共查询到20条相似文献,搜索用时 31 毫秒
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Dorman CJ 《Science progress》2006,89(PT 3-4):151-166
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Ada Collura Laetitia Marisa Diletta Trojan Olivier Buhard Anaïs Lagrange Arnaud Saget Marianne Bombled Patricia Méchighel Mira Ayadi Martine Muleris Aurélien de Reynies Magali Svrcek Jean-François Fléjou Jean-Claude Florent Florence Mahuteau-Betzer Anne-Marie Faussat Alex Duval 《Cellular and molecular life sciences : CMLS》2013,70(4):729-742
Links between cancer and stem cells have been proposed for many years. As the cancer stem cell (CSC) theory became widely studied, new methods were developed to culture and expand cancer cells with conserved determinants of “stemness”. These cells show increased ability to grow in suspension as spheres in serum-free medium supplemented with growth factors and chemicals. The physiological relevance of this phenomenon in established cancer cell lines remains unclear. Cell lines have traditionally been used to explore tumor biology and serve as preclinical models for the screening of potential therapeutic agents. Here, we grew cell-forming spheres (CFS) from 25 established colorectal cancer cell lines. The molecular and cellular characteristics of CFS were compared to the bulk of tumor cells. CFS could be isolated from 72 % of the cell lines. Both CFS and their parental CRC cell lines were highly tumorigenic. Compared to their parental cells, they showed similar expression of putative CSC markers. The ability of CRC cells to grow as CFS was greatly enhanced by prior treatment with 5-fluorouracil. At the molecular level, CFS and parental CRC cells showed identical gene mutations and very similar genomic profiles, although microarray analysis revealed changes in CFS gene expression that were independent of DNA copy-number. We identified a CFS gene expression signature common to CFS from all CRC cell lines, which was predictive of disease relapse in CRC patients. In conclusion, CFS models derived from CRC cell lines possess interesting phenotypic features that may have clinical relevance for drug resistance and disease relapse. 相似文献
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Albane le Maire William Bourguet Patrick Balaguer 《Cellular and molecular life sciences : CMLS》2010,67(8):1219-1237
Endocrine-disrupting chemicals (EDCs) represent a broad class of exogenous substances that cause adverse effects in the endocrine
system by interfering with hormone biosynthesis, metabolism, or action. The molecular mechanisms of EDCs involve different
pathways including interactions with nuclear hormone receptors (NHRs) which are primary targets of a large variety of environmental
contaminants. Here, based on the crystal structures currently available in the Protein Data Bank, we review recent studies
showing the many ways in which EDCs interact with NHRs and impact their signaling pathways. Like the estrogenic chemical diethylstilbestrol,
some EDCs mimic the natural hormones through conserved protein–ligand contacts, while others, such as organotins, employ radically
different binding mechanisms. Such structure-based knowledge, in addition to providing a better understanding of EDC activities,
can be used to predict the endocrine-disrupting potential of environmental pollutants and may have applications in drug discovery. 相似文献
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Dynamics of estrogen binding by uterine cells in vivo 总被引:1,自引:0,他引:1
The dynamics of the in vivo binding and release of tritiated estradiol in different uterine cell types are described. The very early binding of estrogens by the cytosol-nuclear and the eosinophil receptor systems is in accordance with the hypothesis that some estrogenic effects are mediated by these receptor systems. 相似文献
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Elin Swedenborg Krista A. Power Wen Cai Ingemar Pongratz Joëlle Rüegg 《Cellular and molecular life sciences : CMLS》2009,66(24):3873-3894
Together with the estrogen receptor (ER) alpha, estrogen receptor beta (ERβ) mediates many of the physiological effects of
estrogens. As ERβ is crucially involved in a variety of important physiological processes, its activity should be tightly
regulated. ERβ regulation is achieved by hormone binding as well as by posttranslational modifications of the receptor. Furthermore,
ERβ expression levels are under circadian control and can be regulated by DNA methylation of the ERβ promoter region. There
are also a number of factors that can interfere with ERβ activity, such as phytoestrogens, endocrine disruptive chemicals,
and growth factors. In this article, we outline different mechanisms of ERβ regulation and how they are implicated in various
diseases. We also discuss how these insights might help to specifically target ERβ in drug design. 相似文献
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B Streit 《Experientia》1992,48(10):955-970
The fate of environmental pollutants--the various isotopes of elements, and inorganic or organic compounds--is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them. 相似文献
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B. Streit 《Cellular and molecular life sciences : CMLS》1992,48(10):955-970
The fate of environmental pollutants — the various isotopes of elements, and inorganic or organic compounds — is a fundamental aspect of ecology and ecotoxicology, and bioaccumulation is a phenomenon often discussed in this context. Human activities have drastically altered natural concentrations of many substances in the environment and added numerous new chemicals. An understanding of the processes of bioaccumulation is important for several reasons. 1) Bioaccumulation in organisms may enhance the persistence of industrial chemicals in the ecosystem as a whole, since they can be fixed in the tissues of organisms. 2) Stored chemicals are not exposed to direct physical, chemical, or biochemical degradation. 3) Stored chemicals can directly affect an individual's health. 4) Predators of those organisms that have bioaccumulated harmful substances may be endangered by food chain effects. While former theories on the processes of bioaccumulation focused on single aspects that affect the extent of accumulation (such as the trophic level within the food chain or the lipophilicity of the chemical), modern theories are based on compartmental kinetics and the integration of various environmental interactions. Concepts include results from quantitative structure-activity relationships (QSAR), pharmacokinetics, ecophysiology and general biology, molecular genetic aspects and selection, and finally the structure of communities and man-made alterations in them. 相似文献
10.
Formation of natural intramolecular triple-helical structures of DNA is still an intriguing research topic in view of the possible involvement of these structures in biological processes. The biochemical and biophysical properties of DNA triplex structures have been extensively studied, and experimental data show that H-DNA is likely to form in vivo and may regulate the expression of various genes. However, direct and unambiguous evidence of the possible biological roles of these structures is yet elusive. This review focuses on the basic facts that are in favor of, or against, the hypothesis of the presence and function of natural DNA triple-helical structures in vivo, and outlines the different methods and probes that have been used to support these facts. 相似文献
11.
Chai M McManus DP McInnes R Moertel L Tran M Loukas A Jonesa MK Gobert GN 《Cellular and molecular life sciences : CMLS》2006,63(7-8):919-929
The schistosomulum is the main target of vaccine-induced protective immunity; however, most studies have utilized schistosomula produced by mechanical transformation of infective larvae followed by in vitro culture rather than larvae isolated directly from the lungs of infected mammals. Using transmission electron microscopy, we demonstrated that there was little difference in the ultrastructure of Schistosoma japonicum schistosomula obtained by the two methods. However, significant differences in gene expression profiles were apparent when we used an oligonucleotide microarray to compare the gene expression profiles of schistosomula obtained in vivo from lung tissue with those maintained in vitro, and with adult worms of S. japonicum. It is likely that host environmental factors, which cannot be reliably reproduced in vitro, do influence the growth, development and overall biology of schistosomes. Thus caution is urged when using in vitro-cultured schistosomes and mechanically transformed/cultured schistosomula in molecular, biochemical and immunological studies. 相似文献
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生物转化具有底物选择性、立构选择性、化学选择性、对映选择性等一般化学反应中不具备的优点,在精细化工中占有很大的优势,其中Baeyer-Villiger氧化反应在生物转化中占有很重要的地位,产生的许多中间体或产物可以被用来生产多种化学产品和药物,在工业生物催化中有很好的应用前景。本文主要对生物转化中的Baeyer-Villiger氧化反应在利用酶或细胞作为催化剂时存在的问题和解决方法以及基因技术的运用近况进行了综述。 相似文献
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C. Pieau M. Dorizzi N. Richard-Mercier 《Cellular and molecular life sciences : CMLS》1999,55(6-7):887-900
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Complex diseases arise from a combination of heritable and environmental factors. The contribution made by environmental factors
may be mediated through epigenetics. Epigenetics is the study of changes in gene expression that occur without a change in
DNA sequence and are meiotically or mitotically heritable. Such changes in gene expression are achieved through the methylation
of DNA, the post-translational modifications of histone proteins, and RNA-based silencing. Epigenetics has been implicated
in complex diseases such as cancer, schizophrenia, bipolar disorder, autism and systemic lupus erythematosus. The prevalence
and severity of these diseases may be influenced by factors that affect the epigenotype, such as ageing, folate status, in vitro fertilization and our ancestors’ lifestyles. Although our understanding of the role played by epigenetics in complex diseases
remains in its infancy, it has already led to the development of novel diagnostic methods and treatments, which augurs well
for its future health benefits.
Received 6 December 2006; received after revision 29 January 2007; accepted 15 March 2007 相似文献
18.
Endothelial nitric oxide synthase: insight into cell-specific gene regulation in the vascular endothelium 总被引:2,自引:0,他引:2
The vascular endothelium plays a crucial role in regulating normal blood vessel physiology. The gene products responsible
are commonly expressed exclusively, or preferentially, in this cell type. However, despite the importance of regulated gene
expression in the vascular endothelium, relatively little is known about the mechanisms that restrict endothelial-specific
gene expression to this cell type. While significant progress has been made towards understanding the regulation of endothelial
genes through cis/trans paradigms, it has become apparent that additional mechanisms must also be operative. For example,
chromatin-based mechanisms, including cell-specific DNA methylation patterns and post-translational histone modifications,
have recently been demonstrated to play important roles in the cell-specific expression of endothelial nitric oxide synthase
(eNOS). This review investigates the involvement of epigenetic regulatory mechanisms in vascular endothelial cell-specific
gene expression using eNOS as a prototypical model, and will address the possible contributions of these pathways to diseases
of the vasculature.
Received 13 September 2005; received after revision 13 October 2005; accepted 19 October 2005 相似文献
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Sheng-Ming Wu Ya-Hui Huang Yi-Hsin Lu Ling-Fang Chien Chau-Ting Yeh Ming-Ming Tsai Chen-Hsin Liao Wei-Jan Chen Chia-Jung Liao Wan-Li Cheng Kwang-Huei Lin 《Cellular and molecular life sciences : CMLS》2010,67(11):1831-1843
The thyroid hormone T3 regulates differentiation, growth, and development. We demonstrated that methionine adenosyltransferase 1A (MAT1A) was positively regulated by T3 identified by cDNA microarray previously. The expression of the MAT1A was upregulated by T3 in hepatoma cell lines overexpressing thyroid hormone receptors (TRs). Additionally, these findings indicate that MAT1A may be regulated by CCAAT/enhancer binding protein (C/EBP). The critical role of the C/EBP binding sites was confirmed by the reporter or chromatin immuno-precipitation (ChIP) assay. In addition, C/EBP was upregulated in hepatoma cells after T3 treatment and ectopic expression of MAT1A inhibited cell migration and invasion in J7 hepatoma cells. Conversely, knockdown of MAT1A expression increased cell migration. Together, these findings suggest that the expression of the MAT1A gene is mediated by C/EBP and is indirectly upregulated by T3. Finally, TR was downregulated in a small subset of hepatocellular carcinoma cells concomitantly reduced the expression of C/EBPα and MAT1A. 相似文献