MBNL1 Regulates the Expression and Alternative Splicing of Genes Enriched in Cell Adhesion and Apoptosis

2021 ◽  
Author(s):  
Meijia Liu ◽  
Xianjing Song ◽  
Longbo Li ◽  
Chunli Song ◽  
Yongfeng Shi
Keyword(s):  
Cell Proliferation ◽  
Cell Adhesion ◽  
Alternative Splicing ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Signal Pathways ◽  
Apoptotic Process ◽  
Cancer Pathogenesis ◽  
Splicing Regulator ◽  
Underlying Mechanisms

Abstract Muscleblind Like Splicing Regulator 1 (MBNL1), one canonical RNA binding protein (RBP), plays important roles in the regulation of the alternative splicing (AS) on pre-mRNAs. MBNL1 has traditionally been considered involved in the pathogenesis of myotonic dystrophy. Recent researches point out that MBNL1 has an effect on cancer progress, but the underlying mechanisms are unclear. In this study, we obtained the regulated transcriptome profile of MBNL1 in HeLa cells by RNA-seq analysis. The results showed that the knockdown of MBNL1 promoted cell proliferation while inhibited apoptosis. We found 398 genes were differentially up-regulated and 277 down-regulated by MBNL1 knockdown (KD). The differentially expressed genes (DEGs) regulated by MBNL1-KD were enriched in the signal pathways of homophilic cell adhesion, apoptotic process, extracellular matrix organization and cell migration. Systematical AS analysis revealed 504 MBNL1-regulated AS events. The regulated alternative splicing genes (RASGs) were enriched in the signal pathways of apoptotic signaling pathway, positive regulation of apoptotic process, adherent junction, fatty acid elongation and DNA repair. In summary, our results demonstrate that the knockdown of MBNL1 have significant effects on cell proliferation and apoptosis by regulating the expression and alternative splicing of associated genes, illustrating the possible molecular mechanisms of MBNL1 in cancer pathogenesis and progression and other diseases.

scholarly journals A 5′-tRNA halve, tiRNA-Gly promotes cell proliferation and migration via binding to RBM17 and inducing alternative splicing in papillary thyroid cancer

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Litao Han ◽  
Hejing Lai ◽  
Yichen Yang ◽  
Jiaqian Hu ◽  
Zhe Li ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Thyroid Cancer ◽  
Alternative Splicing ◽  
Papillary Thyroid Cancer ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Papillary Thyroid ◽  
Cell Proliferation And Migration ◽  
And Migration ◽  
Proliferation And Migration

Abstract Background tRNA-derived small noncoding RNAs (sncRNAs) are mainly categorized into tRNA halves (tiRNAs) and fragments (tRFs). Biological functions of tiRNAs in human solid tumor are attracting more and more attention, but researches concerning the mechanisms in tiRNAs-mediated tumorigenesis are rarely. The direct regulatory relationship between tiRNAs and splicing-related proteins remain elusive. Methods Papillary thyroid carcinoma (PTC) associated tRNA fragments were screened by tRNA fragments deep sequencing and validated by qRT-PCR and Northern Blot in PTC tissues. The biological function of tRNA fragments were assessed by cell counting kit, transwells and subcutaneous transplantation tumor of nude mice. For mechanistic study, tRNA fragments pull-down, RNA immunoprecipitation, Western Blot, Immunofluorescence, Immunohistochemical staining were performed. Results Herein, we have identified a 33 nt tiRNA-Gly significantly increases in papillary thyroid cancer (PTC) based on tRFs & tiRNAs sequencing. The ectopic expression of tiRNA-Gly promotes cell proliferation and migration, whereas down-regulation of tiRNA-Gly exhibits reverse effects. Mechanistic investigations reveal tiRNA-Gly directly bind the UHM domain of a splicing-related RNA-binding protein RBM17. The interaction with tiRNA-Gly could translocate RBM17 from cytoplasm into nucleus. In addition, tiRNA-Gly increases RBM17 protein expression via inhibiting its degradation in a ubiquitin/proteasome-dependent way. Moreover, RBM17 level in tiRNA-Gly high-expressing human PTC tissues is upregulated. In vivo mouse model shows that suppression of tiRNA-Gly decreases RBM17 expression. Importantly, tiRNA-Gly can induce exon 16 splicing of MAP4K4 mRNA leading to phosphorylation of downstream signaling pathway, which is RBM17 dependent. Conclusions Our study firstly illustrates tiRNA-Gly can directly bind to RBM17 and display oncogenic effect via RBM17-mediated alternative splicing. This fully novel model broadens our understanding of molecular mechanism in which tRNA fragment in tumor cells directly bind RNA binding protein and play a role in alternative splicing.

Abstract 12192: MBNL1 Directly Regulates the Alternative Splicing of mRNAs That Promote Myofibroblast Differentiation

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jennifer Davis ◽  
Michelle Sargent ◽  
Jianjian Shi ◽  
Lei Wei ◽  
Maurice S Swanson ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Transforming Growth Factor ◽  
Ventricular Remodeling ◽  
Cardiac Injury ◽  
Myofibroblast Differentiation ◽  
Genome Wide ◽  
A Genome

Rationale: During the cardiac injury response fibroblasts differentiate into myofibroblasts, a cell type that enhances extracellular matrix production and facilitates ventricular remodeling. To better understand the molecular mechanisms whereby myofibroblasts are generated in the heart we performed a genome-wide screen with 18,000 cDNAs, which identified the RNA-binding protein muscleblind-like splicing regulator 1 (MBNL1), suggesting a novel association between mRNA alternative splicing and the regulation of myofibroblast differentiation. Objective: To determine the mechanism whereby MBNL1 regulates myofibroblast differentiation and the cardiac fibrotic response. Methods and Results: Confirming the results from our genome wide screen, adenoviral-mediated overexpression of MBNL1 promoted transformation of rat cardiac fibroblasts and mouse embryonic fibroblasts (MEFs) into myofibroblasts, similar to the level of conversion obtained by the profibrotic agonist transforming growth factor β (TGFβ). Antithetically, Mbnl1 -/- MEFs were refractory to TGFβ-induced myofibroblast differentiation. MBNL1 expression is induced in transforming fibroblasts in response to TGFβ and angiotensin II. These results were extended in vivo by analysis of dermal wound healing, a process dependent on myofibroblast differentiation and their proper activity. By day 6 control mice had achieved 82% skin wound closure compared with only 40% in Mbnl1 -/- mice. Moreover, Mbnl1 -/- mice had reduced survival following myocardial infarction injury due to defective fibrotic scar formation and healing. High throughput RNA sequencing (RNAseq) and RNA immunoprecipitation revealed that MBNL1 directly regulates the alternative splicing of transcripts for myofibroblast signaling factors and cytoskeletal-assembly elements. Functional analysis of these factors as mediators of MBNL1 activity is also described here. Conclusions: Collectively, our data suggest that MBNL1 coordinates myofibroblast transformation by directly mediating the alternative splicing of an array of mRNAs encoding differentiation-specific signaling transcripts, which then alter the fibroblast proteome for myofibroblast structure and function.

Cancer cachexia: molecular mechanism and pharmacological management

2021 ◽  
Vol 478 (9) ◽  
pp. 1663-1688
Author(s):  
Yonghua Li ◽  
Huan Jin ◽  
Yibing Chen ◽  
Ting Huang ◽  
Yanjun Mi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Cancer Cachexia ◽  
Molecular Mechanisms ◽  
Malignant Tumors ◽  
Life Quality ◽  
Signal Pathways ◽  
Pharmacological Management ◽  
Early Phase Trials ◽  
Molecular Substrates ◽  
Underlying Mechanisms

Cancer cachexia often occurs in malignant tumors and is a multifactorial and complex symptom characterized by wasting of skeletal muscle and adipose tissue, resulting in weight loss, poor life quality and shorter survival. The pathogenic mechanism of cancer cachexia is complex, involving a variety of molecular substrates and signal pathways. Advancements in understanding the molecular mechanisms of cancer cachexia have provided a platform for the development of new targeted therapies. Although recent outcomes of early-phase trials have showed that several drugs presented an ideal curative effect, monotherapy cannot be entirely satisfactory in the treatment of cachexia-associated symptoms due to its complex and multifactorial pathogenesis. Therefore, the lack of definitive therapeutic strategies for cancer cachexia emphasizes the need to develop a better understanding of the underlying mechanisms. Increasing evidences show that the progression of cachexia is associated with metabolic alternations, which mainly include excessive energy expenditure, increased proteolysis and mitochondrial dysfunction. In this review, we provided an overview of the key mechanisms of cancer cachexia, with a major focus on muscle atrophy, adipose tissue wasting, anorexia and fatigue and updated the latest progress of pharmacological management of cancer cachexia, thereby further advancing the interventions that can counteract cancer cachexia.

scholarly journals Neurogenesis: Regulation by Alternative Splicing and Related Posttranscriptional Processes

2016 ◽  
Vol 23 (5) ◽  
pp. 466-477 ◽  
Author(s):  
Enrique Lara-Pezzi ◽  
Manuel Desco ◽  
Alberto Gatto ◽  
María Victoria Gómez-Gaviro
Keyword(s):  
Alternative Splicing ◽  
Protein Function ◽  
Posttranscriptional Regulation ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Rna Degradation ◽  
Protein Isoforms ◽  
Mammalian Brain ◽  
Nonsense Mediated Decay

The complexity of the mammalian brain requires highly specialized protein function and diversity. As neurons differentiate and the neuronal circuitry is established, several mRNAs undergo alternative splicing and other posttranscriptional changes that expand the variety of protein isoforms produced. Recent advances are beginning to shed light on the molecular mechanisms that regulate isoform switching during neurogenesis and the role played by specific RNA binding proteins in this process. Neurogenesis and neuronal wiring were recently shown to also be regulated by RNA degradation through nonsense-mediated decay. An additional layer of regulatory complexity in these biological processes is the interplay between alternative splicing and long noncoding RNAs. Dysregulation of posttranscriptional regulation results in defective neuronal differentiation and/or synaptic connections that lead to neurodevelopmental and psychiatric disorders.

scholarly journals PSI controls tim splicing and circadian period in Drosophila

2018 ◽  
Author(s):  
Lauren Foley ◽  
Jinli Ling ◽  
Radhika Joshi ◽  
Naveh Evantal ◽  
Sebastian Kadener ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Circadian Rhythms ◽  
Translational Regulation ◽  
Transcriptional Control ◽  
Rna Binding ◽  
P Element ◽  
Peripheral Tissues ◽  
Associated Proteins ◽  
Splicing Regulator ◽  
Post Transcriptional Regulation

AbstractThe Drosophila circadian pacemaker consists of transcriptional feedback loops subjected to both post-transcriptional and post-translational regulation. While post-translational regulatory mechanisms have been studied in detail, much less is known about circadian post-transcriptional control. To have a better understanding of the role and mechanisms of circadian post-transcriptional regulation, we targeted 364 RNA binding and RNA associated proteins with RNA interference. Among the 43 genes we identified was the alternative splicing regulator P-element somatic inhibitor (PSI). PSI downregulation shortens the period of circadian rhythms both in the brain and in peripheral tissues. Interestingly, we found that PSI regulates the thermosensitive alternative splicing of timeless (tim), promoting splicing events favored at warm temperature over those increased at cold temperature. Moreover, the period of circadian behavior was insensitive to PSI downregulation when flies could produce functional TIM proteins only from a transgene that cannot form the thermosensitive splicing isoforms. Therefore, we conclude that PSI regulates the period of Drosophila circadian rhythms through its modulation of the tim splicing pattern.

scholarly journals Transformer 2β Regulates the Alternative Splicing of Cell Cycle Regulator Genes to Promote Ovarian Cancer Cell Progression

2021 ◽  
Author(s):  
Peiying Fu ◽  
Ting Zhou ◽  
Dong Chen ◽  
ShiXuan Wang ◽  
Ronghua Liu
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Alternative Splicing ◽  
Cancer Progression ◽  
Poor Prognosis ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Level

Abstract Background: Late-stage ovarian cancer (OV) has a poor prognosis and a high metastasis rate, but the underlying molecular mechanism is ambiguous. RNA binding proteins (RBPs) play important roles in posttranscriptional regulation in the contexts of neoplasia and tumor metastasis. Results: In this study, we explored the molecular functions of a canonical RBP, TRA2B, in cancer cells. TRA2B knockdown in HeLa cells and whole-transcriptome sequencing (RNA-seq) experiments revealed that the TRA2B-regulated alternative splicing (AS) profile was tightly associated with the mitotic cell cycle, apoptosis, and several cancer pathways. Moreover, hundreds of genes were regulated by TRA2B at the expression level, and their functions were enriched in cell proliferation, cell adhesion and angiogenesis, which are related to cancer progression. We also observed that AS regulation and expression regulation occurred independently by integrating the alternatively spliced and differentially expressed genes. We then explored and validated the carcinogenic functions of TRA2B by knocking down its expression in OV cells. In vivo, a high expression level of TRA2B was associated with a poor prognosis in OV patients. Conclusions: We demonstrated the important roles of TRA2B in ovarian neoplasia and OV progression and identified the underlying molecular mechanisms, facilitating the targeted treatment of OV in the future.

scholarly journals Posttranscriptional Regulation of Splicing Factor SRSF1 and Its Role in Cancer Cell Biology

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Vânia Gonçalves ◽  
Peter Jordan
Keyword(s):  
Alternative Splicing ◽  
Cancer Cell ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Current Knowledge ◽  
Expression Patterns ◽  
Regulatory Protein ◽  
Gene Transcript

Over the past decade, alternative splicing has been progressively recognized as a major mechanism regulating gene expression patterns in different tissues and disease states through the generation of multiple mRNAs from the same gene transcript. This process requires the joining of selected exons or usage of different pairs of splice sites and is regulated by gene-specific combinations of RNA-binding proteins. One archetypical splicing regulator is SRSF1, for which we review the molecular mechanisms and posttranscriptional modifications involved in its life cycle. These include alternative splicing of SRSF1 itself, regulatory protein phosphorylation events, and the role of nuclear versus cytoplasmic SRSF1 localization. In addition, we resume current knowledge on deregulated SRSF1 expression in tumors and describe SRSF1-regulated alternative transcripts with functional consequences for cancer cell biology at different stages of tumor development.

scholarly journals Hypoxia-induced TGF-β–RBFOX2–ESRP1 axis regulates human MENA alternative splicing and promotes EMT in breast cancer

NAR Cancer ◽  
2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Neha Ahuja ◽  
Cheemala Ashok ◽  
Subhashis Natua ◽  
Deepak Pant ◽  
Anna Cherian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Alternative Splicing ◽  
Transcriptional Repression ◽  
Rna Binding ◽  
Epithelial Mesenchymal Transition ◽  
Global Changes ◽  
Invasion And Metastasis ◽  
New Paradigm ◽  
Mesenchymal Transition ◽  
Splicing Regulator

Abstract Hypoxic microenvironment heralds epithelial–mesenchymal transition (EMT), invasion and metastasis in solid tumors. Deregulation of alternative splicing (AS) of several cancer-associated genes has been instrumental in hypoxia-induced EMT. Our study in breast cancer unveils a previously unreported mechanism underlying hypoxia-mediated AS of hMENA, a crucial cytoskeleton remodeler during EMT. We report that the hypoxia-driven depletion of splicing regulator ESRP1 leads to skipping of hMENA exon 11a producing a pro-metastatic isoform, hMENAΔ11a. The transcriptional repression of ESRP1 is mediated by SLUG, which gets stimulated via hypoxia-driven TGF-β signaling. Interestingly, RBFOX2, an otherwise RNA-binding protein, is also found to transcriptionally repress ESRP1 while interacting with SLUG. Similar to SLUG, RBFOX2 gets upregulated under hypoxia via TGF-β signaling. Notably, we found that the exosomal delivery of TGF-β contributes to the elevation of TGF-β signaling under hypoxia. Moreover, our results show that in addition to hMENA, hypoxia-induced TGF-β signaling contributes to global changes in AS of genes associated with EMT. Overall, our findings reveal a new paradigm of hypoxia-driven AS regulation of hMENA and insinuate important implications in therapeutics targeting EMT.

scholarly journals Alternative splicing regulation of cell cycle genes by SPF45/SR140/CHERP complex controls cell proliferation

RNA ◽  
2021 ◽  
pp. rna.078935.121
Author(s):  
Elena Martin ◽  
Claudia Vivori ◽  
Malgorzata Rogalska ◽  
Jorge Herrero ◽  
Juan Valcarcel
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Alternative Splicing ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Splicing Factors ◽  
Splicing Regulation ◽  
Cancer Cell Proliferation ◽  
Cycle Progression ◽  
Regulation Of Cell Cycle

The regulation of pre-mRNA processing has important consequences for cell division and the control of cancer cell proliferation but the underlying molecular mechanisms remain poorly understood. We report that three splicing factors, SPF45, SR140 and CHERP form a tight physical and functionally coherent complex that regulates a variety of alternative splicing events, frequently by repressing short exons flanked by suboptimal 3' splice sites. These comprise alternative exons embedded in genes with important functions in cell cycle progression, including the G2/M key regulator FOXM1 and the spindle regulator SPDL1. Knockdown of either of the three factors leads to G2/M arrest and to enhanced apoptosis in HeLa cells. Promoting the changes in FOXM1 or SPDL1 splicing induced by SPF45/SR140/CHERP knockdown partially recapitulate the effects on cell growth, arguing that the complex orchestrates a program of alternative splicing necessary for efficient cell proliferation.

scholarly journals USP15 and USP4 facilitate lung cancer cell proliferation by regulating the alternative splicing of SRSF1

2022 ◽  
Vol 8 (1) ◽  
Author(s):  
Tanuza Das ◽  
Eun-Young Lee ◽  
Hye Jin You ◽  
Eunice EunKyeong Kim ◽  
Eun Joo Song
Keyword(s):  
Lung Cancer ◽  
Cell Proliferation ◽  
Alternative Splicing ◽  
Cancer Cell ◽  
Molecular Mechanisms ◽  
Cell Phenotype ◽  
Cancer Cell Proliferation ◽  
Lung Cancer Cell ◽  
Endogenous Expression ◽  
Depletion Effect

AbstractThe deubiquitinating enzyme USP15 is implicated in several human cancers by regulating different cellular processes, including splicing regulation. However, the underlying molecular mechanisms of its functional relevance and the successive roles in enhanced tumorigenesis remain ambiguous. Here, we found that USP15 and its close paralog USP4 are overexpressed and facilitate lung cancer cell proliferation by regulating the alternative splicing of SRSF1. Depletion of USP15 and USP4 impair SRSF1 splicing characterized by the replacement of exon 4 with non-coding intron sequences retained at its C-terminus, resulting in an alternative isoform SRSF1-3. We observed an increased endogenous expression of SRSF1 in lung cancer cells as well, and its overexpression significantly enhanced cancer cell phenotype and rescued the depletion effect of USP15 and USP4. However, the alternatively spliced isoform SRSF1-3 was deficient in such aspects for its premature degradation through nonsense-mediated mRNA decay. The increased USP15 expression contributes to the lung adenocarcinoma (LUAD) development and shows significantly lower disease-specific survival of patients with USP15 alteration. In short, we identified USP15 and USP4 as key regulators of SRSF1 alternative splicing with altered functions, which may represent the novel prognostic biomarker as well as a potential target for LUAD.

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