9,216 research outputs found

    The DHX33 RNA helicase promotes mRNA translation initiation

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    DEAD/DEAH box RNA helicases play essential roles in numerous RNA metabolic processes, such as mRNA translation, pre-mRNA splicing, ribosome biogenesis, and double-stranded RNA sensing. Herein we show that a recently characterized DEAD/DEAH box RNA helicase, DHX33, promotes mRNA translation initiation. We isolated intact DHX33 protein/RNA complexes in cells and identified several ribosomal proteins, translation factors, and mRNAs. Reduction of DHX33 protein levels markedly reduced polyribosome formation and caused the global inhibition of mRNA translation that was rescued with wild-type DHX33 but not helicase-defective DHX33. Moreover, we observed an accumulation of mRNA complexes with the 80S ribosome in the absence of functional DHX33, consistent with a stalling in initiation, and DHX33 more preferentially promoted structured mRNA translation. We conclude that DHX33 functions to promote elongation-competent 80S ribosome assembly at the late stage of mRNA translation initiation. Our results reveal a newly recognized function of DHX33 in mRNA translation initiation, further solidifying its central role in promoting cell growth and proliferation

    VPRSM Based Decision Tree Classifier

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    A new approach for inducing decision trees is proposed based on the Variable Precision Rough Set Model. From the rough set theory point of view, in the process of inducing decision trees with evaluations of candidate attributes, some methods based on purity measurements, such as information entropy based methods, emphasize the effect of class distribution. The more unbalanced the class distribution is, the more favorable it is. The rough set based approaches emphasize the effect of certainty. The more certain it is, the better. The criterion for node selection in the new method is based on the measurement of the variable precision explicit regions corresponding to candidate attributes. We compared the presented approach with C4.5 on some data sets from the UCI machine learning repository, which instantiates the feasibility of the proposed method

    DHX33 transcriptionally controls genes involved in the cell cycle

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    The RNA helicase DHX33 has been shown to be a critical regulator of cell proliferation and growth. However, the underlying mechanisms behind DHX33 function remain incompletely understood. We present original evidence in multiple cell lines that DHX33 transcriptionally controls the expression of genes involved in the cell cycle, notably cyclin, E2F1, cell division cycle (CDC), and minichromosome maintenance (MCM) genes. DHX33 physically associates with the promoters of these genes and controls the loading of active RNA polymerase II onto these promoters. DHX33 deficiency abrogates cell cycle progression and DNA replication and leads to cell apoptosis. In zebrafish, CRISPR-mediated knockout of DHX33 results in downregulation of cyclin A2, cyclin B2, cyclin D1, cyclin E2, cdc6, cdc20, E2F1, and MCM complexes in DHX33 knockout embryos. Additionally, we found the overexpression of DHX33 in a subset of non-small-cell lung cancers and in Ras-mutated human lung cancer cell lines. Forced reduction of DHX33 in these cancer cells abolished tumor formation in vivo. Our study demonstrates for the first time that DHX33 acts as a direct transcriptional regulator to promote cell cycle progression and plays an important role in driving cell proliferation during both embryo development and tumorigenesis

    RIPK2: a promising target for cancer treatment

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    As an essential mediator of inflammation and innate immunity, the receptor-interacting serine/threonine-protein kinase-2 (RIPK2) is responsible for transducing signaling downstream of the intracellular peptidoglycan sensors nucleotide oligomerization domain (NOD)-like receptors 1 and 2 (NOD1/2), which will further activate nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, leading to the transcription activation of pro-inflammatory cytokines and productive inflammatory response. Thus, the NOD2-RIPK2 signaling pathway has attracted extensive attention due to its significant role in numerous autoimmune diseases, making pharmacologic RIPK2 inhibition a promising strategy, but little is known about its role outside the immune system. Recently, RIPK2 has been related to tumorigenesis and malignant progression for which there is an urgent need for targeted therapies. Herein, we would like to evaluate the feasibility of RIPK2 being the anti-tumor drug target and summarize the research progress of RIPK2 inhibitors. More importantly, following the above contents, we will analyze the possibility of applying small molecule RIPK2 inhibitors to anti-tumor therapy
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