Reference

junio15Proc Natl Acad Sci U S A. 2015 May 5;112(18):5785-90. doi: 10.1073/pnas.1421197112. Epub 2015 Apr 22.

Authors

Raquel Boque-Sastre, Marta Soler, Cristina Oliveira-Mateos, Anna Portela, Catia Moutinho, Sergi Sayols, Alberto Villanueva, Manel Esteller, and Sonia Guil

Abstract

The mechanisms used by antisense transcripts to regulate their corresponding sense mRNAs are not fully understood. Herein, we have addressed this issue for the vimentin (VIM) gene, a member of the intermediate filament family involved in cell and tissue integrity that is deregulated in different types of cancer. VIM mRNA levels are positively correlated with the expression of a previously uncharacterized head-to-head antisense transcript, both transcripts being silenced in colon primary tumors concomitant with promoter hypermethylation. Furthermore, antisense transcription promotes formation of an R-loop structure that can be disfavored in vitro and in vivo by ribonuclease H1 overexpression, resulting in VIM down-regulation. Antisense knockdown and R-loop destabilization both result in chromatin compaction around the VIM promoter and a reduction in the binding of transcriptional activators of the NF-κB pathway. These results are the first examples to our knowledge of R-loop–mediated enhancement of gene expression involving head-to-head antisense transcription at a cancer-related locus.

Description

En los últimos años la visión del RNA no codificante de proteínas ha cambiado radicalmente, de llamarlo “genoma basura” a apreciar la variedad de funciones independientemente de la capacidad codificante de estos RNAs. Los transcritos naturales antisense (NATs, RNAs endógenos que se solapan total o parcialmente con transcritos originados en la cadena contraria) son el tipo más abundante de RNAs no codificantes largos (lncRNAs). Se estima que un 50-70% de los transcritos tienen su correspondiente antisense. Aún así, se sabe muy poco del mecanismo que utilizan los transcritos antisense para regular al RNA mensajero de la cadena contraria (el transcrito sense). En nuestro grupo hemos descrito el primer caso de activación transcripcional que involucraría la formación de un híbrido RNA:DNA (o R loop) con participación del transcrito antisense no codificante cerca del inicio de transcripción del gen vimentina (VIM), el cual es muy importante en la progresión tumoral de distintos tipos de cánceres. Esta estructura favorece la descondensación local de la cromatina y la unión de factores de transcripción. Esta investigación confiere a los R loops formados por un transcrito antisense un papel regulador positivo hasta ahora desconocido, lo que abre las puertas a estudiar este mecanismo en más genes relacionados con cáncer.

pnas boque sastrefotogrupo

REFERENCIA DEL GRUPO INVESTIGADOR

El grupo de Epigenética del Cáncer del Instituto de Investigación Biomédica de Bellvitge (IDIBELL) dirigido por el Dr. Manel Esteller tiene como objetivo la investigación de las alteraciones de la metilación del DNA, las modificaciones de histonas y el RNA no codificante de proteínas (ncRNAs), para encontrar la relación de estos fenómenos con el desarrollo del cáncer en humanos. En concreto la investigadora Sònia Guil se centra en el estudio de funciones reguladoras por parte de ncRNAs que actúen a nivel transcripcional o post-transcripcional y que puedan tener un impacto en la expresión génica de genes de especial interés en cáncer.

Descárgate este artículo aquí.

Did you publish an interesting article recently?

Send it through our application form and we will contact you. Age limit: 32.

The selected articles will participate at the Award to the best article of young people of the SEBBM which will be given during SEBBM conference, that will take place at Spain (free registration, travel and accommodation).

More articles of the month

Glucose restriction promotes osteocyte specification by activating a PGC-1α-dependent transcriptional program

03-06-2019

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bone matrix. This encasement limits their access to nutrients and likely affects their differentiation, a process...

Read more

ParB dynamics and the critical role of the CTD in DNA condensation unveiled by combined force-fluorescence measurements

01-05-2019

/Bacillus subtilis/ ParB forms multimeric networks involving non-specific DNA binding leading to DNA condensation. Previously, we found that an excess of the free C-terminal domain (CTD) of ParB impeded DNA...

Read more

Therapeutic targeting of HER2-CB2R heteromers in HER2-positive breast cancer

01-04-2019

Although human epidermal growth factor receptor 2 (HER2)-targeted therapies have dramatically improved the clinical outcome of HER2-positive breast cancer patients, innate and acquired resistance remains an important clinical challenge. New...

Read more

p73 regulates ependymal planar cell polarity by modulating actin and microtubule cytoskeleton

01-03-2019

Planar cell polarity (PCP) and intercellular junctional complexes establish tissue structure and coordinated behaviors across epithelial sheets. In multiciliated ependymal cells, rotational and translational PCP coordinate cilia beating and direct...

Read more

β‐RA reduces DMQ/CoQ ratio and rescues the encephalopathic phenotype in Coq9R239X mice

01-02-2019

Coenzyme Q (CoQ) deficiency has been associated with primary defects in the CoQ biosynthetic pathway or to secondary events. In some cases, the exogenous CoQ supplementation has limited efficacy. In...

Read more

Small molecule inhibits α-synuclein aggregation, disrupts amyloid fibrils, and prevents degeneration of dopaminergic neurons

02-01-2019

Parkinson's disease (PD) is characterized by a progressive loss of dopaminergic neurons, a process that current therapeutic approaches cannot prevent. In PD, the typical pathological hallmark is the accumulation of...

Read more

Dynamic acetylation of cytosolic phosphoenolpyruvate carboxykinase toggles enzyme activity between gluconeogenic and anaplerotic reactions

01-12-2018

Cytosolic phosphoenolpyruvate carboxykinase (PCK1) is considered a gluconeogenic enzyme; however, its metabolic functions and regulatory mechanisms beyond gluconeogenesis are poorly understood. Here, we describe that dynamic acetylation of PCK1 interconverts...

Read more

The Helicase PIF1 Facilitates Resection overSequences Prone to Forming G4 Structures

02-11-2018

DNA breaks are complex lesions that can be repaired either by non-homologous end joining (NHEJ) or by homologous recombination (HR). The decision between these two routes of DNA repair is...

Read more

Preventing loss of mechanosensation by the nuclear membranes of alveolar cells reduces lung injury in mice during mechanical ventilation

01-10-2018

The nuclear membrane acts as a mechanosensor that drives cellular responses following changes in the extracellular environment. Mechanically ventilated lungs are exposed to an abnormally high mechanical load that may...

Read more

Oxidative stress is tightly regulated by cytochrome c phosphorylation and respirasome factors in mitochondria

03-09-2018

Respiratory cytochrome c has been found to be phosphorylated at tyrosine 97 in the postischemic brain upon neuroprotective insulin treatment, but how such posttranslational modification affects mitochondrial metabolism is unclear...

Read more

Protector Members