Search results for "Helicase"
showing 10 items of 67 documents
Expression inactivation of SMARCA4 by microRNAs in lung tumors
2014
SMARCA4 is the catalytic subunit of the SWI/SNF chromatin-remodeling complex, which alters the interactions between DNA and histones and modifies the availability of the DNA for transcription. The latest deep sequencing of tumor genomes has reinforced the important and ubiquitous tumor suppressor role of the SWI/SNF complex in cancer. However, although SWI/SNF complex plays a key role in gene expression, the regulation of this complex itself is poorly understood. Significantly, an understanding of the regulation of SMARCA4 expression has gained in importance due to recent proposals incorporating it in therapeutic strategies that use synthetic lethal interactions between SMARCA4-MAX and SMAR…
Neuroblastoma after Childhood: Prognostic Relevance of Segmental Chromosome Aberrations, ATRX Protein Status, and Immune Cell Infiltration
2014
AbstractNeuroblastoma (NB) is a common malignancy in children but rarely occurs during adolescence or adulthood. This subgroup is characterized by an indolent disease course, almost uniformly fatal, yet little is known about the biologic characteristics. The aim of this study was to identify differential features regarding DNA copy number alterations, α-thalassemia/mental retardation syndrome X-linked (ATRX) protein expression, and the presence of tumor-associated inflammatory cells. Thirty-one NB patients older than 10 years who were included in the Spanish NB Registry were considered for the current study; seven young and middle-aged adult patients (range 18-60 years) formed part of the c…
The Drosophila Cystoblast Differentiation Factor, benign gonial cell neoplasm, Is Related to DExH-box Proteins and Interacts Genetically With bag-of-…
2000
Abstract Selection of asymmetric cell fates can involve both intrinsic and extrinsic factors. Previously we have identified the bag-of-marbles (bam) gene as an intrinsic factor for cystoblast fate in Drosophila germline cells and shown that it requires active product from the benign gonial cell neoplasm (bgcn) gene. Here we present the cloning and characterization of bgcn. The predicted Bgcn protein is related to the DExH-box family of RNA-dependent helicases but lacks critical residues for ATPase and helicase functions. Expression of the bgcn gene is extremely limited in ovaries but, significantly, bgcn mRNA is expressed in a very limited number of germline cells, including the stem cells.…
Dicer and drosha expression and response to bevacizumab-based therapy in advanced colorectal cancer patients.
2013
PURPOSE: The miRNA-regulating enzymes Dicer and Drosha exhibit aberrant expression in several cancer types. Dicer and Drosha play a crucial role during the angiogenetic process in vitro and, for Dicer, in vivo. We aimed to investigate the potential role of Dicer and Drosha in predicting response to Bevacizumab-based therapy in advanced colorectal cancer (CRC) patients. METHODS: Dicer and Drosha mRNA levels were analysed in formalin-fixed paraffin-embedded specimens from patients affected by advanced CRC treated with or without Bevacizumab-containing regimens (n=116 and n=50, respectively) and from patients with diverticulosis as control group (n=20). The experimental data were obtained usin…
Deregulation of dicer and mir-155 expression in liposarcoma
2015
Liposarcoma (LPS) is the most common soft tissue sarcoma. It has been demonstrated that mir-155 was the most overexpressed miRNA in well-differentiated LPS(WDLPS)/dedifferentiated LPS (DDLPS). The aim of this study is to evaluate the involvement of Dicer, Drosha and mir-155 in development of LPS and their possible role in stratification of different histological subtypes. Dicer, Drosha and mir-155 mRNA levels were analyzed in formalin-fixed paraffin-embedded specimens from patients diagnosed with 62 LPS and compared with samples of adipose tissues of healthy donors. The experimental data were obtained using qRT-PCR comparing Dicer, Drosha and mir-155 expression levels in tumor samples versu…
XRCC5 as a Risk Gene for Alcohol Dependence : Evidence from a Genome-Wide Gene-Set-Based Analysis and Follow-up Studies in Drosophila and Humans
2015
Genetic factors play as large a role as environmental factors in the etiology of alcohol dependence. Although genome-wide association studies (GWAS) enable systematic searches for loci not hitherto implicated in the etiology of alcohol dependence, many true findings may be missed due to correction for multiple testing. The aim of the present study was to circumvent this limitation by searching for biological system-level differences, and then following up these findings in humans and animals. Gene-set based analysis of GWAS data from 1333 cases and 2168 controls identified 19 significantly associated gene-sets of which five could be replicated in an independent sample. Clustered in these ge…
Germline copy number variation in theYTHDC2gene: does it have a role in finding a novel potential molecular target involved in pancreatic adenocarcin…
2014
Abstract: Objective: The vast majority of pancreatic cancers occurs sporadically. The discovery of frequent variations in germline gene copy number can significantly influence the expression levels of genes that predispose to pancreatic adenocarcinoma. We prospectively investigated whether patients with sporadic pancreatic adenocarcinoma share specific gene copy number variations (CNVs) in their germline DNA. Patients and methods: DNA samples were analyzed from peripheral leukocytes from 72 patients with a diagnosis of sporadic pancreatic adenocarcinoma and from 60 controls using Affymetrix 500K array set. Multiplex ligation-dependent probe amplification (MLPA) assay was performed using a s…
Gain-of-function mutations in IFIH1 cause a spectrum of human disease phenotypes associated with upregulated type I interferon signaling.
2014
The type I interferon system is integral to human antiviral immunity. However, inappropriate stimulation or defective negative regulation of this system can lead to inflammatory disease. We sought to determine the molecular basis of genetically uncharacterized cases of the type I interferonopathy Aicardi-Goutières syndrome, and of other patients with undefined neurological and immunological phenotypes also demonstrating an upregulated type I interferon response. We found that heterozygous mutations in the cytosolic double-stranded RNA receptor gene IFIH1 (MDA5) cause a spectrum of neuro-immunological features consistently associated with an enhanced interferon state. Cellular and biochemica…
Effect of ATP Binding and Hydrolysis on Dynamics of Canine Parvovirus NS1▿ †
2010
ABSTRACT The replication protein NS1 is essential for genome replication and protein production in parvoviral infection. Many of its functions, including recognition and site-specific nicking of the viral genome, helicase activity, and transactivation of the viral capsid promoter, are dependent on ATP. An ATP-binding pocket resides in the middle of the modular NS1 protein in a superfamily 3 helicase domain. Here we have identified key ATP-binding amino acid residues in canine parvovirus (CPV) NS1 protein and mutated amino acids from the conserved A motif (K406), B motif (E444 and E445), and positively charged region (R508 and R510). All mutations prevented the formation of infectious viruse…
The NS3/4A proteinase of the hepatitis C virus: unravelling structure and function of an unusual enzyme and a prime target for antiviral therapy
1999
The hepatitis C virus (HCV) is a major causative agent of transfusion-acquired and sporadic non-A, non-B hepatitis worldwide. Infections most often persist and lead, in approximately 50% of all patients, to chronic liver disease. As is characteristic for a member of the family Flaviviridae, HCV has a plus-strand RNA genome encoding a polyprotein, which is cleaved co- and post-translationally into at least 10 different products. These cleavages are mediated, among others, by a virally encoded chymotrypsin-like serine proteinase located in the N-terminal domain of non-structural protein 3 (NS3). Activity of this enzyme requires NS4A, a 54-residue polyprotein cleavage product, to form a stable…