scholarly journals Puf-A promotes cancer progression by interacting with nucleophosmin in nucleolus

Oncogene ◽  
2022 ◽  
Author(s):  
Huan-Chieh Cho ◽  
Yenlin Huang ◽  
Jung-Tung Hung ◽  
Tsai-Hsien Hung ◽  
Kai-Chun Cheng ◽  
...  

AbstractPreviously, we identified Puf-A as a novel member of Puf-family RNA-binding proteins; however, its biological functions remain obscure. Analysis of tumor samples of non-small cell lung cancer (NSCLC) showed that high Puf-A expression correlated with high histology grade and abnormal p53 status. Kaplan–Meier curve for overall survival revealed high expression of Puf-A to predict poor prognosis in stage I NSCLC. Among patients with colorectal cancer, high Puf-A expression also showed an adverse impact on overall survival. In lung cancer cell lines, downregulation of p53 increased Puf-A expression, and upregulation of p53 dampened its expression. However, luciferase reporter assays indicated that PUF-A locus harbored the p53-response element, but regulated Puf-A transcription indirectly. In vivo suppression of p53 in CCSP-rtTA/TetO-Cre/LSL-KrasG12D/p53flox/flox conditional mutant mice accelerated the progression of the KrasG12D-driven lung cancer, along with enhanced expression of Puf-A. Importantly, intranasal delivery of shPuf-A to the inducible KrasG12D/p53flox/flox mice suppressed tumor progression. Puf-A silencing led to marked decreases in the 80S ribosomes, along with decrease in S6 and L5 in the cytoplasm and accumulation in the nucleolus. Based on immunofluorescence staining and immunoprecipitation studies, Puf-A interacted with NPM1 in nucleolus. Puf-A silencing resulted in NPM1 translocation from nucleolus to nucleoplasm and this disruption of NPM1 localization was reversed by a rescue experiment. Mechanistically, Puf-A silencing altered NPM1 localization, leading to the retention of ribosomal proteins in nucleolus and diminished ribosome biogenesis, followed by cell-cycle arrest/cell death. Puf-A is a potential theranostic target for cancer therapy and an important player in cancer progression.

Author(s):  
Jiongwei Pan ◽  
Gang Huang ◽  
Zhangyong Yin ◽  
Xiaoping Cai ◽  
Enhui Gong ◽  
...  

AbstractSignificantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.


2020 ◽  
Vol 21 (3) ◽  
pp. 1151 ◽  
Author(s):  
Shannon E. Dougherty ◽  
Austin O. Maduka ◽  
Toshifumi Inada ◽  
Gustavo M. Silva

The eukaryotic proteome has to be precisely regulated at multiple levels of gene expression, from transcription, translation, and degradation of RNA and protein to adjust to several cellular conditions. Particularly at the translational level, regulation is controlled by a variety of RNA binding proteins, translation and associated factors, numerous enzymes, and by post-translational modifications (PTM). Ubiquitination, a prominent PTM discovered as the signal for protein degradation, has newly emerged as a modulator of protein synthesis by controlling several processes in translation. Advances in proteomics and cryo-electron microscopy have identified ubiquitin modifications of several ribosomal proteins and provided numerous insights on how this modification affects ribosome structure and function. The variety of pathways and functions of translation controlled by ubiquitin are determined by the various enzymes involved in ubiquitin conjugation and removal, by the ubiquitin chain type used, by the target sites of ubiquitination, and by the physiologic signals triggering its accumulation. Current research is now elucidating multiple ubiquitin-mediated mechanisms of translational control, including ribosome biogenesis, ribosome degradation, ribosome-associated protein quality control (RQC), and redox control of translation by ubiquitin (RTU). This review discusses the central role of ubiquitin in modulating the dynamism of the cellular proteome and explores the molecular aspects responsible for the expanding puzzle of ubiquitin signals and functions in translation.


2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S21-S21
Author(s):  
Andrey Buyan ◽  
Ivan Kulakovskiy ◽  
Sergey Dmitriev

Background: The ribosome is a protein-synthesizing molecular machine composed of four ribosomal RNAs (rRNAs) and dozens of ribosomal proteins. In mammals, the ribosome has a complicated structure with an additional outer layer of rRNA, including large tentacle-like extensions. A number of RNA binding proteins (RBPs) interact with this layer to assist ribosome biogenesis, nuclear export and decay, or to modulate translation. Plenty of methods have been developed in the last decade in order to study such protein-RNA interactions, including RNA pulldown and crosslinking-immunoprecipitation (CLIP) assays. Methods: In the current study, using publicly available data of the enhanced CLIP (eCLIP) experiments for 223 proteins studied in the ENCODE project, we found a number of RBPs that bind rRNAs in human cells. To locate their binding sites in rRNAs, we used a newly developed computational protocol for mapping and evaluation of the eCLIP data with the respect to the repetitive sequences. Results: For two proteins with known ribosomal localization, uS3/RPS3 and uS17/RPS11, the identified sites were in good agreement with structural data, thus validating our approach. Then, we identified rRNA contacts of overall 22 RBPs involved in rRNA processing and ribosome maturation (DDX21, DDX51, DDX52, NIP7, SBDS, UTP18, UTP3, WDR3, and WDR43), translational control during stress (SERBP1, G3BP1, SND1), IRES activity (PCBP1/hnRNPE1), and other translation-related functions. In many cases, the identified proteins interact with the rRNA expansion segments (ES) of the human ribosome pointing to their important role in protein synthesis. Conclusion: Our study identifies a number of RBPs as interacting partners of the human ribosome and sheds light on the role of rRNA expansion segments in translation.


2021 ◽  
Vol 23 (1) ◽  
pp. 215
Author(s):  
Florence Bonnet-Magnaval ◽  
Leïla Halidou Diallo ◽  
Valérie Brunchault ◽  
Nathalie Laugero ◽  
Florent Morfoisse ◽  
...  

Stau1 is a pluripotent RNA-binding protein that is responsible for the post-transcriptional regulation of a multitude of transcripts. Here, we observed that lung cancer patients with a high Stau1 expression have a longer recurrence free survival. Strikingly, Stau1 did not impair cell proliferation in vitro, but rather cell migration and cell adhesion. In vivo, Stau1 depletion favored tumor progression and metastases development. In addition, Stau1 depletion strongly impaired vessel maturation. Among a panel of candidate genes, we specifically identified the mRNA encoding the cell adhesion molecule Thrombospondin 1 (THBS1) as a new target for Staufen-mediated mRNA decay. Altogether, our results suggest that regulation of THBS1 expression by Stau1 may be a key process involved in lung cancer progression.


2021 ◽  
Author(s):  
Peiying Fu ◽  
Ting Zhou ◽  
Dong Chen ◽  
ShiXuan Wang ◽  
Ronghua Liu

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.


2021 ◽  
Author(s):  
Shuxin Li ◽  
Jianyi Lv ◽  
Xing Zhang ◽  
Zhihui Li ◽  
Xueyun Huo ◽  
...  

Abstract Background: Small cell lung cancer (SCLC) is one of the most malignant tumors with poor prognosis. RNA-binding protein (RBP) human antigen D (HuD) has been indicated in the process of tumorigenesis and progression of lung tumors, as well as long noncoding RNAs (lncRNA). However, the role of HuD and lncRNA in SCLC remains unknown. Methods: Realtime PCR were used to examine the circulating levels of LYPLAL1-DT in the 46 SCLC patients and 18 normal controls. Assays of dual- luciferase reporter system, RNA pull-down were performed to determine that LYPLAL1-DT could sponge miR-204-5p to upregulate the expression of PFN2. Migration and invasion assay, CCK8 and colony formation assay were used to detect the malignant effect of HuD and LYPLAL1-DT. Tumor xenograft model was established and IHC assay was performed to determine how HuD and LAPLAL1-DT impact in vivo. Results: We revealed that HuD was highly expressed in SCLC tissues and cell lines. HuD boosts the proliferation, migration, invasion of SCLC cells by increasing the PFN2 mRNA stability, which promotes cytoskeleton formation. HuD also enhanced the stability of lncRNA LYPLAL1-DT, which expressed highly in the serum of patients with SCLC and acted as an oncogenic lncRNA in SCLC cells as confirmed in vitro and in vivo. Mechanistically, LYPLAL1-DT functioned as a competing endogenous RNA (ceRNA) for sponging miR-204-5p, leading to the upregulation of its target PFN2 to promote SCLC cell proliferation and invasion. In summary, our data reveal a regulatory pathway in which HuD stabilizes PFN2 mRNA and LYPLAL1-DT, which in turn increases PFN2 expression by binding to miR-204-5p, and ultimately promotes tumorigenesis and invasion in SCLC.Conclusions: Our findings reveal novel regulatory axes involving HuD/PFN2 and lncRNA LYPLAL1-DT/miR-204-5p/PFN2 in the development and progression of small cell lung cancer (SCLC), providing novel prognostic indicators and promising therapeutic targets.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Valentina Tassinari ◽  
Valeriana Cesarini ◽  
Sara Tomaselli ◽  
Zaira Ianniello ◽  
Domenico Alessandro Silvestris ◽  
...  

Abstract Background N6-methyladenosine (m6A) and adenosine-to-inosine (A-to-I) RNA editing are two of the most abundant RNA modification events affecting adenosines in mammals. Both these RNA modifications determine mRNA fate and play a pivotal role in tumor development and progression. Results Here, we show that METTL3, upregulated in glioblastoma, methylates ADAR1 mRNA and increases its protein level leading to a pro-tumorigenic mechanism connecting METTL3, YTHDF1, and ADAR1. We show that ADAR1 plays a cancer-promoting role independently of its deaminase activity by binding CDK2 mRNA, underlining the importance of ADARs as essential RNA-binding proteins for cell homeostasis as well as cancer progression. Additionally, we show that ADAR1 knockdown is sufficient to strongly inhibit glioblastoma growth in vivo. Conclusions Hence, our findings underscore METTL3/ADAR1 axis as a novel crucial pathway in cancer progression that connects m6A and A-to-I editing post-transcriptional events.


2020 ◽  
Vol 15 (1) ◽  
pp. 683-695
Author(s):  
Feng Gu ◽  
Junhan Zhang ◽  
Lin Yan ◽  
Dong Li

AbstractLung cancer is a lethal malignancy. Plenty of circular RNAs (circRNAs) have been identified to be the vital regulators in lung cancer development. Here, we intended to clarify the functional role of circRNA HIPK3 (circHIPK3, also called hsa_circ_0021593) and its underlying mechanism of action. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was employed to evaluate the levels of circHIPK3 and miR-381-3p. Cell viability and apoptosis rate were monitored by Cell Counting Kit-8 assay and flow cytometry, respectively. Cell migration was estimated through the Transwell assay. To assess glycolysis, commercial kits were utilized to measure the levels of glucose and lactate and the enzyme activity of hexokinase-2 (HK2). Expression of related proteins was detected via western blot analysis. The target connection between circHIPK3 and miR-381-3p was validated by dual-luciferase reporter, RIP, and pull-down assays. The role of circHIPK3 in vivo was determined via the xenograft assay. CircHIPK3 was upregulated, while miR-381-3p was downregulated in lung cancer tissues and cells. And circHIPK3 deficiency inhibited lung cancer progression by lowering cell proliferation, migration, glycolysis, and promoting apoptosis of lung cancer cells in vitro. MiR-381-3p was a target of circHIPK3, and miR-381-3p interference alleviated circHIPK3 knockdown-induced lung cancer progression inhibition. CircHIPK3 could activate the protein kinase B/mammalian target of rapamycin (AKT/mTOR) signaling pathway. Moreover, circHIPK3 knockdown suppressed tumor growth in vivo by inactivating the AKT/mTOR signaling pathway. In conclusion, the silencing of circHIPK3 inhibited lung cancer progression, at least in part, by sponging miR-381-3p and inactivating the AKT/mTOR signaling pathway.


2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Yun-ping Hu ◽  
Yun-peng Jin ◽  
Xiang-song Wu ◽  
Yang Yang ◽  
Yong-sheng Li ◽  
...  

Abstract Backgrounds Long non-coding RNAs (lncRNAs) are essential factors that regulate tumor development and metastasis via diverse molecular mechanisms in a broad type of cancers. However, the pathological roles of lncRNAs in gallbladder carcinoma (GBC) remain largely unknown. Here we discovered a novel lncRNA termed lncRNA Highly expressed in GBC (lncRNA-HGBC) which was upregulated in GBC tissue and aimed to investigate its role and regulatory mechanism in the development and progression of GBC. Methods The expression level of lncRNA-HGBC in GBC tissue and different cell lines was determined by quantitative real-time PCR. The full length of lncRNA-HGBC was obtained by 5′ and 3′ rapid amplification of the cDNA ends (RACE). Cellular localization of lncRNA-HGBC was detected by fluorescence in situ hybridization (FISH) assays and subcellular fractionation assay. In vitro and in vivo assays were preformed to explore the biological effects of lncRNA-HGBC in GBC cells. RNA pull-down assay, mass spectrometry, and RNA immunoprecipitation (RIP) assay were used to identify lncRNA-HGBC-interacting proteins. Dual luciferase reporter assays, AGO2-RIP, and MS2-RIP assays were performed to verify the interaction between lncRNA-HGBC and miR-502-3p. Results We found that lncRNA-HGBC was upregulated in GBC and its upregulation could predict poor survival. Overexpression or knockdown of lncRNA-HGBC in GBC cell lines resulted in increased or decreased, respectively, cell proliferation and invasion in vitro and in xenografted tumors. LncRNA-HGBC specifically bound to RNA binding protein Hu Antigen R (HuR) that in turn stabilized lncRNA-HGBC. LncRNA-HGBC functioned as a competitive endogenous RNA to bind to miR-502-3p that inhibits target gene SET. Overexpression, knockdown or mutation of lncRNA-HGBC altered the inhibitory effects of miR-502-3p on SET expression and downstream activation of AKT. Clinically, lncRNA-HGBC expression was negatively correlated with miR-502-3p, but positively correlated with SET and HuR in GBC tissue. Conclusions Our study demonstrates that lncRNA-HGBC promotes GBC metastasis via activation of the miR-502-3p-SET-AKT cascade, pointing to lncRNA-HGBC as a new prognostic predictor and a therapeutic target.


2020 ◽  
Vol 52 (10) ◽  
pp. 1071-1080
Author(s):  
Danjie Zhang ◽  
Yuefeng Ma ◽  
Zhenchuan Ma ◽  
Shiyuan Liu ◽  
Liangzhang Sun ◽  
...  

Abstract Circular RNAs (circRNAs) have good stability and long half-life in blood and other body fluid, and possess regulatory effects on various biological processes as miRNA/RNA-binding protein sponges, or by competing endogenous RNA, indicating their great potential as biomarkers or targets of cancer therapy. In this study, we mainly explored the role and mechanism of circular RNA SMARCA5 (circsSMARCA5) in non-small cell lung cancer (NSCLC). Quantitative RT-PCR was applied to measure the expression levels of genes, and then, the relationships among circsSMARCA5, microRNA-670-5p (miR-670-5p), and RBM24 were further analyzed. Animal and cell experiments were performed to explore the functions of circsSMARCA5 in NSCLC cells. The results showed that circsSMARCA5 was expressed at low level in NSCLC tissues and cells, while miR-670-5p had high level in NSCLC tissues. Dual luciferase reporter assay verified that miR-670-5p was the target of circsSMARCA5, and RBM24 has the binding site of miR-670-5p. Further analysis showed that circsSMARCA5 could negatively regulate miR-670-5p and had positive relationship with RBM24. Moreover, circsSMARCA5 obviously inhibited tumor growth in vivo, reduced cell proliferation and increased cell apoptosis in vitro, while miR-670-5p mimic or RBM24 knockdown could reverse these effects. Thus, circsSMARCA5 may serve as an NSCLC suppressor by regulating the miR-670-5p/RBM24 axis, and it may have the potential to be a biomarker or therapeutic target for NSCLC.


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