Roles of noncoding RNAs in drug resistance in multiple myeloma

Despite the administration of new effective drugs in recent years, relapse and drug resistance are still the main obstacles in multiple myeloma (MM) treatment, making MM an incurable disease. To overcome drug resistance in MM, it is critical to understand the underlying mechanisms of malfunctioning gene expression and develop novel targeted therapies. During the past few decades, with the discovery and characterization of noncoding RNAs (ncRNAs), the landscape of dysregulated ncRNAs of cancers as well as their biological and pathobiological functions in tumorigenesis and drug resistance have been recognized. Studies about ncRNAs improved the understanding of variations of drug response among individuals at a level distinguished from genetic polymorphism, and provided with new orientations for targeted therapies. In this review, we will summarize the emerging impact and underlying molecular mechanisms of the most relevant classes of ncRNAs in drug resistance of MM, and discuss the potential as well as strategies of treating ncRNAs as therapeutic targets.     

A novel risk signature that combines 10 long noncoding RNAs to predict neuroblastoma prognosis

Neuroblastoma (NBL) is the most frequently encountered extracranial solid neoplasm and impacts significantly on the survival of patients, especially in cases of advanced tumor stage or relapse. A long noncoding RNA (lncRNA) signature to predict the survival of patients with NBL is proposed in this paper. Differentially expressed lncRNA (DElncRNA) was selected using the Limma plus Voom package in R based on the RNA-sequencing data downloaded from the Therapeutically Applicable Research To Generate Effective Treatments database and Genotype-Tissue Expression database. Univariate cox regression analysis, least absolute shrinkage and selection operator regression analysis, and multivariate cox regression analysis were conducted to identify candidate DElncRNAs for the risk signature. Consequently, 10 DElncRNAs were designated as candidate DElncRNAs for the risk signature. Time-dependent receiver operating characteristic curves and Kapan–Meier survival curves confirmed the efficacy of the risk signature in predicting the survival of patients with NBL (area under the curve = 0.941; p ≤ .001). One of the DElncRNA constituent subparts (LINC01010) was significantly associated with the survival outcome of patients with NBL in GSE62564 (p = .004). Thus, a risk signature comprising 10 DElncRNAs was identified as effective for individual risk stratification and the survival prediction outcomes of patients with NBL.     

A role of long noncoding RNAs in carcinogenesis

Molecular Biology - The review describes the changes observed in long noncoding RNA (lncRNA) content and function at various stages of carcinogenesis, as well as the prospects of lncRNA application...     

A common heritable factor influences prosocial obligations across multiple domains

Although it has been shown that prosocial behaviour is heritable, it has not yet been established whether narrower aspects of prosociality are heritable, nor whether a common mechanism influences prosociality across its multiple domains. Here, we examine civic duty, work-place commitment and concern for the welfare of others with a study of prosocial obligations in 958 adult twin-pairs. Multivariate modelling indicated the existence of genetic factors underlying general prosocial obligations in females, with familial effects (genetic and shared-environment effects were indistinguishable) influencing this general mechanism in males. At the domain-specific level, modest genetic effects were observed in females for civic and work obligations, with shared-environment effects influencing welfare obligations. In males, genetic influences were observed for welfare obligation, with unique environments affecting work and civic duty.     

Molecular mechanisms of long noncoding RNAs

Long noncoding RNAs (lncRNAs) are an important class of pervasive genes involved in a variety of biological functions. Here we discuss the emerging archetypes of molecular functions that lncRNAs execute-as signals, decoys, guides, and scaffolds. For each archetype, examples from several disparate biological contexts illustrate the commonality of the molecular mechanisms, and these mechanistic views provide useful explanations and predictions of biological outcomes. These archetypes of lncRNA function may be a useful framework to consider how lncRNAs acquire properties as biological signal transducers and hint at their possible origins in evolution. As new lncRNAs are being discovered at a rapid pace, the molecular mechanisms of lncRNAs are likely to be enriched and diversified.     

长非编码RNA

人类基因组序列的约5%～10%被稳定转录,蛋白质编码基因仅约占1%,其余4%～9%的序列虽能转录,但转录物功能尚不明确。尽管如此,已确证在非蛋白质编码转录物中,含有具备调节功能的非编码RNA(noncoding RNA,ncRNA)。与具有调节功能的短链非编码RNA[如微RNA(microRNA)、小干扰RNA(siRNA),、Piwi-RNA]相比,长非编码RNA(long noncoding RNA,lncRNA)在数量上占大多数。lncRNA通过多种方式产生,以多种途径调节靶基因表达,参与调控生物体生长、发育、衰老、死亡等过程;lncRNA功能异常往往导致疾病发生。本文综述了lncRNA的起源、分类、作用分子机制及lncRNA异常与疾病的相关性等内容,旨在充分了解这一重要新型调控分子。     

A nuclear import pathway exploited by pathogenic noncoding RNAs

The prevailing view of intracellular RNA trafficking in eukaryotic cells is that RNAs transcribed in the nucleus either stay in the nucleus or cross the nuclear envelope, entering the cytoplasm for function. However, emerging evidence illustrates that numerous functional RNAs move in the reverse direction, from the cytoplasm to the nucleus. The mechanism underlying RNA nuclear import has not been well elucidated. Viroids are single-stranded circular noncoding RNAs that infect plants. Using Nicotiana benthamiana, tomato (Solanum lycopersicum), and nuclear-replicating viroids as a model, we showed that cellular IMPORTIN ALPHA-4 (IMPa-4) is likely involved in viroid RNA nuclear import, empirically supporting the involvement of Importin-based cellular pathway in RNA nuclear import. We also confirmed the involvement of a cellular protein (viroid RNA-binding protein 1 [VIRP1]) that binds both IMPa-4 and viroids. Moreover, a conserved C-loop in nuclear-replicating viroids serves as a key signal for nuclear import. Disrupting C-loop impairs VIRP1 binding, viroid nuclear accumulation, and infectivity. Further, C-loop exists in a subviral satellite noncoding RNA that relies on VIRP1 for nuclear import. These results advance our understanding of subviral RNA infection and the regulation of RNA nuclear import.

RNA C-loop motif is a key signal recognized by the VIRP1 for the nuclear import of pathogenic noncoding RNAs (i.e. nuclear-replicating viroids and possibly a viral satellite RNA), via the IMPORTIN ALPHA-4-based cellular pathway.

IN A NUTSHELL Background: During the course of evolution, eukaryotic cells gained a nuclear envelope to protect their genomes. However, to coordinate diverse biological processes, cellular contents need to communicate between the nucleus and the cytoplasm. The nuclear/cytoplasmic shuttling of proteins has been well studied, but only the nuclear export of RNAs has been analyzed in detail. Nevertheless, increasing evidence has shown that multiple functional RNAs traffic from the cytoplasm to the nucleus, by a yet-to-be-elucidated mechanism. Questions: How can RNA be recognized for nuclear import? Which cellular proteins serve as vehicles for RNA nuclear import? Findings: We used a pathogenic noncoding RNA (potato spindle tuber viroid [PSTVd]) as a model to study RNA nuclear import and found a particular RNA structure (C-loop) that is critical for PSTVd nuclear accumulation. PSTVd C-loop is recognized and bound by the cellular viroid RNA-binding protein 1 (VIRP1). Since nuclear import of proteins often relies on Importin, we performed a screen and identified IMPORTIN ALPHA-4 (IMPa-4) in a complex with PSTVd. Reducing the amount of IMPa-4 in cells inhibited PSTVd nuclear accumulation and infectivity. Interestingly, VIRP1 also relies on IMPa-4 for nuclear accumulation. Therefore, we propose a model that IMPa-4 transports the VIRP1–PSTVd complex into the nucleus. Notably, nearly all nuclear-replicating viroids and a viral satellite RNA contain a C-loop, suggesting that the C-loop is a conserved signal for RNA nuclear import. Next steps: We are interested in identifying the C-loop structure in cellular RNAs. Once we find cellular RNAs with a C-loop, we will test whether those cellular RNAs are transported into the nucleus and explore the biological significance of their nuclear import.     

Integrating phenotype ontologies across multiple species

Phenotype ontologies are typically constructed to serve the needs of a particular community, such as annotation of genotype-phenotype associations in mouse or human. Here we demonstrate how these ontologies can be improved through assignment of logical definitions using a core ontology of phenotypic qualities and multiple additional ontologies from the Open Biological Ontologies library. We also show how these logical definitions can be used for data integration when combined with a unified multi-species anatomy ontology.     

Structural features that distinguish kinetically distinct biomineralization polypeptides

AP7 and AP24 are mollusk shell proteins which are responsible for aragonite polymorph formation and stabilization within the nacre layer of the Pacific red abalone, Haliotis rufescens. It is known that the 30-AA N-terminal mineral modification domains of both proteins (AP7N, AP24N) possess identical multifunctional mineralization capabilities within in vitro assays but differ in terms of rate kinetics, with AP24N > AP7N. In this report, we identify previously unreported molecular features of AP24N and contrast the lowest energy polypeptide backbone structures of AP24N (planar configuration) with that of AP7N ("bent paper clip" configuration) using NMR data and simulated annealing molecular dynamics structure refinement. Like AP7N, we find that AP24N possesses an unfolded conformation, can sequester Ca(II) and other multivalent metal ions, can adsorb onto or within calcite crystals, and possesses anionic and cationic electrostatic "pocket" regions on its molecular surfaces. However, AP24N has some unique features: greater conformational responsiveness to Ca(II), the tendency to form a more planar backbone configuration, and longer anionic and hydrogen-bonding donor/acceptor sequence blocks. We conclude that the presence of unfolded polypeptide conformation, electrostatic surface pockets, and interactive sequence clustering endow both AP7N and AP24N with similar features that lead to comparable effects on crystal morphology and nucleation. However, AP24N possesses longer anionic and hydrogen-bonding sequence clusters and exhibits a tendency to adopt a more planar backbone configuration than AP7N does. We believe that these features facilitate peptide-mineral, peptide-ion, or water cluster interactions, thereby enhancing the mineralization kinetics of AP24N over AP7N.     

Encoding memory of winter by noncoding RNAs

In some plant species, prolonged exposure to low temperature during the winter season is necessary to acquire the competence to flower in the following spring. This process, known as vernalization, is an epigenetic change in that a mitotically stable change of the developmental potential of the meristem (competence to flower) is maintained even in the absence of the inducing signal (prolonged cold exposure). In Arabidopsis, vernalization results in stable epigenetic repression of a potent floral repressor, FLOWERING LOCUS C (FLC). Increased enrichment of Polycomb Repressive Complex 2 (PRC2) and trimethylated Histone H3 Lys 27 (H3K27me3) at FLC chromatin is necessary for the stable maintenance of FLC repression by vernalization. Recent recognition of long noncoding RNAs (ncRNAs) in vernalization response indicates that long ncRNAs are evolutionarily conserved components for PRC2-mediated repression in eukaryotes.