Natural Antisense Transcripts: Molecular Mechanisms and Implications in Breast Cancers.

Natural antisense transcripts are RNA sequences that can be transcribed from both DNA strands at the same locus but in the opposite direction from the gene transcript. Because strand-specific high-throughput sequencing of the antisense transcriptome has only been available for less than a decade, many natural antisense transcripts were first described as long non-coding RNAs. Although the precise biological roles of natural antisense transcripts are not known yet, an increasing number of studies report their implication in gene expression regulation. Their expression levels are altered in many physiological and pathological conditions, including breast cancers. Among the potential clinical utilities of the natural antisense transcripts, the non-coding|coding transcript pairs are of high interest for treatment. Indeed, these pairs can be targeted by antisense oligonucleotides to specifically tune the expression of the coding-gene. Here, we describe the current knowledge about natural antisense transcripts, their varying molecular mechanisms as gene expression regulators, and their potential as prognostic or predictive biomarkers in breast cancers

Spinocerebellar ataxia type 2 (SCA2): clinical features and genetic analysis.

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disease that results from the expansion of an unstable trinucleotide CAG repeat encoding for a polyglutamine tract. In normal individuals, alleles contain between 14 and 31 CAG repeats, whereas the pathological alleles have more than 35 CAG repeats. The clinical phenotype of SCA2 includes a progressive cerebellar ataxia with additional features such as ophthalmoplegia, extra-pyramidal or pyramidal signs and peripheral neuropathy. We report a SCA2 large African family with several affected individuals. A major pathological allele carrying 43 CAG repeats was identified in the proband. To our knowledge, this is a first report of a SCA disorder described in Central African patients, thus indicating the need to consider this diagnosis in young African ataxic patients

Regulation of major histocompatibility complex class I expression by NF-kB-related proteins in breast cancer cells

Downregulation of MHC Class I antigens has been observed in many cancers and usually results from a decreased gene transcription. A reporter CAT gene dependent on the MHC Class I kB site or on a longer promoter is transactivated by NF-kB complexes contain- ing p65 or RelB. p100 as well as IkB-a are potent inhibitors of this transcription and p100 sequesters RelB and p65 complexes in the cytoplasm of breast cancer cells. However, although p100 is highly expressed in a number of breast cancer cell lines, MHC Class I antigen expression was observed on all the cell lines we analysed and could be further induced by stimulation with the cytokines IFN-g or TNF-a. Stable transfection of a unresponsive mutated IkB-a Ser 32-36 expression vector showed that TNF-a induced MHC Cl I expression in an NF-kB-dependent way while IFN-g did it independently of any NF-kB activation

Study of cancer risks associated with Lynch syndrome in the Liège region

Lynch syndrome is a hereditary predisposition to several cancers. The goals of our study were to know the different mutations in our Lynch population, to evaluate the prevalence of cancers in this population and to determine the mean age of onset of those cancers. This retrospective study includes proven carriers of a MMR mutation diagnosed either by the CHU of Liège or either by the CHC Saint-Joseph in Liège, Belgium. We noted a clear majority of MSH2 mutations (50 %) in the Lynch families recorded in Liège, which is different from the main literature. In our study population (106 subjects), 65 % of subjects were affected by at least one cancer. Prevalences for colorectal and endometrial cancers are, respectively, 50 % and 27.5 %. We found no difference in the mean age of onset of cancers compared to literature. We discuss the follow-up of Lynch patients and the interest of additional exams such as hysteroscopy and cystoscopy. © 2019 Revue Medicale de Liege. All rights reserved

Phosphorylation of NF-kappa B and I kappa B proteins: implications in cancer and inflammation

peer reviewedNuclear factor-kappaB (NF-kappaB) is a transcription factor that has crucial roles in inflammation, immunity, cell proliferation and apoptosis. Activation of NF-kappaB mainly occurs via IkappaB kinase (IKK)-mediated phosphorylation of inhibitory molecules, including IkappaBalpha. Optimal induction of NF-kappaB target genes also requires phosphorylation of NF-kappaB proteins, such as p65, within their transactivation domain by a variety of kinases in response to distinct stimuli. Whether, and how, phosphorylation modulates the function of other NF-kappaB and IkappaB proteins, such as B-cell lymphoma 3, remains unclear. The identification and characterization of all the kinases known to phosphorylate NF-kappaB and IkappaB proteins are described here. Because deregulation of NF-kappaB and IkappaB phosphorylations is a hallmark of chronic inflammatory diseases and cancer, newly designed drugs targeting these constitutively activated signalling pathways represent promising therapeutic tools.Insight into the oncogenic potential of BCL-

VPS51 biallelic variants cause microcephaly with brain malformations: A confirmatory report

International audienc

Cancer du sein : de la thérapie ciblée à la médecine personnalisée

peer reviewedDans cet article, les auteurs passent en revue les grands principes de prise en charge du traitement systémique du cancer du sein et posent la question suivante : jusqu'où réellement aujourd'hui ce traitement est-il individualisé ? Les nouvelles technologies permettent une analyse détaillée des anomalies génomiques au niveau des cellules cancéreuses. Malheureusement, nous n'avons pas encore compris comment utiliser au mieux ces données au bénéfice du patient. La majorité des modifications du génome sont des évènements relativement rares compliquant le développement de nouveaux médicaments dans le cadre d'une médecine de précision. De plus, les tumeurs présentent une grande hétérogénéité temporelle et spatiale dont il faudra tenir compte lors de ce développement. Une collaboration internationale intensive est en cours pour tenter de confirmer que la médecine de précision permet d'optimiser les résultats du traitement systémique dans le cancer du sein

Normalization and correction for batch effects via RUV for RNA-seq data: practical implications for Breast Cancer Research

The whole transcriptome contains information about nonsense, missense, silent, in-frame and frameshift mutations, as observed at whole-exome level, as well as splicing and (allelic) gene-expression changes which are missed by DNA analysis. One important step in the analysis of gene expression data arising from RNA-seq is the detection of differential expression (DE) levels. Several methods are available and the choice is sometimes controversial. For a reliable DE analysis that reduces False Positive DE genes, and accurate estimation of gene expression levels, a good and suitable normalization approach (including correction for confounders) is mandatory. Several normalization methods have been proposed to correct for both within-sample and between-sample biases. RUV (Removing Unwanted Variation) is one of them and has the advantage to correct for batch effects including potentially unknown unwanted variation in gene expression. In this study, we present a comparison on real-life Illumina paired-end sequencing data for Estrogen-Receptor-Positive (ER+) Breast Cancer tissues versus matched controls between RUV (RUVg using in silico negative control genes) and more commonly used methods for RNA-seq data normalization, such as DESeq2, edgeR, and UQ. The set of in silico empirical negative control genes for RUVg was defined as the set of least significant DE genes obtained after a first DE analysis performed prior to RUVg correction. Box plots of relative log expression (RLE) among the samples and PCA plots show that RUVg performs well and leads to a stabilization of read count across samples with a clear clustering of biological replicates

Modulating effect of COMT genotype on the brain regions underlying proactive control process during inhibition

peer reviewedIntroduction. Genetic variability related to the catechol-O-methyltransferase (COMT) gene (Val158Met polymorphism) has received increasing attention as a possible modulator of cognitive control functions. Methods. In an event-related fMRI study, a modified version of the Stroop task was administered to three groups of 15 young adults according to their COMT Val158Met genotype [Val/Val (VV), Val/Met (VM) and Met/Met (MM)]. Based on the theory of dual mechanisms of control (Braver, et al., 2007), the Stroop task has been built to induce proactive or reactive control processes according to the task context. Results. Behavioral results did not show any significant group differences for reaction times but Val allele carriers individuals are less accurate in the processing of incongruent items. fMRI results revealed that proactive control is specifically associated with increased activity in the anterior cingulate cortex (ACC) in carriers of the Met allele, while increased activity is observed in the middle frontal gyrus (MFG) in carriers of the Val allele. Conclusion. These observations, in keeping with a higher cortical dopamine level in MM individuals, support the hypothesis of a COMT Val158Met genotype modulation of the brain regions underlying proactive control, especially in frontal areas as suggested by Braver et al