scholarly journals RANBP2 Activates O-GlcNAcylation through Inducing CEBPα-Dependent OGA Downregulation to Promote Hepatocellular Carcinoma Malignant Phenotypes

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3475
Author(s):  
Xiaoming Liu ◽  
Xingyu Chen ◽  
Mengqing Xiao ◽  
Yuxing Zhu ◽  
Renjie Gong ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Binding Protein ◽  
Dependent Manner ◽  
Post Translational Modification ◽  
E3 Ligases ◽  
Enhancer Binding Protein ◽  
Underlying Mechanisms ◽  
Glcnac Transferase

O-GlcNAcylation is an important post-translational modification (PTM) jointly controlled by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Aberrant hyper-O-GlcNAcylation is reported to yield hepatocellular carcinoma (HCC) malignancy, but the underlying mechanisms of the OGT/OGA imbalance responsible for HCC tumorigenesis remain largely unknown. Here, we report that RAN-binding protein 2 (RANBP2), one of the small ubiquitin-like modifier (SUMO) E3 ligases, contributed to malignant phenotypes in HCC. RANBP2 was found to facilitate CCAAT/enhancer-binding protein alpha (CEBPα) SUMOylation and degradation by direct interplay with CEBPα. As a transcriptional factor, CEBPα was verified to augment OGA transcription, and further experiments demonstrated that RANBP2 enhanced the O-GlcNAc level by downregulating OGA transcription while not affecting OGT expression. Importantly, we provided in vitro and in vivo evidence of HCC malignant phenotypes that RANBP2 triggered through an imbalance of OGT/OGA and subsequent higher O-GlcNAcylation events for oncogenic proteins such as peroxisome proliferative-activated receptor gamma coactivator 1 alpha (PGC1α) in a CEBPα-dependent manner. Altogether, our results show a novel molecular mechanism whereby RANBP2 regulates its function through CEBPα-dependent OGA downregulation to induce a global change in the hyper-O-GlcNAcylation of genes, such as PGC1α, encouraging the further study of promising implications for HCC therapy.

Estrogen receptor mediates the effects of pseudoprotodiocsin on adipogenesis in 3T3-L1 cells

2010 ◽  
Vol 299 (1) ◽  
pp. C128-C138 ◽  
Author(s):  
Jing Xiao ◽  
Nai-li Wang ◽  
Bing Sun ◽  
Guo-ping Cai
Keyword(s):  
Leucine Zipper ◽  
Binding Protein ◽  
Adipogenic Differentiation ◽  
Mitogen Activated Protein Kinase ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Underlying Mechanisms

Estrogen receptors (ERs) play a pivotal role in adipogenesis; therefore, compounds targeting ERs may also affect fat formation. Recent studies have shown that the Dioscorea plant (commonly called yam) exhibits an antiobesity effect on rodents. However, the active compounds and underlying mechanisms responsible for this effect are not yet fully understood. We evaluated the effects of pseudoprotodiocsin (PPD), a steroid saponin from Dioscorea nipponica Makino (a type of Dioscorea), on adipogenesis and the mechanisms underlying this effect. Treatment with PPD at the onset of adipogenic differentiation resulted in significantly decreased adipogenesis in both in vitro and in vivo experimental systems. An increased amount of ERα mRNA, protein, and the accumulation of ERα in the nucleus were also observed. However, the expression pattern of ERβ was not altered. Furthermore, the antiadipogenic effect of PPD was found to be ER dependent. It was also accompanied by the decreased expression of several genes involved in adipogenesis, including lipoprotein lipase (LPL), leptin, CCAAT/enhancer-binding-protein-α (C/EBPα), and peroxisome proliferator-activated receptor-γ (PPARγ), as well as the increased expression of some negative factors of adipogenesis, including preadipocyte factor 1 (Pre-1), GATA-binding protein 2 (GATA-2), GC-induced leucine-zipper protein (GILZ), and C/EBP homologous protein (CHOP-10). In addition to its estrogenic action, PPD also abolished the p38 mitogen-activated protein kinase (p38 MAPK) activation. Our results suggest that PPD inhibits adipogenesis in an ER-dependent manner and induces the expression of ERα. These findings may provide a lead toward a novel agent that can be used to treat obesity.

scholarly journals CircFAM13B promotes the proliferation of hepatocellular carcinoma by sponging miR-212, upregulating E2F5 expression and activating the P53 pathway

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying Xie ◽  
Xiaofeng Hang ◽  
Wensheng Xu ◽  
Jing Gu ◽  
Yuanjing Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatocellular Carcinoma ◽  
Gene Expression Omnibus ◽  
Differentially Expressed ◽  
In Vivo Studies ◽  
Circular Rnas ◽  
Novel Target ◽  
Underlying Mechanisms

Abstract Background Most of the biological functions of circular RNAs (circRNAs) and the potential underlying mechanisms in hepatocellular carcinoma (HCC) have not yet been discovered. Methods In this study, using circRNA expression data from HCC tumor tissues and adjacent tissues from the Gene Expression Omnibus database, we identified out differentially expressed circRNAs and verified them by qRT-PCT. Functional experiments were performed to evaluate the effects of circFAM13B in HCC in vitro and in vivo. Results We found that circFAM13B was the most significantly differentially expressed circRNA in HCC tissue. Subsequently, in vitro and in vivo studies also demonstrated that circFAM13B promoted the proliferation of HCC. Further studies revealed that circFAM13B, a sponge of miR-212, is involved in the regulation of E2F5 gene expression by competitively binding to miR-212, inhibits the activation of the P53 signalling pathway, and promotes the proliferation of HCC cells. Conclusions Our findings revealed the mechanism underlying the regulatory role played by circFAM13B, miR-212 and E2F5 in HCC. This study provides a new theoretical basis and novel target for the clinical prevention and treatment of HCC.

scholarly journals Tumor-Stroma Crosstalk Enhances REG3A Expressions that Drive the Progression of Hepatocellular Carcinoma

2020 ◽  
Vol 21 (2) ◽  
pp. 472 ◽  
Author(s):  
Yuri Cho ◽  
Min Ji Park ◽  
Koeun Kim ◽  
Jae-Young Park ◽  
Jihye Kim ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Microarray Analysis ◽  
Cdna Microarray ◽  
Tumor Stroma ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Cdna Microarray Analysis ◽  
Hcc Cells

Abstract: Background: Crosstalk between tumors and their microenvironment plays a crucial role in the progression of hepatocellular carcinoma (HCC). However, there is little existing information about the key signaling molecule that modulates tumor-stroma crosstalk. Methods: Complementary DNA (cDNA) microarray analysis was performed to identify the key molecule in tumor-stroma crosstalk. Subcutaneous xenograft in vivo murine model, immunoblotting, immunofluorescence, and real-time polymerase chain reaction using HCC cells and tissues were performed. Results: The key molecule, regenerating gene protein-3A (REG3A), was most significantly enhanced when coculturing HCC cells and activated human hepatic stellate cells (HSCs) (+8.2 log) compared with monoculturing HCC cells using cDNA microarray analysis. Downregulation of REG3A using small interfering RNA significantly decreased the proliferation of HSC-cocultured HCC cells in vitro and in vivo, and enhanced deoxycholic acid-induced HCC cell apoptosis. Crosstalk-induced REG3A upregulation was modulated by platelet-derived growth factor ββ (PDGF-ββ) in p42/44-dependent manner. REG3A mRNA levels in human HCC tissues were upregulated 1.8-fold compared with non-tumor tissues and positively correlated with PDGF-ββ levels. Conclusions: REG3A/p42/44 pathway/PDGF-ββ signaling plays a significant role in hepatocarcinogenesis via tumor-stroma crosstalk. Targeting REG3A is a potential novel therapeutic target for the management of HCCs by inhibiting crosstalk between HCC cells and HSCs.

scholarly journals HDAC6 inhibitor WT161 performs antitumor effect on osteosarcoma and synergistically interacts with 5-FU

2021 ◽  
Author(s):  
Jun Sun ◽  
Wei Wu ◽  
Xiaofeng Tang ◽  
Feifei Zhang ◽  
Cheng Ju ◽  
...  
Keyword(s):  
Dependent Manner ◽  
Osteosarcoma Cells ◽  
Synergistic Inhibition ◽  
Proliferative Effect ◽  
Xenograft Models ◽  
Hdac6 Inhibitor ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Background: WT161, as a selective HDAC6 inhibitor, has been shown to play anti-tumor effects on several kinds of cancers. The aim of this study is to explore the roles of WT161 in osteosarcoma and its underlying mechanisms. Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were established to evaluate the anti-proliferative effect of WT161 in vivo. Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein level of PTEN and decreased the phosphorylation level of AKT. More importantly, WT161 show synergistic inhibition with 5-FU on osteosarcoma cells in vitro and in vivo. Conclusions: These results indicate that WT161 inhibits the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

Reticulon 3-mediated Chk2/p53 activation suppresses hepatocellular carcinogenesis and is blocked by hepatitis B virus

Gut ◽  
2020 ◽  
pp. gutjnl-2020-321386
Author(s):  
Shushu Song ◽  
Yinghong Shi ◽  
Weicheng Wu ◽  
Hao Wu ◽  
Lei Chang ◽  
...  
Keyword(s):  
Cellular Proliferation ◽  
Dependent Manner ◽  
Mice Model ◽  
Calcium Dependent ◽  
B Virus ◽  
P53 Activation ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

ObjectiveDysfunction of endoplasmic reticulum (ER) proteins is closely related to homeostasis disturbance and malignant transformation of hepatocellular carcinoma (HCC). Reticulons (RTN) are a family of ER-resident proteins critical for maintaining ER function. Nevertheless, the precise roles of RTN in HCC remain largely unclear. The aim of the study is to examine the effect of reticulon family member RTN3 on HCC development and explore the underlying mechanisms.DesignClinical HCC samples were collected to assess the relationship between RTN3 expression and patients’ outcome. HCC cell lines were employed to examine the effects of RTN3 on cellular proliferation, apoptosis and signal transduction in vitro. Nude mice model was used to detect the role of RTN3 in modulating tumour growth in vivo.ResultsWe found that RTN3 was highly expressed in normal hepatocytes but frequently downregulated in HCC. Low RTN3 expression predicted poor outcome in patients with HCC in TP53 gene mutation and HBV infection status-dependent manner. RTN3 restrained HCC growth and induced apoptosis by activating p53. Mechanism studies indicated that RTN3 facilitated p53 Ser392 phosphorylation via Chk2 and enhanced subsequent p53 nuclear localisation. RTN3 interacted with Chk2, recruited it to ER and promoted its activation in an ER calcium-dependent manner. Nevertheless, the tumour suppressive effects of RTN3 were abrogated in HBV-positive cells. HBV surface antigen competed with Chk2 for RTN3 binding and blocked RTN3-mediated Chk2/p53 activation.ConclusionThe findings suggest that RTN3 functions as a novel suppressor of HCC by activating Chk2/p53 pathway and provide more clues to better understand the oncogenic effects of HBV.

scholarly journals SET7/9-dependent methylation of ARTD1 at K508 stimulates poly-ADP-ribose formation after oxidative stress

Open Biology ◽  
2013 ◽  
Vol 3 (10) ◽  
pp. 120173 ◽  
Author(s):  
Ingrid Kassner ◽  
Anneli Andersson ◽  
Monika Fey ◽  
Martin Tomas ◽  
Elisa Ferrando-May ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Interactions ◽  
Protein Function ◽  
Dependent Manner ◽  
Protein Protein Interactions ◽  
Post Translational Modification ◽  
Target Proteins ◽  
Protein Methyltransferase

ADP-ribosyltransferase diphtheria toxin-like 1 (ARTD1, formerly PARP1) is localized in the nucleus, where it ADP-ribosylates specific target proteins. The post-translational modification (PTM) with a single ADP-ribose unit or with polymeric ADP-ribose (PAR) chains regulates protein function as well as protein–protein interactions and is implicated in many biological processes and diseases. SET7/9 (Setd7, KMT7) is a protein methyltransferase that catalyses lysine monomethylation of histones, but also methylates many non-histone target proteins such as p53 or DNMT1. Here, we identify ARTD1 as a new SET7/9 target protein that is methylated at K508 in vitro and in vivo . ARTD1 auto-modification inhibits its methylation by SET7/9, while auto-poly-ADP-ribosylation is not impaired by prior methylation of ARTD1. Moreover, ARTD1 methylation by SET7/9 enhances the synthesis of PAR upon oxidative stress in vivo . Furthermore, laser irradiation-induced PAR formation and ARTD1 recruitment to sites of DNA damage in a SET7/9-dependent manner. Together, these results reveal a novel mechanism for the regulation of cellular ARTD1 activity by SET7/9 to assure efficient PAR formation upon cellular stress.

scholarly journals LncRNA-URHC Functions as a ceRNA to Regulate Danjb9 Expression by Competitively Binding to miR-5007-3p in Hepatocellular Carcinoma

2021 ◽  
Author(s):  
kunwei niu ◽  
Shibin Qu ◽  
Xuan Zhang ◽  
Jimin Dai ◽  
Jianlin Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Biological Effects ◽  
Luciferase Reporter ◽  
Underlying Mechanisms ◽  
Proliferation In Vitro ◽  
Hcc Cells

Abstract Background: Hepatocellular carcinoma (HCC) is often diagnosed at a late stage, when the prognosis is poor. The regulation of long non-coding RNAs (lncRNAs) plays a crucial role in HCC. However, the precise regulatory mechanisms of lncRNA signaling in HCC remain largely unknown. We study aim to investigate the underlying mechanisms of lncRNA (upregulated in hepatocellular carcinoma) URHC in HCC. Methods: RT-qPCR, fluorescence in situ hybridization (FISH) staining, EdU, colony formation, and tumor xenografts experiments were used to identify localized and biological effects of URHC on HCC cells in vitro and in vivo. The bioinformatics analysis, Dual-luciferase reporter assay, and rescue experiments revealed the potential mechanism of URHC.Results: URHC silencing may inhibit the HCC cells proliferation in vitro and in vivo. We found that URHC was mainly localized in the cytoplasm. The expression of miR-5007-3p was negatively regulated by URHC. And miR-5007-3p could reverse the effect of URHC in HCC cells. The expression of DNAJB9 was negatively regulated by miR-5007-3p but positively regulated by URHC. These suggesting of lncRNA-URHC positively regulated the level of DNAJB9 by sponging miR-5007-3p.Conclusion: Together, our study elucidated the role of URHC as a miRNA sponge in HCC, and shed new light on lncRNA-directed diagnostics and therapeutics in HCC.

scholarly journals Multivalent interactions with RNA drive RNA binding protein recruitment and dynamics in biomolecular condensates in Xenopus oocytes

2021 ◽  
Author(s):  
Sarah E Cabral ◽  
Kimberly Mowry
Keyword(s):  
Protein Interactions ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Dependent Manner ◽  
Binding Domains ◽  
Multivalent Interactions

RNA localization and biomolecular condensate formation are key biological strategies for organizing the cytoplasm and generating cellular and developmental polarity. While enrichment of RNAs and RNA-binding proteins (RBPs) is a hallmark of both processes, the functional and structural roles of RNA-RNA and RNA-protein interactions within condensates remain unclear. Recent work from our laboratory has shown that RNAs required for germ layer patterning in Xenopus oocytes localize in novel biomolecular condensates, termed Localization bodies (L-bodies). L-bodies are composed of a non-dynamic RNA phase enmeshed in a more dynamic protein-containing phase. However, the interactions that drive the biophysical characteristics of L-bodies are not known. Here, we test the role of RNA-protein interactions using an L-body RNA-binding protein, PTBP3, which contains four RNA-binding domains (RBDs). We find that binding of RNA to PTB is required for both RNA and PTBP3 to be enriched in L-bodies in vivo. Importantly, while RNA binding to a single RBD is sufficient to drive PTBP3 localization to L-bodies, interactions between multiple RRMs and RNA tunes the dynamics of PTBP3 within L-bodies. In vitro, recombinant PTBP3 phase separates into non-dynamic structures in an RNA-dependent manner, supporting a role for RNA-protein interactions as a driver of both recruitment of components to L-bodies and the dynamics of the components after enrichment. Our results point to a model where RNA serves as a concentration-dependent, non-dynamic substructure and multivalent interactions with RNA are a key driver of protein dynamics.

scholarly journals LncRNA CASC11 Promotes Hepatocellular Carcinoma Progression via Upregulation of UBE2T in a m6A-Dependent Manner

2021 ◽  
Vol 11 ◽  
Author(s):  
Fei Chen ◽  
Meijun Li ◽  
Liang Wang
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cancer Progression ◽  
Cancer Susceptibility ◽  
Underlying Mechanism ◽  
Epigenetic Mechanism ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
Tumor Growth And Metastasis

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and the third leading cause of cancer-related deaths worldwide. Besides, it has been revealed that long non-coding RNA (LncRNA) cancer susceptibility candidate 11 (CASC11) is involved in cancer progression. However, the functional role and underlying mechanism of CASC11 in HCC remains largely unknown. In this context, here, it was found that CASC11 was upregulated in HCC tissues and associated with tumor grades, metastasis, and prognosis of HCC patients. Functionally, CASC11 facilitated HCC cell proliferation, migration, and invasion in vitro, and enhanced tumor growth and metastasis in vivo. Mechanistically, CASC11 associated with and stabilized Ubiquitin-conjugating enzyme E2T (UBE2T) mRNA. To be specific, it decreased UBE2T N6-methyladenosine (m6A) level via recruiting ALKBH5. Moreover, CASC11 inhibited the association between UBE2T mRNA and m6A reader protein YTHDF2. Taken together, our findings demonstrate the epigenetic mechanism of CASC11 in the regulation of UBE2T expression and possibly provide a novel therapeutic target for HCC treatment.

scholarly journals Epigenetic regulation of ferroptosis via ETS1/miR-23a-3p/ACSL4 axis mediates sorafenib resistance in human hepatocellular carcinoma

2022 ◽  
Vol 41 (1) ◽  
Author(s):  
Yuanjun Lu ◽  
Yau-Tuen Chan ◽  
Hor-Yue Tan ◽  
Cheng Zhang ◽  
Wei Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Resistance ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

Abstract Background Drug resistance to sorafenib greatly limited the benefits of treatment in patients with hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) participate in the development of drug resistance. The key miRNA regulators related to the clinical outcome of sorafenib treatment and their molecular mechanisms remain to be identified. Methods The clinical significance of miRNA-related epigenetic changes in sorafenib-resistant HCC was evaluated by analyzing publicly available databases and in-house human HCC tissues. The biological functions of miR-23a-3p were investigated both in vitro and in vivo. Proteomics and bioinformatics analyses were conducted to identify the mechanisms that regulating miR-23a-3p. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to validate the binding relationship of miR-23a-3p and its targets. Results We found that miR-23a-3p was the most prominent miRNA in HCC, which was overexpressed in sorafenib non-responders and indicated poor survival and HCC relapse. Sorafenib-resistant cells exhibited increased miR-23a-3p transcription in an ETS Proto-Oncogene 1 (ETS1)-dependent manner. CRISPR-Cas9 knockout of miR-23a-3p improved sorafenib response in HCC cells as well as orthotopic HCC tumours. Proteomics analysis suggested that sorafenib-induced ferroptosis was the key pathway suppressed by miR-23a-3p with reduced cellular iron accumulation and lipid peroxidation. MiR-23a-3p directly targeted the 3′-untranslated regions (UTR) of ACSL4, the key positive regulator of ferroptosis. The miR-23a-3p inhibitor rescued ACSL4 expression and induced ferrotoptic cell death in sorafenib-treated HCC cells. The co-delivery of ACSL4 siRNA and miR-23a-3p inhibitor abolished sorafenib response. Conclusion Our study demonstrates that ETS1/miR-23a-3p/ACSL4 axis contributes to sorafenib resistance in HCC through regulating ferroptosis. Our findings suggest that miR-23a-3p could be a potential target to improve sorafenib responsiveness in HCC patients.

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