Citations

X chromosome inactivation (XCI) is the most dramatic example of epigenetic silencing in eukaryotes. Once established, the inactivated X chromosome (Xi) remains silenced throughout subsequent cell divisions. Though the initiation of XCI has been studied extensively, the protein factors involved in Xi silencing and maintenance are largely unknown. Here we report the discovery of a diverse set of 32 proteins involved in maintenance of Xi silencing through a genome-wide RNAi screen. In addition, we describe the mechanistic roles of two proteins—origin recognition complex 2 (Orc2) and heterochromatin protein 1 (HP1α)—in Xi silencing. Immunofluorescence studies indicate that Orc2 and HP1α localize on Xi in mouse cells. Depletion of Orc2 by shRNA leads to the loss of both Orc2 and HP1α localization on Xi. Furthermore, the silencing of genes on Xi is disrupted in both Orc2- and HP1α-depleted cells. Finally, we show, using ChIP assay, that the localization of HP1α and Orc2 to the promoter regions of Xi-silenced genes is interdependent. These findings reveal a diverse set of proteins involved in Xi silencing, show how Orc2 and HP1α impact Xi silencing, and provide a basis for future studies on the maintenance of Xi silencing.

OBJECTIVE To examine elevated depressive symptoms and antidepressant use in relation to diabetes incidence in the Women’s Health Initiative. RESEARCH DESIGN AND METHODS A total of 161,808 postmenopausal women were followed for over an average of 7.6 years. Hazard ratios (HRs) estimating the effects of elevated depressive symptoms and antidepressant use on newly diagnosed incident diabetes were obtained using Cox proportional hazards models adjusted for known diabetes risk factors. RESULTS Multivariable-adjusted HRs indicated an increased risk of incident diabetes with elevated baseline depressive symptoms (HR 1.13 [95% CI 1.07–1.20]) and antidepressant use (1.18 [1.10–1.28]). These associations persisted through year 3 data, in which respective adjusted HRs were 1.23 (1.09–1.39) and 1.31 (1.14–1.50). CONCLUSIONS Postmenopausal women with elevated depressive symptoms who also use antidepressants have a greater risk of developing incident diabetes. In addition, longstanding elevated depressive symptoms and recent antidepressant medication use increase the risk of incident diabetes.

BackgroundThe cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)‐42, total‐tau (T‐tau), and phosphorylated‐tau (P‐tau) demonstrate good diagnostic accuracy for Alzheimer's disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer's Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch‐to‐batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.MethodsThe program is open for laboratories using commercially available kits for Aβ, T‐tau, or P‐tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.ResultsForty laboratories participated. Twenty‐six used INNOTEST enzyme‐linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO‐BIA AlzBio3 kit (both measure Aβ‐(1‐42), P‐tau(181P), and T‐tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN‐42, AβN‐40, and AβN‐38) or T‐tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within‐laboratory precisions differed considerably between biomarkers within individual laboratories.ConclusionsMeasurements of CSF AD biomarkers show large between‐laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

Abstract Noninfectious uveitis is a leading cause of blindness and thought to involve autoimmune T cell responses to retinal proteins (e.g., retinal arrestin [soluble-Ag (S-Ag)]). There are no known biomarkers for the disease. Susceptibility is associated with HLA, but little is known about susceptible class II alleles or the potentially pathogenic epitopes that they present. Using a humanized HLA-transgenic mouse model of S-Ag–induced autoimmune uveitis, we identified several susceptible and resistant alleles of HLA-DR and -DQ genes and defined pathogenic epitopes of S-Ag presented by the susceptible alleles. The sequences of these epitopes overlap with some previously identified peptides of S-Ag (“M” and “N”), known to elicit memory responses in lymphocytes of uveitis patients. HLA-DR–restricted, S-Ag–specific CD4+ T cells could be detected in blood and draining lymph nodes of uveitic mice with HLA class II tetramers and transferred the disease to healthy mice. Importantly, tetramer-positive cells were detected in peripheral blood of a uveitis patient. To our knowledge, these findings provide the first tangible evidence that an autoimmune response to retina is causally involved in pathogenesis of human uveitis, demonstrating the feasibility of identifying and isolating retinal Ag-specific T cells from uveitis patients and may facilitate their development as biomarkers for the disease.

Abstract During the course of multiple myeloma (MM), new monoclonal proteins of an isotype distinct from the original clone, referred to as secondary monoclonal gammopathy of undetermined significance (MGUS), have been described. We report on the frequency, characteristics, and outcome of secondary MGUS. Of the 1942 patients with MM, 128 (6.6%) developed a secondary MGUS, at a median of 12 months from the diagnosis of MM. The median duration of secondary MGUS was 5.9 months. Secondary MGUS was more common in patients after stem cell transplantation than in those who had not undergone such treatment (22.7% vs 1.6%, P < .001). Overall survival was significantly superior in MM patients who developed secondary MGUS compared with the rest of the cohort (73 vs 38 months, respectively; P < .001). The time of onset and the duration of secondary MGUS, as well as failure to resolve spontaneously, had an effect on overall survival and require further study.

Background Magnetic resonance imaging (MRI) has been frequently used to determine a preoperative treatment plan for gynecologic cancers. However, the MR accuracy for staging an endometrial cancer is not satisfactory based on the old FIGO staging system. Purpose To evaluate MR accuracy for staging endometrial cancer using the new FIGO staging system. Material and Methods Between January 2005 and May 2009, 199 women underwent surgery due to endometrial cancer. In each patient, an endometrial cancer was staged using MR findings based on the old FIGO staging system and then repeated according to the new FIGO staging system for comparison. Histopathologic findings were used as a standard of reference. Results The accuracy of MRI in the staging of endometrial carcinoma stage I, II, III, and IV using the old FIGO staging system were 80% (159/199), 89% (178/199), 90% (179/199), and 99% (198/199), respectively, compared to 87% (174/199), 97% (193/199), 90% (179/199), and 99% (198/199), respectively, when using the new FIGO staging criteria. The overall MR accuracy of the old and new staging systems were 51% (101/199) and 81% (161/199), respectively. Conclusion MRI has become a more useful tool in the preoperative staging of endometrial cancers using the new FIGO staging system compared to the old one with increased accuracy.

Background— Communicating prognosis to enable shared decision-making is strongly endorsed by heart failure (HF) guidelines. Patients are concerned with both their quantity and quality of life (QoL). To facilitate the recognition of patients at high risk for unfavorable future QoL or death, we created a simple prognostic tool to estimate this combined outcome. Methods and Results— We identified factors associated with 6-month mortality or persistently unfavorable QoL, defined by Kansas City Cardiomyopathy Questionnaire (KCCQ) scores <45 at 1 and 24 weeks after hospital discharge, among 1458 patients from the Efficacy of Vasopressin Antagonism in HF Outcome Study with Tolvaptan (EVEREST). Within 24 weeks of discharge, 478 (32.8%) patients had died and 192 (13.2%) patients had serial KCCQ scores <45. After adjusting for 23 predischarge covariates, independent predictors of the combined end point included low admission KCCQ score, high B-type natriuretic peptide, hyponatremia, tachycardia, hypotension, absence of β-blocker therapy, and history of diabetes mellitus and arrhythmia. A simplified predischarge HF score for subsequent death or unfavorable QoL had moderate discrimination ( c -statistic 0.72). Predischarge clinical covariates were substantially different in predicting the QoL end point as compared with traditional death or rehospitalization end points. Conclusions— At the time of hospital discharge, readily available clinical characteristics are associated with HF patients at high risk for persistently unfavorable QoL or death over the next 6 months. Such information can target patients for whom aggressive treatment options (eg, devices or transplantation) and/or end-of-life discussions should be strongly considered before hospital discharge. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00071331.

Abstract Background: NKTR-102, a topoisomerase 1 inhibitor-polymer conjugate with reduced peak concentrations and a continuous concentration profile, demonstrated evidence of anti-tumor activity in a broad range of tumors in phase 1 (Von Hoff; EORTC-NCI-AACR 2008, abstract #595), including three patients (pts) with triple negative breast cancer (one confirmed PR by RECIST, one 20% reduction in tumor burden and one 50%+ reduction in CA 27.29). We now report data of a randomized phase 2 study in pts with MBC following progression to taxane-based therapy. Methods: This open-label, phase 2 study enrolled pts to receive NKTR-102 intravenously (IV) at a target dose of 145 mg/m2. Eligible patients had progressive MBC following taxane therapy, ECOG PS 0-1, adequate renal, hepatic, and marrow function. The study randomized pts to receive NKTR-102 q14d or q21d; each schedule followed a two-stage Simon design to ensure adequate response rate prior to proceeding to full enrollment. The primary endpoint was objective response rate (ORR) by RECIST v1.0; secondary endpoints were safety and PFS. Results: 70 pts were randomized from Feb09 to Apr10 and treated (35 on each schedule); 20 patients remain active on study as of 14Jun2010. Median age was 55 (range 33-83); all but 1 pt was female. ECOG PS 0/1 equaled 40%/60%. Prior neo-adjuvant and adjuvant therapy had been administered in 15 and 39 patients respectively; 23 pts had received prior hormonal therapy. Median number of prior non-hormonal regimens for metastatic disease was 2 (range 0-4). All pts had received prior taxane therapy; 11 in the adjuvant setting and 60 in the metastatic setting). 45 pts had received only prior anthracycline/taxane therapy (“AT”); an additional 14 pts had received prior AT/capecitabine therapy (“ATC”). 42 were estrogen or progesterone receptor positive and 20 pts had triple negative disease. Best RECIST response rate (confirmed and unconfirmed) equaled 27% (9 pts; 2 awaiting confirmation) and 24% (8 pts; 4 awaiting confirmation) for the q14d and q21d schedules (n=33 and 34, respectively; 3 patients had not undergone first on-study CT exam). As ORR results were similar for each schedule, the combined best RECIST ORR for in AT/ATC pts equaled 23%/29%, respectively and in pts with triple negative disease, this equaled 25%. Common related Grade 3/4 toxicities (q14d/q21d schedules; n=67 pts with AE data available): diarrhea (15%/12%), neutropenia (15%/9%),fatigue (12%/3%), and dehydration (6%/3%). One pt in each schedule died due to septic shock and acute renal failure secondary to hypovolemia. Conclusion: Single-agent NKTR-102 demonstrates significant anti-tumor activity in pts with MBC, including pts having tumor progression after ATC-based therapy and pts with triple negative disease, with a tolerable toxicity profile. Mature ORR and median PFS will be available by December 2010. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-11-01.