Long Noncoding RNA and Cancer: A New Paradigm Bhan, Arunoday; Soleimani, Milad; Mandal, Subhrangsu S
Cancer research (Chicago, Ill.),
08/2017, Letnik:
77, Številka:
15
Journal Article
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Odprti dostop
In addition to mutations or aberrant expression in the protein-coding genes, mutations and misregulation of noncoding RNAs, in particular long noncoding RNAs (lncRNA), appear to play major roles in ...cancer. Genome-wide association studies of tumor samples have identified a large number of lncRNAs associated with various types of cancer. Alterations in lncRNA expression and their mutations promote tumorigenesis and metastasis. LncRNAs may exhibit tumor-suppressive and -promoting (oncogenic) functions. Because of their genome-wide expression patterns in a variety of tissues and their tissue-specific expression characteristics, lncRNAs hold strong promise as novel biomarkers and therapeutic targets for cancer. In this article, we have reviewed the emerging functions and association of lncRNAs in different types of cancer and discussed their potential implications in cancer diagnosis and therapy.
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The removal of Cr(VI) from aqueous solution by batch adsorption technique using different low-cost adsorbents was investigated. Adsorbents such as clarified sludge—a steel industry waste material, ...rice husk ash, activated alumina, fuller's earth, fly ash, saw dust and neem bark were used to determine the adsorption efficiency. The influence of pH, adsorbent type and concentration, initial Cr(VI) concentration and contact time on the selectivity and sensitivity of the removal process were investigated. Adsorption process was found to be highly pH dependent. The optimum pH range for adsorption of Cr(VI) was found to be between 2 and 3. Kinetics studies were performed to understand the mechanistic steps of the adsorption process and the rate kinetics for the adsorption of Cr(VI) was best fitted with the pseudo-2nd-order kinetic model. Langmuir and Freundlich adsorption isotherms were applicable to the adsorption process and their constants were evaluated. The thermodynamic equilibrium constant and the Gibbs free energy were determined for each system. The adsorption capacity (
q
max) calculated from Langmuir isotherm and the Gibbs free energy (Δ
G
o) value obtained for the different adsorbents showed that clarified sludge was the most effective among the selected adsorbents for the removal of Cr(VI) from aqueous solution. The adsorption efficiencies of rice husk ash and activated alumina were also equally comparable with that of clarified sludge.
Performing efficient homing, i.e., returning to a previously known place, is crucial for the survival of any motile animal. Animals perform homing across different spatial scales and environments, ...employing various mechanisms with the aid of different sensorimotor systems molded by their varied evolutionary histories and ecological constraints. Despite these differences, most of the homing mechanisms across different taxa can be explained by some general basic mechanisms. Studies from social hymenopterans contribute substantially to the knowledge base of this study field and are, especially, interesting—they show excellent homing capabilities while possessing relatively simple neural architectures, and hence, their homing mechanisms are considered as economic solutions to a complex problem. Moreover, many of their homing mechanisms have also been observed in other taxa including vertebrates. With the advent of new technologies and increased research, our understanding of the hymenopteran homing is improving faster than ever—and therefore, a regular contemporary update might be of much help. In this review, I present a brief synthesis of previous and current understanding of homing mechanisms in social hymenopterans, with descriptions of the cues that they exploit for homing, and a comparative discussion on terminologies frequently used in social Hymenoptera with analogous terminologies used to describe similar phenomena in other taxa. I conclude with a note on the potential of applying the knowledge from homing studies in other fields of research like neurobiology and robotics, and possible future directions.
Noncoding RNAs (ncRNAs) are classes of transcripts that are encoded by the genome and transcribed but never get translated into proteins. Though not translated into proteins, ncRNAs play pivotal ...roles in a variety of cellular functions. Here, we review the functions of long noncoding RNAs (lncRNAs) and their implications in various human diseases. Increasing numbers of studies demonstrate that lncRNAs play critical roles in regulation of protein-coding genes, maintenance of genomic integrity, dosage compensation, genomic imprinting, mRNA processing, cell differentiation, and development. Misregulation of lncRNAs is associated with a variety of human diseases, including cancer, immune and neurological disorders. Different classes of lncRNAs, their functions, mechanisms of action, and associations with different human diseases are summarized in detail, highlighting their as yet untapped potential in therapy.
ABSTRACT The 2011 outburst of the black hole candidate IGR J17091-3624 followed the canonical track of state transitions along with the evolution of quasi-periodic oscillation (QPO) frequencies ...before it began exhibiting various variability classes similar to GRS 1915+105. We use this canonical evolution of spectral and temporal properties to determine the mass of IGR J17091-3624, using three different methods: photon index (Γ)-QPO frequency ( ) correlation, QPO frequency ( )-time (day) evolution, and broadband spectral modeling based on two-component advective flow (TCAF). We provide a combined mass estimate for the source using a naive Bayes based joint likelihood approach. This gives a probable mass range of . Considering each individual estimate and taking the lowermost and uppermost bounds among all three methods, we get a mass range of with 90% confidence. We discuss the possible implications of our findings in the context of two-component accretion flow.
The rising complexity of real-life optimization problems has constantly inspired computer researchers to develop new efficient optimization methods. Evolutionary computation and metaheuristics based ...on swarm intelligence are very popular nature-inspired optimization techniques. In this paper, the author has proposed a novel elephant swarm water search algorithm (ESWSA) inspired by the behaviour of social elephants, to solve different optimization problems. This algorithm is mainly based on the water search strategy of intelligent and social elephants during drought. Initially, we perform preliminary parametric sensitivity analysis for our proposed algorithm, developing guidelines for choosing the parameter values in real-life problems. In addition, the algorithm is evaluated against a number of widely used benchmark functions for global optimizations, and it is observed that the proposed algorithm has better performance for most of the cases compared with other state-of-the-art metaheuristics. Moreover, ESWSA performs better during fitness test, convergence test, computational complexity test, success rate test and scalability test for most of the benchmarks. Next, ESWSA is tested against two well-known constrained optimization problems, where ESWSA is found to be very efficient in term of execution speed and best fitness. As an application of ESWSA to real-life problem, it has been tested against a benchmark problem of computational biology, i.e., inference of Gene Regulatory Network based on Recurrent Neural Network. It has been observed that the proposed ESWSA is able to reach nearest to global minima and enabled inference of all true regulations of GRN correctly with less computational time compared with the other existing metaheuristics.
Recently realized higher order topological insulators have taken a surge of interest among the theoretical and experimental condensed matter community. The two-dimensional second order topological ...insulators give rise to zero-dimensional localized corner modes that reside within the band gap of the system along with edge modes that inhabit a band edge next to bulk modes. Thanks to the topological nature, information can be trapped at the corners of these systems, which will be unhampered even in the presence of disorder. Being localized at the corners, the exchange of information among the corner states is an issue. Here we show that the nonlinearity in an exciton polariton system can allow the coupling between the different corners through the edge states based on optical parametric scattering, realizing a system of multiple connectible topological modes.
ABSTRACT
Protostellar jets and outflows are pointers of star-formation and serve as important sources of momentum and energy transfer to the interstellar medium. Radio emission from ionized jets have ...been detected towards a number of protostellar objects. In few cases, negative spectral indices and polarized emission have also been observed suggesting the presence of synchrotron emission from relativistic electrons. In this work, we develop a numerical model that incorporates both thermal free–free and non-thermal synchrotron emission mechanisms in the jet geometry. The flux densities include contribution from an inner thermal jet, and a combination of emission from thermal and non-thermal distributions along the edges and extremities, where the jet interacts with the interstellar medium. We also include the effect of varying ionization fraction laterally across the jet. An investigation of radio emission and spectra along the jet shows the dependence of the emission process and optical depth along the line of sight. We explore the effect of various parameters on the turnover frequencies and the radio spectral indices (between 10 MHz and 300 GHz) associated with them.
Aims.
We study the spectral evolution of the H1743−322 during outbursts in the RXTE era. We aim to connect the variation of the spectral parameters with the accretion parameters along with the ...progress of the outbursts. We understand the evolution of the accretion parameters and hence the dynamics of the accretion process in light of the irradiated disc instability model.
Methods.
We provide a comprehensive study of all the outbursts of H1743−322 between 2003 and 2011. We performed spectral modelling of all the RXTE/PCA observations using phenomenological models. Also, we carried out spectral modelling by a hydrodynamic accretion flow model and estimated the accretion parameters. We applied the irradiated disc instability scenario in the presence of both Keplerian and sub-Keplerain accretion components to understand the evolution of accretion parameters. For this purpose, we propose a toy model for the time variation of the accretion rates following a powerlaw during outbursts.
Results.
All of the outbursts show spectral state transitions in the hardness-intensity diagram. The 2003 and 2004 outbursts are long-duration outbursts and relatively softer than the other outbursts. The 2008b and 2011 outbursts provide a unique opportunity to estimate the critical accretion rate (
ṁ
dc
) for triggering an outburst in this system within a narrow range of 0.076 <
ṁ
dc
< 0.086 (in Eddington units). In the absence of any dynamical measurement, we attempt to constrain a few orbital parameters of the system using an assumed mass and
ṁ
dc
in the range.
HOTAIR (HOX antisense intergenic RNA) is a long noncoding RNA (lncRNA) that is transcribed from the antisense strand of homeobox C gene locus in chromosome 12. HOTAIR coordinates with ...chromatin-modifying enzymes and regulates gene silencing. It is overexpressed in various carcinomas including breast cancer. Herein, we demonstrated that HOTAIR is crucial for cell growth and viability and its knockdown induced apoptosis in breast cancer cells. We also demonstrated that HOTAIR is transcriptionally induced by estradiol (E2). Its promoter contains multiple functional estrogen response elements (EREs). Estrogen receptors (ERs) along with various ER coregulators such as histone methylases MLL1 (mixed lineage leukemia 1) and MLL3 and CREB-binding protein/p300 bind to the promoter of HOTAIR in an E2-dependent manner. Level of histone H3 lysine-4 trimethylation, histone acetylation, and RNA polymerase II recruitment is enriched at the HOTAIR promoter in the presence of E2. Knockdown of ERs and MLLs downregulated the E2-induced HOTAIR expression. Thus, similar to protein-coding gene transcription, E2-induced transcription of antisense transcript HOTAIR is coordinated via ERs and ER coregulators, and this mechanism of HOTAIR overexpression potentially contributes towards breast cancer progression.
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► LncRNA HOTAIR is critical for cell growth and viability. ► Knockdown of HOTAIR induces apoptosis in breast cancer cells. ► HOTAIR is transcriptionally induced by E2. ► ERs coordinate with MLLs during E2-induced HOTAIR expression. ► Results provide novel mechanistic insight of antisense strand gene expression.
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