54 research outputs found

    Novel Functional MAR Elements of Double Minute Chromosomes in Human Ovarian Cells Capable of Enhancing Gene Expression

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    Double minute chromosomes or double minutes (DMs) are cytogenetic hallmarks of extrachromosomal genomic amplification and play a critical role in tumorigenesis. Amplified copies of oncogenes in DMs have been associated with increased growth and survival of cancer cells but DNA sequences in DMs which are mostly non-coding remain to be characterized. Following sequencing and bioinformatics analyses, we have found 5 novel matrix attachment regions (MARs) in a 682 kb DM in the human ovarian cancer cell line, UACC-1598. By electrophoretic mobility shift assay (EMSA), we determined that all 5 MARs interact with the nuclear matrix in vitro. Furthermore, qPCR analysis revealed that these MARs associate with the nuclear matrix in vivo, indicating that they are functional. Transfection of MARs constructs into human embryonic kidney 293T cells showed significant enhancement of gene expression as measured by luciferase assay, suggesting that the identified MARS, particularly MARs 1 to 4, regulate their target genes in vivo and are potentially involved in DM-mediated oncogene activation

    Proteome analysis of human gastric cardia adenocarcinoma by laser capture microdissection

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    <p>Abstract</p> <p>Background</p> <p>The incidence of gastric cardiac adenocarcinoma (GCA) has been increasing in the past two decades in China, but the molecular changes relating to carcinogenesis have not been well characterised.</p> <p>Methods</p> <p>In this study, we used a comparative proteomic approach to analyse the malignant and nonmalignant gastric cardia epithelial cells isolated by navigated laser capture microdissection (LCM) from paired surgical specimens of human GCA.</p> <p>Results</p> <p>Twenty-seven spots corresponding to 23 proteins were consistently differentially regulated. Fifteen proteins were shown to be up-regulated, while eight proteins were shown to be down-regulated in malignant cells compared with nonmalignant columnar epithelial cells. The identified proteins appeared to be involved in metabolism, chaperone, antioxidation, signal transduction, apoptosis, cell proliferation, and differentiation. In addition, expressions of HSP27, 60, and Prx-2 in GCA specimens were further confirmed by immunohistochemical and western blot analyses.</p> <p>Conclusion</p> <p>These data indicate that the combination of navigated LCM with 2-DE provides an effective strategy for discovering proteins that are differentially expressed in GCA. Such proteins may contribute in elucidating the molecular mechanisms of GCA carcinogenesis. Furthermore, the combination provides potential clinical biomarkers that aid in early detection and provide potential therapeutic targets.</p

    Women with positive cervical smears but without surgical intervention. A follow-up study.

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    By a collaborative effort among British cytopathologists, 101 women were identified who had had unsuspected "positive" cervical smears but who, after at least 2 years, had still escaped biopsy through refusal, default, or failure to trace. Of these, 31 still could not be traced; 10 were traced but could not be further examined (8 because they refused); 7 had clinically diagnosed carcinoma of the cervix; and the remaining 53 had further smears and/or biopsies after a mean interval of 5.2 years. In 19 of the 53 the smear had become negative or biopsy showed no lesion. Regression was confined to women aged under 40 at the time of the initial positive smear. In 20 cases biopsy showed dysplasia or carcinoma-in-situ, in 3 microinvasive carcinoma, and in 3 occult invasive carcinoma. Of the 7 women who presented clinically with carcinoma of the cervix, this caused death in 5
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