Long noncoding RNA NEAT1 inhibits the acetylation of PTEN through the miR-524-5p /HDAC1 axis to promote the proliferation and invasion of laryngeal cancer cells

Decoding PTEN: from biological functions to signaling pathways in tumors

The tumor suppressor gene Phosphatase and tensin homologue deleted on chromosome 10 (PTEN), possessing both protein and lipid phosphatase activities, is frequently mutated in various human cancers. PTEN aberrations disrupt critical cellular processes like proliferation, apoptosis, migration, and invasion, thereby promoting tumor growth. In the cells, PTEN localizes to the nucleus, cytoplasm, or cell membrane, and its roles depends on the subcellular localization. PTEN is regulated at the transcriptional, post-transcriptional, and post-translational levels, implying that its functions on the tumors are complex. The relationship between PTEN abnormalities and tumors has garnered significant interest in recent years. PTEN regulates essential cellular processes involved in tumorigenesis. Mutations or deletions in the PTEN gene often correlate with unfavorable prognosis and increased cancer recurrence. Numerous studies suggest that PTEN expression levels in tumors could be a valuable biomarker for cancer diagnosis, treatment, and predicting patient outcomes. This paper provides a comprehensive review of the biological function, regulatory mechanisms, and post-translational modifications of PTEN. Furthermore, this review explores the expression and regulation of PTEN in different tumor types, as well as its interactions with environmental factors in tumorigenesis. This comprehensive analysis aims to deepen our understanding of the signaling pathways between PTEN and cancer.

Exosomal circKIAA1797 Regulates Cell Progression and Glycolysis by Targeting miR-4429/PBX3 Pathway in Gastric Cancer

In recent years, circular RNAs (circRNAs) are extensively studied in the progression of various types of cancer, while the mechanism of circKIAA1797 is rarely studied in gastric cancer (GC). Hence, this research aimed to investigate the expression of exosomal circKIAA1797 and its biological function in GC cells. Exosomes were extracted from the serum of GC patients and identified by transmission electron microscopy (TEM) and nanoparticle tracking analyzer (NTA). CD81, CD63, Bcl-2, Bax, and pre-leukemia transcription factor 3 (PBX3) protein levels were detected using western blot assay. circKIAA1797, microRNA-4429 (miR-4429), and PBX3 mRNA were determined by quantitative real-time PCR (RT-qPCR). Cell proliferation, migration, invasion, and apoptosis were assessed using colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, transwell assay, and flow cytometry assay. Glucose consumption and lactate production levels were examined using glycolysis detection kits. The interaction between miR-4429 and circKIAA1797 or PBX3 was identified using dual-luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation (RIP) assay. Xenograft mouse model assay was used to investigate the effect of exosomal circKIAA1797 in vivo. It was found that circKIAA1797 was up-regulated in GC tissues and cells, as well as in the exosomes derived from the serum of GC patients. Silencing of exosomal circKIAA1797 could hamper cell progression and glycolytic metabolism of GC. Mechanically, circKIAA1797 acted as a sponge of miR-4429 to regulate PBX3 expression. Moreover, the knockdown of exosomal circKIAA1797 repressed tumor growth in vivo. Our data demonstrated that knockdown of exosomal circKIAA1797 suppressed GC malignant phenotypes by regulating miR-4429/PBX3 axis, which might offer a promising therapeutic strategy for GC treatment.

Long non-coding RNA NEAT1 promotes aerobic glycolysis and progression of cervical cancer through WNT/β-catenin/PDK1 axis

BACKGROUND

Cervical cancer is one of the most common gynecological cancers. Accumulated evidence shows that long non-coding RNAs (lncRNAs) play essential roles in cervical cancer occurrence and progression, but their specific functions and mechanisms remain to be further explored.

METHODS

The RT-qPCR assay was used to detect the expression of NEAT1 in cervical cancer tissues and cell lines. CCK-8, colony formation, flow cytometry, western blotting, and Transwell assays were used to evaluate the impact of NEAT1 on the malignant behavior of cervical cancer cells. Glucose consumption, lactate production, ATP levels, ROS levels, MMP levels, and the mRNA expressions of glycolysis-related genes and tricarboxylic acid cycle-related genes were detected to analyze the effect of NEAT1 on metabolism reprograming in cervical cancer cells. The expressions of PDK1, β-catenin and downstream molecules of the WNT/β-catenin signaling pathway in cervical cancer cells and tissues were detected by western blotting, RT-qPCR, immunofluorescence and immunohistochemistry assays.

RESULTS

This study investigated the role and possible molecular mechanism of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in cervical cancer. Our results showed that NEAT1 was highly expressed in cervical cancer tissues and cell lines. Downregulation of NEAT1 inhibited the proliferation, migration, invasion and glycolysis of cervical cancer cells, while overexpression of NEAT1 led to the opposite effects. Mechanistically, NEAT1 upregulated pyruvate dehydrogenase kinase (PDK1) through the WNT/β-catenin signaling pathway, which enhanced glycolysis and then facilitated cervical cancer metastasis. Furthermore, NEAT1 maintained the protein stability of β-catenin but did not affect its mRNA level. We also excluded the direct binding of NEAT1 to the β-catenin protein via RNA pull-down assay. The suppressive impact of NEAT1 knockdown on cell proliferation, invasion, and migration was rescued by β-catenin overexpression. The WNT inhibitor iCRT3 attenuated the carcinogenic effect induced by NEAT1 overexpression.

CONCLUSION

In summary, these findings indicated that NEAT1 may contribute to the progression of cervical cancer by activating the WNT/β-catenin/PDK1 signaling axis.

Identification of long noncoding RNA NEAT1 as a key gene involved in the extramedullary disease of multiple myeloma by bioinformatics analysis

OBJECTIVE

Long non-coding RNAs (lncRNAs) are involved in tumorigenesis and play a key role in cancer progression. To determine whether lncRNAs are involved in extramedullary disease of multiple myeloma (EMD), we analyzed the expression profile of lncRNAs in EMD.

METHODS

Three pairs of EMD patients and their intramedullary MM cells were screened by microarray first. We extracted data from gene chips and made an identification of lncRNAs and mRNAs with significant differences between EMD group and non EMD group. WGCNA confirmed the EMD related gene module and drew a heat map to further determine the key gene lncRNA-NEAT1. In the meantime, bone marrow and extramedullary samples (hydrothorax and ascites) were collected from 2 MM patients and subjected to single-cell RNA-seq. Single cell Transcriptome analysis was conducted to verify the gene expression difference of malignant plasma cells derived from intramedullary and extramedullary. Then we verified high expression level of lncRNA-NEAT1 in EMD patients by using quantitative real-time PCR (qRT-PCR) and analyzed the correlation between expression patterns and survival and molecular genetics analysis of the LncRNA (NEAT1) involved in MM patients. At last, cell experiments were conducted to observe the effects of down-regulation of NEAT1on the proliferation, cell cycle and PTEN pathway related proteins of multiple myeloma cell lines U266 and RPMI8226.

RESULTS

We identified one of the EMD related key gene is lncRNA-NEAT1. Compared with patients without extramedullary lesions, intramedullary MM cells in EMD patients expressed NEAT1 highly. The outcome of parallel single-cell RNA sequencing (RNA-seq) revealed NEAT1 level of plasma cells came from pleural effusion /ascites increased significantly compared with myeloma-stricken bone marrow. By survival and molecular genetic analysis, NEAT1 gene expression was not associated with OS and PFS in MM patients. However, the expression of NEAT1 is related to adverse therapeutic reactions and the progression of MM. We found that the expressions of NEAT1 were negatively associated with albumin levels and were positively associated with gain of chromosome 1q, IGH-CCND1, IGH@-FGFR3/WHSC1,and IGH-MAF gene fusion, respectively. At the level of cell experiment, CCK-8, soft agar clone formation experiment and CFSE staining showed that down regulating NEAT1 could inhibit the proliferation of U266 and RPMI8226 cells; Cell cycle detection showed that down-regulation of NEAT1 would interfere with the cell cycle process, and RPMI 8226 cells were blocked in G1 phase. Western blot analysis showed that when the expression of NEAT1 was down regulated in U266 and RPMI 8226 cells, the expression of PTEN and p-PTEN (phosphorylated phosphatase and tensin homologue) was up-regulated, and the expression of PI3K, p-PI3K (human phosphorylated inositol 3 kinase), Akt, p-Akt (phosphorylated protein kinase B).

DISCUCCION AND CONCLUSION

This study provides novel insights into the lncRNA-NEAT1 and reveals that NEAT1 maybe a potential lncRNA biomarkers in EMD.

LncRNA NEAT1 antagonizes the inhibition of melanoma proliferation, migration, invasion and EMT by Polyphyllin B

Polyphyllin B (PPB) is a compound with anti-tumor effects. Nuclear paraspeckle assembly transcript 1 (NEAT1) is a long-stranded noncoding RNA that induces epithelial-mesenchymal transition (EMT) of tumor cells and promotes tumor growth and metastasis. However, the role and mechanism of PPB on melanoma and the correlation between them remain unclear. In this study we screened NEAT1 by using LncRNA transcriptomic sequencing, and then transfected B16F10 cells using OVER-NEAT1 lentivirus. Next, we found that PPB had significant proliferation inhibition of melanoma and B16F10 cells through MTT assay and establishment of mouse subcutaneous transplantation tumor model; in addition, through wound healing assay, transwell assay and establishment of mouse melanoma lung metastasis model, we found that PPB significantly inhibited the invasion and migration of B16F10 cells in vitro, and inhibited the metastasis of melanoma to lung, bone and liver in vivo. Finally, changes in the expression levels of EMT-related proteins were assessed by western blot (WB) and immunohistochemistry, and PPB significantly downregulated the expression levels of MMP-9, N-cadherin, etc., and upregulated E-cadherin. While overexpressed NEAT1 showed the ability to promote melanoma proliferation, migration and invasion, in addition to partially reversed the inhibition of proliferation, migration and invasion of melanoma by PPB mentioned above.

Silencing EIF3A ameliorates pulmonary arterial hypertension through HDAC1 and PTEN/PI3K/AKT pathway in vitro and in vivo

Pulmonary vascular remodeling caused by the excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs) is the hallmark feature of pulmonary arterial hypertension (PAH). Eukaryotic initiation factor 3 subunit A (EIF3A) exhibited proliferative activity in multiple cell types. The present study investigated the role of EIF3A in the progression of PAH. A monocrotaline (MCT)-induced PAH rat model was constructed, and adeno-associated virus type 1 (AAV1) carrying EIF3A shRNA was intratracheally delivered to PAH rats to block EIF3A expression. PASMCs were isolated from rats and treated with PDGF-BB to simulate PASMC proliferation, and shRNA for EIF3 was conducted to investigate the mechanism behind the role of EIF3A in PASMC function in vitro. EIF3A expression was upregulated in pulmonary arteries, and EIF3A inhibition effectively improved pulmonary hypertension and right ventricular hypertrophy and suppressed MCT-induced vascular remodeling in vivo. In addition, we found that genetic knockdown of EIF3A reduced PDGF-triggered proliferation and arrested cell cycle, accompanied by downregulated proliferation-related protein expression in PASMCs. Mechanistically, the histone deacetylase 1 (HDAC1)-mediated PTEN/PI3K/AKT pathway was recognized as a primary mechanism in PAH progression. Silencing EIF3A decreased HDAC1 expression, and further inhibited the excessive proliferation of PASMCs by increasing the phosphatase and tension homolog (PTEN) expression and suppressing the AKT phosphorylation. Notably, HDAC1 expression reversed the effect of silencing EIF3A on PAH and PTEN/PI3K/AKT pathway. Collectively, silencing EIF3A improved PAH by decreasing PASMC proliferation through the HDAC1-mediated PTEN/PI3K/AKT pathway. These findings suggest that targeting EIF3A may represent a potential approach for the treatment of PAH.

Expression, Significance, and Correlation of Histone Deacetylase 1/RE-1 Silencing Transcription Factor and Neuronal Markers in Glioma

BACKGROUND

Inducing the differentiation of glioma cells into neuron-like cells may be an effective strategy to combat glioma. The histone deacetylase 1/RE-1 silencing transcription factor (HDAC1/REST) complex regulates the expression of multiple neuronal genes. In this study, we analyzed the presence and significance of this regulatory effect in glioma based on bioinformatics methods.

METHODS

The Human Protein Atlas database was used to obtain immunohistochemical staining images. The Gene Expression Profiling Interactive Analysis and Chinese Glioma Genome Atlas databases were used to analyze the expression of HDAC1/REST and neuronal markers in glioma, their effects on survival, and the association between HDAC1/REST and the expression of neuronal markers and stem cell markers. The differentially expressed genes between the high and low HDAC1/REST groups were explored. The Database for Annotation, Visualization and Integrated Discovery database was used for gene ontology and kyoto encyclopedia of genes and genomes pathway enrichment analysis.

RESULTS

The results showed that the expression of HDAC1 and REST increased with the grade of glioma, while the expression of neuronal markers decreased with the grade of glioma. High expression of HDAC1/REST and low expression of neuronal markers were associated with poor prognosis. HDAC1/REST expression was negatively correlated with the expression of neuronal markers, and positively correlated with the expression of neural stem cell markers. The genes up-regulated in the high HDAC1/REST group were mainly related to extracellular matrix and inflammation, and the down-regulated genes were mainly related to synapsis.

CONCLUSIONS

This study suggested that HDAC1/REST may be involved in maintaining the malignant phenotype of glioma cells and the stem cell status of glioma stem cells by inhibiting the expression of neuronal markers, which promote the progression of glioma.

Effect of CADM1 on TPF-induced chemotherapy in laryngeal squamous cell carcinoma

OBJECTIVES

To explore the relationship between CADM1 expression and sensitivity to TPF-induced chemotherapy in laryngeal squamous cell carcinoma (LSCC) patients, then investigate its potential mechanisms.

METHODS

Differential CADM1 expression was examined in chemotherapy-sensitive and chemotherapy-insensitive LSCC patient samples after TPF-induced chemotherapy using microarray analysis. Receiver operating characteristic (ROC) curve analysis and bioinformatics approaches were used to investigate the diagnostic value of CADM1. Small interfering RNAs (siRNAs) were used to knock down CADM1 expression in an LSCC cell line. Differential CADM1 expression was compared by qRT-PCR assays in 35 LSCC patients treated with chemotherapy, including 20 chemotherapy-sensitive and 15 chemotherapy-insensitive patients.

RESULTS

Public database and primary patient data both suggest that CADM1 mRNA is expressed at lower levels in chemotherapy-insensitive LSCC samples, suggesting its potential usefulness as a biomarker. Knockdown of CADM1 with siRNAs led to decreased sensitivity of LSCC cells to TPF chemotherapy.

CONCLUSIONS

Upregulation of CADM1 expression can alter the sensitivity of LSCC tumors to TPF induction chemotherapy. CADM1 is a possible molecular marker and therapeutic target for induction chemotherapy in LSCC patients.

Diagnostic and Prognostic Value of microRNAs in Patients with Laryngeal Cancer: A Systematic Review

Laryngeal squamous cell cancer (LSCC) is one of the most common malignant tumors of the head and neck region, with a poor survival rate (5-year overall survival 50-80%) as a consequence of an advanced-stage diagnosis and high recurrence rate. Tobacco smoking and alcohol abuse are the main risk factors of LSCC development. An early diagnosis of LSCC, a prompt detection of recurrence and a more precise monitoring of the efficacy of different treatment modalities are currently needed to reduce the mortality. Therefore, the identification of effective diagnostic and prognostic biomarkers for LSCC is crucial to guide disease management and improve clinical outcomes. In the past years, a dysregulated expression of small non-coding RNAs, including microRNAs (miRNAs), has been reported in many human cancers, including LSCC, and many miRNAs have been explored for their diagnostic and prognostic potential and proposed as biomarkers. We searched electronic databases for original papers that were focused on miRNAs and LSCC, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. According to the outcome, 566 articles were initially screened, of which 177 studies were selected and included in the analysis. In this systematic review, we provide an overview of the current literature on the function and the potential diagnostic and prognostic role of tissue and circulating miRNAs in LSCC.

RBM10 regulates alternative splicing of lncRNA Neat1 to inhibit the invasion and metastasis of NSCLC

Background

Non-small cell lung cancer (NSCLC) accounts for more than 85% of the total cases with lung cancer. NSCLC is characterized by easy metastasis, which often spreads to bones, brains and livers. RNA-binding motif protein 10 (RBM10) is an alternative splicing (AS) regulator frequently mutated in NSCLC. We found that there were multiple peak binding sites between RBM10 and long non-coding RNA nuclear enriched abundant transcript 1 (LncRNA Neat1) by crosslinking-immunprecipitation and high-throughput sequencing (Clip-Seq). LncRNA Neat1 plays an indispensable role in promoting cancer in a variety of tumors and produces two splicing variants: Neat1_1 and Neat1_2. This study aims to explore the mechanism of RBM10 and LncRNA Neat1 in invasion and metastasis of NSCLC.

Methods

Through histological and cytological experiments, we assessed the expression level of RBM10 protein expression. The interaction between RBM10 and Neat1 was evaluated via Clip-Seq and RNA immunoprecipitation assay. The effect of RBM10 on Neat1 and its splicing variants was identified by RT-qPCR. The effect of RBM10 and Neat1 on invasive and metastasis phenotypes of NSCLC was analyzed using transwell invasion assay and scratch test. Additionally, downstream signaling pathway of RBM10 were identified by immunofluorescence and western blot.

Results

RBM10 exhibited low levels of expression in NSCLC tissues and cells. RBM10 inhibited the invasion and metastasis of NSCLC and recruited Neat1 and Neat1_2. Overexpression of RBM10 simultaneously inhibited Neat1 and Neat1_2, and promoted the expression of Neat1_1. On the other hand, silencing RBM10 promoted Neat1 and Neat1_2, and inhibited the expression of Neat1_1. From this, we concluded that RBM10 regulated AS of Neat1, and the tumor-promoting effect of Neat1 was mainly attributed to Neat1_2. RBM10 had a negative correlation with Neat1_2. In addition, RBM10 upregulated the expression of PTEN and downregulated the phosphorylation of PI3K/AKT/mTOR through Neat1_2, which ultimately inhibited the invasion and metastasis of NSCLC.

Conclusion

The RBM10 regulated AS of Neat1 to cause the imbalance of Neat1_1 and Neat1_2, and RBM10 suppressed the activation of the PTEN/PI3K/AKT/mTOR signal by downregulating Neat1_2, finally affected the invasion and metastasis of NSCLC.

Metabolite-derived protein modifications modulating oncogenic signaling

Malignant growth is defined by multiple aberrant cellular features, including metabolic rewiring, inactivation of tumor suppressors and the activation of oncogenes. Even though these features have been described as separate hallmarks, many studies have shown an extensive mutual regulatory relationship amongst them. On one hand, the change in expression or activity of tumor suppressors and oncogenes has extensive direct and indirect effects on cellular metabolism, activating metabolic pathways required for malignant growth. On the other hand, the tumor microenvironment and tumor intrinsic metabolic alterations result in changes in intracellular metabolite levels, which directly modulate the protein modification of oncogenes and tumor suppressors at both epigenetic and post-translational levels. In this mini-review, we summarize the crosstalk between tumor suppressors/oncogenes and metabolism-induced protein modifications at both levels and explore the impact of metabolic (micro)environments in shaping these.

Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) modulates inhibitor of DNA binding 1 (ID1) to facilitate papillary thyroid carcinoma development by sponging microRNA-524-5p

Long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) exerts a pro-oncogenic role in several cancers, whereas its underlying regulatory mechanism in papillary thyroid carcinoma (PTC) progression remains unknown. This research mainly explored the roles of NEAT1 in PTC development. Quantitative real-time polymerase-chain reaction (qRT-PCR) was applied to measure NEAT1, miR-524-5p, and inhibitor of DNA binding 1 (ID1) expression in PTC tissues and cells. Western blot was conducted for detecting the protein levels. MTT, transwell, and flow cytometry assays were applied to assess cell proliferation, metastasis, and apoptosis in PTC cells in vitro. The PTC xenograft tumor model was used for investigating the role of NEAT1 in vivo. Dual-luciferase reporter assay was utilized for confirming the interaction between miR-524-5p and NEAT1 or ID1. In PTC tissues and cells, NEAT1 was significantly up-regulated. NEAT1 silencing blocked cell proliferation, metastasis, and facilitated apoptosis in vitro and impeded xenograft tumor growth in vivo. Bioinformatics prediction revealed the existence of binding sites between NEAT1 and miR-524-5p. Besides, ID1 was confirmed as a direct target to miR-524-5p, and the enhancement of ID1 reversed the regulation of miR-524-5p upregulation on cell progression. In addition, NEAT1 promoted PTC development by regulating ID1 expression via sponging miR-524-5p in PTC. In summary, we demonstrate that NEAT1 advanced the process of PTC by miR-524-5p/ID1 axis, which may enhance our comprehension of PTC pathogenesis.

Histone Modifications and Non-Coding RNAs: Mutual Epigenetic Regulation and Role in Pathogenesis

In the last few years, more and more scientists have suggested and confirmed that epigenetic regulators are tightly connected and form a comprehensive network of regulatory pathways and feedback loops. This is particularly interesting for a better understanding of processes that occur in the development and progression of various diseases. Appearing on the preclinical stages of diseases, epigenetic aberrations may be prominent biomarkers. Being dynamic and reversible, epigenetic modifications could become targets for a novel option for therapy. Therefore, in this review, we are focusing on histone modifications and ncRNAs, their mutual regulation, role in cellular processes and potential clinical application.

Mechanism of miR-340-5p in laryngeal cancer cell proliferation and invasion through the lncRNA NEAT1/MMP11 axis

OBJECTIVES

Laryngeal cancer (LC), with a relatively rare diagnosis, is a primary malignancy originating from laryngeal mucosa. This study investigated the mechanisms of microRNA (miR)- 340-5p in LC cell proliferation and invasion.

METHODS

The expression patterns of miR-340-5p, long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1), and matrix metallopeptidase 11 (MMP11) in LC cells, tissues, and para-carcinoma tissues, and human bronchial epithelial cells (HBEC) were examined via RT-qPCR. The effects of elevating or silencing miR-340-5p on LC cell proliferation and invasion were examined. The subcellular localization of lncRNA NEAT1 was determined. The binding relations among miR-340-5p, lncRNA NEAT1, and MMP11 were verified. Functional rescue experiments were designed to verify the functions of lncRNA NEAT1 and MMP11 on LC cell proliferation and invasion. Nude-mouse tumor models were established to assess the role of miR-340-5p in LC in vivo.

RESULTS

miR-340-5p was under-expressed in LC, and miR-340-5p overexpression repressed LC cell proliferation and invasion. Mechanically, miR-340-5p decreased lncRNA NEAT1 stability via directly binding to lncRNA NEAT1 and thus declined lncRNA NEAT1 expression in LC cells, while lncRNA NEAT1 accelerated MMP11 transcription via binding to heat shock factor 1 (HSF1). Overexpression of lncRNA NEAT1 or MMP11 reversed the repression of miR-340-5p overexpression on LC cell proliferation and invasion. In vivo, miR-340-5p overexpression repressed the tumor growth.

CONCLUSION

miR-340-5p overexpression reduced lncRNA NEAT1 stability via binding to lncRNA NEAT1, which declined lncRNA NEAT1 expression and reduced the binding of lncRNA NEAT1 to HSF1 to further inhibit MMP11 transcription, thus repressing LC cell proliferation and invasion.