA molecules condense on mica surfaces via a pathway different from the formation of toroids, rods or globules in bulk solutions. We give an explanation to why toroid structures are difficult to be observed by AFM, and further discuss the relationship between DNA condensations in solutions and on mica surfaces. The present work will be helpful for understanding the behaviors of DNA on charged surfaces, which might be significantly different from that in solutions. 相似文献