p113 isoform encoded by CUX1 circular RNA drives tumor progression via facilitating ZRF1/BRD4 transactivation.

BACKGROUND: Metabolic reprogramming sustains tumorigenesis and aggressiveness of neuroblastoma (NB), the most common extracranial malignancy in childhood, while underlying mechanisms and therapeutic approaches still remain elusive. METHODS: Circular RNAs (circRNAs) were validated by Sanger sequencing. Co-immunoprecipitation, mass spectrometry, chromatin immunoprecipitation (ChIP) sequencing, and RNA sequencing assays were applied to explore protein interaction and target genes. Gene expression regulation was observed by ChIP, dual-luciferase reporter, real-time quantitative RT-PCR, and western blot assays. Gain- and loss-of-function studies were performed to observe the impacts of circRNA-encoded protein and its partners on the lipid metabolism, mitochondrial activity, growth, invasion, and metastasis of NB cells. RESULTS: A novel 113-amino acid protein (p113) of CUT-like homeobox 1 (CUX1) was identified in NB cells treated by serum deprivation. Further validating studies revealed that nuclear p113 was encoded by circRNA of CUX1, and promoted the lipid metabolic reprogramming, mitochondrial activity, proliferation, invasion, and metastasis of NB cells. Mechanistically, p113 interacted with Zuotin-related factor 1 (ZRF1) and bromodomain protein 4 (BRD4) to form a transcriptional regulatory complex, and mediated the transactivation of ZRF1/BRD4 in upregulating ALDH3A1, NDUFA1, and NDUFAF5 essential for conversion of fatty aldehydes into fatty acids, fatty acid ß-oxidation, and mitochondrial complex I activity. Administration of an inhibitory peptide blocking p113-ZRF1 interaction suppressed the tumorigenesis and aggressiveness of NB cells. In clinical NB cases, high expression of p113, ZRF1, or BRD4 was associated with poor survival of patients. CONCLUSIONS: These results indicate that p113 isoform encoded by CUX1 circular RNA drives tumor progression via facilitating ZRF1/BRD4 transactivation.

Long Noncoding RNA NHEG1 Drives ß-Catenin Transactivation and Neuroblastoma Progression through Interacting with DDX5.

Recent studies suggest that long noncoding RNAs (lncRNAs) play essential roles in tumor progression. However, the functional roles and underlying mechanisms of lncRNAs in neuroblastoma (NB), the most common malignant solid tumor in pediatric population, still remain elusive. Herein, through integrating analysis of a public RNA sequencing dataset, neuroblastoma highly expressed 1 (NHEG1) was identified as a risk-associated lncRNA, contributing to an unfavorable outcome of NB. Depletion of NHEG1 led to facilitated differentiation and decreased growth and aggressiveness of NB cells. Mechanistically, NHEG1 bound to and stabilized DEAD-box helicase 5 (DDX5) protein through repressing proteasome-mediated degradation, resulting in ß-catenin transactivation that altered target gene expression associated with NB progression. We further determined a lymphoid enhancer binding factor 1 (LEF1)/transcription factor 7-like 2 (TCF7L2)/NHEG1/DDX5/ß-catenin axis with a positive feedback loop and demonstrated that NHEG1 harbored oncogenic properties via its interplay with DDX5. Administration of small interfering RNAs against NHEG1 or DDX5 reduced tumor growth and prolonged survival of nude mice bearing xenografts. High NHEG1 or DDX5 expression was associated with poor survival of NB patients. These results indicate that lncRNA NHEG1 exhibits oncogenic activity that affects NB progression via stabilizing the DDX5 protein, which might serve as a potential therapeutic target for NB.

Circ-HuR suppresses HuR expression and gastric cancer progression by inhibiting CNBP transactivation.

BACKGROUND: Circular RNAs (circRNAs), a subclass of non-coding RNAs, play essential roles in tumorigenesis and aggressiveness. Our previous study has identified that circAGO2 drives gastric cancer progression through activating human antigen R (HuR), a protein stabilizing AU-rich element-containing mRNAs. However, the functions and underlying mechanisms of circRNAs derived from HuR in gastric cancer progression remain elusive. METHODS: CircRNAs derived from HuR were detected by real-time quantitative RT-PCR and validated by Sanger sequencing. Biotin-labeled RNA pull-down, mass spectrometry, RNA immunoprecipitation, RNA electrophoretic mobility shift, and in vitro binding assays were applied to identify proteins interacting with circRNA. Gene expression regulation was observed by chromatin immunoprecipitation, dual-luciferase assay, real-time quantitative RT-PCR, and western blot assays. Gain- and loss-of-function studies were performed to observe the impacts of circRNA and its protein partner on the growth, invasion, and metastasis of gastric cancer cells in vitro and in vivo. RESULTS: Circ-HuR (hsa_circ_0049027) was predominantly detected in the nucleus, and was down-regulated in gastric cancer tissues and cell lines. Ectopic expression of circ-HuR suppressed the growth, invasion, and metastasis of gastric cancer cells in vitro and in vivo. Mechanistically, circ-HuR interacted with CCHC-type zinc finger nucleic acid binding protein (CNBP), and subsequently restrained its binding to HuR promoter, resulting in down-regulation of HuR and repression of tumor progression. CONCLUSIONS: Circ-HuR serves as a tumor suppressor to inhibit CNBP-facilitated HuR expression and gastric cancer progression, indicating a potential therapeutic target for gastric cancer.

Valproic acid suppresses Warburg effect and tumor progression in neuroblastoma.

Altered glucose metabolism is a hallmark for cancer, which is characterized by a unique metabolic phenotype known as Warburg effect or aerobic glycolysis. Emerging studies show that valproic acid (VPA), an established histone deacetylase inhibitor, possesses tumor suppressive properties. However, the effects of VPA on the regulation of Warburg effect in neuroblastoma (NB), the most common extracranial malignancy in childhood, still remain elusive. In this study, we show that VPA inhibits the aerobic glycolysis in NB cells by decreasing glucose uptake and reducing lactate and ATP production. Mechanistically, VPA suppresses aerobic glycolysis via reducing the levels of E2F transcription factor 1 (E2F1), resulting in repressed expression of glycolytic genes glucose-6-phosphate isomerase (GPI) and phosphoglycerate pinase 1 (PGK1). Rescue experiments show that VPA inhibits the aerobic glycolysis and NB progression through down-regulation of E2F1. These results demonstrate that VPA suppresses the Warburg effect and tumor progression, indicating a novel therapeutic strategy for NB.

Genetic deletion of ß2 adrenergic receptors exacerbates hepatocellular lipid accumulation in high-fat diet mice.

ß2 Adrenergic receptors (ß2ARs) are G protein-coupled receptors (GPCRs) that are expressed in major insulin target tissues. ß2ARs play an important role in the regulation of lipid metabolism during aging; however, little is known about the significance of ß2ARs in the pathogenesis of hepatic fat accumulation in high-fat diet (HFD) mice. This study aims to examine the role of ß2AR in the development of nonalcoholic fatty liver disease (NAFLD) induced by HFD and the underlying mechanisms. Surprisingly, we found that genetic deletion of ß2AR significantly increased the liver weight of mice fed a HFD for 20 weeks compared to that of wild-type (WT) mice. Moreover, genetic deletion of ß2AR could aggravate HFD-induced liver lipid accumulation and liver injury in mice. Mechanistically, we demonstrated that ß2AR deletion significantly activated PPARγ/CD36 signaling via inactivation of the cAMP response element-binding (CREB) protein to facilitate hepatocellular lipid deposition in HFD mice. Together, our results identify ß2AR as a plausible therapeutic target for preventing or treating NAFLD.

Risk-Associated Long Noncoding RNA FOXD3-AS1 Inhibits Neuroblastoma Progression by Repressing PARP1-Mediated Activation of CTCF.

Neuroblastoma (NB) is the most common extracranial tumor in childhood. Recent studies have implicated the emerging roles of long noncoding RNAs (lncRNAs) in tumorigenesis and aggressiveness. However, the functions and targets of risk-associated lncRNAs in NB progression still remain to be determined. Herein, through mining of public microarray datasets, we identify lncRNA forkhead box D3 antisense RNA 1 (FOXD3-AS1) as an independent prognostic marker for favorable outcome of NB patients. FOXD3-AS1 is downregulated in NB tissues and cell lines, and ectopic expression of FOXD3-AS1 induces neuronal differentiation and decreases the aggressiveness of NB cells in vitro and in vivo. Mechanistically, as a nuclear lncRNA, FOXD3-AS1 interacts with poly(ADP-ribose) polymerase 1 (PARP1) to inhibit the poly(ADP-ribosyl)ation and activation of CCCTC-binding factor (CTCF), resulting in derepressed expression of downstream tumor-suppressive genes. Rescue experiments indicate that FOXD3-AS1 harbors tumor-suppressive properties by inhibiting the oncogenic roles of PARP1 or CTCF and plays crucial roles in all-trans-retinoic-acid-mediated therapeutic effects on NB. Administration of FOXD3-AS1 construct or siRNAs against PARP1 or CTCF reduces the tumor growth and prolongs the survival of nude mice. These findings suggest that as a risk-associated lncRNA, FOXD3-AS1 inhibits the progression of NB through repressing PARP1-mediated CTCF activation.

miRNA-558 promotes tumorigenesis and aggressiveness of neuroblastoma cells through activating the transcription of heparanase.

Heparanase (HPSE) is the endogenous endoglycosidase that degrades heparan sulfate proteoglycans and promotes the tumor growth, invasion, metastasis and angiogenesis. Our previous studies have shown that HPSE is highly expressed in neuroblastoma (NB), the most common extracranial solid tumor in childhood. However, the underlying regulatory mechanisms remain largely unknown. In this study, we identified one binding site of microRNA-558 (miR-558) within the HPSE promoter. In NB tissues and cell lines, miR-558 was up-regulated and positively correlated with HPSE expression. Gain- and loss-of-function studies demonstrated that miR-558 facilitated the transcript and protein levels of HPSE and its downstream gene, vascular endothelial growth factor, in NB cell lines. In addition, miR-558 enhanced the promoter activities of HPSE, and these effects were abolished by the mutation of the miR-558-binding site. Mechanistically, miR-558 induced the enrichment of the active epigenetic marker and RNA polymerase II on the HPSE promoter in NB cells in an Argonaute 1-dependent manner, which was abolished by repressing the miR-558-promoter interaction. Knockdown of endogenous miR-558 decreased the growth, invasion, metastasis and angiogenesis of NB cells in vitro and in vivo. In contrast, over-expression of miR-558 promoted the growth, invasion, metastasis and angiogenesis of SH-SY5Y and SK-N-SH cells. Restoration of HPSE expression prevented the NB cells from changes in these biological features induced by knockdown or over-expression of miR-558. These data indicate that miR-558 induces the transcriptional activation of HPSE via the binding site within promoter, thus facilitating the tumorigenesis and aggressiveness of NB.

miRNA-584-5p exerts tumor suppressive functions in human neuroblastoma through repressing transcription of matrix metalloproteinase 14.

Matrix metalloproteinase 14 (MMP-14) is a membrane-anchored MMP crucial for tumorigenesis and aggressiveness, and is highly expressed in neuroblastoma (NB), the most common extracranial solid tumor in childhood. Recent evidence shows the emerging roles of endogenous promoter-targeting microRNAs (miRNAs) in regulating gene transcription. However, the roles of miRNAs in the transcription of MMP-14 still remain largely unknown. In this study, through mining computational algorithm program and Argonaute-chromosome interaction dataset, we identified one binding site of miRNA-584-5p (miR-584-5p) within the MMP-14 promoter. In NB tissues, miR-584-5p was under-expressed and inversely correlated with MMP-14 expression, and was an independent prognostic factor for favorable outcome of patients. miR-584-5p precursor attenuated the expression of MMP-14 in a Dicer-dependent manner, resulting in decreased levels of vascular endothelial growth factor, in cultured NB cell lines. In addition, miR-584-5p suppressed the promoter activity of MMP-14, and mutation of miR-584-5p binding site abolished these effects. Mechanistically, miR-584-5p recruited Argonaute 2 to facilitate the enrichment of enhancer of zeste homolog 2, histone H3 lysine 27 trimethylation, and histone H3 lysine 9 dimethylation on MMP-14 promoter in NB cells, which was abolished by repressing the miR-584-5p-promoter interaction. Gain- and loss-of-function studies demonstrated that miR-584-5p suppressed the growth, invasion, metastasis, and angiogenesis of NB cells in vitro and in vivo. Moreover, restoration of MMP-14 expression rescued the NB cells from changes in these biological features. Taken together, these results indicate that promoter-targeting miR-584-5p exerts tumor suppressive functions in NB through repressing the transcription of MMP-14.

Intelectin 1 suppresses the growth, invasion and metastasis of neuroblastoma cells through up-regulation of N-myc downstream regulated gene 2.

BACKGROUND: Recent studies have revealed the potential roles of intelectin 1 (ITLN1) in tumorigenesis. However, its functions and underlying mechanisms in neuroblastoma (NB), the most common extracranial solid tumor in childhood, still remain largely unknown. METHODS: Human neuroblastoma cell lines were treated with recombinant ITLN1 protein or stably transfected with ITLN1 expression and short hairpin RNA vectors. Gene expression and signaling pathway were detected by western blot and real-time quantitative RT-PCR. Gene promoter activity and transcription factor binding were detected by luciferase reporter and chromatin immunoprecipitation assays. Growth and aggressiveness of tumor cells were measured by MTT colorimetry, colony formation, scratch assay, matrigel invasion assay, and nude mice model. RESULTS: Mining of public microarray databases revealed that N-myc downstream regulated gene 2 (NDRG2) was significantly correlated with ITLN1 in NB. Gain- and loss-of-function studies indicated that secretory ITLN1 facilitated the NDRG2 expression, resulting in down-regulation of vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP-9), in NB cell lines SH-SY5Y, SK-N-BE(2), and SK-N-SH. Krüppel-like factor 4 (KLF4), a transcription factor crucial for NDRG2 expression, was up-regulated by ITLN1 in NB cells via inactivation of phosphoinositide 3-kinase (PI3K)/AKT signaling. Ectopic expression of ITLN1 suppressed the growth, invasion and metastasis of NB cells in vitro and in vivo. Conversely, knockdown of ITLN1 promoted the growth, invasion, and metastasis of NB cells. In addition, rescue experiments in ITLN1 over-expressed or silenced NB cells showed that restoration of NDRG2 expression prevented the tumor cells from ITLN1-mediated changes in these biological features. In clinical NB tissues, ITLN1 was down-regulated and positively correlated with NDRG2 expression. Patients with high ITLN1 or NDRG2 expression had greater survival probability. CONCLUSIONS: These findings indicate that ITLN1 functions as a tumor suppressor that affects the growth, invasion and metastasis of NB through up-regulation of NDRG2.

Association of Ureaplasma urealyticum colonization with development of bronchopulmonary dysplasia: a systemic review and meta-analysis.

There is controversy regarding the roles of Ureaplasma urealyticum (U. urealyticum) colonization in the development of bronchopulmonary dysplasia (BPD). This study explored the association between U. urealyticum and bronchopulmonary dysplasia at 36 weeks post-menstrual age (BPD36). Studies published before December 31, 2013 were searched from Medline, Embase, Ovid, Web of Science, and Cochrane databases, with the terms "Ureaplasma urealyticum", "chronic lung disease", or "BPD36" used, and English language as a limit. The association between U. urealyticum colonization and BPD36 was analyzed with RevMan 4.2.10 software, using the odds ratio (OR) and relative risk (RR) for dichotomous variables. Out of the enrolled 81 studies, 11 investigated the BPD36 in total 1193 infants. Pooled studies showed no association between U. urealyticum colonization and subsequent development of BPD36, with the OR and RR being 1.03 (95% CI=0.78-1.37; P=0.84) and 1.01 (95% CI= 0.88-1.16, P=0.84), respectively. These findings indicated no association between U. urealyticum colonization and the development of BPD36.

Over-expression of testis-specific expressed gene 1 attenuates the proliferation and induces apoptosis of GC-1spg cells.

The effects of over-expression of testis-specific expressed gene 1 (TSEG-1) on the viability and apoptosis of cultured spermatogonial GC-1spg cells were investigated, and the immortal spermatogonial cell line GC-1spg (CRL-2053™) was obtained as the cell model in order to explore the function of TSEG-1. We transfected the eukaryotic vector of TSEG-1, named as pEGFP-TSEG-1 into cultured spermatogonial GC-1spg cells. Over-expression of TSEG-1 inhibited the proliferation of GC-1spg cells, and arrested cell cycle slightly at G0/G1 phase. Transfection of TSEG-1 attenuated the transcript levels of Ki-67, PCNA and cyclin D1. In addition, over-expression of TSEG-1 induced early and late apoptosis, and reduced the mitochondrial membrane potential of GC-1spg cells. Moreover, transfection of TSEG-1 significantly enhanced the ratio of Bax/Bcl-2 and transcript levels of caspase 9, and decreased the expression of Fas and caspase 8 in GC-1spg cells. These results indicated over-expression of TSEG-1 suppresses the proliferation and induces the apoptosis of GC-1spg cells, which establishes a basis for further study on the function of TSEG-1.

Targeting c-Myc transactivation by LMNA inhibits tRNA processing essential for malate-aspartate shuttle and tumour progression.

BACKGROUND: A series of studies have demonstrated the emerging involvement of transfer RNA (tRNA) processing during the progression of tumours. Nevertheless, the roles and regulating mechanisms of tRNA processing genes in neuroblastoma (NB), the prevalent malignant tumour outside the brain in children, are yet unknown. METHODS: Analysis of multi-omics results was conducted to identify crucial regulators of downstream tRNA processing genes. Co-immunoprecipitation and mass spectrometry methods were utilised to measure interaction between proteins. The impact of transcriptional regulators on expression of downstream genes was measured by dual-luciferase reporter, chromatin immunoprecipitation, western blotting and real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) methods. Studies have been conducted to reveal impact and mechanisms of transcriptional regulators on biological processes of NB. Survival differences were analysed using the log-rank test. RESULTS: c-Myc was identified as a transcription factor driving tRNA processing gene expression and subsequent malate-aspartate shuttle (MAS) in NB cells. Mechanistically, c-Myc directly promoted the expression of glutamyl-prolyl-tRNA synthetase (EPRS) and leucyl-tRNA synthetase (LARS), resulting in translational up-regulation of glutamic-oxaloacetic transaminase 1 (GOT1) as well as malate dehydrogenase 1 (MDH1) via inhibiting general control nonrepressed 2 or activating mechanistic target of rapamycin signalling. Meanwhile, lamin A (LMNA) inhibited c-Myc transactivation via physical interaction, leading to suppression of MAS, aerobic glycolysis, tumourigenesis and aggressiveness. Pre-clinically, lobeline was discovered as a LMNA-binding compound to facilitate its interaction with c-Myc, which inhibited aminoacyl-tRNA synthetase expression, MAS and tumour progression of NB, as well as growth of organoid derived from c-Myc knock-in mice. Low levels of LMNA or elevated expression of c-Myc, EPRS, LARS, GOT1 or MDH1 were linked to a worse outcome and a shorter survival time of clinical NB patients. CONCLUSIONS: These results suggest that targeting c-Myc transactivation by LMNA inhibits tRNA processing essential for MAS and tumour progression.

Methyl jasmonate abolishes the migration, invasion and angiogenesis of gastric cancer cells through down-regulation of matrix metalloproteinase 14.

BACKGROUND: Recent evidence indicates that methyl jasmonate (MJ), a plant stress hormone, exhibits anti-cancer activity on human cancer cells. The aim of this study is to determine whether sub-cytotoxic MJ can abolish the migration, invasion and angiogenesis gastric cancer cells. METHODS: Human gastric cancer cell lines SGC-7901 and MKN-45 were treated with diverse concentrations of MJ. Cell viability, proliferation, migration, invasion and angiogenesis capabilities of cancer cells were measured by MTT colorimetry, EdU incorporation, scratch assay, matrigel invasion assay, and tube formation assay. Gene expression was detected by western blot and real-time quantitative RT-PCR. Binding of transcription factor on gene promoter was detected by chromatin immunoprecipitation. RESULTS: Sub-cytotoxic (0.05 to 0.2 mM) MJ attenuated the migration, invasion and angiogenesis, but not the cell viability or proliferation, of gastric cancer cells in a time- and dose-dependent manner, with down-regulation of matrix metalloproteinase 14 (MMP-14) and its downstream gene vascular endothelial growth factor. Restoration of MMP-14 expression rescued the SGC-7901 and MKN-45 cells from sub-cytotoxic MJ-inhibited migration, invasion and angiogenesis. In addition, sub-cytotoxic MJ decreased the specificity protein 1 (Sp1) expression and binding on MMP-14 promoter, while restoration of Sp1 expression rescued the cancer cells from sub-cytotoxic MJ-mediated defects in MMP-14 expression, migration, invasion and angiogenesis. CONCLUSIONS: Sub-cytotoxic MJ attenuates the MMP-14 expression via decreasing the Sp1 expression and binding on MMP-14 promoter, thus inhibiting the migration, invasion and angiogenesis of gastric cancer cells.

The mTOR signaling pathway in pediatric neuroblastoma.

Neuroblastoma (NB) is the most common extracranial malignant solid tumors of childhood, and the majority of these high-risk tumors is resistant to nearly all the treatments and has a significantly worse outcome. The mammalian target of rapamycin (mTOR) plays a critical role in oncogenesis and cancer progression of many tumors. This review will describe the function of mTOR, its genetic regulation in pediatric neuroblastoma, and its value as a target for inhibition by anticancer agents for patients with NB.

Acetyl-CoA metabolism as a therapeutic target for cancer.

Acetyl-coenzyme A (acetyl-CoA), an essential metabolite, not only takes part in numerous intracellular metabolic processes, powers the tricarboxylic acid cycle, serves as a key hub for the biosynthesis of fatty acids and isoprenoids, but also serves as a signaling substrate for acetylation reactions in post-translational modification of proteins, which is crucial for the epigenetic inheritance of cells. Acetyl-CoA links lipid metabolism with histone acetylation to create a more intricate regulatory system that affects the growth, aggressiveness, and drug resistance of malignancies such as glioblastoma, breast cancer, and hepatocellular carcinoma. These fascinating advances in the knowledge of acetyl-CoA metabolism during carcinogenesis and normal physiology have raised interest regarding its modulation in malignancies. In this review, we provide an overview of the regulation and cancer relevance of main metabolic pathways in which acetyl-CoA participates. We also summarize the role of acetyl-CoA in the metabolic reprogramming and stress regulation of cancer cells, as well as medical application of inhibitors targeting its dysregulation in therapeutic intervention of cancers.

Long-Term Survival of Neuroblastoma Patients Receiving Surgery, Chemotherapy, and Radiotherapy: A Propensity Score Matching Study.

Neuroblastoma is the most common extracranial solid malignancy in children. This study was undertaken to determine the long-term survival of neuroblastoma patients receiving conventional therapeutics (surgery, chemotherapy, and radiotherapy). The neuroblastoma patients examined were registered in the Surveillance, Epidemiology and End Results (SEER) database (1975-2016). Using propensity score matching analysis, the patients were paired by record depending on whether they received surgery, chemotherapy, or radiotherapy. Univariate and multivariate analyses of the disease-specific survival of the paired patients were performed by the log-rank test and Cox regression assay. A total of 4568 neuroblastoma patients were included in this study. During 1975-2016, the proportion of histopathological grade III/IV cases receiving surgery gradually increased, while the number of patients with tumors of grade I to IV undergoing chemotherapy or radiotherapy was stable or even decreased. After propensity score analysis, for Grade I + II and Grade III tumors, surgery obviously improved the disease-specific survival of patients, while chemotherapy was unfavorable for patient prognosis, and radiotherapy exerted no obvious effect on the patients. However, no matter what treatment was chosen, the patients with advanced-histopathological-grade tumors had a poor prognosis. Meanwhile, for all histopathological grades, the patients receiving surgery and subsequent chemotherapy or radiotherapy suffered from worsen disease-specific survival than those simply undergoing surgery. Fortunately, the negative effects of surgery, chemotherapy, or radiotherapy improved gradually over time. Surgery improved the long-term survival of the neuroblastoma patients, while chemotherapy and radiotherapy exerted an unfavorable impact on patient outcome. These results provide an important reference for the clinical treatment of neuroblastoma.

Therapeutic targeting of FUBP3 phase separation by GATA2-AS1 inhibits malate-aspartate shuttle and neuroblastoma progression via modulating SUZ12 activity.

Malate-aspartate shuttle (MAS) is essential for maintaining glycolysis and energy metabolism in tumors, while its regulatory mechanisms in neuroblastoma (NB), the commonest extracranial malignancy during childhood, still remain to be elucidated. Herein, by analyzing multi-omics data, GATA binding protein 2 (GATA2) and its antisense RNA 1 (GATA2-AS1) were identified to suppress MAS during NB progression. Mechanistic studies revealed that GATA2 inhibited the transcription of glutamic-oxaloacetic transaminase 2 (GOT2) and malate dehydrogenase 2 (MDH2). As a long non-coding RNA destabilized by RNA binding motif protein 15-mediated N6-methyladenosine methylation, GATA2-AS1 bound with far upstream element binding protein 3 (FUBP3) to repress its liquid-liquid phase separation and interaction with suppressor of zest 12 (SUZ12), resulting in decrease of SUZ12 activity and epigenetic up-regulation of GATA2 and other tumor suppressors. Rescue experiments revealed that GATA2-AS1 inhibited MAS and NB progression via repressing interaction between FUBP3 and SUZ12. Pre-clinically, administration of lentivirus carrying GATA2-AS1 suppressed MAS, aerobic glycolysis, and aggressive behaviors of NB xenografts. Notably, low GATA2-AS1 or GATA2 expression and high FUBP3, SUZ12, GOT2 or MDH2 levels were linked with unfavorable outcome of NB patients. These findings suggest that GATA2-AS1 inhibits FUBP3 phase separation to repress MAS and NB progression via modulating SUZ12 activity.

Therapeutic targeting of CNBP phase separation inhibits ribosome biogenesis and neuroblastoma progression via modulating SWI/SNF complex activity.

BACKGROUND: Neuroblastoma (NB) is the most common extracranial malignancy in childhood; however, the mechanisms underlying its aggressive characteristics still remain elusive. METHODS: Integrative data analysis was performed to reveal tumour-driving transcriptional regulators. Co-immunoprecipitation and mass spectrometry assays were applied for protein interaction studies. Real-time reverse transcription-polymerase chain reaction, western blotting, sequential chromatin immunoprecipitation and dual-luciferase reporter assays were carried out to explore gene expression regulation. The biological characteristics of NB cell lines were examined via gain- and loss-of-function assays. For survival analysis, the Cox regression model and log-rank tests were used. RESULTS: Cellular nucleic acid-binding protein (CNBP) was found to be an independent factor affecting NB outcome, which exerted oncogenic roles in ribosome biogenesis, tumourigenesis and aggressiveness. Mechanistically, karyopherin subunit beta 1 (KPNB1) was responsible for nuclear transport of CNBP, whereas liquid condensates of CNBP repressed the activity of switch/sucrose-nonfermentable (SWI/SNF) core subunits (SMARCC2/SMARCC1/SMARCA4) via interaction with SMARCC2, leading to alternatively increased activity of SMARCC1/SMARCA4 binary complex in facilitating gene expression essential for 18S ribosomal RNA (rRNA) processing in tumour cells, extracellular vesicle-mediated delivery of 18S rRNA and subsequent M2 macrophage polarisation. A cell-penetrating peptide blocking phase separation and interaction of CNBP with SMARCC2 inhibited ribosome biogenesis and NB progression. High KPNB1, CNBP, SMARCC1 or SMARCA4 expression or low SMARCC2 levels were associated with poor survival of NB patients. CONCLUSIONS: These findings suggest that CNBP phase separation is a target for inhibiting ribosome biogenesis and tumour progression in NB via modulating SWI/SNF complex activity.