85 research outputs found

    Gross hematuria caused by a congenital intrarenal arteriovenous malformation: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>We report the case of a woman who presented with gross hematuria and was treated with a percutaneous embolization.</p> <p>Case presentation</p> <p>A 48-year-old Caucasian woman presented with gross hematuria, left flank pain, and clot retention. The patient had no history of renal trauma, hypertension, urolithiasis, or recent medical intervention with percutaneous instrumentation. The patient did not report any bleeding disorder and was not taking any medication. Her systolic and diastolic blood pressure values were normal at presentation. The patient had anemia (8 mg/dL) and tachycardia (110 bpm). She underwent color and spectral Doppler sonography, multi-slice computed tomography, and angiography of the kidneys, which showed a renal arteriovenous malformation pole on top of the left kidney.</p> <p>Conclusions</p> <p>The feeding artery of the arteriovenous malformation was selectively embolized with a microcatheter introduced using a right transfemoral approach. By using this technique, we stopped the bleeding, preserved renal parenchymal function, and relieved the patient's symptoms. The hemodynamic effects associated with the abnormality were also corrected.</p

    Cellular senescence and chromatin organisation

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    Despite the potential importance of senescence in tumour suppression, its effector mechanism is poorly understood. Recent studies suggest that alterations in the chromatin environment might add an additional layer of stability to the phenotype. In this review, recent discoveries on the interplay between senescence and chromatin biology are overviewed

    Hsa-miRNA-765 as a key mediator for inhibiting growth, migration and invasion in fulvestrant-treated prostate cancer

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    Fulvestrant (ICI-182,780) has recently been shown to effectively suppress prostate cancer cell growth in vitro and in vivo. But it is unclear whether microRNAs play a role in regulating oncogene expression in fulvestrant-treated prostate cancer. Here, this study reports hsa-miR-765 as the first fulvestrant-driven, ERβ-regulated miRNA exhibiting significant tumor suppressor activities like fulvestrant, against prostate cancer cell growth via blockage of cell-cycle progression at the G2/M transition, and cell migration and invasion possibly via reduction of filopodia/intense stress-fiber formation. Fulvestrant was shown to upregulate hsa-miR-765 expression through recruitment of ERβ to the 5′-regulatory-region of hsa-miR-765. HMGA1, an oncogenic protein in prostate cancer, was identified as a downstream target of hsa-miR-765 and fulvestrant in cell-based experiments and a clinical study. Both the antiestrogen and the hsa-miR-765 mimic suppressed HMGA1 protein expression. In a neo-adjuvant study, levels of hsa-miR-765 were increased and HMGA1 expression was almost completely lost in prostate cancer specimens from patients treated with a single dose (250 mg) of fulvestrant 28 days before prostatectomy. These findings reveal a novel fulvestrant signaling cascade involving ERβ-mediated transcriptional upregulation of hsa-miR-765 that suppresses HMGA1 protein expression as part of the mechanism underlying the tumor suppressor action of fulvestrant in prostate cancer. © 2014 Leung et al

    HMGA1 drives stem cell, inflammatory pathway, and cell cycle progression genes during lymphoid tumorigenesis

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    <p>Abstract</p> <p>Background</p> <p>Although the <it>high mobility group A1 </it>(<it>HMGA1</it>) gene is widely overexpressed in diverse cancers and portends a poor prognosis in some tumors, the molecular mechanisms that mediate its role in transformation have remained elusive. <it>HMGA1 </it>functions as a potent oncogene in cultured cells and induces aggressive lymphoid tumors in transgenic mice. Because HMGA1 chromatin remodeling proteins regulate transcription, <it>HMGA1 </it>is thought to drive malignant transformation by modulating expression of specific genes. Genome-wide studies to define HMGA1 transcriptional networks during tumorigenesis, however, are lacking. To define the HMGA1 transcriptome, we analyzed gene expression profiles in lymphoid cells from <it>HMGA1a </it>transgenic mice at different stages in tumorigenesis.</p> <p>Results</p> <p>RNA from lymphoid samples at 2 months (before tumors develop) and 12 months (after tumors are well-established) was screened for differential expression of > 20,000 unique genes by microarray analysis (Affymetrix) using a parametric and nonparametric approach. Differential expression was confirmed by quantitative RT-PCR in a subset of genes. Differentially expressed genes were analyzed for cellular pathways and functions using Ingenuity Pathway Analysis. Early in tumorigenesis, HMGA1 induced inflammatory pathways with NFkappaB identified as a major node. In established tumors, HMGA1 induced pathways involved in cell cycle progression, cell-mediated immune response, and cancer. At both stages in tumorigenesis, HMGA1 induced pathways involved in cellular development, hematopoiesis, and hematologic development. Gene set enrichment analysis showed that stem cell and immature T cell genes are enriched in the established tumors. To determine if these results are relevant to human tumors, we knocked-down HMGA1 in human T-cell leukemia cells and identified a subset of genes dysregulated in both the transgenic and human lymphoid tumors.</p> <p>Conclusions</p> <p>We found that <it>HMGA1 </it>induces inflammatory pathways early in lymphoid tumorigenesis and pathways involved in stem cells, cell cycle progression, and cancer in established tumors. <it>HMGA1 </it>also dyregulates genes and pathways involved in stem cells, cellular development and hematopoiesis at both early and late stages of tumorigenesis. These results provide insight into <it>HMGA1 </it>function during tumor development and point to cellular pathways that could serve as therapeutic targets in lymphoid and other human cancers with aberrant <it>HMGA1 </it>expression.</p

    HMGA1 Reprograms Somatic Cells into Pluripotent Stem Cells by Inducing Stem Cell Transcriptional Networks

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    PMC3499526BACKGROUND: Although recent studies have identified genes expressed in human embryonic stem cells (hESCs) that induce pluripotency, the molecular underpinnings of normal stem cell function remain poorly understood. The high mobility group A1 (HMGA1) gene is highly expressed in hESCs and poorly differentiated, stem-like cancers; however, its role in these settings has been unclear. METHODS/PRINCIPAL FINDINGS: We show that HMGA1 is highly expressed in fully reprogrammed iPSCs and hESCs, with intermediate levels in ECCs and low levels in fibroblasts. When hESCs are induced to differentiate, HMGA1 decreases and parallels that of other pluripotency factors. Conversely, forced expression of HMGA1 blocks differentiation of hESCs. We also discovered that HMGA1 enhances cellular reprogramming of somatic cells to iPSCs together with the Yamanaka factors (OCT4, SOX2, KLF4, cMYC - OSKM). HMGA1 increases the number and size of iPSC colonies compared to OSKM controls. Surprisingly, there was normal differentiation in vitro and benign teratoma formation in vivo of the HMGA1-derived iPSCs. During the reprogramming process, HMGA1 induces the expression of pluripotency genes, including SOX2, LIN28, and cMYC, while knockdown of HMGA1 in hESCs results in the repression of these genes. Chromatin immunoprecipitation shows that HMGA1 binds to the promoters of these pluripotency genes in vivo. In addition, interfering with HMGA1 function using a short hairpin RNA or a dominant-negative construct blocks cellular reprogramming to a pluripotent state. CONCLUSIONS: Our findings demonstrate for the first time that HMGA1 enhances cellular reprogramming from a somatic cell to a fully pluripotent stem cell. These findings identify a novel role for HMGA1 as a key regulator of the stem cell state by inducing transcriptional networks that drive pluripotency. Although further studies are needed, these HMGA1 pathways could be exploited in regenerative medicine or as novel therapeutic targets for poorly differentiated, stem-like cancers.JH Libraries Open Access Fun

    Cyclization reaction catalyzed by branching enzyme.

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    The action of branching enzyme (EC 2.4.l.l8) from Bacillus stearothermophilus on amylose was analyzed. The enzyme reduced the molecular size of amylose without increasing the reducing power. This result could not be explained by the normal branching reaction model. When the product was treated with glucoamylase (an exo++-type amylase), a resistant component remained. The glucoamylase-resistant component was easily digested by an endo-type alpha-amylase or by isoamylase plus glucoamylase. These results suggested that the glucoamylase-resistant component was a cyclic glucan composed of alpha-1,4- and alpha-l,6-glucosidic linkages. In other words, it was suggested that branching enzyme catalyzed cyclization of the alpha-l,4-glucan chain of the amylose molecule to form an alpha-l,6-glucosidic linkage, thereby forming two smaller molecules. Mass spectrometry also supported the cyclic nature of the product
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