242 research outputs found
The ZNF217 Biomarker Predicts Low- and High-Risk Oncotype DX® Recurrence Score in ER-Positive Invasive Breast Cancers
We assessed mRNA and protein expression levels of the ZN217 oncogene in 17 clinical FFPE ER-positive invasive breast cancer specimens with known (low or high) Oncotype DX® Recurrence Scores. This study shows that mRNA or nuclear protein levels of the ZNF217 significantly correlate with Oncotype DX® Recurrence Score
ZNF217 confers resistance to the pro-apoptotic signals of paclitaxel and aberrant expression of Aurora-A in breast cancer cells
<p>Abstract</p> <p>Background</p> <p>ZNF217 is a candidate oncogene located at 20q13, a chromosomal region frequently amplified in breast cancers. The precise mechanisms involved in ZNF217 pro-survival function are currently unknown, and utmost importance is given to deciphering the role of ZNF217 in cancer therapy response.</p> <p>Results</p> <p>We provide evidence that stable overexpression of ZNF217 in MDA-MB-231 breast cancer cells conferred resistance to paclitaxel, stimulated cell proliferation <it>in vitro </it>associated with aberrant expression of several cyclins, and increased tumor growth in mouse xenograft models. Conversely, siRNA-mediated silencing of ZNF217 expression in MCF7 breast cancer cells, which possess high endogenous levels of ZNF217, led to decreased cell proliferation and increased sensitivity to paclitaxel. The paclitaxel resistance developed by ZNF217-overexpressing MDA-MB-231 cells was not mediated by the ABCB1/PgP transporter. However, ZNF217 was able to counteract the apoptotic signals mediated by paclitaxel as a consequence of alterations in the intrinsic apoptotic pathway through constitutive deregulation of the balance of Bcl-2 family proteins. Interestingly, ZNF217 expression levels were correlated with the oncogenic kinase Aurora-A expression levels, as ZNF217 overexpression led to increased expression of the Aurora-A protein, whereas ZNF217 silencing was associated with low Aurora-A expression levels. We showed that a potent Aurora-A kinase inhibitor was able to reverse paclitaxel resistance in the ZNF217-overexpressing cells.</p> <p>Conclusion</p> <p>Altogether, these data suggest that ZNF217 might play an important role in breast neoplastic progression and chemoresistance, and that Aurora-A might be involved in ZNF217-mediated effects.</p
Young Stellar Objects and Triggered Star Formation in the Vulpecula OB Association
The Vulpecula OB association, VulOB1, is a region of active star formation
located in the Galactic plane at 2.3 kpc from the Sun. Previous studies suggest
that sequential star formation is propagating along this 100 pc long molecular
complex. In this paper, we use Spitzer MIPSGAL and GLIMPSE data to reconstruct
the star formation history of VulOB1, and search for signatures of past
triggering events. We make a census of Young Stellar Objects (YSO) in VulOB1
based on IR color and magnitude criteria, and we rely on the properties and
nature of these YSOs to trace recent episodes of massive star formation. We
find 856 YSO candidates, and show that the evolutionary stage of the YSO
population in VulOB1 is rather homogeneous - ruling out the scenario of
propagating star formation. We estimate the current star formation efficiency
to be ~8 %. We also report the discovery of a dozen pillar-like structures,
which are confirmed to be sites of small scale triggered star formation.Comment: 30 pages, 11 figures, accepted for publication in Ap
Evaluating ZNF217 mRNA Expression Levels as a Predictor of Response to Endocrine Therapy in ER+ Breast Cancer
ZNF217 is a candidate oncogene with a wide variety of deleterious functions in breast cancer. Here, we aimed at investigating in a pilot prospective study the association between ZNF217 mRNA expression levels and the clinical response to neoadjuvant endocrine therapy (ET) in postmenopausal ER-positive (ER C) breast cancer patients. Core surgical biopsy samples before treatment initiation and post-treatment were obtained from 68 patients, and Ki-67 values measured by immunohistochemistry (IHC) were used to identify responders (n = 59) and non-responders (n = 9) after 4 months of ET. We report for the first time that high ZNF217 mRNA expression level measured by RT-qPCR in the initial tumor samples (pre-treatment) is associated with poor response to neoadjuvant ET. Indeed, the clinical positive response rate in patients with low ZNF217 expression levels was significantly higher than that in those with high ZNF217 expression levels (P = 0.027). Additionally, a retrospective analysis evaluating ZNF217 expression levels in primary breast tumor of ER+/HER2-/LNO breast cancer patients treated with adjuvant ET enabled the identification of poorer responders prone to earlier relapse (P = 0.013), while ZNF217 did not retain any prognostic value in the ER+/HER2-/LNO breast cancer patients who did not receive any treatment. Altogether, these data suggest that ZNF217 expression might be predictive of clinical response to ET
Are JWST/NIRCam Color Gradients in the Lensed z = 2.3 Dusty Star-forming Galaxy El Anzuelo Due to Central Dust Attenuation or Inside-out Galaxy Growth?
Gradients in the mass-to-light ratio of distant galaxies impede our ability to characterize their size and compactness. The long-wavelength filters of JWST?s NIRCam offer a significant step forward. For galaxies at Cosmic Noon (z ? 2), this regime corresponds to the rest-frame near-infrared, which is less biased toward young stars and captures emission from the bulk of a galaxy?s stellar population. We present an initial analysis of an extraordinary lensed dusty star-forming galaxy at z = 2.3 behind the El Gordo cluster (z = 0.87), named El Anzuelo (?The Fishhook?) after its partial Einstein-ring morphology. The far-UV to near-IR spectral energy distribution suggests an intrinsic star formation rate of 81 yr 2 7 M 1 - ?+ - and dust attenuation AV ? 1.6, in line with other DSFGs on the star-forming main sequence. We develop a parametric lens model to reconstruct the source plane structure of dust imaged by the Atacama Large Millimeter/submillimeter Array, far-UV to optical light from Hubble, and near-IR imaging with 8 filters of JWST/NIRCam, as part of the Prime Extragalactic Areas for Reionization and Lensing Science program. The source-plane half-light radius is remarkably consistent from ?1 to 4.5 ?m, despite a clear color gradient where the inferred galaxy center is redder than the outskirts. We interpret this to be the result of both a radially decreasing gradient in attenuation and substantial spatial offsets between UV- and IR-emitting components. A spatial decomposition of the SED reveals modestly suppressed star formation in the inner kiloparsec, which suggests that we are witnessing the early stages of inside-out quenching
JWST Spectroscopy of SN H0pe: Classification and Time Delays of a Triply-imaged Type Ia Supernova at z = 1.78
SN H0pe is a triply imaged supernova (SN) at redshift discovered
using the James Webb Space Telescope (JWST). In order to classify the SN
spectroscopically and measure the relative time delays of its three images
(designated A, B, and C), we acquired NIRSpec follow-up spectroscopy spanning
0.6 to 5 microns. From the high signal-to-noise spectra of the two bright
images B and C, we first classify the SN, whose spectra most closely match
those of SN 1994D and SN 2013dy, as a Type Ia SN. We identify prominent
blueshifted absorption features corresponding to Si II and Ca II
H and K . We next measure the absolute phases of the
three images from our spectra, which allows us to constrain their relative time
delays. The absolute phases of the three images, determined by fitting the
three spectra to Hsiao07 SN templates, are d,
d, and d for the brightest to
faintest images. These correspond to relative time delays between Image A and
Image B and between Image B and Image C of d and
d, respectively. The SALT3-NIR model yields phases and
time delays consistent with these values. After unblinding, we additionally
explored the effect of using Hsiao07 template spectra for simulations through
eighty instead of sixty days past maximum, and found a small (11.5 and 1.0
days, respectively) yet statistically insignificant (0.25 and
0.1) effect on the inferred image delays.Comment: 27 pages (including appendices), 11 figures, 13 supplemental figure
A Strong-Lensing Model for the WMDF JWST/GTO Very Rich Cluster Abell 1489
We present a first strong-lensing model for the galaxy cluster RM
J121218.5+273255.1 (; hereafter RMJ1212; also known as Abell 1489).
This cluster is amongst the top 0.1\% richest clusters in the redMaPPer
catalog; it is significantly detected in X-ray and through the
Sunyaev-Zel'dovich effect in ROSAT and \emph{Planck} data, respectively; and
its optical luminosity distribution implies a very large lens, following
mass-to-light scaling relations. Based on these properties it was chosen for
the Webb Medium Deep Fields (WMDF) JWST/GTO program. In preparation for this
program, RMJ1212 was recently imaged with GMOS on Gemini North and in seven
optical and near-infrared bands with the \emph{Hubble Space Telescope}. We use
these data to map the inner mass distribution of the cluster, uncovering
various sets of multiple images. We also search for high-redshift candidates in
the data, as well as for transient sources. We find over a dozen high-redshift
() candidates based on both photometric redshift and the dropout
technique. No prominent () transients were found in the data
between the two HST visits. Our lensing analysis reveals a relatively large
lens with an effective Einstein radius of
(), in broad agreement with the scaling-relation expectations. RMJ1212
demonstrates that powerful lensing clusters can be selected in a robust and
automated way following the light-traces-mass assumption.Comment: 17 pages, 6 figures, 2 tables; To be submitte
Herschel-ATLAS: Far-infrared properties of radio-loud and radio-quiet quasars
This is pre-copyedited, author-produced pdf of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record, E. Kalfountzou, et al., ‘Herschel-ATLAS: Far-infrared properties of radio-loud and radio-quiet quasars’, MNRAS, Vol 42(2): 1181-1196, first published online June 11, 2014, is available online via doi: 10.1093/mnras/stu782 Published by Oxford University Press on behalf of the Royal Astronomical Society.We have constructed a sample of radio-loud and radio-quiet quasars from the Faint Images Radio Sky at Twenty-one centimetres and the Sloan Digital Sky Survey Data Release 7, over the Herschel-ATLAS Phase 1 area (9h, 12h and 14 h . 5 ). Using a stacking analysis, we find a significant correlation between the far-infrared (FIR) luminosity and 1.4-GHz luminosity for radio-loud quasars. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution, while for radio-quiet quasars, no partial correlation is found. Using a single-temperature grey-body model, we find a general trend of lower dust temperatures in case of radio-loud quasars compared to radio-quiet quasars. Also, radio-loud quasars are found to have almost constant mean values of dust mass along redshift and optical luminosity bins. In addition, we find that radio-loud quasars at lower optical luminosities tend to have on average higher FIR and 250-μm luminosity with respect to radio-quiet quasars with the same optical luminosites. Even if we use a two-temperature grey-body model to describe the FIR data, the FIR luminosity excess remains at lower optical luminosities. These results suggest that powerful radio jets are associated with star formation especially at lower accretion ratesPeer reviewe
The JWST PEARLS View of the El Gordo galaxy cluster and of the structure it magnifies
We dedicate this study to the memory of Jill Bechtold, scholar and mentor, who with her great patience and investment in undergraduate and graduate education set many of us onto a career path in astronomy. We thank Sergey Cherkis for useful conversations and the anonymous referee for suggestions that improved the manuscript. B.L.F. obtained student support through a Faculty Challenge Grant for Increasing Access to Undergraduate Research and the Arthur L. and Lee G. Herbst Endowment for Innovation and the Science Deanʼs Innovation and Education Fund, both obtained at the University of Arizona. R.A.W. was funded by NASA JWST Interdisciplinary Scientist grants NAG5-12460, NNX14AN10G, and 80GNSSC18K0200 from NASA Goddard Space Flight Center. The BGU lensing group, L.J.F., and A.Z., acknowledge support by grant 2020750 from the United States–Israel Binational Science Foundation (BSF), grant 2109066 from the United States National Science Foundation (NSF), and the Ministry of Science & Technology, Israel. K.I.C. acknowledges funding from the Netherlands Research School for Astronomy (NOVA) and also from the Dutch Research Council (NWO), through the award of the Vici Grant VI.C.212.036. We thank the JWST Project at NASA GSFC and JWST Program at NASA HQ for their many-decades-long dedication to making the JWST mission a success. We especially thank Tony Roman, the JWST scheduling group, and Mission Operations Center staff at STScI for their continued dedicated support to getting the JWST observations scheduled. This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. These observations are associated with JWST program 1176. This work is also based on observations made with the NASA/ESA Hubble Space Telescope (HST). The data were obtained from the Barbara A. Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute (STScI), which is operated by the Associationof Universities for Research in Astronomy (AURA) Inc., under NASA contract NAS 5-26555 for HST. This research has made use of data obtained from the Chandra Data Archive and software provided by the Chandra X-ray Center (CXC) in the application package CIAO
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