Non-coding RNAs: new biomarkers and therapeutic targets for esophageal cancer

Learning Association Characteristics by Dynamic Hypergraph and Gated Convolution Enhanced Pairwise Attributes for Prediction of Disease-Related lncRNAs

As the long non-coding RNAs (lncRNAs) play important roles during the incurrence and development of various human diseases, identifying disease-related lncRNAs can contribute to clarifying the pathogenesis of diseases. Most of the recent lncRNA-disease association prediction methods utilized the multi-source data about the lncRNAs and diseases. A single lncRNA may participate in multiple disease processes, and multiple lncRNAs usually are involved in the same disease process synergistically. However, the previous methods did not completely exploit the biological characteristics to construct the informative prediction models. We construct a prediction model based on adaptive hypergraph and gated convolution for lncRNA-disease association prediction (AGLDA), to embed and encode the biological characteristics about lncRNA-disease associations, the topological features from the entire heterogeneous graph perspective, and the gated enhanced pairwise features. First, the strategy for constructing hyperedges is designed to reflect the biological characteristic that multiple lncRNAs are involved in multiple disease processes. Furthermore, each hyperedge has its own biological perspective, and multiple hyperedges are beneficial for revealing the diverse relationships among multiple lncRNAs and diseases. Second, we encode the biological features of each lncRNA (disease) node using a strategy based on dynamic hypergraph convolutional networks. The strategy may adaptively learn the features of the hyperedges and formulate the dynamically evolved hypergraph topological structure. Third, a group convolutional network is established to integrate the entire heterogeneous topological structure and multiple types of node attributes within an lncRNA-disease-miRNA graph. Finally, a gated convolutional strategy is proposed to enhance the informative features of the lncRNA-disease node pairs. The comparison experiments indicate that AGLDA outperforms seven advanced prediction methods. The ablation studies confirm the effectiveness of major innovations, and the case studies validate AGLDA's ability in application for discovering potential disease-related lncRNA candidates.

MiR-199a-5p Decreases Esophageal Cancer Cell Proliferation Partially through Repression of Jun-B

MicroRNA (miR)-199a-5p has been shown to function as a tumor suppressor in some malignancies but its role in esophageal cancer is poorly understood. To further explore its role in esophageal cancer, we sought to investigate the interaction between miR-199a-5p and Jun-B, an important component of the AP1 transcription factor, which contains a potential binding site for miR-199a-5p in its mRNA. We found that levels of miR-199a-5p are reduced in both human esophageal cancer specimens and in multiple esophageal cancer cell lines compared to esophageal epithelial cells. Jun-B expression is correspondingly elevated in these tumor specimens and in several cell lines compared to esophageal epithelial cells. Jun-B mRNA expression and stability, as well as protein expression, are markedly decreased following miR-199a-5p overexpression. A direct interaction between miR-199a-5p and Jun-B mRNA was confirmed by a biotinylated RNA-pull down assay and luciferase reporter constructs. Either forced expression of miR-199a-5p or Jun-B silencing led to a significant decrease in cellular proliferation as well as in AP-1 promoter activity. Our results provide evidence that miR-199a-5p functions as a tumor suppressor in esophageal cancer cells by regulating cellular proliferation, partially through repression of Jun B.

Biomarkers for Early Detection, Prognosis, and Therapeutics of Esophageal Cancers

Esophageal cancer (EC) is the deadliest cancer worldwide, with a 92% annual mortality rate per incidence. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of ECs, with EAC having one of the worst prognoses in oncology. Limited screening techniques and a lack of molecular analysis of diseased tissues have led to late-stage presentation and very low survival durations. The five-year survival rate of EC is less than 20%. Thus, early diagnosis of EC may prolong survival and improve clinical outcomes. Cellular and molecular biomarkers are used for diagnosis. At present, esophageal biopsy during upper endoscopy and histopathological analysis is the standard screening modality for both ESCC and EAC. However, this is an invasive method that fails to yield a molecular profile of the diseased compartment. To decrease the invasiveness of the procedures for diagnosis, researchers are proposing non-invasive biomarkers for early diagnosis and point-of-care screening options. Liquid biopsy involves the collection of body fluids (blood, urine, and saliva) non-invasively or with minimal invasiveness. In this review, we have critically discussed various biomarkers and specimen retrieval techniques for ESCC and EAC.

Circ_0003340 regulates the expression of ENAH to affect the development of esophageal cancer through miR-874-3p

BACKGROUND

Esophageal cancer is a malignant tumor with a poor prognosis and high incidence. Circular RNAs (circRNAs) have been shown to be involved in the pathogenesis of cancers, including esophageal cancer. Here, we explored the precise role of circ_0003340 in esophageal cancer development.

METHODS

The expression levels of circ_0003340, miR-874-3p and enabled homolog (ENAH) were detected by quantitative real-time polymerase chain reaction and western blot. Subcellular localization and RNase R assays were used to characterize circ_0003340. Cell Counting Kit 8, flow cytometry, transwell assays were used to analyze cell proliferation, apoptosis, migration and invasion. The effect of circ_0003340 on tumor growth was assessed by tumor experiments in vivo. Dual-luciferase reporter assay was used to analyze the relationship between miR-874-3p and circ_0003340 or ENAH.

RESULTS

Circ_0003340 was mainly located in the cytoplasm and was upregulated in esophageal cancer tissues and cells. Circ_0003340 knockdown inhibited cell proliferation, migration, invasion, glucose consumption, and lactate production and induced cell apoptosis in esophageal cancer cells. Moreover, circ_0003340 knockdown suppressed tumor growth in vivo. MiR-874-3p was reduced in esophageal cancer tissues and cells, and it was a molecular mediator of circ_0003340 function in esophageal cancer cells. ENAH was identified as a direct and functional target of miR-874-3p in esophageal cancer cells. The promotion effect of circ_0003340 on ENAH was ameliorated by miR-874-3p.

CONCLUSION

The data demonstrated that circ_0003340 promoted the progression of esophageal cancer through miR-874-3p/ENAH axis, which might provide novel therapeutic targets for esophageal cancer intervention.

LncRNA HOXA10-AS promotes the progression of esophageal carcinoma by regulating the expression of HOXA10

Esophageal cancer (EC) remains a primary cause of cancer-associated fatality worldwide and is characterized by poor prognosis. HOXA10-AS is reported to be relevant with the development of different human cancers. However, its role and regulatory mechanism in EC are still obscure. Our study targeted at investigating the functional and mechanical roles of HOXA10-AS in EC. We confirmed by RT-qPCR that HOXA10-AS presented a remarkably high expression in EC cells. Functional experiments demonstrated that knocking down HOXA10-AS weakened proliferation, invasion and migration in vitro and impeded tumorigenesis in vivo. Further, we found that HOXA10-AS positively regulated its neighbor gene HOXA10 and influenced EC cell biological activities depending on HOXA10. Mechanistically, we showed that HOXA10-AS combined with FMR1 to target and stabilize HOXA10 mRNA. Moreover, HOXA10 served as a transcriptional factor to stimulate the transcription of its target gene CHDH. Finally, rescue assays confirmed that HOXA10 influenced EC cell growth through modulating CHDH. In conclusion, our study first determines the function of HOXA10-AS in EC and demonstrates its mechanism relating to HOXA10/CHDH, suggesting HOXA10-AS as a potential novel target for EC treatment. [Figure: see text].

circPOLR1C Promotes the Development of Esophageal Cancer by Adsorbing miR-361-3p and Regulating Cancer Cell Apoptosis and Metastasis

Background

The effect of circular RNA-RNA polymerase I and III subunit C (circPOLR1C) on esophageal cancer (EC) has not been reported. Herein, this study is designed to unveil the effect and the regulatory mechanism of circPOLR1C on EC.

Methods

The expression of circPOLR1C in EC tissues and cells was detected by qRT-PCR. Circular structure, stability, and cell localization of circPOLR1C were confirmed by qRT-PCR, RNase R, actinomycin D, and fluorescence in situ hybridization (FISH) assay. Cell function experiments, nude mouse xenograft, lung transplant model, and HE staining were performed to evaluate the effects of CircPOLR1C on EC in vitro and in vivo. A regulatory relationship between miR-361-3p and circPOLR1C was confirmed by qRT-PCR, circRNA in vivo precipitation, RIP, FISH, CircInteractome database, dual-luciferase reporter assay, and immunohistochemistry. Rescue experiments were applied to assess the effects of miR-361-3p and circPOLR1C on EC cells and tissues. Apoptosis- and epithelial-mesenchymal transformation (EMT)-related gene expressions were quantified by qRT-PCR and Western blot.

Results

Highly expressed circPOLR1C in EC was related to tumor differentiation and invasion. circPOLR1C, which mainly exists in the cytoplasm, is a stable circular RNA. circPOLR1C silencing inhibited circPOLR1C expression and EC cell malignant function, while circPOLR1C overexpression promoted the growth of transplanted tumors and lung metastasis. The enrichment of miR-361-3p was higher than that of other targeted miRNAs. circPOLR1C adsorbed miR-361-3p to regulate apoptosis- and EMT-related genes and partially reversed the tumor suppressive effect of miR-361-3p, which was lowly expressed in EC tissues. Silencing the target genes of miR-361-3p also inhibited the malignant development of EC cells.

Conclusion

circPOLR1C adsorbs miR-361-3p and regulates apoptosis- and EMT-related gene expressions to promote the development of EC.

Identification of the miRNA-mRNA regulatory network associated with radiosensitivity in esophageal cancer based on integrative analysis of the TCGA and GEO data

BACKGROUND

The current study set out to identify the miRNA-mRNA regulatory networks that influence the radiosensitivity in esophageal cancer based on the The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases.

METHODS

Firstly, esophageal cancer-related miRNA-seq and mRNA-seq data were retrieved from the TCGA database, and the mRNA dataset of esophageal cancer radiotherapy was downloaded from the GEO database to analyze the differential expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs) in radiosensitive and radioresistant samples, followed by the construction of the miRNA-mRNA regulatory network and Gene Ontology and KEGG enrichment analysis. Additionally, a prognostic risk model was constructed, and its accuracy was evaluated by means of receiver operating characteristic analysis.

RESULTS

A total of 125 DEmiRNAs and 42 DEmRNAs were closely related to the radiosensitivity in patients with esophageal cancer. Based on 47 miRNA-mRNA interactions, including 21 miRNAs and 21 mRNAs, the miRNA-mRNA regulatory network was constructed. The prognostic risk model based on 2 miRNAs (miR-132-3p and miR-576-5p) and 4 mRNAs (CAND1, ZDHHC23, AHR, and MTMR4) could accurately predict the prognosis of esophageal cancer patients. Finally, it was verified that miR-132-3p/CAND1/ZDHHC23 and miR-576-5p/AHR could affect the radiosensitivity in esophageal cancer.

CONCLUSION

Our study demonstrated that miR-132-3p/CAND1/ZDHHC23 and miR-576-5p/AHR were critical molecular pathways related to the radiosensitivity of esophageal cancer.

Demystifying the Functional Role of Nuclear Receptors in Esophageal Cancer

Esophageal cancer (EC), an aggressive and poorly understood disease, is one of the top causes of cancer-related fatalities. GLOBOCAN 2020 reports that there are 544,076 deaths and 604,100 new cases expected worldwide. Even though there are various advancements in treatment procedures, this cancer has been reported as one of the most difficult cancers to cure, and to increase patient survival; treatment targets still need to be established. Nuclear receptors (NRs) are a type of transcription factor, which has a key role in several biological processes such as reproduction, development, cellular differentiation, stress response, immunity, metabolism, lipids, and drugs, and are essential regulators of several diseases, including cancer. Numerous studies have demonstrated the importance of NRs in tumor immunology and proved the well-known roles of multiple NRs in modulating proliferation, differentiation, and apoptosis. There are surplus of studies conducted on NRs and their implications in EC, but only a few studies have demonstrated the diagnostic and prognostic potential of NRs. Therefore, there is still a paucity of the role of NRs and different ways to target them in EC cells to stop them from spreading malignancy. This review emphasizes the significance of NRs in EC by discussing their diverse agonists as well as antagonists and their response to tumor progression. Additionally, we emphasize NRs’ potential to serve as a novel therapeutic target and their capacity to treat and prevent EC.

Untargeted serum metabolomics reveals potential biomarkers and metabolic pathways associated with esophageal cancer

Metabolomics has been reported as an efficient tool to screen biomarkers that are related to esophageal cancer. However, the metabolic biomarkers identifying malignant degrees and therapeutic efficacy are still largely unknown in the disease. Here, GC-MS-based metabolomics was used to understand metabolic alteration in 137 serum specimens from patients with esophageal cancer, which is approximately two- to fivefold as many plasma specimens as the previous reports. The elevated amino acid metabolism is in sharp contrast to the reduced carbohydrate as a characteristic feature of esophageal cancer. Comparative metabolomics showed that most metabolic differences were determined between the early stage (0–II) and the late stage (III and IV) among the 0–IV stages of esophageal cancer and between patients who received treatment and those who did not receive treatment. Glycine, serine, and threonine metabolism and glycine were identified as the potentially overlapped metabolic pathway and metabolite, respectively, in both disease progress and treatment effect. Glycine, fructose, ornithine, and threonine can be a potential array for the evaluation of disease prognosis and therapy in esophageal cancer. These results highlight the means of identifying previously unknown biomarkers related to esophageal cancer by a metabolomics approach.

Learning global dependencies and multi-semantics within heterogeneous graph for predicting disease-related lncRNAs

Motivation

Long noncoding RNAs (lncRNAs) play an important role in the occurrence and development of diseases. Predicting disease-related lncRNAs can help to understand the pathogenesis of diseases deeply. The existing methods mainly rely on multi-source data related to lncRNAs and diseases when predicting the associations between lncRNAs and diseases. There are interdependencies among node attributes in a heterogeneous graph composed of all lncRNAs, diseases and micro RNAs. The meta-paths composed of various connections between them also contain rich semantic information. However, the existing methods neglect to integrate attribute information of intermediate nodes in meta-paths.

Results

We propose a novel association prediction model, GSMV, to learn and deeply integrate the global dependencies, semantic information of meta-paths and node-pair multi-view features related to lncRNAs and diseases. We firstly formulate the global representations of the lncRNA and disease nodes by establishing a self-attention mechanism to capture and learn the global dependencies among node attributes. Second, starting from the lncRNA and disease nodes, respectively, multiple meta-pathways are established to reveal different semantic information. Considering that each meta-path contains specific semantics and has multiple meta-path instances which have different contributions to revealing meta-path semantics, we design a graph neural network based module which consists of a meta-path instance encoding strategy and two novel attention mechanisms. The proposed meta-path instance encoding strategy is used to learn the contextual connections between nodes within a meta-path instance. One of the two new attention mechanisms is at the meta-path instance level, which learns rich and informative meta-path instances. The other attention mechanism integrates various semantic information from multiple meta-paths to learn the semantic representation of lncRNA and disease nodes. Finally, a dilated convolution-based learning module with adjustable receptive fields is proposed to learn multi-view features of lncRNA-disease node pairs. The experimental results prove that our method outperforms seven state-of-the-art comparing methods for lncRNA-disease association prediction. Ablation experiments demonstrate the contributions of the proposed global representation learning, semantic information learning, pairwise multi-view feature learning and the meta-path instance encoding strategy. Case studies on three cancers further demonstrate our method’s ability to discover potential disease-related lncRNA candidates.

Contact

zhang@hlju.edu.cn or peiliangwu@ysu.edu.cn

Supplementary information

Supplementary data are available at Briefings in Bioinformatics online.

Circ_0,007,331 Promotes the PTX Resistance and Progression of Breast Cancer via miR-200b-3p/ANLN

INTRODUCTION

The objective of our study was to explore the expression pattern of circular ribonucleic acid (RNA)_0,007,331 (circ_0,007,331) in breast cancer (BC) and its functional association with cellular paclitaxel (PTX) resistance and proliferation, migration, invasion and apoptosis.

METHODS

Real-time quantitative polymerase chain reaction was applied to measure RNA expression. The PTX resistance of BC cells was analyzed by cell counting kit-8 assay. Flow cytometry was applied to assess cell cycle progression and cell apoptosis. Transwell assays were utilized to analyze cell migration and invasion abilities. Protein expression was determined by Western blot assay. The target relationship between microRNA-200b-3p (miR-200b-3p) and circ_0,007,331 or Anillin (ANLN) was verified by dual-luciferase reporter assay and RNA-pull down assay. The in vivo role of circ_0,007,331 was analyzed using xenograft tumor model.

RESULTS

Circ_0,007,331 expression was elevated in PTX-resistant BC cell lines relative to parental BC cell lines. Circ_0,007,331 contributed to the PTX resistance, proliferation, migration, invasion and suppressed the apoptosis of BC cells. Circ_0,007,331 interacted with miR-200b-3p in BC cells. Circ_0,007,331 silencing-mediated effects in BC cells were largely overturned by the knockdown of miR-200b-3p. ANLN was a target of miR-200b-3p in BC cells. Circ_0,007,331 silencing reduced ANLN expression partly through upregulating miR-200b-3p in BC cells. miR-200b-3p overexpression-induced effects in BC cells were largely counteracted by the accumulation of ANLN. Circ_0,007,331 silencing aggravated PTX-mediated inhibitory effect on tumor growth in vivo.

CONCLUSIONS

Circ_0,007,331 contributed to the PTX resistance, proliferation and motility and inhibited the apoptosis of BC cells through mediating miR-200b-3p/ANLN signaling.

Construction of a novel necroptosis-related lncRNA signature for prognosis prediction in esophageal cancer

Background

Esophageal cancer (EC), one highly malignant gastrointestinal cancer, is the 6th leading cause of cancer-related deaths worldwide. Necroptosis and long non-coding RNA (lncRNA) play important roles in the occurrence and development of EC, but the research on the role of necroptosis-related lncRNA in EC is not conclusive. This study aims to use bioinformatics to investigate the prognostic value of necroptosis-related lncRNA in EC.

Methods

Transcriptome data containing EC and normal samples, and clinical information were obtained from the Cancer Genome Atlas database. 102 necroptosis-related genes were obtained from Kanehisa Laboratories. Necroptosis-related lncRNAs were screened out via univariate, multivariate Cox and the least absolute shrinkage and selection operator regression analyses to construct the risk predictive model. The reliability of the risk model was evaluated mainly through quantitative real-time PCR (qRT-PCR), the receiver operating characteristic (ROC) curves and the constructed nomogram. KEGG pathways were explored in the high- and low-risk groups of EC patients via gene set enrichment analyses (GSEA) software. Immune microenvironment and potential therapeutic agents in risk groups were also analyzed.

Results

A 6 necroptosis-related lncRNAs risk model composed of AC022211.2, Z94721.1, AC007991.2, SAMD12-AS1, AL035461.2 and AC051619.4 was established to predict the prognosis level of EC patients. qRT-PCR analysis showed upregulated Z94721.1 and AL035461.2 mRNA levels and downregulated AC051619.4 mRNA level in EC tissues compared with normal tissues. According to clinical characteristics, the patients in the high-risk group had a shorter overall survival than the low-risk group. The ROC curve and nomogram confirmed this model as one independent and predominant predictor. GSEA analysis showed metabolic and immune-related pathways enriched in the risk model. Most of the immune cells and immune checkpoints were positively correlated with the risk model, mainly active in the high-risk group. For the prediction of potential therapeutic drugs, 16 compounds in the high-risk group and 2 compounds in the low-risk group exhibited higher sensitivity.

Conclusions

Our results supported the necroptosis-related lncRNA signature could independently predict prognosis of EC patients, and provided theoretical basis for improving the clinical treatment of EC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02421-8.

The Role and Interactions of Programmed Cell Death 4 and its Regulation by microRNA in Transformed Cells of the Gastrointestinal Tract

Data from GLOBOCAN 2020 estimates that there were 19.3 million new cases of cancer and 10.0 million cancer-related deaths in 2020 and that this is predicted to increase by 47% in 2040. The combined burden of cancers of the gastrointestinal (GI) tract, including oesophageal-, gastric- and colorectal cancers, resulted in 22.6% of the cancer-related deaths in 2020 and 18.7% of new diagnosed cases. Understanding the aetiology of GI tract cancers should have a major impact on future therapies and lessen this substantial burden of disease. Many cancers of the GI tract have suppression of the tumour suppressor Programmed Cell Death 4 (PDCD4) and this has been linked to the expression of microRNAs which bind to the untranslated region of PDCD4 mRNA and either inhibit translation or target the mRNA for degradation. This review highlights the properties of PDCD4 and documents the evidence for the regulation of PDCD4 expression by microRNAs in cancers of the GI tract.

Silencing of histone deacetylase 3 suppresses the development of esophageal squamous cell carcinoma through regulation of miR-494-mediated TGIF1

BACKGROUND

Deacetylation of histones by histone deacetylase 3 (HDAC3) acts importantly in modulating apoptosis, DNA damage and cellular progression. Herein, we aimed to unravel the functional role of HDAC3 in a lethal disease, esophageal squamous cell carcinoma (ESCC).

METHODS

The expression of HDAC3 in clinically collected ESCC tissues was determined by RT-qPCR and immunohistochemistry. As revealed from bioinformatics analysis, the putative relations between HDAC3 and microRNA-494 (miR-494) and between miR-494 and transforming growth factor beta (TGFβ)-inducing factor 1 (TGIF1) were further verified by chromatin immunoprecipitation and dual-luciferase reporter gene assay. Functional roles of shRNA-mediated depletion of HDAC3, miR-494 mimic and overexpressed TGIF1 were explored by gain- and loss-of-function assays with regard to ESCC cell biological behaviors. A nude mouse model of ESCC was developed for in vivo validation.

RESULTS

HDAC3 was highly expressed in ESCC tissues, suggestive of poor prognosis while TGIF1 was upregulated and miR-494 was downregulated. Mechanistic investigation revealed that HDAC3 inhibited miR-494 expression and TGIF1 was a direct target of miR-494. Furthermore, silencing HDAC3 or overexpressing miR-494 was demonstrated to suppress aggressive phenotypes of ESCC cells both in vitro through the activated TGFβ signaling pathway and in vivo, while TGIF1 overexpression induced opposite results.

CONCLUSION

Collectively, our findings provided demonstration regarding the oncogenic property of HDAC3 in ESCC via the miR-494/TGIF1/TGFβ axis.

Immunotherapy Mechanism of Esophageal Squamous Cell Carcinoma with the Effect of STK11/AMPK Signaling Pathway

This study was aimed at exploring the mechanism of serine threonine protein kinase 11 (STK11)/Adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway after immunotherapy for esophageal squamous cell carcinoma (ESCC), providing basic information for the clinical treatment of ESCC. In this study, tissue specimens from 100 patients with ESCC who underwent surgical treatment in Taizhou People's Hospital (group A) and 20 patients with recurrent or metastatic ESCC who received second-line immunotherapy (group B) were collected. The real-time fluorescent quantitative polymerase chain reaction (PCR) (RT-qPCR) technology was used to detect the expression levels of STK11, interferon-γ (IFN-γ), interleukin 6 (IL-6), and vascular endothelial growth factor (VEGF) in the tissues. The immunohistochemical staining was used to detect the positive expression levels (PELs) of STK11 and AMPKα in the tissues, and immunofluorescence staining was used to detect the PELs Teff cells (CD3 and CD8), Treg cells (CD4 and FOXP3), and neutrophils (CD68 and CD163). RT-qPCR results showed that the expression levels of STK11 and IFN-γ in group A were obviously lower, and those of IL-6 and VEGF were much higher in contrast to group B (P < 0.05). The results of immunohistochemical staining showed that the number of STK11- and AMPKα-positive staining cells in group A was dramatically less than that in group B (P <0.05). The results of immunofluorescence staining revealed that the number of positive staining cells for Teff cells, Treg cells, and neutrophils in group A was also less dramatically than that in group B (P <0.05). In summary, immunotherapy can play a therapeutic effect on ESCC by regulating STK11/AMPK pathway and immune cell infiltration.

LINC00114 stimulates growth and glycolysis of esophageal cancer cells by recruiting EZH2 to enhance H3K27me3 of DLC1

Objective

LINC00114 could promote the development of colorectal cancer, but its mechanism has been rarely discussed in esophageal cancer (EC). Herein, we explored the molecular mechanism of LINC00114 via mediating enhancer of zeste homolog 2/deleted in liver cancer 1 (EZH2/DLC1) axis in EC.

Methods

LINC00114, EZH2 and DLC1 expression in EC tissues and cells were tested. LINC00114, EZH2 and DLC1 expression were altered in EC cells through transfection with different constructs, and cell proliferation, migration, invasion, apoptosis and glycolysis were subsequently observed. The interaction between LINC00114 and EZH2 and that between EZH2 and DLC1 were explored. Tumor formation was also conducted to confirm the in vitro results.

Results

The expression levels of LINC00114 and EZH2 were elevated while those of DLC1 were reduced in EC. Inhibiting LINC00114 or reducing EZH2 blocked cell proliferation, migration, invasion and glycolysis and induce cell apoptosis in EC. LINC00114 promoted H3K27 trimethylation of DLC1 by recruiting EZH2. Knockdown of DLC1 stimulated cell growth and glycolysis in EC and even mitigated the role of LINC00114 inhibition in EC. In vivo experiment further confirmed the anti-tumor effect of LINC00114 inhibition in EC.

Conclusion

The data indicate that LINC00114 promotes the development of EC by recruiting EZH2 to enhance H3K27me3 of DLC1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01258-y.

Dexmedetomidine inhibits the growth and metastasis of esophageal cancer cells by down-regulation of lncRNA MALAT1

This study aims to evaluate the effect of dexmedetomidine (DEX)-on esophageal cancer (EC) via regulating long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). The effect of DEX on MALAT1 expression and EC cell viability was detected. EC cells were divided into Blank, DEX, scrambled/MALAT1 siRNA, and DEX + control/MALAT1 groups, followed by a series of experiments including quantitative reverse-transcription polymerase chain reaction (qRT-PCR), western blotting, 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT), Annexin V-FITC/PI staining, wound healing, and Transwell assays. Additionally, mice were subjected to the subcutaneous injection of Eca109 cells transfected by control/MALAT1 activation lentiviral vector to construct EC models with the DEX treatment, and then the tumor volume and the expression of Ki-67 and active caspase-3 were determined. DEX reduced the expression of MALAT1 in EC cells in a dose-dependent manner. DEX inhibited the viability of EC cells, but increased the cell apoptosis, which, however, was reversed by MALAT1 overexpression. Moreover, MALAT1 overexpression abolished the inhibitory effect of DEX on the epithelial-mesenchymal transition (EMT) of EC cells, with enhanced migration and invasion. Furthermore, DEX succeeded in decreasing the tumor volume with the down-regulation of MALAT1. In comparison with the DEX group, mice in the DEX + MALAT1 group had larger tumors, with the up-regulation of Ki-67 and the down-regulation of active caspase-3. DEX can reduce the expression of MALAT1 in EC cells, thereby inhibiting the proliferation, invasion and migration, as well as EMT, and promoting the apoptosis of EC cells.

Integrative bioinformatics analysis identifies LINC01614 as a potential prognostic signature in esophageal cancer

Background

Esophageal cancer (EC) is one of the most common gastrointestinal cancers and the incidence is on the increase in recent years. The aim of the present study was to assess novel long non-coding RNA (lncRNA) biomarkers for the prognosis of EC through the analysis of gene expression microarrays.

Methods

Three datasets (GSE53622, GSE53624, and GSE53625) were downloaded from the Gene Expression Omnibus (GEO) database and EC patients’ clinical information were from The Cancer Genome Atlas (TCGA) databases. Differentially expressed genes (DEGs) were screened by comparing tumor tissues with normal tissues using limma R package. The Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database was used to obtain the novel lncRNAs and their co-expression genes in EC and these were visualized with the Cytoscape software. The Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthology Based Annotation System (KOBAS) database was used to analyze the functions enrichment of selected DEGs. Cell Counting Kit-8 (CCK8) and Transwell assays were used to further confirm the function of target lncRNAs.

Results

We identified 24 differentially expressed (DE) lncRNAs and 659 DE mRNAs from the intersection of GEO and TCGA databases. And we found that only LINC01614 was concerned with a candidate prognostic signature in EC. “Extracellular matrix (ECM)-receptor interaction” and “PI3K-Akt signaling pathway” were observed, and we constructed a lncRNA-mRNA co-expression network for EC that includes LINC01614 and 64 mRNAs. The results of CCK8 and Transwell assays showed that suppression of LINC01614 inhibited EC cell proliferation and migration.

Conclusions

Our study might provide LINC01614 as a novel lncRNA biomarker for diagnosis and prognosis in EC.

Long non-coding RNA HAGLROS regulates the proliferation, migration, and apoptosis of esophageal cancer cells via the HAGLROS-miR-206-NOTCH3 axis

Background

Esophageal cancer (EC) is a common malignant tumor of the digestive tract, the treatment of which involves surgery combined with radiotherapy and chemotherapy, as well as other comprehensive types of treatment. The pathogenesis of EC remains unclear, which hinders the development of clinical therapy and the identification of molecular targets for this disease. Long non-coding RNAs (lncRNAs) have been shown to be associated with the malignant biological behavior of EC, but the specific molecular mechanisms underlying the carcinogenesis of EC are not fully understood.

Methods

Reverse transcription-quantitative PCR (RT-qPCR) was applied to measure the lncRNA HAGLR opposite strand lncRNA (HAGLROS) levels in EC cell lines and tissues. Cell Counting Kit-8 (CCK-8) detection, scratch test, and Transwell assay were performed to determine the proliferation, migration and invasion of EC cell. The interaction between HAGLROS, microRNA (miR)-206, and notch receptor 3 (NOTCH3) was confirmed by RNA immunoprecipitation and dual luciferase reporter gene assays.

Results

HAGLROS is upregulated in esophageal squamous cell carcinoma (ESCC) tissues and predicts poor prognosis. Silent HAGLROS is negatively associated with malignant behavior in EC cells. Low expression of HAGLROS can induce decreased invasive and migratory abilities in EC cells. Downregulated HAGLROS significantly inhibits the proliferation of EC cells and accelerates apoptosis. HAGLROS promotes EC cell tumorigenesis in vivo. HAGLROS participates in the HAGLROS/miR-206/NOTCH3 regulatory axis in EC cells.

Conclusions

HAGLROS may play a role in the progression of EC by modulating the miR-206/NOTCH3 signaling axis, and may be a novel target for the diagnosis and treatment of EC.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

MicroRNA-4732 is downregulated in non-small cell lung cancer and inhibits tumor cell proliferation, migration, and invasion

BACKGROUND

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death with increasing morbidity and mortality. MicroRNA-4732-5p (miR-4732-5p) has been reported to be dysregulated in various cancers and identified as a tumor suppressor. This study aims to explore the expression and role of miR-4732-5p in NSCLC.

METHODS

Reverse transcription-quantitative polymerase chain reaction (qRT-PCR) assay was employed to detect the expression of miR-4732-5p in NSCLC. With the help of Kaplan-Meier survival and Cox regression, the prognostic significance of miR-4732-5p was investigated. Meanwhile, the effects of miR-4732-5p on cell proliferation, migration, and invasion were also studied.

RESULTS

The expression of miR-4732-5p decreased in NSCLC tissues and cells. The downregulation of miR-4732-5p was closely associated with lymph node metastasis, TNM stage, and poor prognosis. Multivariate Cox regression analysis results showed that miR-4732-5p was an independent prognosis factor for NSCLC. In addition, the overexpression of miR-4732-5p inhibited the proliferation, migration, and invasion of NSCLC cells through modulating TSPAN13.

CONCLUSIONS

These data showed that miR-4732-5p might be involved in the development of NSCLC, which can act as an independent prognostic biomarker and therapeutic target.

Significance of Circular FAT1 as a Prognostic Factor and Tumor Suppressor for Esophageal Squamous Cell Carcinoma

Background

Circular RNA is a novel endogenous non-coding RNA with a stable loop structure, and theories for its biogenesis and usefulness as a biomarker in various cancers have been proposed. The present study investigated the significance of circular FAT1 (circFAT1) as a novel biomarker in esophageal squamous cell carcinoma (ESCC).

Method

CircFAT1 expression levels were measured in ESCC cell lines and the effects of downregulating circFAT1 on cell migration and invasion were examined using a transwell assay. The functions of miR-548g, which will be sponged by circFAT1, were assessed. Furthermore, the expression of circFAT1 was evaluated in 51 radically resected ESCC tissue samples using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relationships between circFAT1 expression, clinicopathological factors, and patient prognosis were analyzed.

Results

CircFAT1 expression levels were significantly lower in tumor tissue than in adjacent non-tumorous mucosal tissue (p = 0.01). The downregulation of circFAT1 expression promoted ESCC cell migration and invasive ability, but not proliferation. The expression of miR-548g was upregulated by the downregulation of circFAT1. The overexpression of miR-548g also promoted ESCC cell migration and invasion. Recurrence-free survival (p = 0.02) and cancer-specific survival (p = 0.04) rates were significantly higher in patients with elevated circFAT1 expression levels.

Conclusion

The expression level of circFAT1 is a novel prognostic marker in ESCC patients. New treatment strategies may be developed using the tumor suppressive functions of circFAT1.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10089-9.

Prognostic value of microRNA-378 in esophageal cancer and its regulatory effect on tumor progression

The incidence and mortality rates of esophageal squamous cell carcinoma (ESCC) are high in China, which has increased the clinical and economic burden. The present study aimed to investigate the role of microRNA (miRNA/miR)-378 in ESCC. Reverse transcription-quantitative polymerase chain reaction analysis was performed to detect miR-378 expression in ESCC tissues and cell lines. Survival analysis was performed using the Kaplan-Meier method, while Cox regression analysis was performed to determine the prognostic value of miR-378 in ESCC. miR-378 mimic and miR-378 inhibitor was transfected into ESCC cells to overexpress or knockdown miR-378 expression levels in ESCC cells. The Cell Counting Kit-8 assay was performed to assess the proliferative ability of ESCC cells, while the Transwell assay was conducted to assess the effect of miR-378 on the migratory and invasive abilities of ESCC cells. The results demonstrated that miR-378 displayed significantly lower expression both in ESCC cells and tissues by comparison with those in normal cells and adjacent tissues. In addition, patients with low miR-378 expression had a worse prognosis and a shorter overall survival time than those with high miR-378 expression. Furthermore, low miR-378 expression promoted ESCC cell proliferation, migration and invasion. Taken together, the results of the present study suggest that miR-378 may act as a tumor suppressor in the occurrence and development of ESCC.

Blood-based biomarkers of human papillomavirus-associated cancers: A systematic review and meta-analysis

BACKGROUND

Despite the significant societal burden of human papillomavirus (HPV)-associated cancers, clinical screening interventions for HPV-associated noncervical cancers are not available. Blood-based biomarkers may help close this gap in care.

METHODS

Five databases were searched, 5687 articles were identified, and 3631 unique candidate titles and abstracts were independently reviewed by 2 authors; 702 articles underwent a full-text review. Eligibility criteria included the assessment of a blood-based biomarker within a cohort or case-control study.

RESULTS

One hundred thirty-seven studies were included. Among all biomarkers assessed, HPV-16 E seropositivity and circulating HPV DNA were most significantly correlated with HPV-associated cancers in comparison with cancer-free controls. In most scenarios, HPV-16 E6 seropositivity varied nonsignificantly according to tumor type, specimen collection timing, and anatomic site (crude odds ratio [cOR] for p16+ or HPV+ oropharyngeal cancer [OPC], 133.10; 95% confidence interval [CI], 59.40-298.21; cOR for HPV-unspecified OPC, 25.41; 95% CI, 8.71-74.06; cOR for prediagnostic HPV-unspecified OPC, 59.00; 95% CI, 15.39-226.25; cOR for HPV-unspecified cervical cancer, 12.05; 95% CI, 3.23-44.97; cOR for HPV-unspecified anal cancer, 73.60; 95% CI, 19.68-275.33; cOR for HPV-unspecified penile cancer, 16.25; 95% CI, 2.83-93.48). Circulating HPV-16 DNA was a valid biomarker for cervical cancer (cOR, 15.72; 95% CI, 3.41-72.57). In 3 cervical cancer case-control studies, cases exhibited unique microRNA expression profiles in comparison with controls. Other assessed biomarker candidates were not valid.

CONCLUSIONS

HPV-16 E6 antibodies and circulating HPV-16 DNA are the most robustly analyzed and most promising blood-based biomarkers for HPV-associated cancers to date. Comparative validity analyses are warranted. Variations in tumor type-specific, high-risk HPV DNA prevalence according to anatomic site and world region highlight the need for biomarkers targeting more high-risk HPV types. Further investigation of blood-based microRNA expression profiling appears indicated.

The mechanisms and reversal strategies of tumor radioresistance in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of most lethal malignancies with high aggressive potential in the world. Radiotherapy is used as one curative treatment modality for ESCC patients. Due to radioresistance, the 5-year survival rates of patients after radiotherapy is less than 20%. Tumor radioresistance is very complex and heterogeneous. Cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment (TME), play critical roles in regulating tumor radioresponse through multiple mechanisms and are increasingly considered as important anti-cancer targets. Cancer stemness, which renders cancer cells to be extremely resistant to conventional therapies, is involved in ESCC radioresistance due to the activation of Wnt/β-catenin, Notch, Hedgehog and Hippo (HH) pathways, or the induction of epithelial-mesenchymal transition (EMT), hypoxia and autophagy. Non-protein-coding RNAs (ncRNAs), which account for more than 90% of the genome, are involved in esophageal cancer initiation and progression through regulating the activation or inactivation of downstream signaling pathways and the expressions of target genes. Herein, we mainly reviewed the role of CAFs, cancer stemness, non-coding RNAs as well as others in the development of radioresistance and clarify the involved mechanisms. Furthermore, we summarized the potential strategies which were reported to reverse radioresistance in ESCC. Together, this review gives a systematic coverage of radioresistance mechanisms and reversal strategies and contributes to better understanding of tumor radioresistance for the exploitation of novel intervention strategies in ESCC.

Knockdown of circRNA circ_0087378 Represses the Tumorigenesis and Progression of Esophageal Squamous Cell Carcinoma Through Modulating the miR-140-3p/E2F3 Axis

BACKGROUND

We aimed to investigate the function and underlying mechanisms of circ_0087378 in esophageal squamous cell carcinoma (ESCC).

METHODS

We verified higher circ_0087378 expression in ESCC tissues by performing qRT-PCR assays. We further confirmed the oncogenic roles of circ_0087378 in ESCC cells through a series of biological function assays. Then, we used an RNA pull-down assay and luciferase reporter assay to identify miR-140-3p that directly interacts with circ_0087378. Subsequent studies were performed to demonstrate that the circ_0087378/miR-140-3p/E2F3 axis promotes ESCC development.

RESULTS

We demonstrated that upregulated circ_0087378 expression was positively associated with tumor size, histological grade, tumor stage, the presence of metastasis, and worse survival in patients with ESCC. Our results further revealed that knockdown of circ_0087378 suppressed the proliferation, migration, and invasion of ESCC cells and reduced tumor growth in vivo. Mechanistically, we showed that circ_0087378 could directly bind to miR-miR-140-3p and relieve the suppression for target E2F3, which accelerated cell proliferation, migration, and invasion. Correlation analysis in ESCC specimens supported the involvement of the circ_0087378/miR-140-3p/E2F3 axis in ESCC progression.

CONCLUSIONS

This study demonstrated that circ_0087378 might act as a competing endogenous RNA for miR-140-3p, which could inhibit the tumorigenesis and progression of ESCC through upregulating E2F3 expression.

The ER Stress/UPR Axis in Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis

Cellular protein homeostasis in the lungs is constantly disrupted by recurrent exposure to various external and internal stressors, which may cause considerable protein secretion pressure on the endoplasmic reticulum (ER), resulting in the survival and differentiation of these cell types to meet the increased functional demands. Cells are able to induce a highly conserved adaptive mechanism, known as the unfolded protein response (UPR), to manage such stresses. UPR dysregulation and ER stress are involved in numerous human illnesses, such as metabolic syndrome, fibrotic diseases, and neurodegeneration, and cancer. Therefore, effective and specific compounds targeting the UPR pathway are being considered as potential therapies. This review focuses on the impact of both external and internal stressors on the ER in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) and discusses the role of the UPR signaling pathway activation in the control of cellular damage and specifically highlights the potential involvement of non-coding RNAs in COPD. Summaries of pathogenic mechanisms associated with the ER stress/UPR axis contributing to IPF and COPD, and promising pharmacological intervention strategies, are also presented.

Long noncoding RNA HEIH depletion depresses esophageal carcinoma cell progression by upregulating microRNA-185 and downregulating KLK5

Numerous studies have reported the association of long non-coding RNAs (lncRNAs) in cancers, yet the function of lncRNA high expressed in hepatocellular carcinoma (HEIH) in esophageal carcinoma (EC) has seldom been explored. Here, we aimed to explore the mechanism of HEIH on EC via microRNA-185 (miR-185)/kallikrein-related peptidase 5 (KLK5) modulation. Cancer and non-tumoral tissues were collected, in which HEIH, miR-185 and KLK5 expression were detected, as well as their correlations. Also, the relation between the prognosis of EC patients and HEIH/miR-185/KLK5 expression was clarified. EC cells (KYSE-30 and TE-1) were screened for subsequent gain- and loss-of-function assays and their biological functions were further monitored. Tumor volume and weight in EC mice were also measured. Results from this study indicated that HEIH and KLK5 were elevated and miR-185 was declined in EC. The positive correlation was seen in HEIH and KLK5 expression, while the negative correlation was observed in HEIH or KLK5 and miR-185 expression. High HEIH and KLK5 indicated worse prognosis and high miR-185 suggested better prognosis of EC patients. Depleting HEIH or restoring miR-185 suppressed the malignant phenotypes of EC cells, and delayed tumor growth in EC mice. HEIH was found to bind with miR-185 to regulate KLK5 expression. Overexpressing KLK5 alone promoted EC cell progression while up-regulating miR-185 reversed such effects on EC cells. Collectively, we reveal that HEIH depletion dampens EC progression by upregulating miR-185 and downregulating KLK5, which provides novel treatments for EC.

Exosomal long non-coding RNA UCA1 functions as growth inhibitor in esophageal cancer

PURPOSE

Esophageal cancer is a highly lethal and broad-spreading malignant tumor worldwide. Exosome-carrying lncRNAs play an essential role in the pathogenesis of various cancers.

RESULTS

The results revealed that the expression of UCA1 was decreased in esophageal cancer tissues and plasma exosomes. UCA1 was enriched in exosomes, and exosomal UCA1 was a promising biomarker for the diagnosis of esophageal cancer with 86.7% sensitivity and 70.2% specificity. Overexpression of UCA1 played anticancer roles in esophageal cancer cells through inhibiting cell proliferation, invasion and migration, and colony formation. Also, exosomal UCA1 was taken up by esophageal cancer cells and inhibited the progression of esophageal cancer in vitro and tumor growth in vivo. Furthermore, exosomal UCA1 could directly target miRNA-613 in esophageal cancer cells.

CONCLUSIONS

The results suggested that exosomal UCA1 inhibits tumorigenesis and progression of esophageal cancer in vitro and in vivo, and might be a promising biomarker for esophageal cancer.

PATIENT AND METHODS

In this study, we determined the expression of UCA1 in esophageal cancer tissues, plasma exosomes of patients with esophageal cancer. We determined the potential of exosomal UCA1 as a biomarker and its effect on the pathogenesis and progression of esophageal cancer in vitro and in vivo.

The Depletion of ABI3BP by MicroRNA-183 Promotes the Development of Esophageal Carcinoma

Background

Esophageal cancer (EC), as a serious threat to human life and health, is one of the most common cancers around the world. Many studies have suggested that many microRNAs are involved in tumorigenesis and progression.

Methods

To search for a novel and promising predictive therapeutic target or biomarker to achieve the goal of the early diagnosis and treatment of EC, we used the EC cell lines Eca-109 and KYSE-150 and normal human esophageal epithelial cells (HEECs) to investigate the effect of ABI3BP on EC.

Results

We found that ABI family member 3 binding protein (ABI3BP) was downregulated in EC and suppressed the proliferation, activity, migration, and invasion of EC cells. ABI3BP was downregulated by miR-183, which plays the role of an oncogene.

Conclusion

ABI3BP and miR-183 can be considered potential biomarkers for the diagnosis of patients with EC and can be effective targets for antitumor therapy.

Knockdown of lncRNA PVT1 inhibits prostate cancer progression in vitro and in vivo by the suppression of KIF23 through stimulating miR-15a-5p

BACKGROUND

Prostate cancer (PCa) greatly threatens men's lives, with high incidence and mortality. Recently, the research of long non-coding RNAs (lncRNAs) has made breakthroughs in the development of human cancers. This study aimed to figure out the role and action mechanism of lncRNA PVT1 (PVT1) in PCa.

METHODS

The expression of PVT1, microRNA-15a-5p (miR-15a-5p) and kinesin family member 23 (KIF23) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry and transwell assays, respectively. The protein levels of KIF23 and proliferation, apoptosis, and epithelial-mesenchymal transition (EMT)-related markers were quantified by western blot. The relationship between miR-15a-5p and PVT1 or KIF23 was predicted by starBase v2.0 and verified by dual-luciferase reporter assay. Xenograft assay was conducted to determine the role of PVT1 in vivo.

RESULTS

The expression of PVT1 and KIF23 was enhanced, while miR-15a-5p expression was reduced in PCa tissues and cells. PVT1 interference inhibited proliferation, migration and invasion but promoted apoptosis of PCa cells. MiR-15a-5p was a target of PVT1, and KIF23 was a target of miR-15a-5p. The inhibition of miR-15a-5p reversed the effects of PVT1 interference and suppressed the roles of KIF23 knockdown. KIF23 expression was regulated by PVT1 through miR-15a-5p. PVT1 interference blocked PCa progression in vivo.

CONCLUSION

PVT1 knockdown had effects on the progression of PCa by inhibiting the expression of KIF23 via enriching miR-15a-5p in vitro and in vivo, suggesting that PVT1 might be a novel biomarker for the treatment of PCa.

Transcription/Expression of KLRB1 Gene as A Prognostic Indicator in Human Esophageal Squamous Cell Carcinoma

AIM AND OBJECTIVE

Esophageal squamous cell carcinoma (ESCC) is the most prevalent type of cancer with worldwide distribution and dismal prognosis despite ongoing efforts to improve treatment options. Therefore, it is essential to determine the prognostic factors for ESCC.

METHODS AND RESULTS

We determined KLRB1 to be a prognostic indicator of human ESCC. KLRB1 was expressed at low levels in ESCC patients. Based on the risk score, patients were divided into high and low-risk groups. High-risk patients showed a poor survival rate. The prediction model based on the N stage, sex, and KLRB1 was significantly better than that based on the N stage and sex. The modified prediction model showed a robust ROC curve with an AUC value of 0.973. The knockdown of KLRB1 inhibited the growth of human ESCC cells. KLRB1 regulated Akt, mTOR, p27, p38, NF-κB, Cyclin D1, and JNK signaling, which was consistent with the result of GSEA.

CONCLUSION

KLRB1 is a potential prognostic marker for human ESCC patients.

Long noncoding RNA LINC01234 silencing exerts an anti-oncogenic effect in esophageal cancer cells through microRNA-193a-5p-mediated CCNE1 downregulation

BACKGROUND

Long non-coding RNAs (lncRNAs) are transcribed pervasively in the genome and act to regulate chromatin remodeling and gene expression. Dysregulated lncRNA expression has been reported in many cancers, but the role of lncRNAs in esophageal cancer (EC) has so far remained poorly understood. In this study, we aimed to understand the effect of lncRNA LINC01234 on EC development through competitively binding to microRNA-193a-5p (miR-193a-5p).

METHODS

The Gene Expression Omnibus (GEO) database was used for microarray-based EC expression profiling. Gain- and loss-of-function analyses were carried out in human EC-derived Eca-109 and EC9706 cells. Expression analyses of miR-193a-5p, LINC01234, CCNE1, caspase-3, p21, Bax, cyclinD1 and Bcl-2 were performed using RT-qPCR and Western blotting. Cell proliferation, colony formation and apoptosis analyses were carried out using MTT, Hoechst 33258 and flow cytometry assays. A xenograft EC model in nude mice was used to evaluate in vivo tumor growth and CCNE1 expression.

RESULTS

Microarray-based analyses revealed that LINC01234 expression was increased in primary EC samples, whereas that of miR-193a-5p was decreased. We found that CCNE1 was a target of miR-193a-5p and that LINC01234, in turn, sponges miR-193a-5p. After treatment with si-LINC01234 or miR-193a-5p mimic, EC cells (Eca-109 and EC9706) exhibited cyclinD1 and Bcl-2 downregulation, and caspase-3, p21, Bax and cleaved caspase-3 upregulation. LINC01234 silencing or miR-193a-5p upregulation resulted in decreased proliferation and colony formation, and increased apoptosis of EC cells. In addition, LINC01234 silencing or miR-193a-5p upregulation resulted in reduced in vivo EC tumor growth and CCNE1 expression in nude mice.

CONCLUSIONS

We found that silencing of LINC01234 suppresses EC development by inhibiting CCNE1 through competitively binding to miR-193a-5p, which suggests that LINC01234 may represent a novel target for EC therapy.

Down-regulated lncRNA TP73-AS1 reduces radioresistance in hepatocellular carcinoma via the PTEN/Akt signaling pathway

Objective: Recently, the role of long non-coding RNAs (lncRNAs) in hepatocellular carcinoma (HCC) has been assessed. Our research was determined to investigate the impacts of lncRNA TP73-AS1 on radioresistance of HCC by modulating PTEN/Akt signaling pathway. Methods: Expression of TP73-AS1 in HCC tissues and cells was detected using reverse transcription quantitative polymerase chain reaction (RT-qPCR). The HCC cells were conducted with different doses of irradiation, then the survival, colony formation and apoptosis were determined by a series of assays. The HCC cell line with a higher expression of TP73-AS1 was transfected with TP73-AS1-siRNA and X-rayed, the expression of TP73-AS1, cell survival, radiosensitivity, and apoptosis were evaluated. Subcutaneous tumorigenesis in nude mice was adopted to record the size of tumors before and after the radiation. RT-qPCR and Western blot analysis were used to clarify the activation of PTEN/Akt signaling pathway. Results: TP73-AS1 was highly expressed in HCC tissues and cells. With the increasing dose of radiation, the relative proliferation activity and survival fraction (SF) of HCC cells was gradually reduced, while the total apoptosis rate was gradually elevated. TP73-AS1 knockdown promoted radiosensitivity and apoptosis, repressed cell proliferation, making it an inhibitor of tumor in HCC. Moreover, reduced TP73-AS1 was able to decline the phosphorylation of Akt and increase the expression of PTEN in HCC. Down-regulated TP73-AS1 could repress tumorigenesis by promoting radiosensitivity in nude mice with HCC. Conclusion: Our study suggests that lncRNA TP73-AS1 was highly expressed in HCC and participated in radioresistance of HCC via PTEN/Akt signaling pathway. Abbreviations: lncRNAs: long non-coding RNAs; lncRNAs: HCC: hepatocellular carcinoma; RT-qPCR: reverse transcription quantitative polymerase chain reaction; survival fraction: SF; lncRNA TP73-AS1: LncRNA P73 antisense RNA 1T; PTEN: Phosphatase and tensin homologue; Akt: Protein kinase B; P13K: phosphatidylinositol 3-kinase; TNM: tumor, node and metastasis; ACJJ: American Joint Committee on Cancer; FBS: fetal bovine serum; EDTA: ethylene diamine tetraacetic acid; NC: negative control; DMEM: Dulbecco's modified Eagle medium; OD: optical density; PE: Plating efficiency; FITC/PI: fluoresceine isothiocyanate/propidium iodide; PBS: phosphate buffered solution; GAPDH: Glyceraldehyde phosphate dehydrogenase; ANOVA: one-way analysis of variance; LSD-t: least significant difference test.

SNHG8 is upregulated in esophageal squamous cell carcinoma and directly sponges microRNA-411 to increase oncogenicity by upregulating KPNA2

Background

The long noncoding RNA, small nucleolar RNA host gene 8 (SNHG8), is upregulated in multiple human cancer types. However, whether SNHG8 is aberrantly expressed in esophageal squamous cell carcinoma (ESCC) and its biological functions have yet to be elucidated. Thus, we aimed to determine the expression status of SNHG8 in ESCC, explore the effects of SNHG8 on the oncogenicity of ESCC, and investigate the potential underlying mechanisms.

Methods

SNHG8 expression in ESCC tissues and cell lines was determined via reverse-transcription quantitative polymerase chain reaction. The actions of SNHG8 on the malignant characteristics of ESCC were explored using CCK-8 assay, flow-cytometric analysis, Transwell migration and invasion assays, and tumor xenografts in nude mice.

Results

SNHG8 expression was significantly higher in ESCC tissues and cell lines. High SNHG8 expression was revealed to closely correlate with primary tumor invasion depth, lymph node metastases, TNM stage, and worse overall survival among patients with ESCC. Functional investigation showed that ablation of SNHG8 notably restricted ESCC cell proliferation, migration, and invasion while inducing apoptosis in vitro and hindered tumor growth in vivo. In the meantime, SNHG8 acted as a molecular sponge of microRNA-411 (miR-411) in ESCC. Furthermore, miR-411 exerted a tumor-suppressive effect on ESCC cells, and karyopherin alpha 2 (KPNA2) turned out to be a direct target gene of miR-411. Restoring KPNA2 expression neutralized the inhibitory effects of miR-411 overexpression on the malignant behaviors of ESCC cells. Moreover, silencing of miR-411 abrogated the influence of SNHG8 downregulation in ESCC cells.

Conclusion

SNHG8 may play oncogenic roles in the malignancy of ESCC by sponging miR-411 to increase KPNA2 expression. The SNHG8–miR-411–KPNA2 pathway may be a novel target for the treatment of patients with ESCC and offer potential biomarkers for the diagnosis and prognosis of ESCC.

A world map of esophagus cancer research: a critical accounting

Background

Esophageal cancer (EC) is one of the deadliest cancers worldwide. The contemporary strong increase of the adenocarcinomas in Western countries and the high mortality rates require the intensification of prospective multinational studies.

Methods

Therefore, this global health issue has been chosen for the bibliometric review of the global publication output. As source for meta and citation data, the Web of Science has been used and Density Equalizing Maps were applied for visualization.

Results

17,387 articles on EC could be identified. The years with publication and citation maxima correspond to the appearance of the most prolific articles. China is the most publishing country, followed by Japan and the USA. Germany and the UK ranked 4th and 5th. The analysis of the ratios articles and socio-economic parameters emphasizes the leading position of the Scandinavian countries and Japan. Here, the high-income countries come out on top. The high incidence regions are mainly represented by Chinese and Japanese research. The association of the publication output and the overall research funding could be shown.

Conclusions

A strengthened international network increasingly consisting of the scientifically best positioned countries as well as more of the high incidence countries worldwide is mandatory for future research. The findings deliver scientists, clinicians and decision makers backgrounds for future decisions all over the world.

Identifying potential metastasis-related long non-coding RNAs, microRNAs, and message RNAs in the esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the predominant form with the highest incidence. We aimed to find metastasis-related differentially expressed long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNA (mRNAs) in ESCC. We first obtained the lncRNAs, miRNAs, and mRNAs profiles. The differentially expressed lncRNAs, miRNAs, and mRNAs were obtained, followed by the functional annotation. Then the interaction networks of miRNA-mRNA, lncRNA-mRNA coexpression, lncRNA-miRNA, and lncRNA-miRNA-mRNA were constructed. In addition, systematic expression pattern analysis of differentially expressed lncRNAs, miRNA, and mRNA in the normal, metastasis, and nonmetastasis was performed. Survivability of differentially expressed lncRNAs, miRNAs, and mRNA was analyzed. A total of 613 differentially expressed lncRNAs, 35 differentially expressed miRNAs, and 1586 differentially expressed mRNAs were obtained. Several interactions of H19-hsa-mir-222-chromobox 2 (CBX2), H19-hsa-mir-330-phosphoinositide-3-kinase regulatory subunit 4 (PIK3R4), KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1)/CTB-89H12.4-hsa-mir-374a-vascular endothelial growth factor A (VEGFA), MALAT1/X inactive specific transcript (XIST)/XIST antisense RNA (TSIX)-hsa-mir-340-tumor necrosis factor receptor superfamily member 10A (NFRSF10A) were identified to play key roles in the metastasis of ESCC. In addition, KCNQ1OT1, TSIX, and XIST were significantly associated with the survival time of patients. In conclusion, our study may be helpful in understanding the pathological mechanism and providing new diagnostic and therapeutic biomarkers for ESCC.

Profiles of differentially expressed circRNAs in esophageal and breast cancer

Introduction

Circular RNAs (circRNAs) function as efficient microRNA sponges with gene-regulatory potential and are promising cancer biomarkers. In this study, we used the Arraystar Human circRNA Array to construct a genome-wide circRNA profile of esophageal squamous cell cancer (ESCC) and breast cancer (BC).

Patients and methods

Expression levels between cancer lesions and adjacent normal-appearing tissues were compared. We observed 469 upregulated circRNAs and 275 downregulated circRNAs in ESCC. Hsa_circRNA_103670 was upregulated 20.3-fold, while hsa_circRNA_030162 was downregulated 12.1-fold. For BC, 715 circRNAs were upregulated, and 440 circRNAs were downregulated. Hsa_circRNA_005230 was upregulated 12.2-fold, while hsa_circRNA_406225 was downregulated 12.4-fold.

Results

When we set the criteria as fold change in expression ≥2 between cancer and adjacent normal-appearing tissue with a P-value <0.01, there were 22 common circRNAs (11 upregulated and 11 downregulated) in relation to both ESCC and BC. Gene ontology and the Kyoto encyclopedia of genes and genomes analyses showed that these circRNAs were involved in the tumorigenesis of human cancers.

Conclusion

Our study revealed that circRNAs are promising candidates as valuable biomarkers for ESCC and BC, although relevant research is still in its infancy and the functional role of specific circRNAs in tumorigenesis is just starting to be elucidated.

Esophageal cancer research today and tomorrow: Lessons from algae and other perspectives

Esophageal cancer is an increasing concern due to poor prognosis, aggressive disease modalities, and a lack of efficient therapeutics. The two types of esophageal cancer: esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are responsible for an estimated 450,000 annual deaths, with over 457,000 new patients diagnosed in 2015, making it the eighth most prevalent and the 10th most fatal cancer worldwide. As esophageal cancer prevalence continues to increase, and so does the pressing need for the development of new and effective strategies for the early diagnostics, prevention, and treatment of this cancer, as well for building the innovative research tools to understand the affected molecular mechanisms. This short review summarizes the current statistics and recent research of the problems and solutions related to the esophageal cancer, and offer a brief overview of its epidemiology, molecular alterations, and existing biomedical tools. We will discuss currently available research tools and discuss selected approaches we deem relevant to find new model systems and therapies for the future with the special focus on novel opportunities presented by the unique molecules found in algae, namely carbohydrates and lipids. Their remarkable chemical variability is connected to their striking structural and functional properties, which combined with the relative novelty of these compounds to cancer biology, warrants interest of the wide biomedical community to these molecules, especially in the esophageal cancer theory and practice.

Circular RNAs: A novel type of non-coding RNA and their potential implications in antiviral immunity

Circular RNAs (circRNAs), a novel type of non-coding RNAs (ncRNAs), are ubiquitously expressed in eukaryotic cells during post-transcriptional processes. Unlike linear RNAs, circRNAs form covalent-closed continuous loops without 5' to 3' polarities and poly (A) tails. With advances in high-throughput sequencing technology, numerous circRNAs have been identified in plants, animals and humans. Notably, circRNAs display cell-type, tissue-type and developmental-stage specific expression patterns in eukaryotic transcriptome, which reveals their significant regulatory functions in gene expression. More importantly, circRNAs serve as microRNA (miRNA) sponges and crucial regulators of gene expression. Additionally, circRNAs modulate pre-mRNA alternative splicing and possess protein-coding capacity. CircRNAs exhibit altered expression under pathological conditions and are strongly associated with the development of various human diseases. Interestingly, circRNAs can also induce antiviral immune responses. A recent study found that the delivery of circRNAs generated in vitro activates RIG-I-mediated innate immune responses and provides protection against viral infection. The antiviral dsRNA-binding proteins, NF90/NF110, act as key regulators in circRNA biogenesis. NF90/NF110 are also functional in inhibiting viral replication through binding to viral mRNAs. In this review, we provide a comprehensive overview on the classification, biogenesis and functions of circRNAs. We also discuss the critical role of circRNAs in eliciting antiviral immunity, providing evidence for the potential implications of circRNAs in antiviral therapies.

Prognostic role of long non-coding RNA TUG1 expression in various cancers: a meta-analysis

Several studies were conducted to explore the prognostic role of long non-coding RNA taurine upregulated gene 1 (lncRNA TUG1) expression in various cancers, with contradictory. This study aims to summarize the prognostic role of lncRNA TUG1 expression in various cancers. Embase, PubMed and Cochrane Library were completely retrieved. The cohort studies focusing on the prognostic role of lncRNA TUG1 expression in various cancers were eligible. The endpoints were overall survival (OS) and clinicopathological parameters. 9 studies involving a total of 1,078 patients were identified. The results showed that high lncRNA TUG1 expression was obviously associated with worse OS when compared to the low lncRNA TUG1 expression (HR = 1.37, 95% CI = 1.07–1.76, P = 0.01; I² = 85%). However, No distinct relationship was observed between the lncRNA TUG1 expression and age (OR = 0.99, 95% CI = 0.76–1.28, P = 0.92; I2 = 4%), gender (OR = 0.92, 95% CI = 0.70–1.22, P = 0.57; I² = 0%), diameter (OR = 0.83, 95% CI = 0.34–2.01, P = 0.67; I² = 85%), smoking (OR = 1.09, 95% CI = 0.37–3.21, P = 0.87; I² = 73%), TNM stage (OR = 0.60, 95% CI = 0.25–1.43, P = 0.25; I² = 86%) and lymph node metastasis (OR = 1.07, 95% CI = 0.47–2.45, P = 0.87; I² = 86%). In conclusion, it was revealed that high lncRNA TUG1 expression is an unfavorable predictor of OS in patients with cancers, and lncRNA TUG1 expression is a promising prognostic biomarker for various cancers.