排序方式: 共有17条查询结果,搜索用时 15 毫秒
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The melanocyte differentiation program predisposes to metastasis after neoplastic transformation 总被引:1,自引:0,他引:1
Gupta PB Kuperwasser C Brunet JP Ramaswamy S Kuo WL Gray JW Naber SP Weinberg RA 《Nature genetics》2005,37(10):1047-1054
The aggressive clinical behavior of melanoma suggests that the developmental origins of melanocytes in the neural crest might be relevant to their metastatic propensity. Here we show that primary human melanocytes, transformed using a specific set of introduced genes, form melanomas that frequently metastasize to multiple secondary sites, whereas human fibroblasts and epithelial cells transformed using an identical set of genes generate primary tumors that rarely do so. Notably, these melanomas have a metastasis spectrum similar to that observed in humans with melanoma. These observations indicate that part of the metastatic proclivity of melanoma is attributable to lineage-specific factors expressed in melanocytes and not in other cell types analyzed. Analysis of microarray data from human nevi shows that the expression pattern of Slug, a master regulator of neural crest cell specification and migration, correlates with those of other genes that are important for neural crest cell migrations during development. Moreover, Slug is required for the metastasis of the transformed melanoma cells. These findings indicate that melanocyte-specific factors present before neoplastic transformation can have a pivotal role in governing melanoma progression. 相似文献
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This paper develops a new procedure for simultaneously performing multidimensional scaling and cluster analysis on two-way
compositional data of proportions. The objective of the proposed procedure is to delineate patterns of variability in compositions
across subjects by simultaneously clustering subjects into latent classes or groups and estimating a joint space of stimulus
coordinates and class-specific vectors in a multidimensional space. We use a conditional mixture, maximum likelihood framework
with an E-M algorithm for parameter estimation. The proposed procedure is illustrated using a compositional data set reflecting
proportions of viewing time across television networks for an area sample of households. 相似文献
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MJ Claesson IB Jeffery S Conde SE Power EM O'Connor S Cusack HM Harris M Coakley B Lakshminarayanan O O'Sullivan GF Fitzgerald J Deane M O'Connor N Harnedy K O'Connor D O'Mahony D van Sinderen M Wallace L Brennan C Stanton JR Marchesi AP Fitzgerald F Shanahan C Hill RP Ross PW O'Toole 《Nature》2012,488(7410):178-184
Alterations in intestinal microbiota composition are associated with several chronic conditions, including obesity and inflammatory diseases. The microbiota of older people displays greater inter-individual variation than that of younger adults. Here we show that the faecal microbiota composition from 178 elderly subjects formed groups, correlating with residence location in the community, day-hospital, rehabilitation or in long-term residential care. However, clustering of subjects by diet separated them by the same residence location and microbiota groupings. The separation of microbiota composition significantly correlated with measures of frailty, co-morbidity, nutritional status, markers of inflammation and with metabolites in faecal water. The individual microbiota of people in long-stay care was significantly less diverse than that of community dwellers. Loss of community-associated microbiota correlated with increased frailty. Collectively, the data support a relationship between diet, microbiota and health status, and indicate a role for diet-driven microbiota alterations in varying rates of health decline upon ageing. 相似文献
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V. Gopalakrishnan S. Ramaswamy N. Padmanabha Pillai S. Ranganathan M. N. Ghosh 《Cellular and molecular life sciences : CMLS》1980,36(12):1423-1425
Summary Incubation of red cells with higher concentrations of prolactin in vitro enhanced the cellular sodium level and produced a significant reduction in erythrocyte membrane adenosine triphosphatase activity. This effect was dose and time-dependent. It is the result of an inhibition of the active sodium pump similar to that produced by ouabain, suggesting altered red cell function and electrolyte balance in hyperprolactinemic states.Acknowledgments. Ovine prolactin was generously supplied by Ferring (Malmö, Sweden) and NPA, NIH (Maryland, USA). Thanks are also due to Prof. S. Dutta, Wayne State University, Detroit, for the gift, of ouabain octahydrate and Dr M. Ramachandran and Prof. S. Ramakrishnan, Department of Biochemistry, JIPMER, Pondicherry, for their encouragement and keen interest in this study. 相似文献
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Ramaswamy Bhuvaneswari Yik Yuen Gan Khee Chee Soo Malini Olivo 《Cellular and molecular life sciences : CMLS》2009,66(14):2275-2283
Photodynamic therapy (PDT), the activation of a photosensitive drug in tumor tissue with light of specific wavelength, has
been used effectively to treat certain solid tumors. Though therapeutic responses are encouraging, PDT-mediated oxidative
stress can act as an angiogenic switch that ultimately leads to neovascularization and tumor recurrence. This article explores
the effect of PDT on angiogenesis in different tumor models. Overexpression of proangiogenic vascular endothelial growth factor,
cyclooxygenase-2 and matrix metalloproteases has often been reported post-illumination. Recent clinical studies have demonstrated
that inhibiting angiogenesis after chemotherapy and radiotherapy is an attractive and valuable approach to cancer treatment.
In this review, we report the effective therapeutic strategy of combining angiogenesis inhibitors with PDT to control and
treat tumors. 相似文献
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1 Introduction Proton conducting solid polymer electrolytes have been extensively studied due to their potential applications in electrochemical devices such as batteries, super capacitors, electrochromic windows, sensors etc~([1,2]). Many researchers have studied the behaviour of inorganic based polymer electrolytes as proton conductors and their applications in solid state devices at room temperature~([3]). But, inorganic acid doped electrolytes have some serious disadvantages like corrosion… 相似文献
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M Yu DT Ting SL Stott BS Wittner F Ozsolak S Paul JC Ciciliano ME Smas D Winokur AJ Gilman MJ Ulman K Xega G Contino B Alagesan BW Brannigan PM Milos DP Ryan LV Sequist N Bardeesy S Ramaswamy M Toner S Maheswaran DA Haber 《Nature》2012,487(7408):510-513
Circulating tumour cells (CTCs) shed into blood from primary cancers include putative precursors that initiate distal metastases. Although these cells are extraordinarily rare, they may identify cellular pathways contributing to the blood-borne dissemination of cancer. Here, we adapted a microfluidic device for efficient capture of CTCs from an endogenous mouse pancreatic cancer model and subjected CTCs to single-molecule RNA sequencing, identifying Wnt2 as a candidate gene enriched in CTCs. Expression of WNT2 in pancreatic cancer cells suppresses anoikis, enhances anchorage-independent sphere formation, and increases metastatic propensity in vivo. This effect is correlated with fibronectin upregulation and suppressed by inhibition of MAP3K7 (also known as TAK1) kinase. In humans, formation of non-adherent tumour spheres by pancreatic cancer cells is associated with upregulation of multiple WNT genes, and pancreatic CTCs revealed enrichment for WNT signalling in 5 out of 11 cases. Thus, molecular analysis of CTCs may identify candidate therapeutic targets to prevent the distal spread of cancer. 相似文献
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In this report we describe the main features of the initially determined alcohol dehydrogenase, that of horse liver, relate
this to the human enzyme structures and review recent structural studies on mutants and new complexes of the enzymes. We further
review the structure of a bacterial alcohol dehydrogenase to arrive at a coherent picture of medium-chain dehydrogenase/reductase
alcohol dehydrogenases in general. 相似文献