28 research outputs found

    CTCF genetic alterations in endometrial carcinoma are pro-tumorigenic

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    CTCF is a haploinsufficient tumour suppressor gene with diverse normal functions in genome structure and gene regulation. However the mechanism by which CTCF haploinsufficiency contributes to cancer development is not well understood. CTCF is frequently mutated in endometrial cancer. Here we show that most CTCF mutations effectively result in CTCF haploinsufficiency through nonsense-mediated decay of mutant transcripts, or loss-of-function missense mutation. Conversely, we identified a recurrent CTCF mutation K365T, which alters a DNA binding residue, and acts as a gain-of-function mutation enhancing cell survival. CTCF genetic deletion occurs predominantly in poor prognosis serous subtype tumours, and this genetic deletion is associated with poor overall survival. In addition, we have shown that CTCF haploinsufficiency also occurs in poor prognosis endometrial clear cell carcinomas and has some association with endometrial cancer relapse and metastasis. Using shRNA targeting CTCF to recapitulate CTCF haploinsufficiency, we have identified a novel role for CTCF in the regulation of cellular polarity of endometrial glandular epithelium. Overall, we have identified two novel pro-tumorigenic roles (promoting cell survival and altering cell polarity) for genetic alterations of CTCF in endometrial cancer

    Validation of a novel luminal flow velocimeter with video fluoroscopy and manometry in the human esophagus

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    There is currently no ideal method for concurrently assessing intraluminal pressures and flows in humans with high temporal resolution. We have developed and assessed the performance of a novel fiber-optic laser-Doppler velocimeter, mounted in a multichannel manometric assembly. Velocimeter recordings were compared with concurrent fluoroscopy and manometry following 50 barium swallows in healthy subjects. During these swallows, the velocimeter sensor was situated in either the proximal (24 swallows) or the distal (26 swallows) esophagus. It signaled intraluminal flow following 46 of 50 swallows. A greater mean number of deflections were recorded in the distal compared with the proximal esophagus (4. 3 vs. 2.4, P = 0.001). The maximal flow velocity recorded did not differ between the proximal and distal esophagus (76.7 vs. 73.8 mm/s). No velocimeter signals commenced after fluoroscopic lumen occlusion. The velocimeter signals were closely temporally related to fluoroscopic barium flow. Upward catheter movement on swallowing sometimes appeared to cause a velocimeter signal. Manometrically "normal" swallows were no different from "abnormal" swallows in the number and velocity of deflections recorded by the velocimeter. This novel instrument measures intraluminal flow velocity and pressures concurrently, thus enabling direct study of pressure-flow relationships. Flow patterns differed between the proximal and distal esophagus.J. M. Andrews, H. Nathan, C. H. Malbert, M. A. M. T. Verhagen, M. Gabb, G. S. Hebbard, D. Kilpatrick, S. MacDonald, C. K. Rayner, S. Doran, T. Omari, E. O'Young, C. Frisby, R. J. Fraser, M. Schoeman, M. Horowitz, and J. Den

    Synthesis and Catalytic Behavior of Ferrierite Zeolite Nanoneedles

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    International audienceThe proton form of nanosized, needlelike ferrierite zeolite, which was synthesized using choline and Na+ cations as structure-directing agents, was found to be much more efficient for the skeletal isomerization of 1-butene to isobutene than the corresponding cation form of conventional, submicrometric ferrierite with a platelike shape, mainly because of the considerably lower density of strong acid sites, but as well as a result of the higher density of 10-ring pore mouths
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