22 research outputs found

    Clustering financial time series

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    Time series clustering is heavily based on choosing a proper dissimilarity measure between a pair of time series. We present several dissimilarity measures and use two synthetic datasets to evaluate their performance. Hierarchical clustering and network analysis methods are used to perform cluster analysis on stock price time series of 594 US-based companies in order to verify whether stock prices of companies operating within an industry have common uctuations. The results of the thesis show that some companies within the same industry do form clusters, while others are relatively scattered

    The Oncogenic EWS-FLI1 Protein Binds In Vivo GGAA Microsatellite Sequences with Potential Transcriptional Activation Function

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    The fusion between EWS and ETS family members is a key oncogenic event in Ewing tumors and important EWS-FLI1 target genes have been identified. However, until now, the search for EWS-FLI1 targets has been limited to promoter regions and no genome-wide comprehensive analysis of in vivo EWS-FLI1 binding sites has been undertaken. Using a ChIP-Seq approach to investigate EWS-FLI1-bound DNA sequences in two Ewing cell lines, we show that this chimeric transcription factor preferentially binds two types of sequences including consensus ETS motifs and microsatellite sequences. Most bound sites are found outside promoter regions. Microsatellites containing more than 9 GGAA repeats are very significantly enriched in EWS-FLI1 immunoprecipitates. Moreover, in reporter gene experiments, the transcription activation is highly dependent upon the number of repeats that are included in the construct. Importantly, in vivo EWS-FLI1-bound microsatellites are significantly associated with EWS-FLI1-driven gene activation. Put together, these results point out the likely contribution of microsatellite elements to long-distance transcription regulation and to oncogenesis

    Advantages and opportunities of developing and investing in micro-units

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    Thesis: S.M. in Real Estate Development, Massachusetts Institute of Technology, Program in Real Estate Development in conjunction with the Center for Real Estate, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 47-52).I was raised in a formerly-communist country, where small apartments were mainly built to house working class families. People did not have many options and had to take whatever housing the state assigned to them. Most of those families remained in these assigned small units for the rest of their lives, many of which were growing families of 4 and more. With this unique personal perspective, I felt as if small units were the legacy of a past and archaic system. It appeared to me that in an economy where people have a choice, such type of housing would not be a very viable solution. However, to my surprise, the recent developments in major housing markets proved to me that I was wrong in my initial judgment. It sparked my interest to further research micro-unit housing market in gateway cities, the reasons and trends that influenced its growth in such cities as San Francisco and Los Angeles.by Marine Potikyan.S.M. in Real Estate Developmen

    Multiple aromatic side chains within a disordered structure are critical for transcription and transforming activity of EWS family oncoproteins

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    Chromosomal translocations involving the N-terminal approximate to 250 residues of the Ewings sarcoma (EWS) oncogene produce a group of EWS fusion proteins (EFPs) that cause several distinct human cancers. EFPs are potent transcriptional activators and interact with other proteins required for mRNA biogenesis, indicating that EFPs induce tumorigenesis by perturbing gene expression. Although EFPs were discovered more than a decade ago, molecular analysis has been greatly hindered by the repetitive EWS activation domain (EAD) structure, containing multiple degenerate hexapeptide repeats (consensus SYGQQS) with a conserved tyrosine residue. By exploiting total gene synthesis, we have been able to systematically mutagenize the EAD and determine the effect on transcriptional activation by EWS/ATF1 and cellular transformation by EWS/Fli1. In both assays, we find the following requirements for EAD function. First, multiple tyrosine residues are essential. Second, phenylalanine can effectively substitute for tyrosine, showing that an aromatic ring can confer EAD function in the absence of tyrosine phosphorylation. Third, there is little requirement for specific peptide sequences and, thus, overall sequence composition (and not the degenerate hexapeptide repeat) confers EAD activity. Consistent with the above findings, we also report that the EAD is intrinsically disordered. However, a sensitive computational predictor of natural protein disorder (PONDR VL3) identifies potential molecular recognition features that are tyrosine-dependent and that correlate well with EAD function. In summary we have uncovered several molecular features of the EAD that will impact future studies of the broader EFP family and molecular recognition by complex intrinsically disordered proteins

    Oncogenic Fusion Protein EWS/FLI1 Down-regulates Gene Expression by Both Transcriptional and Posttranscriptional Mechanisms*

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    Ewing family tumors are characterized by a translocation between the RNA binding protein EWS and one of five ETS transcription factors, most commonly FLI1. The fusion protein produced by the translocation has been thought to act as an aberrant transcription factor, leading to changes in gene expression and cellular transformation. In this study, we investigated the specific processes EWS/FLI1 utilizes to alter gene expression. Using both heterologous NIH 3T3 and human Ewing Family Tumor cell lines, we have demonstrated by quantitative pre-mRNA analysis that EWS/FLI1 repressed the expression of previously validated direct target genes at the level of transcript synthesis. ChIP experiments showed that EWS/FLI1 decreases the amount of Pol II at the promoter of down-regulated genes in both murine and human model systems. However, in down-regulated target genes, there was a significant disparity between the modulation of cognate mRNA and pre-mRNAs, suggesting that these genes could also be regulated at a posttranscriptional level. Confirming this, we found that EWS/FLI1 decreased the transcript half-life of insulin-like growth factor binding protein 3, a down-regulated direct target gene in human tumor-derived Ewing's sarcoma cell lines. Additionally, we have shown through reexpression experiments that full EWS/FLI1-mediated transcriptional repression requires intact EWS and ETS domains. Together these data demonstrate that EWS/FLI1 can dictate steady-state target gene expression by modulating both transcript synthesis and degradation

    Antiangiogenic activity of trabectedin in myxoid liposarcoma: Involvement of host TIMP-1 and TIMP-2 and tumor thrombospondin-1

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    Trabectedin is a marine natural product, approved in Europe for the treatment of soft tissue sarcoma and relapsed ovarian cancer. Clinical and experimental evidence indicates that trabectedin is particularly effective against myxoid liposarcomas where response is associated to regression of capillary networks. Here, we investigated the mechanism of the antiangiogenic activity of trabectedin in myxoid liposarcomas. Trabectedin directly targeted endothelial cells, impairing functions relying on extracellular matrix remodeling (invasion and branching morphogenesis) through the upregulation of the inhibitors of matrix metalloproteinases TIMP-1 and TIMP-2. Increased TIMPs synthesis by the tumor microenvironment following trabectedin treatment was confirmed in xenograft models of myxoid liposarcoma. In addition, trabectedin upregulated tumor cell expression of the endogenous inhibitor thrombospondin-1 (TSP-1, a key regulator of angiogenesis-dependent dormancy in sarcoma), in in vivo models of myxoid liposarcomas, in vitro cell lines and primary cell cultures from patients' myxoid liposarcomas. Chromatin Immunoprecipitation analysis showed that trabectedin displaced the master regulator of adipogenesis C/EBP\u3b2 from the TSP-1 promoter, indicating an association between the up-regulation of TSP-1 and induction of adipocytic differentiation program by trabectedin. We conclude that trabectedin inhibits angiogenesis through multiple mechanisms, including directly affecting endothelial cells in the tumor microenvironment--with a potentially widespread activity--and targeting tumor cells' angiogenic activity, linked to a tumor-specific molecular alteration
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