Publications by authors named "Grunberg S"

While all native tRNAs undergo extensive post-transcriptional modifications as a mechanism to regulate gene expression, mapping these modifications remains challenging. The critical barrier is the difficulty of readthrough of modifications by reverse transcriptases (RTs). Here we use Induro-a new group-II intron-encoded RT-to map and quantify genome-wide tRNA modifications in Induro-tRNAseq.

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The chemical modification of RNA bases represents a ubiquitous activity that spans all domains of life. Pseudouridylation is the most common RNA modification and is observed within tRNA, rRNA, ncRNA and mRNAs. Pseudouridine synthase or 'PUS' enzymes include those that rely on guide RNA molecules and others that function as 'stand-alone' enzymes.

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With the rapid growth of synthetic messenger RNA (mRNA)-based therapeutics and vaccines, the development of analytical tools for characterization of long, complex RNAs has become essential. Tandem liquid chromatography-mass spectrometry (LC-MS/MS) permits direct assessment of the mRNA primary sequence and modifications thereof without conversion to cDNA or amplification. It relies upon digestion of mRNA with site-specific endoribonucleases to generate pools of short oligonucleotides that are then amenable to MS-based sequence analysis.

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Connexins (Cx) are a large family of membrane proteins that can form intercellular connections, so-called gap junctions between adjacent cells. Cx43 is widely expressed in mammals and has a variety of different functions, such as the propagation of electrical conduction in the cardiac ventricle. Despite Cx43 knockout models, many questions regarding the biology of Cx43 in health and disease remain unanswered.

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Combinations of ribonucleases (RNases) are commonly used to digest RNA into oligoribonucleotide fragments prior to liquid chromatography-mass spectrometry (LC-MS) analysis. The distribution of the RNase target sequences or nucleobase sites within an RNA molecule is critical for achieving a high mapping coverage. Cusativin and MC1 are nucleotide-specific endoribonucleases encoded in the cucumber and bitter melon genomes, respectively.

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Since its initial characterization, Escherichia coli RNase I has been described as a single-strand specific RNA endonuclease that cleaves its substrate in a largely sequence independent manner. Here, we describe a strong calcium (Ca2+)-dependent activity of RNase I on double-stranded RNA (dsRNA), and a Ca2+-dependent novel hybridase activity, digesting the RNA strand in a DNA:RNA hybrid. Surprisingly, Ca2+ does not affect the activity of RNase I on single stranded RNA (ssRNA), suggesting a specific role for Ca2+ in the modulation of RNase I activity.

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The general transcription factor IID (TFIID) is a critical component of the eukaryotic transcription preinitiation complex (PIC) and is responsible for recognizing the core promoter DNA and initiating PIC assembly. We used cryo-electron microscopy, chemical cross-linking mass spectrometry, and biochemical reconstitution to determine the complete molecular architecture of TFIID and define the conformational landscape of TFIID in the process of TATA box-binding protein (TBP) loading onto promoter DNA. Our structural analysis revealed five structural states of TFIID in the presence of TFIIA and promoter DNA, showing that the initial binding of TFIID to the downstream promoter positions the upstream DNA and facilitates scanning of TBP for a TATA box and the subsequent engagement of the promoter.

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The transcriptional coactivators Mediator and two histone acetyltransferase (HAT) complexes, NuA4 and SAGA, play global roles in transcriptional activation. Here we explore the relative contributions of these factors to RNA polymerase II association at specific genes and gene classes by rapid nuclear depletion of key complex subunits. We show that the NuA4 HAT Esa1 differentially affects certain groups of genes, whereas the SAGA HAT Gcn5 has a weaker but more uniform effect.

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Prior studies suggested that SAGA and TFIID are alternative factors that promote RNA polymerase II transcription, with about 10% of genes in S. cerevisiae dependent on SAGA. We reassessed the role of SAGA by mapping its genome-wide location and role in global transcription in budding yeast.

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Genome-wide mapping of protein-DNA interactions is critical for understanding gene regulation, chromatin remodeling, and other chromatin-resident processes. Formaldehyde crosslinking followed by chromatin immunoprecipitation and high-throughput sequencing (X-ChIP-seq) has been used to gain many valuable insights into genome biology. However, X-ChIP-seq has notable limitations linked to crosslinking and sonication.

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Mediator is a conserved and essential coactivator complex broadly required for RNA polymerase II (RNAPII) transcription. Recent genome-wide studies of Mediator binding in budding yeast have revealed new insights into the functions of this critical complex and raised new questions about its role in the regulation of gene expression.

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Mediator is a conserved, essential transcriptional coactivator complex, but its in vivo functions have remained unclear due to conflicting data regarding its genome-wide binding pattern obtained by genome-wide ChIP Here, we used ChEC-seq, a method orthogonal to ChIP, to generate a high-resolution map of Mediator binding to the yeast genome. We find that Mediator associates with upstream activating sequences (UASs) rather than the core promoter or gene body under all conditions tested. Mediator occupancy is surprisingly correlated with transcription levels at only a small fraction of genes.

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Purpose: Progesterone receptors are expressed in approximately 70% of meningiomas. Mifepristone is an oral antiprogestational agent reported to have modest activity in a phase II study. This multicenter, prospective, randomized, placebo-controlled phase III trial conducted by SWOG was planned to define the role of mifepristone in the treatment of unresectable meningioma.

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Background: Oral manifestations are common in Crohn's disease (CD). Here we characterized the subgingival microbiota in pediatric patients with CD initiating therapy and after 8 weeks to identify microbial community features associated with CD and therapy.

Methods: Pediatric patients with CD were recruited from The Children's Hospital of Pennsylvania.

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Background: Inflammatory bowel disease (IBD) involves dysregulation of mucosal immunity in response to environmental factors such as the gut microbiota. The bacterial microbiota is often altered in IBD, but the connection to disease is not fully clarified and gut fungi have recently been suggested to play a role as well. In this study, we compared microbes from all 3 domains of life-bacteria, archaea, and eukaryota-in pediatric patients with IBD and healthy controls.

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Purpose: This study aims to compare the efficacy and safety of oral palonosetron with intravenous (IV) palonosetron for the prevention of cisplatin-related chemotherapy-induced nausea and vomiting (CINV).

Methods: A multinational, randomized, double-blind study enrolling adult chemotherapy-naive patients with malignant solid tumors scheduled to receive cisplatin-based highly emetogenic chemotherapy (HEC). Patients received oral palonosetron (0.

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Purpose: To better understand the indirect effects of standard courses of radiation therapy (RT) on distant tissue toxicity, we evaluated the frequency, course, and health and economic burden of regimen-related diarrhea in a large, multinational group of patients who were being treated for cancers of the head and neck (HNC) or lung (NSCLC).

Methods: In this exploratory, prospective study, 284 patients being treated for HNC and 60 being treated for NSCLC were stratified into four cohorts to evaluate the effect of radiation alone and radiation plus concomitant chemotherapy (CRT) on radiation-induced diarrhea (RID). RID was assessed daily throughout RT using a patient-reported five-point categorical scale.

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Background: Diarrhea is a common toxicity of chemotherapy, but the practice of reporting only severe grades (≥ 3) in clinical trials results in misleading conclusions of significance. Epidemiology remains poorly described, and effects of multi-cycle regimens have not been investigated. To better understand the risks, symptom burden and consequences of CID, we studied patients receiving chemotherapy for colorectal cancer (CRC).

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Background & Aims: The gut microbiota is a complex and densely populated community in a dynamic environment determined by host physiology. We investigated how intestinal oxygen levels affect the composition of the fecal and mucosally adherent microbiota.

Methods: We used the phosphorescence quenching method and a specially designed intraluminal oxygen probe to dynamically quantify gut luminal oxygen levels in mice.

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Background: Antiemetic guidelines recommend co-administration of agents that target multiple molecular pathways involved in emesis to maximize prevention and control of chemotherapy-induced nausea and vomiting (CINV). NEPA is a new oral fixed-dose combination of 300 mg netupitant, a highly selective NK1 receptor antagonist (RA) and 0.50 mg palonosetron (PALO), a pharmacologically and clinically distinct 5-HT3 RA, which targets dual antiemetic pathways.

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Background: Weight loss and cachexia are common, reduce tolerance of cancer treatment and the likelihood of response, and independently predict poor outcome.

Methods: A group of experts met under the auspices of the European School of Oncology to review the literature and-on the basis of the limited evidence at present-make recommendations for malnutrition and cachexia management and future research.

Conclusions: Our focus should move from end-stage wasting to supporting patients' nutritional and functional state throughout the increasingly complex and prolonged course of anti-cancer treatment.

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The development and severity of inflammatory bowel diseases and other chronic inflammatory conditions can be influenced by host genetic and environmental factors, including signals derived from commensal bacteria. However, the mechanisms that integrate these diverse cues remain undefined. Here we demonstrate that mice with an intestinal epithelial cell (IEC)-specific deletion of the epigenome-modifying enzyme histone deacetylase 3 (HDAC3(ΔIEC) mice) exhibited extensive dysregulation of IEC-intrinsic gene expression, including decreased basal expression of genes associated with antimicrobial defence.

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Transcriptional regulation is one of the most important steps in control of cell identity, growth, differentiation, and development. Many signaling pathways controlling these processes ultimately target the core transcription machinery that, for protein coding genes, consists of RNA polymerase II (Pol II) and the general transcription factors (GTFs). New studies on the structure and mechanism of the core assembly and how it interfaces with promoter DNA and coactivator complexes have given tremendous insight into early steps in the initiation process, genome-wide binding, and mechanisms conserved for all nuclear and archaeal Pols.

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Breast cancer patients may have unmet supportive care needs during treatment, including symptom management of treatment-related toxicities, and educational, psychosocial, and spiritual needs. Delivery of supportive care is often a low priority in low- and middle-income settings, and is also dependent on resources available. This consensus statement describes twelve key recommendations for supportive care during treatment in low- and middle-income countries, identified by an expert international panel as part of the 5th Breast Health Global Initiative (BHGI) Global Summit for Supportive Care, which was held in October 2012, in Vienna, Austria.

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