scholarly journals Hsa_circ_0004296 inhibits metastasis of prostate cancer by interacting with EIF4A3 to prevent nuclear export of ETS1 mRNA

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Shiyu Mao ◽  
Wentao Zhang ◽  
Fuhan Yang ◽  
Yadong Guo ◽  
Hong Wang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Nuclear Export ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Transcriptional Level ◽  
Loss Of Function ◽  
Mesenchymal Transition ◽  
Potential Biomarker ◽  
Gain And Loss

Abstract Background Circular RNAs (circRNAs) have been shown to play vital biological functions in various tumors, including prostate cancer (PCa). However, the roles of circRNAs in the metastasis of PCa remain unclear. In the present study, differentially expressed circRNAs associated with PCa metastasis were screened using high-throughput RNA sequencing, from which hsa_circ_0004296 was identified. Methods Quantitative real-time PCR (qRT-PCR) was used to detect the expression of circ_0004296 in PCa tissues and adjacent normal tissues as well as in blood and urine. Gain and loss of function experiments were performed to investigate the function of circ_0004296 in PCa. Bioinformatics analyses, RNA pull-down assay, and mass spectrometry were conducted to identify RNA-binding proteins. RNA immunoprecipitation and RNA and protein nuclear-cytoplasmic fractionation were performed to investigate the underlying mechanism. A xenograft mouse model was used to analyze the effect of circ_0004296 on PCa growth and metastasis in vivo. Results The expression of circ_0004296 was decreased in PCa tissues, blood, and urine, which was negatively associated with metastasis. Furthermore, gain and loss of function experiments in vitro and in vivo showed that circ_0004296 inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition of PCa cells. Mechanistically, circ_0004296 regulated host gene ETS1 expression at the post-transcriptional level. EIF4A3 was identified and confirmed as the downstream binding protein of circ_0004296. EIF4A3 expression was significantly upregulated in PCa tissues and associated with PCa metastasis. Silencing EIF4A3 suppressed PCa cell proliferation, migration, invasion, and EMT. Conclusions Circ_0004296 overexpression efficiently inhibited ETS1 mRNA nuclear export by promoting EIF4A3 retention in the nucleus, leading to the downregulation of ETS1 expression and suppression of PCa metastasis; thus, circ_0004296 might be a potential biomarker and therapeutic target for patients with PCa.

scholarly journals Musashi proteins are post-transcriptional regulators of the epithelial-luminal cell state

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Yarden Katz ◽  
Feifei Li ◽  
Nicole J Lambert ◽  
Ethan S Sokol ◽  
Wai-Leong Tam ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Biology ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
State Regulation ◽  
Ribosome Profiling ◽  
Luminal Cell ◽  
Mesenchymal Transition ◽  
Cell State

The conserved Musashi (Msi) family of RNA binding proteins are expressed in stem/progenitor and cancer cells, but generally absent from differentiated cells, consistent with a role in cell state regulation. We found that Msi genes are rarely mutated but frequently overexpressed in human cancers and are associated with an epithelial-luminal cell state. Using ribosome profiling and RNA-seq analysis, we found that Msi proteins regulate translation of genes implicated in epithelial cell biology and epithelial-to-mesenchymal transition (EMT), and promote an epithelial splicing pattern. Overexpression of Msi proteins inhibited the translation of Jagged1, a factor required for EMT, and repressed EMT in cell culture and in mammary gland in vivo. Knockdown of Msis in epithelial cancer cells promoted loss of epithelial identity. Our results show that mammalian Msi proteins contribute to an epithelial gene expression program in neural and mammary cell types.

scholarly journals Multiple roles of heterogeneous nuclear ribonucleoprotein K during skeletal muscle cell differentiation

2021 ◽  
Author(s):  
Keisuke Hitachi ◽  
Yuri Kiyofuji ◽  
Masashi Nakatani ◽  
Kunihiro Tsuchida
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Protein Complexes ◽  
Myogenic Differentiation ◽  
Cell Physiology ◽  
Transcriptional Level ◽  
Loss Of Function ◽  
Independent Manner ◽  
Multiple Functions

RNA-binding proteins (RBPs) regulate cell physiology via the formation of ribonucleic-protein complexes with coding and non-coding RNAs. RBPs have multiple functions in the same cells; however, the precise mechanism through which their pleiotropic functions are determined remains unknown. In this study, we revealed the multiple inhibitory functions of hnRNPK for myogenic differentiation. We first identified hnRNPK as a lncRNA Myoparr binding protein. Gain- and loss-of-function experiments showed that hnRNPK repressed the expression of myogenin at the transcriptional level via binding to Myoparr. Moreover, hnRNPK repressed the expression of a set of genes coding for aminoacyl-tRNA synthetases in a Myoparr-independent manner. Mechanistically, hnRNPK regulated the eIF2α/Atf4 pathway, one branch of the intrinsic pathways of the endoplasmic reticulum sensors, in differentiating myoblasts. Thus, our findings demonstrate that hnRNPK plays multiple lncRNA-dependent and -independent roles in the inhibition of myogenic differentiation, indicating that the analysis of lncRNA-binding proteins will be useful for elucidating both the physiological functions of lncRNAs and the multiple functions of RBPs.

scholarly journals LncRNA SNHG1 and RNA Binding Protein hnRNPL form a Complex and Coregulate CDH1 to Boost the Growth and Metastasis of Prostate Cancer

2020 ◽  
Author(s):  
Xiao Tan ◽  
Wen-Bin Chen ◽  
Dao-Jun Lv ◽  
Tao-Wei Yang ◽  
Kai-Hui Wu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Rna Binding ◽  
Epithelial Mesenchymal Transition ◽  
Binding Protein ◽  
Expression Profiles ◽  
Mrna Level ◽  
Rna Binding Protein ◽  
Loss Of Function ◽  
Mesenchymal Transition ◽  
E Cadherin

Abstract Background: The interaction between LncRNA and RNA-binding protein (RBPs) plays an essential role in the regulation over the malignant progression of tumors. Previous studies on the mechanism of SNHG1, an emerging lncRNA, have primarily focused on the competing endogenous RNA (ceRNA) mechanism. Nevertheless, the underlying mechanism between SNHG1 and RBPs in tumors remains to be explored, especially in prostate cancer (PCa).Methods：SNHG1 expression profiles in PCa were determined through the analysis of TCGA data and tissue microarray at the mRNA level. Gain- and loss-of-function experiments were performed to investigate the biological role of SNHG1 in PCa initiation and progression. RNA-seq, immunoblotting, RNA pull-down and RNA immunoprecipitation analyses were utilized to clarify potential pathways with which SNHG1 might be involved. Finally, rescue experiments were carried out to further confirm this mechanism.Results: We found that SNHG1 was dominantly expressed in the nuclei of PCa cells and significantly upregulated in PCa patients. The higher expression level of SNHG1 was dramatically correlated with tumor metastasis and patient survival. Functionally, overexpression of SNHG1 in PCa cells induced epithelial–mesenchymal transition (EMT), accompanied by down-regulation of the epithelial marker, E-cadherin, and up-regulation of the mesenchymal marker, vimentin. Increased proliferation and migration, as well as accelerated xenograft tumor growth, were observed in SNHG1-overexpressing PCa cells, while opposite effects were achieved in SNHG1-silenced cells. Mechanistically, SNHG1 competitively interacted with hnRNPL to impair the translation of protein E-cadherin, thus activating the effect of SNHG1 on the EMT pathway, eventually promoting the metastasis of PCa. Conclusion: Our findings demonstrate that SNHG1 is a positive regulator of EMT activation through the SNHG1-hnRNPL-CDH1 axis. SNHG1 may serve as a novel potential therapeutic target for PCa.

scholarly journals The Akt-mTOR pathway drives myelin sheath growth by regulating cap-dependent translation

2021 ◽  
Author(s):  
Karlie N Fedder-Semmes ◽  
Bruce Appel
Keyword(s):  
Myelin Sheath ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mtor Pathway ◽  
Mtor Signaling ◽  
Loss Of Function ◽  
Myelin Sheaths ◽  
Transduction Mechanisms ◽  
Myelin Deficits

In the vertebrate central nervous system, oligodendrocytes produce myelin, a specialized proteolipid rich membrane, to insulate and support axons. Individual oligodendrocytes wrap multiple axons with myelin sheaths of variable lengths and thicknesses. Myelin grows at the distal ends of oligodendrocyte processes and multiple lines of work have provided evidence that mRNAs and RNA binding proteins localize to myelin, together supporting a model where local translation controls myelin sheath growth. What signal transduction mechanisms could control this? One strong candidate is the Akt-mTOR pathway, a major cellular signaling hub that coordinates transcription, translation, metabolism, and cytoskeletal organization. Here, using zebrafish as a model system, we found that Akt-mTOR signaling promotes myelin sheath growth and stability during development. Through cell-specific manipulations to oligodendrocytes, we show that the Akt-mTOR pathway drives cap-dependent translation to promote myelination and that restoration of cap-dependent translation is sufficient to rescue myelin deficits in mTOR loss-of-function animals. Moreover, an mTOR-dependent translational regulator co-localized with mRNA encoding a canonically myelin-translated protein in vivo and bioinformatic investigation revealed numerous putative translational targets in the myelin transcriptome. Together, these data raise the possibility that Akt-mTOR signaling in nascent myelin sheaths promotes sheath growth via translation of myelin-resident mRNAs during development.

scholarly journals Scanning mutagenesis of RNA-binding protein ProQ reveals a quality control role for the Lon protease

RNA ◽  
2021 ◽  
pp. rna.078954.121
Author(s):  
Youssef El Mouali ◽  
Falk Ponath ◽  
Vincent Scharrer ◽  
Nicolas Wenner ◽  
Jay CD Hinton ◽  
...  
Keyword(s):  
Quality Control ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Enteric Bacteria ◽  
Loss Of Function ◽  
Rna Targets ◽  
Bacterial Chromosomes ◽  
Function Selection ◽  
Quality Control Mechanism

The FinO-domain protein ProQ belongs to a widespread family of RNA-binding proteins (RBPs) involved in gene regulation in bacterial chromosomes and mobile elements. Whilst the cellular RNA targets of ProQ have been established in diverse bacteria, the functionally crucial ProQ residues remain to be identified under physiological conditions. Following our discovery that ProQ deficiency alleviates growth suppression of Salmonella with succinate as the sole carbon source, an experimental evolution approach was devised to exploit this phenotype. By coupling mutational scanning with loss-of-function selection, we identified multiple ProQ residues in both the N-terminal FinO domain and the variable C-terminal region that are required for ProQ activity. Two C-terminal mutations abrogated ProQ function and mildly impaired binding of a model RNA target. By contrast, several mutations in the FinO domain rendered ProQ both functionally inactive and unable to interact with target RNA in vivo. Alteration of the FinO domain stimulated the rapid turnover of ProQ by Lon-mediated proteolysis, suggesting a quality control mechanism that prevents the accumulation of non-functional ProQ molecules. We extend this observation to Hfq, the other major sRNA chaperone of enteric bacteria. The Hfq Y55A mutant protein, defective in RNA-binding and oligomerization, proved to be labile and susceptible to degradation by Lon. Taken together, our findings connect the major AAA+ family protease Lon with RNA-dependent quality control of Hfq and ProQ, the two major sRNA chaperones of Gram-negative bacteria.

scholarly journals Comprehensive Characterization of Androgen-Responsive circRNAs in Prostate Cancer

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1096
Author(s):  
Zhe Kong ◽  
Yali Lu ◽  
Xuechao Wan ◽  
Jun Luo ◽  
Dujian Li ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Circular Rnas ◽  
Transcriptional Level ◽  
The Novel ◽  
Cancer Tissues ◽  
Posttranscriptional Level

The androgen receptor (AR) signaling pathway plays an important role in the initiation and progression of prostate cancer. Circular RNAs (circRNAs), the novel noncoding RNAs without 5′ to 3′ polarity or 3′ poly (A), play an important role in multiple diseases. However, the potential roles of androgen-responsive circRNAs in prostate cancer remain unclear. In this study, we identified 3237 androgen-responsive circRNAs and 1954 androgen-responsive mRNAs after dihydrotestosterone (DHT) stimulation using microarray. Among them, the expression of 1296 androgen-responsive circRNAs was consistent with that of their parent genes, and we thought AR might regulate the expression of these circRNAs at the transcriptional level. In addition, 1941 circRNAs expression was not consistent with their parent genes, and we speculated that AR may regulate the expression of those circRNAs at the posttranscriptional level through affecting alternative splicing. Analyzing the androgen-responsive circRNAs regulated at the posttranscriptional level, we identified two key RNA binding proteins (RBPs), WTAP and TNRC6, using the circInteractome database, which may play important role in the biogenesis of androgen-responsive circRNAs. Furthermore, we explored the potential biological functions and predicted the molecular mechanisms of two dysregulated circRNAs (circNFIA and circZNF561) in prostate cancer. In this study, we revealed that circNFIA was upregulated in prostate cancer tissues and plasma samples from patients with prostate cancer; circNFIA may play an oncogenic role in prostate cancer. In contrast, circZNF561 was downregulated and may act as a tumor suppressor in prostate cancer. Our results suggest that androgen-responsive circRNAs might regulate the progression of prostate cancer and could be novel diagnostic biomarkers.

scholarly journals Musashi proteins are post-transcriptional regulators of the epithelial-luminal cell state

2014 ◽  
Author(s):  
Yarden Katz ◽  
Feifei Li ◽  
Nicole Lambert ◽  
Ethan M Sokol ◽  
Wai-Leong Tam ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Biology ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Cell Types ◽  
State Regulation ◽  
Luminal Cell ◽  
Mesenchymal Transition ◽  
Cell State

The conserved Musashi (Msi) family of RNA binding proteins are expressed in stem/progenitor and cancer cells, but mostly absent from differentiated cells, consistent with a role in cell state regulation. We found that Msi genes are rarely mutated but frequently overexpressed in human cancers, and associated with an epithelial-luminal cell state. Using ribosome footprint profiling and RNA-seq analysis of genetic mouse models in neuronal and mammary cell types, we found that Msis regulate translation of genes implicated in epithelial cell biology and epithelial-to-mesenchymal transition (EMT) and promote an epithelial splicing pattern. Overexpression of Msi proteins inhibited translation of genes required for EMT, including Jagged1, and repressed EMT in cell culture and in mammary gland in vivo, while knockdown in epithelial cancer cells led to loss of epithelial identity. Our results show that mammalian Msi proteins contribute to an epithelial gene expression program and promote an epithelial-luminal state in both neural and breast cell types.

scholarly journals Multimerization of human cytomegalovirus regulatory protein UL69 via a domain that is conserved within its herpesvirus homologues

2007 ◽  
Vol 88 (2) ◽  
pp. 405-410 ◽  
Author(s):  
Peter Lischka ◽  
Marco Thomas ◽  
Zsolt Toth ◽  
Regina Mueller ◽  
Thomas Stamminger
Keyword(s):  
Human Cytomegalovirus ◽  
Nuclear Export ◽  
Rna Binding ◽  
Regulatory Protein ◽  
Transcriptional Level ◽  
Homologous Proteins ◽  
Interaction Domain ◽  
Self Association

The UL69 protein of human cytomegalovirus is a multifunctional regulatory protein that has counterparts in all herpesviruses. Some of these proteins have been shown to function primarily at the post-transcriptional level in promoting nuclear export of viral transcripts. Consistently, this group has reported recently that pUL69 is an RNA-binding, nucleocytoplasmic shuttling protein that facilitates the cytoplasmic accumulation of unspliced mRNA via its interaction with the cellular mRNA export factor UAP56. Evidence has been presented to suggest that some of the pUL69 homologues self-interact and function in vivo as multimers. Herein, the possibility of pUL69 self-association was examined and it has been demonstrated that pUL69 can interact with itself in vitro and in vivo in order to form high-molecular-mass complexes. The self-interaction domain within pUL69 was mapped to a central domain of this viral protein that is conserved within the homologous proteins of other herpesviruses, suggesting that multimerization is a conserved feature of this protein family.

scholarly journals The DDX39B/FUT3/TGFβR-I axis promotes tumor metastasis and EMT in colorectal cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chengcheng He ◽  
Aimin Li ◽  
Qiuhua Lai ◽  
Jian Ding ◽  
Qun Yan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Epithelial Mesenchymal Transition ◽  
Mrna Splicing ◽  
Loss Of Function ◽  
Mesenchymal Transition ◽  
Normal Tissues ◽  
Cytoplasmic Rna

AbstractDDX39B is a member of the DEAD box (DDX) RNA helicase family required for nearly all cellular RNA metabolic processes. The exact role and potential molecular mechanism of DDX39B in the progression of human colorectal cancer (CRC) remain to be investigated. In the present study, we demonstrate that DDX39B expression is higher in CRC tissues than in adjacent normal tissues. Gain- and loss-of-function assays revealed that DDX39B facilitates CRC metastasis in vivo and in vitro. Mechanistically, RNA-sequencing (RNA-seq) and RNA-binding protein immunoprecipitation-sequencing (RIP-seq) showed that DDX39B binds directly to the FUT3 pre-mRNA and upregulates FUT3 expression. Splicing experiments in vitro using a Minigene assay confirmed that DDX39B promotes FUT3 pre-mRNA splicing. A nuclear and cytoplasmic RNA separation assay indicates that DDX39B enhances the mRNA export of FUT3. Upregulation of FUT3 accelerates the fucosylation of TGFβR-I, which activates the TGFβ signaling pathway and eventually drives the epithelial–mesenchymal transition (EMT) program and contributes to CRC progression. These findings not only provide new insight into the role of DDX39B in mRNA splicing and export as well as in tumorigenesis, but also shed light on the effects of aberrant fucosylation on CRC progression.

scholarly journals The DDX39B/FUT3/TGFβR-I Axis Promotes Tumor Metastasis and EMT in Colorectal Cancer

2020 ◽  
Author(s):  
Chengcheng He ◽  
Aimin Li ◽  
Qiuhua Lai ◽  
Jian Ding ◽  
Qun Yan ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Nuclear Export ◽  
Rna Binding ◽  
Mrna Splicing ◽  
Migration And Invasion ◽  
Rna Seq ◽  
Exon 2 ◽  
Mesenchymal Transition ◽  
Qrt Pcr

Abstract Background: DDX39B is a member of the DEAD box (DDX) RNA helicase family required for nearly all cellular RNA metabolism processes. The exact role and potential molecular mechanism of DDX39B in the progression of human colorectal cancer (CRC) remain to be investigated. Methods: Western blotting and quantitative real-time PCR (qRT-PCR) were conducted to detect the expression of DDX39B in CRC tissues and cell lines. Transwell and wound healing assays were conducted to assess the migration and invasion ability of CRC cells with DDX39B overexpressed or silencing. Orthotopic transplantation model of nude mice was performed to validate CRC metastasis in vivo. RNA sequencing (RNA-seq) and RNA binding protein immunoprecipitation (RIP) assay verified the direct regulation of DDX39B on the splicing and nuclear export of FUT3 mRNA, cytoplasmic and nuclear RNA isolation confirmed the nuclear export effect of DDX39B on FUT3. qRT-PCR was conducted to quantify FUT3 splicing variants. Lectin blotting was conducted to evaluate the fucosylation level of TGFβR-I.Results: In the present study, we demonstrate that DDX39B expression was higher in CRC tissues than in adjacent normal tissues. Gain- and loss- of- function assays revealed that DDX39B facilitated the metastasis of CRC in vivo and in vitro. Mechanistically, RNA-seq and RIP showed that DDX39B upregulated FUT3 expression by binding the first exon of FUT3 mRNA, which promote the mRNA splicing and export of FUT3. RNA-seq results and qRT-PCR showed that overexpression of DDX39B may favor the longer FUT3 mRNA products that contain the complete and longer exon 2, suggesting an alternative splicing of FUT3. Upregulation of FUT3 accelerated the fucosylation of TGFβR-I, thus activating the TGFβ/SMAD signaling pathway, eventually driving the epithelial-mesenchymal transition (EMT) program and contributing to CRC progression. Conclusions: Our finding demonstrated for the first time that the DDX39B/FUT3/TGFβR-I axis promotes the progression of CRC. These findings not only provide new insight into the role of DDX39B in mRNA splicing and export and tumorigenesis, but also shed light on the effect of aberrant fucosylation on CRC progression.

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